Merge branch 'main' of ssh://gitea.bchen.dev:2222/brendan/project-inter-server

claude/apollo-router-migration-research-y8oVn

.dockerignore

@@ -0,0 +1,4 @@
+node_modules
+npm-debug.log
+Dockerfile
+.dockerignore

.env.example

@@ -1,4 +1,24 @@
+# Set to "1" for true
+APNS_IS_PRODUCTION=
+
 APNS_KEY_ID=
 APNS_TEAM_ID=
 APNS_BUNDLE_ID=
-APNS_KEY_PATH=
+
+# base64-encoded APNs private key
+APNS_PRIVATE_KEY=
+
+# control parking data logging
+PARKING_LOGGING_INTERVAL_MS=
+PARKING_HISTORICAL_AVERAGE_MINIMUM_INTERVAL=
+PARKING_HISTORICAL_AVERAGE_MAXIMUM_TIMESPAN=
+
+# control rate limiting features
+RATE_LIMITS_DISABLED=
+RATE_LIMIT_WINDOW_MS=
+RATE_LIMIT_DELAY_AFTER_REQUESTS=
+RATE_LIMIT_DELAY_MULTIPLIER_MS=
+
+# Redis connection
+REDIS_URL=
+REDIS_USE_TLS=

.github/ISSUE_TEMPLATE/bug-report.md

@@ -0,0 +1,12 @@
+---
+name: Bug report
+about: Describe a bug within the app.
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+## Bug description
+
+A clear and concise description of what the bug is, including how to reproduce it plus relevant screenshots.

.github/ISSUE_TEMPLATE/enhancement.md

@@ -0,0 +1,20 @@
+---
+name: Enhancement
+about: New feature or enhancement for the project.
+title: ''
+labels: enhancement
+assignees: ''
+
+---
+
+## User stories
+
+- As a user...
+
+## Tasks
+
+- [ ] 
+
+## Documentation
+
+-

.github/ISSUE_TEMPLATE/generic-task.md

@@ -0,0 +1,16 @@
+---
+name: Generic task
+about: Task with multiple steps.
+title: ''
+labels: 
+assignees: ''
+
+---
+
+## Tasks
+
+- [ ] 
+
+## Documentation
+
+-

.github/workflows/deploy-coolify.yml

@@ -0,0 +1,47 @@
+name: "Deploy to Coolify"
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Check out repository
+      uses: actions/checkout@v3
+      with:
+        submodules: recursive
+
+    - name: Login to Gitea Container Registry
+      uses: docker/login-action@v4
+      with:
+        registry: gitea.bchen.dev
+        username: ${{ github.actor }}
+        password: ${{ secrets.PAT }}
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v4
+
+    - name: Build and push
+      uses: docker/build-push-action@v7
+      with:
+        context: .
+        push: true
+        tags: gitea.bchen.dev/${{ github.actor }}/project-inter-server:latest
+
+    - name: Set up Tailscale
+      uses: tailscale/github-action@v4
+      with:
+        oauth-client-id: ${{ secrets.TS_OAUTH_CLIENT_ID }}
+        oauth-secret: ${{ secrets.TS_OAUTH_SECRET }}
+        tags: tag:ci
+        use-cache: false
+        tailscaled-args: --tun=userspace-networking --socks5-server=localhost:1055 --outbound-http-proxy-listen=localhost:1055
+
+    - name: Deploy to Coolify
+      run: |
+        curl --request POST '${{ secrets.COOLIFY_WEBHOOK }}' --header 'Authorization: Bearer ${{ secrets.COOLIFY_TOKEN }}'

.github/workflows/test.yml

@@ -1,27 +1,31 @@
 name: Node.js Test
 
 on:
-  push:
-    branches: [ "main" ]
   pull_request:
     branches: [ "main" ]
 
 jobs:
-  build:
-
+  test:
     runs-on: ubuntu-latest
 
-    strategy:
-      matrix:
-        node-version: [20.x]
-        # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
-
     steps:
       - uses: actions/checkout@v4
-      - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v4
+
+      - name: Build and test with Docker Compose
+        run: docker compose run test
+
+      - name: Upload test coverage
+        id: coverage-upload
+        uses: actions/upload-artifact@v4
         with:
-          node-version: ${{ matrix.node-version }}
-          cache: 'npm'
-      - run: npm run build:dev
-      - run: npm run test
+          name: code-coverage-report
+          path: coverage
+
+      - name: Post comment linking to artifact
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh pr comment ${{ github.event.pull_request.number }} \
+            --repo ${{ github.repository }} \
+            --body "Test coverage artifact: ${{ steps.coverage-upload.outputs.artifact-url }}"
+

.gitignore

@@ -20,3 +20,9 @@ yarn-error.log*
 
 # Testing
 /coverage/
+
+# Keys
+private/
+
+# JetBrains
+.idea

.idea/.gitignore

@@ -1,8 +0,0 @@
-# Default ignored files
-/shelf/
-/workspace.xml
-# Editor-based HTTP Client requests
-/httpRequests/
-# Datasource local storage ignored files
-/dataSources/
-/dataSources.local.xml

.idea/codeStyles/codeStyleConfig.xml

@@ -1,5 +0,0 @@
-<component name="ProjectCodeStyleConfiguration">
-  <state>
-    <option name="PREFERRED_PROJECT_CODE_STYLE" value="Default" />
-  </state>
-</component>

.idea/inspectionProfiles/Project_Default.xml

@@ -1,6 +0,0 @@
-<component name="InspectionProjectProfileManager">
-  <profile version="1.0">
-    <option name="myName" value="Project Default" />
-    <inspection_tool class="ExceptionCaughtLocallyJS" enabled="false" level="WARNING" enabled_by_default="false" />
-  </profile>
-</component>

.idea/modules.xml

@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ProjectModuleManager">
-    <modules>
-      <module fileurl="file://$PROJECT_DIR$/.idea/project-inter-server.iml" filepath="$PROJECT_DIR$/.idea/project-inter-server.iml" />
-    </modules>
-  </component>
-</project>

.idea/project-inter-server.iml

@@ -1,12 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<module type="WEB_MODULE" version="4">
-  <component name="NewModuleRootManager">
-    <content url="file://$MODULE_DIR$">
-      <excludeFolder url="file://$MODULE_DIR$/.tmp" />
-      <excludeFolder url="file://$MODULE_DIR$/temp" />
-      <excludeFolder url="file://$MODULE_DIR$/tmp" />
-    </content>
-    <orderEntry type="inheritedJdk" />
-    <orderEntry type="sourceFolder" forTests="false" />
-  </component>
-</module>

.idea/vcs.xml

@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="VcsDirectoryMappings">
-    <mapping directory="$PROJECT_DIR$" vcs="Git" />
-  </component>
-</project>

.nvmrc

@@ -0,0 +1 @@
+v22.15.0

AGENTS.md

@@ -0,0 +1,103 @@
+# CLAUDE.md
+
+This file provides guidance to all agents when working with code in this repository.
+
+## Development Commands
+
+### Core Development
+
+```bash
+# Start development server with hot reloading
+docker compose run dev
+
+# Run comprehensive test suite
+docker compose run test
+
+# Generate GraphQL TypeScript types
+npm run generate
+
+# Build for development (install, codegen, tsc)
+npm run build:dev
+```
+
+Only use Docker Compose for running tests, and only use `docker compose run test`
+to run tests; don't try to run tests for individual files.
+
+## Architecture Overview
+
+Project Inter Server is a GraphQL-based backend for college transit tracking with real-time shuttle data, parking availability, and push notifications.
+
+- InterchangeSystem: Central orchestrator for shuttles, parking, and notifications
+    - Use `InterchangeSystem.build()` in production
+    - Use `InterchangeSystem.buildForTesting()` in tests
+
+- Repository Pattern (data access abstraction)
+    - Shuttle: `UnoptimizedInMemoryShuttleRepository`
+    - Parking: `InMemoryParkingRepository`
+    - Notifications: `RedisNotificationRepository` (prod) / `InMemoryNotificationRepository` (test)
+
+- Data Loaders (external API integration)
+    - `ApiBasedShuttleRepositoryLoader` – Passio GO! API
+    - `ChapmanApiBasedParkingRepositoryLoader` – Parking data
+    - `TimedApiBasedRepositoryLoader` – Periodic refresh wrapper
+
+- Notification System
+    - `ETANotificationScheduler` – Shuttle arrival notifications
+    - `AppleNotificationSender` – APNS integration
+
+## GraphQL
+
+- Schema definition: `schema.graphqls`
+- Generated types: `src/generated/`
+- Resolvers: `src/resolvers/`
+- Resolver merge: `src/MergedResolvers.ts`
+
+## Directory Structure
+
+- `src/entities/` – Core business logic
+- `src/repositories/` – Data access layer
+- `src/loaders/` – External API integrations
+- `src/notifications/` – Push notification system
+- `src/resolvers/` – GraphQL resolvers and tests
+- `testHelpers/` – Test utilities and mock data
+
+## Docker Services
+
+- `dev` – Development server with hot reload
+- `test` – Unit/integration tests
+- `redis` – Persistent Redis
+- `redis-no-persistence` – Ephemeral Redis for tests
+
+## Testing Patterns
+
+- Prefer `buildForTesting()` to construct systems in tests.
+- Mock external APIs using JSON snapshots under `testHelpers/jsonSnapshots`.
+- Use in-memory repositories for speed where possible.
+- When adding features that affect API output, add focused resolver tests in the corresponding `src/resolvers/__tests__` file.
+    - Separate unit tests from integration tests where practical to keep feedback fast and failures well-scoped.
+
+## Development Guidelines
+
+### General Guidelines
+
+- Use test-driven development where possible. Write tests before implementation and run them before and after changes.
+- Use Docker Compose for tests. Run `docker compose run test` so you can see full output.
+
+### Git Workflow
+
+- Name pull requests after their branch name.
+
+### Code Style
+
+- Prefer arrow functions, especially within classes.
+- Keep changes minimal and focused; avoid unrelated refactors. Mention incidental issues separately.
+- Respect existing interfaces and types; use non-destructive edits.
+
+### Agent Tips
+
+- Write or update tests alongside changes; validate with `docker compose run test`.
+- When touching GraphQL resolvers, co-locate new tests in `src/resolvers/__tests__`.
+
+## Multi-tenant Support
+
+Currently supports Chapman University (Passio System ID: `263`). Each university system uses isolated repositories and configuration. New systems should be added via `InterchangeSystem` configuration and appropriate loaders.

CLAUDE.md

@@ -0,0 +1 @@
+See AGENTS.md

Dockerfile

@@ -0,0 +1,7 @@
+FROM node:22-alpine
+WORKDIR /usr/src/app
+COPY . .
+RUN npm run build
+EXPOSE 4000
+
+CMD ["npm", "run", "start"]

README.md

@@ -1,17 +1,19 @@
-# Interchange Node.js Server
+# Interchange Server
 
-This is the server codebase for Interchange, an app for college
-transit.
+This is the server codebase for Interchange, an app for college transit.
 
 ## Setup
 
-You'll need Node.js 20.x installed to run this project.
-Clone this repository and run the following:
+You'll need Docker + Compose installed to run this project.
+Clone this repository and run one of the following:
 
 ```bash
-$ npm start:dev
+# run the standard Node development server and Redis
+$ docker compose run dev
+
+# run with unit/server integration tests
+$ docker compose run test
+
+# run with test data suitable for app integration tests
+$ docker compose run app-integration-tests
 ```
-
-This will run `npm install`, generate GraphQL type definitions,
-and start the server in developer mode.
-

docker-compose.prod.yml

@@ -0,0 +1,42 @@
+# self hosted server setup using Caddy
+
+x-common-environment: &common-server-environment
+  APNS_IS_PRODUCTION: ${APNS_IS_PRODUCTION}
+  APNS_BUNDLE_ID: ${APNS_BUNDLE_ID}
+  APNS_TEAM_ID: ${APNS_TEAM_ID}
+  APNS_KEY_ID: ${APNS_KEY_ID}
+  APNS_PRIVATE_KEY: ${APNS_PRIVATE_KEY}
+  PARKING_LOGGING_INTERVAL_MS: ${PARKING_LOGGING_INTERVAL_MS}
+  REDIS_URL: redis://redis:6379
+  REDIS_USE_TLS: 0
+  RATE_LIMITS_DISABLED: ${RATE_LIMITS_DISABLED}
+  RATE_LIMIT_WINDOW_MS: ${RATE_LIMIT_WINDOW_MS}
+  RATE_LIMIT_DELAY_AFTER_REQUESTS: ${RATE_LIMIT_DELAY_AFTER_REQUESTS}
+  RATE_LIMIT_DELAY_MULTIPLIER_MS: ${RATE_LIMIT_DELAY_MULTIPLIER_MS}
+
+services:
+  app:
+    build: .
+    command: npm run start
+    restart: unless-stopped
+    ports:
+      - "4000:4000"
+    depends_on:
+      - redis
+    environment:
+      <<: *common-server-environment
+      NODE_ENV: production
+
+  redis:
+    image: redis/redis-stack:7.2.0-v17
+    container_name: redis-timeseries
+    restart: unless-stopped
+    volumes:
+      - redis_data:/data
+      - ./redis-stack.conf:/redis-stack.conf
+    command: redis-stack-server /redis-stack.conf
+
+volumes:
+  redis_data:
+  caddy_data:
+  caddy_config:

docker-compose.yml

@@ -0,0 +1,64 @@
+# Note that .env file will automatically populate
+# variables in this file.
+# If these variables are also set on the host system,
+# those will be used over the .env file.
+# See https://vsupalov.com/docker-arg-env-variable-guide/
+
+x-common-environment: &common-server-environment
+  APNS_IS_PRODUCTION: ${APNS_IS_PRODUCTION}
+  APNS_BUNDLE_ID: ${APNS_BUNDLE_ID}
+  APNS_TEAM_ID: ${APNS_TEAM_ID}
+  APNS_KEY_ID: ${APNS_KEY_ID}
+  APNS_PRIVATE_KEY: ${APNS_PRIVATE_KEY}
+  PARKING_LOGGING_INTERVAL_MS: ${PARKING_LOGGING_INTERVAL_MS}
+  REDIS_URL: redis://redis:6379
+  REDIS_USE_TLS: 0
+  RATE_LIMITS_DISABLED: ${RATE_LIMITS_DISABLED}
+  RATE_LIMIT_WINDOW_MS: ${RATE_LIMIT_WINDOW_MS}
+  RATE_LIMIT_DELAY_AFTER_REQUESTS: ${RATE_LIMIT_DELAY_AFTER_REQUESTS}
+  RATE_LIMIT_DELAY_MULTIPLIER_MS: ${RATE_LIMIT_DELAY_MULTIPLIER_MS}
+
+services:
+  dev:
+    build: .
+    command: npm run start:dev
+    ports:
+      - "4000:4000"
+    depends_on:
+      - redis
+    environment:
+      <<: *common-server-environment
+    volumes:
+      - .:/usr/src/app
+
+  test:
+    build: .
+    command: npm run test
+    depends_on:
+      - redis-no-persistence
+    environment:
+      REDIS_URL: redis://redis-no-persistence:6379
+      RATE_LIMITS_DISABLED: 1
+
+    volumes:
+      - .:/usr/src/app
+
+  redis:
+    image: redis/redis-stack:7.2.0-v17
+    container_name: redis-timeseries
+    ports:
+      - "6379:6379"
+    volumes:
+      - redis_data:/data
+      - ./redis-stack.conf:/redis-stack.conf
+    command: redis-stack-server /redis-stack.conf
+
+  redis-no-persistence:
+    image: redis/redis-stack:7.2.0-v17
+    container_name: redis-timeseries-no-persistence
+    ports:
+      - "6379:6379"
+
+volumes:
+  redis_data:  # Add this volume definition
+

jest.config.js

@@ -110,7 +110,7 @@ const config = {
   // reporters: undefined,
 
   // Automatically reset mock state before every test
-  // resetMocks: false,
+  resetMocks: true,
 
   // Reset the module registry before running each individual test
   // resetModules: false,
@@ -119,7 +119,7 @@ const config = {
   // resolver: undefined,
 
   // Automatically restore mock state and implementation before every test
-  // restoreMocks: false,
+  restoreMocks: true,
 
   // The root directory that Jest should scan for tests and modules within
   // rootDir: undefined,

package.json

@@ -4,28 +4,38 @@
   "description": "",
   "main": "dist/index.js",
   "scripts": {
-    "build:dev": "npm install --include=dev && npm run generate && tsc",
-    "build": "npm install --include=dev && npm run generate && tsc && npm prune --omit=dev",
+    "build:dev": "npm install --include=dev && npm run generate && tsc --project tsconfig.build.json",
+    "build": "npm install --include=dev && npm run generate && tsc --project tsconfig.build.json && npm prune --omit=dev",
     "start:dev": "npm run build:dev && node ./dist/index.js",
-    "start": "npm run build && node ./dist/index.js",
+    "start": "node ./dist/index.js",
     "generate": "graphql-codegen --config codegen.ts",
-    "test": "jest"
+    "test": "npm run build:dev && jest --runInBand"
   },
   "devDependencies": {
     "@graphql-codegen/cli": "5.0.3",
     "@graphql-codegen/typescript": "4.1.2",
     "@graphql-codegen/typescript-resolvers": "4.4.1",
     "@jest/globals": "^29.7.0",
+    "@types/express": "^5.0.3",
+    "@types/jsonwebtoken": "^9.0.8",
     "@types/node": "^22.10.2",
+    "@types/redis": "^4.0.11",
     "jest": "^29.7.0",
     "ts-jest": "^29.2.5",
-    "typescript": "^5.7.2",
-    "@types/jsonwebtoken": "^9.0.8"
+    "typescript": "^5.7.2"
   },
   "private": true,
   "dependencies": {
-    "@apollo/server": "^4.11.2",
-    "graphql": "^16.10.0",
-    "jsonwebtoken": "^9.0.2"
+    "@apollo/server": "^5.0.0",
+    "@as-integrations/express5": "^1.1.2",
+    "express": "^5.1.0",
+    "express-rate-limit": "^8.0.1",
+    "express-slow-down": "^3.0.0",
+    "graphql": "^16.11.0",
+    "jsonwebtoken": "^9.0.2",
+    "redis": "^4.7.0"
+  },
+  "engines": {
+    "node": ">=22.15.0"
   }
 }

redis-stack.conf

@@ -0,0 +1,28 @@
+# See https://raw.githubusercontent.com/redis/redis/unstable/redis.conf
+# for a full example
+
+############################## APPEND ONLY MODE ###############################
+
+# By default Redis asynchronously dumps the dataset on disk. This mode is
+# good enough in many applications, but an issue with the Redis process or
+# a power outage may result into a few minutes of writes lost (depending on
+# the configured save points).
+#
+# The Append Only File is an alternative persistence mode that provides
+# much better durability. For instance using the default data fsync policy
+# (see later in the config file) Redis can lose just one second of writes in a
+# dramatic event like a server power outage, or a single write if something
+# wrong with the Redis process itself happens, but the operating system is
+# still running correctly.
+#
+# AOF and RDB persistence can be enabled at the same time without problems.
+# If the AOF is enabled on startup Redis will load the AOF, that is the file
+# with the better durability guarantees.
+#
+# Note that changing this value in a config file of an existing database and
+# restarting the server can lead to data loss. A conversion needs to be done
+# by setting it via CONFIG command on a live server first.
+#
+# Please check https://redis.io/docs/latest/operate/oss_and_stack/management/persistence/ for more information.
+
+appendonly yes

schema.graphqls

@@ -1,26 +1,68 @@
-type Query {
-  systems: [System!]!
-  system(id: ID): System
-}
+scalar DateTime
 
+# The Interchange system schema.
+# Note how Passio ID and parking ID are abstracted away
+# from the endpoints.
 type System {
   id: ID!
   name: String!
+  initialRegion: Region
   routes: [Route!]
   route(id: ID): Route
   stops: [Stop!]
   stop(id: ID): Stop
   shuttles: [Shuttle!]
   shuttle(id: ID): Shuttle
+
+  parkingSystem: ParkingSystem
+}
+
+type Region {
+  topLeft: Coordinates!
+  bottomRight: Coordinates!
+}
+
+type ParkingSystem {
+  systemId: ID!
+  parkingStructures: [ParkingStructure!]
+  parkingStructure(id: ID): ParkingStructure
+}
+
+type ParkingStructure {
+  id: ID!
+  name: String!
+  capacity: Int!
+  spotsAvailable: Int!
+  coordinates: Coordinates!
+  address: String!
+  updatedTime: DateTime
+  systemId: ID!
+
+  historicalAverages(input: HistoricalParkingAverageQueryInput): [HistoricalParkingAverageQueryResult!]
+}
+
+type HistoricalParkingAverageQueryResult {
+  from: DateTime!
+  to: DateTime!
+  averageSpotsAvailable: Float!
+}
+
+input HistoricalParkingAverageQueryInput {
+  from: DateTime!
+  to: DateTime!
+  intervalMs: Int!
 }
 
 type Route {
   name: String!
   id: ID!
+  systemId: ID!
   orderedStop(forStopId: ID): OrderedStop
+  orderedStops: [OrderedStop]
   shuttles: [Shuttle!]
   polylineCoordinates: [Coordinates!]!
   color: String!
+  updatedTime: DateTime
 }
 
 type OrderedStop {
@@ -30,14 +72,18 @@ type OrderedStop {
   routeId: ID!
   stop: Stop
   stopId: ID!
+  systemId: ID!
+  updatedTime: DateTime
 }
 
 type Stop {
   id: ID!
+  systemId: ID!
   name: String!
   coordinates: Coordinates!
   etas: [ETA!]
   orderedStops: [OrderedStop!]
+  updatedTime: DateTime
 }
 
 type Coordinates {
@@ -51,14 +97,57 @@ type ETA {
   shuttle: Shuttle
   shuttleId: ID!
   secondsRemaining: Float!
+  systemId: ID!
+  updatedTime: DateTime
 }
 
 type Shuttle {
   name: String!
+  systemId: ID!
   id: ID!,
   coordinates: Coordinates!
   route: Route
   routeId: ID!
   etas: [ETA!]
   eta(forStopId: ID): ETA
+  orientationInDegrees: Float!
+  updatedTime: DateTime
+}
+
+# Queries
+type Query {
+  systems: [System!]!
+  system(id: ID): System
+
+  isNotificationScheduled(input: NotificationInput!): Boolean
+  secondsThresholdForNotification(input: NotificationInput!): Int
+
+  schemaMinVersion: Int!
+  schemaCurrentVersion: Int!
+}
+
+# Mutations
+type Mutation {
+  scheduleNotification(input: NotificationInput!): NotificationResponse!
+  cancelNotification(input: NotificationInput!): NotificationResponse!
+}
+
+input NotificationInput {
+  deviceId: ID!
+  shuttleId: ID!
+  stopId: ID!
+  secondsThreshold: Int
+}
+
+type NotificationResponse {
+  success: Boolean!
+  message: String!
+  data: Notification
+}
+
+type Notification {
+  deviceId: ID!
+  shuttleId: ID!
+  stopId: ID!
+  secondsThreshold: Int
 }

src/MergedResolvers.ts

@@ -1,4 +1,4 @@
-import { Coordinates, Eta, OrderedStop, Resolvers } from "./generated/graphql";
+import { Resolvers } from "./generated/graphql";
 import { ServerContext } from "./ServerContext";
 import { QueryResolvers } from "./resolvers/QueryResolvers";
 import { SystemResolvers } from "./resolvers/SystemResolvers";
@@ -7,13 +7,21 @@ import { OrderedStopResolvers } from "./resolvers/OrderedStopResolvers";
 import { StopResolvers } from "./resolvers/StopResolvers";
 import { ShuttleResolvers } from "./resolvers/ShuttleResolvers";
 import { RouteResolvers } from "./resolvers/RouteResolvers";
+import { MutationResolvers } from "./resolvers/MutationResolvers";
+import { ParkingSystemResolvers } from "./resolvers/ParkingSystemResolvers";
+import { DateTime } from "./scalars/DateTime";
+import { ParkingStructureResolvers } from "./resolvers/ParkingStructureResolvers";
 
 export const MergedResolvers: Resolvers<ServerContext> = {
   ...QueryResolvers,
+  ...ParkingSystemResolvers,
   ...SystemResolvers,
   ...RouteResolvers,
   ...ShuttleResolvers,
   ...StopResolvers,
   ...OrderedStopResolvers,
   ...EtaResolvers,
-};
+  ...MutationResolvers,
+  ...ParkingStructureResolvers,
+  DateTime: DateTime,
+};

src/ServerContext.ts

@@ -1,5 +1,6 @@
-import { GetterRepository } from "./repositories/GetterRepository";
+import { InterchangeSystem } from "./entities/InterchangeSystem";
 
 export interface ServerContext {
-  repository: GetterRepository;
-}
+  systems: InterchangeSystem[];
+  findSystemById: (id: string) => InterchangeSystem | null;
+}

src/__mocks__/environment.ts

@@ -0,0 +1,11 @@
+export const PARKING_LOGGING_INTERVAL_MS = 10000;
+
+export const PARKING_HISTORICAL_AVERAGE_MINIMUM_INTERVAL = 1000;
+
+export const PARKING_HISTORICAL_AVERAGE_MAXIMUM_TIMESPAN = 60000 * 60 * 24;
+
+export const RATE_LIMITS_DISABLED = true;
+export const RATE_LIMIT_WINDOW_MS = 10000;
+export const RATE_LIMIT_DELAY_AFTER_REQUESTS = 10000;
+export const RATE_LIMIT_DELAY_MULTIPLIER_MS = 1000;
+

src/entities/InterchangeSystem.ts

@@ -0,0 +1,295 @@
+import { ETANotificationScheduler } from "../notifications/schedulers/ETANotificationScheduler";
+import { TimedApiBasedRepositoryLoader } from "../loaders/TimedApiBasedRepositoryLoader";
+import { UnoptimizedInMemoryShuttleRepository } from "../repositories/shuttle/UnoptimizedInMemoryShuttleRepository";
+import { RedisNotificationRepository } from "../repositories/notifications/RedisNotificationRepository";
+import { NotificationRepository } from "../repositories/notifications/NotificationRepository";
+import { ShuttleGetterSetterRepository } from "../repositories/shuttle/ShuttleGetterSetterRepository";
+import { InMemoryNotificationRepository } from "../repositories/notifications/InMemoryNotificationRepository";
+import { AppleNotificationSender } from "../notifications/senders/AppleNotificationSender";
+import { ApiBasedShuttleRepositoryLoader } from "../loaders/shuttle/ApiBasedShuttleRepositoryLoader";
+import { ParkingGetterSetterRepository } from "../repositories/parking/ParkingGetterSetterRepository";
+import { InMemoryParkingRepository } from "../repositories/parking/InMemoryParkingRepository";
+import {
+  buildParkingRepositoryLoaderIfExists,
+  ParkingRepositoryLoaderBuilderArguments
+} from "../loaders/parking/buildParkingRepositoryLoaderIfExists";
+import { RedisParkingRepository } from "../repositories/parking/RedisParkingRepository";
+import { ShuttleGetterRepository } from "../repositories/shuttle/ShuttleGetterRepository";
+import { InMemoryExternalSourceETARepository } from "../repositories/shuttle/eta/InMemoryExternalSourceETARepository";
+import { ETAGetterRepository } from "../repositories/shuttle/eta/ETAGetterRepository";
+import { InMemorySelfUpdatingETARepository } from "../repositories/shuttle/eta/InMemorySelfUpdatingETARepository";
+import { BaseInMemoryETARepository } from "../repositories/shuttle/eta/BaseInMemoryETARepository";
+import { IRegion } from "./SharedEntities";
+
+export interface InterchangeSystemBuilderArguments {
+  name: string;
+
+  /**
+   * ID to identify the system internally and in the API.
+   */
+  id: string;
+
+  /**
+   * ID for fetching shuttle data from the Passio GO! system.
+   */
+  passioSystemId: string;
+
+  /**
+   * ID for the parking repository ID in the codebase.
+   */
+  parkingSystemId?: string;
+
+  /**
+   * Controls whether to self-calculate ETAs or use the external
+   * shuttle provider for them.
+   */
+  useSelfUpdatingEtas: boolean;
+
+  /**
+   * The size of the threshold to detect when a shuttle has arrived
+   * at a stop, in latitude/longitude degrees.
+   */
+  shuttleStopArrivalDegreeDelta: number;
+
+  /**
+   * The initial map region to display when the app first loads
+   * this system. Represents a center coordinate and span.
+   */
+  initialRegion?: IRegion;
+}
+
+export class InterchangeSystem {
+  private constructor(
+    public name: string,
+    public id: string,
+    public shuttleTimedDataLoader: TimedApiBasedRepositoryLoader,
+    public shuttleRepository: ShuttleGetterSetterRepository,
+    public etaRepository: ETAGetterRepository,
+    public notificationScheduler: ETANotificationScheduler,
+    public notificationRepository: NotificationRepository,
+    public parkingTimedDataLoader: TimedApiBasedRepositoryLoader | null,
+    public parkingRepository: ParkingGetterSetterRepository | null,
+    public initialRegion: IRegion | null,
+  ) {
+  }
+
+  /**
+   * Construct an instance of the class where all composited
+   * classes are correctly linked, meant for use in development and production.
+   * @param args
+   */
+  static async build(
+    args: InterchangeSystemBuilderArguments,
+  ) {
+    const { shuttleRepository, timedShuttleDataLoader, etaRepository } = await InterchangeSystem.buildProductionShuttleLoaderAndRepositories(args);
+    timedShuttleDataLoader.start();
+
+    const { notificationScheduler, notificationRepository } = await InterchangeSystem.buildNotificationSchedulerAndRepository(
+      etaRepository,
+      shuttleRepository,
+      args
+    );
+    notificationScheduler.startListeningForUpdates();
+
+    let { parkingRepository, timedParkingLoader } = await InterchangeSystem.buildRedisParkingLoaderAndRepository(args.parkingSystemId);
+    timedParkingLoader?.start();
+
+    return new InterchangeSystem(
+      args.name,
+      args.id,
+      timedShuttleDataLoader,
+      shuttleRepository,
+      etaRepository,
+      notificationScheduler,
+      notificationRepository,
+      timedParkingLoader,
+      parkingRepository,
+      args.initialRegion ?? null,
+    );
+  }
+
+  private static async buildProductionShuttleLoaderAndRepositories(args: InterchangeSystemBuilderArguments) {
+    const shuttleRepository = new UnoptimizedInMemoryShuttleRepository(
+      args.shuttleStopArrivalDegreeDelta,
+    );
+
+    let etaRepository: BaseInMemoryETARepository;
+    let shuttleDataLoader: ApiBasedShuttleRepositoryLoader;
+    if (args.useSelfUpdatingEtas) {
+      etaRepository = new InMemorySelfUpdatingETARepository(shuttleRepository);
+      (etaRepository as InMemorySelfUpdatingETARepository).startListeningForUpdates();
+      shuttleDataLoader = new ApiBasedShuttleRepositoryLoader(
+        args.passioSystemId,
+        args.id,
+        shuttleRepository,
+      );
+    } else {
+      etaRepository = new InMemoryExternalSourceETARepository();
+      shuttleDataLoader = new ApiBasedShuttleRepositoryLoader(
+        args.passioSystemId,
+        args.id,
+        shuttleRepository,
+        etaRepository as InMemoryExternalSourceETARepository,
+      );
+    }
+    const timedShuttleDataLoader = new TimedApiBasedRepositoryLoader(
+      shuttleDataLoader,
+    );
+
+
+    return { shuttleRepository, etaRepository, timedShuttleDataLoader };
+  }
+
+  private static async buildNotificationSchedulerAndRepository(
+    etaRepository: ETAGetterRepository,
+    shuttleRepository: ShuttleGetterRepository,
+    args: InterchangeSystemBuilderArguments
+  ) {
+    const notificationRepository = new RedisNotificationRepository();
+    await notificationRepository.connect();
+    const notificationScheduler = new ETANotificationScheduler(
+      etaRepository,
+      shuttleRepository,
+      notificationRepository,
+      new AppleNotificationSender(),
+      args.id
+    );
+    return { notificationScheduler, notificationRepository };
+  }
+
+  private static async buildRedisParkingLoaderAndRepository(id?: string) {
+    if (id === undefined) {
+      return { parkingRepository: null, timedParkingLoader: null };
+    }
+
+    let parkingRepository: RedisParkingRepository | null = new RedisParkingRepository();
+    await parkingRepository.connect();
+
+    const loaderBuilderArguments: ParkingRepositoryLoaderBuilderArguments = {
+      id,
+      repository: parkingRepository,
+    };
+    let parkingLoader = buildParkingRepositoryLoaderIfExists(
+      loaderBuilderArguments,
+    );
+
+    let timedParkingLoader = null;
+    if (parkingLoader == null) {
+      parkingRepository = null;
+    } else {
+      timedParkingLoader = new TimedApiBasedRepositoryLoader(parkingLoader);
+    }
+    return { parkingRepository, timedParkingLoader };
+  }
+
+  /**
+   * Construct an instance of the class where all composited
+   * classes are correctly linked, meant for unit tests, and server/app
+   * integration tests.
+   * @param args
+   */
+  static buildForTesting(
+    args: InterchangeSystemBuilderArguments,
+  ) {
+    const { shuttleRepository, timedShuttleLoader, etaRepository } = InterchangeSystem.buildTestingShuttleLoaderAndRepositories(args);
+    // Timed shuttle loader is not started here
+
+    const { notificationScheduler, notificationRepository } = InterchangeSystem.buildTestingNotificationSchedulerAndRepository(
+      etaRepository,
+      shuttleRepository,
+      args
+    );
+    notificationScheduler.startListeningForUpdates();
+
+    let { parkingRepository, timedParkingLoader } = this.buildTestingParkingLoaderAndRepository(args.parkingSystemId);
+    // Timed parking loader is not started here
+
+    return new InterchangeSystem(
+      args.name,
+      args.id,
+      timedShuttleLoader,
+      shuttleRepository,
+      etaRepository,
+      notificationScheduler,
+      notificationRepository,
+      timedParkingLoader,
+      parkingRepository,
+      args.initialRegion ?? null,
+    );
+  }
+
+  private static buildTestingNotificationSchedulerAndRepository(
+    etaRepository: ETAGetterRepository,
+    shuttleRepository: UnoptimizedInMemoryShuttleRepository,
+    args: InterchangeSystemBuilderArguments
+  ) {
+    const notificationRepository = new InMemoryNotificationRepository();
+    const notificationScheduler = new ETANotificationScheduler(
+      etaRepository,
+      shuttleRepository,
+      notificationRepository,
+      new AppleNotificationSender(false),
+      args.id
+    );
+    return { notificationScheduler, notificationRepository };
+  }
+
+  private static buildTestingParkingLoaderAndRepository(id?: string) {
+    if (id === undefined) {
+      return { parkingRepository: null, timedParkingLoader: null };
+    }
+
+    let parkingRepository: ParkingGetterSetterRepository | null = new InMemoryParkingRepository();
+    const loaderBuilderArguments: ParkingRepositoryLoaderBuilderArguments = {
+      id,
+      repository: parkingRepository,
+    };
+    let parkingLoader = buildParkingRepositoryLoaderIfExists(
+      loaderBuilderArguments,
+    );
+
+    let timedParkingLoader = null;
+    if (parkingLoader == null) {
+      parkingRepository = null;
+    } else {
+      timedParkingLoader = new TimedApiBasedRepositoryLoader(parkingLoader);
+    }
+    return { parkingRepository, timedParkingLoader };
+  }
+
+  private static buildTestingShuttleLoaderAndRepositories(args: InterchangeSystemBuilderArguments) {
+    const shuttleRepository = new UnoptimizedInMemoryShuttleRepository(
+      args.shuttleStopArrivalDegreeDelta,
+    );
+
+    let etaRepository: BaseInMemoryETARepository;
+    let shuttleDataLoader: ApiBasedShuttleRepositoryLoader;
+    if (args.useSelfUpdatingEtas) {
+      etaRepository = new InMemorySelfUpdatingETARepository(shuttleRepository);
+      (etaRepository as InMemorySelfUpdatingETARepository).startListeningForUpdates();
+      shuttleDataLoader = new ApiBasedShuttleRepositoryLoader(
+        args.passioSystemId,
+        args.id,
+        shuttleRepository,
+      );
+    } else {
+      etaRepository = new InMemoryExternalSourceETARepository();
+      shuttleDataLoader = new ApiBasedShuttleRepositoryLoader(
+        args.passioSystemId,
+        args.id,
+        shuttleRepository,
+        etaRepository as InMemoryExternalSourceETARepository,
+      );
+    }
+
+    // Note that this loader should not be started,
+    // so the test data doesn't get overwritten
+    const timedShuttleLoader = new TimedApiBasedRepositoryLoader(
+      shuttleDataLoader
+    );
+
+
+    return { shuttleRepository, etaRepository, timedShuttleLoader };
+  }
+
+}

src/entities/ParkingRepositoryEntities.ts

@@ -0,0 +1,17 @@
+import { ICoordinates, IEntityWithId, IEntityWithTimestamp } from "./SharedEntities";
+
+export interface IParkingStructure extends IEntityWithTimestamp, IEntityWithId {
+  address: string;
+  capacity: number;
+  spotsAvailable: number;
+  coordinates: ICoordinates;
+  name: string;
+}
+
+export interface IParkingStructureTimestampRecord {
+  timestampMs: Date;
+  id: string;
+  spotsAvailable: number;
+}
+
+// In the future, add support for viewing different levels of the structure

src/entities/SharedEntities.ts

@@ -0,0 +1,18 @@
+export interface IEntityWithTimestamp {
+  updatedTime: Date;
+}
+
+export interface IEntityWithId {
+  id: string;
+}
+
+export interface ICoordinates {
+  latitude: number;
+  longitude: number;
+}
+
+export interface IRegion {
+  topLeft: ICoordinates;
+  bottomRight: ICoordinates;
+}
+

src/entities/ShuttleRepositoryEntities.ts

@@ -0,0 +1,55 @@
+import { ICoordinates, IEntityWithId, IEntityWithTimestamp } from "./SharedEntities";
+
+export interface IRoute extends IEntityWithId, IEntityWithTimestamp {
+  name: string;
+  color: string;
+  polylineCoordinates: ICoordinates[];
+  systemId: string;
+}
+
+export interface IStop extends IEntityWithId, IEntityWithTimestamp {
+  name: string;
+  systemId: string;
+  coordinates: ICoordinates;
+}
+
+export interface IShuttle extends IEntityWithId, IEntityWithTimestamp {
+  coordinates: ICoordinates;
+  name: string;
+  routeId: string;
+  systemId: string;
+  orientationInDegrees: number;
+}
+
+export interface IEta extends IEntityWithTimestamp {
+  secondsRemaining: number;
+  shuttleId: string;
+  stopId: string;
+  systemId: string;
+}
+
+export interface IOrderedStop extends IEntityWithTimestamp {
+  nextStop?: IOrderedStop;
+  previousStop?: IOrderedStop;
+  routeId: string;
+  stopId: string;
+  position: number;
+  systemId: string;
+}
+
+/**
+ * Checks if a shuttle has arrived at a stop based on coordinate proximity.
+ * Uses a threshold of 0.001 degrees (~111 meters at the equator).
+ */
+export function shuttleHasArrivedAtStop(
+  shuttle: IShuttle,
+  stop: IStop,
+  delta = 0.001
+) {
+  const isWithinLatitudeRange = shuttle.coordinates.latitude > stop.coordinates.latitude - delta
+    && shuttle.coordinates.latitude < stop.coordinates.latitude + delta;
+  const isWithinLongitudeRange = shuttle.coordinates.longitude > stop.coordinates.longitude - delta
+    && shuttle.coordinates.longitude < stop.coordinates.longitude + delta
+  return isWithinLatitudeRange && isWithinLongitudeRange;
+}
+

src/entities/__tests__/ShuttleRepositoryEntities.test.ts

@@ -0,0 +1,65 @@
+import { describe, expect, it } from "@jest/globals";
+import { shuttleHasArrivedAtStop, IShuttle, IStop } from "../ShuttleRepositoryEntities";
+
+describe("shuttleHasArrivedAtStop", () => {
+  const baseStop: IStop = {
+    id: "stop1",
+    name: "Test Stop",
+    systemId: "263",
+    coordinates: {
+      latitude: 33.7963,
+      longitude: -117.8540,
+    },
+    updatedTime: new Date(),
+  };
+
+  const createShuttle = (latitude: number, longitude: number): IShuttle => ({
+    id: "shuttle1",
+    name: "Test Shuttle",
+    routeId: "route1",
+    systemId: "263",
+    coordinates: { latitude, longitude },
+    orientationInDegrees: 0,
+    updatedTime: new Date(),
+  });
+
+  it("returns false when shuttle is above latitude range", () => {
+    const shuttle = createShuttle(
+      baseStop.coordinates.latitude + 0.0011,
+      baseStop.coordinates.longitude
+    );
+    expect(shuttleHasArrivedAtStop(shuttle, baseStop)).toBe(false);
+  });
+
+  it("returns false when shuttle is below latitude range", () => {
+    const shuttle = createShuttle(
+      baseStop.coordinates.latitude - 0.0011,
+      baseStop.coordinates.longitude
+    );
+    expect(shuttleHasArrivedAtStop(shuttle, baseStop)).toBe(false);
+  });
+
+  it("returns false when shuttle is to left of longitude range", () => {
+    const shuttle = createShuttle(
+      baseStop.coordinates.latitude,
+      baseStop.coordinates.longitude - 0.0011
+    );
+    expect(shuttleHasArrivedAtStop(shuttle, baseStop)).toBe(false);
+  });
+
+  it("returns false when shuttle is to right of longitude range", () => {
+    const shuttle = createShuttle(
+      baseStop.coordinates.latitude,
+      baseStop.coordinates.longitude + 0.0011
+    );
+    expect(shuttleHasArrivedAtStop(shuttle, baseStop)).toBe(false);
+  });
+
+  it("returns true when shuttle is in the range", () => {
+    const shuttle = createShuttle(
+      baseStop.coordinates.latitude + 0.0005,
+      baseStop.coordinates.longitude - 0.0005
+    );
+    expect(shuttleHasArrivedAtStop(shuttle, baseStop)).toBe(true);
+  });
+});

src/entities/entities.ts

@@ -1,51 +0,0 @@
-export interface IEntityWithOptionalTimestamp {
-  millisecondsSinceEpoch?: number;
-}
-
-export interface IEntityWithId {
-  id: string;
-}
-
-export interface ISystem extends IEntityWithId, IEntityWithOptionalTimestamp {
-  name: string;
-}
-
-export interface ICoordinates {
-  latitude: number;
-  longitude: number;
-}
-
-export interface IRoute extends IEntityWithId, IEntityWithOptionalTimestamp {
-  name: string;
-  color: string;
-  polylineCoordinates: ICoordinates[];
-  systemId: string;
-}
-
-export interface IStop extends IEntityWithId, IEntityWithOptionalTimestamp {
-  name: string;
-  systemId: string;
-  coordinates: ICoordinates;
-}
-
-export interface IShuttle extends IEntityWithId, IEntityWithOptionalTimestamp {
-  coordinates: ICoordinates;
-  name: string;
-  routeId: string;
-  systemId: string;
-}
-
-export interface IEta extends IEntityWithOptionalTimestamp {
-  secondsRemaining: number;
-  shuttleId: string;
-  stopId: string;
-}
-
-export interface IOrderedStop extends IEntityWithOptionalTimestamp {
-  nextStop?: IOrderedStop;
-  previousStop?: IOrderedStop;
-  routeId: string;
-  stopId: string;
-  position: number;
-}
-

src/environment.ts

@@ -0,0 +1,26 @@
+export const PARKING_LOGGING_INTERVAL_MS = process.env.PARKING_LOGGING_INTERVAL_MS
+  ? parseInt(process.env.PARKING_LOGGING_INTERVAL_MS)
+  : 600000; // Every 10 minutes
+
+export const PARKING_HISTORICAL_AVERAGE_MINIMUM_INTERVAL = process.env.PARKING_HISTORICAL_AVERAGE_MINIMUM_INTERVAL
+  ? parseInt(process.env.PARKING_HISTORICAL_AVERAGE_MINIMUM_INTERVAL)
+  : 60000 * 60 * 2;
+
+export const PARKING_HISTORICAL_AVERAGE_MAXIMUM_TIMESPAN = process.env.PARKING_HISTORICAL_AVERAGE_MAXIMUM_TIMESPAN
+  ? parseInt(process.env.PARKING_HISTORICAL_AVERAGE_MAXIMUM_TIMESPAN)
+  : 60000 * 60 * 24;
+
+export const RATE_LIMITS_DISABLED = process.env.RATE_LIMITS_DISABLED === "1";
+export const RATE_LIMIT_WINDOW_MS = process.env.RATE_LIMIT_WINDOW_MS
+  ? parseInt(process.env.RATE_LIMIT_WINDOW_MS)
+  : 10000;
+export const RATE_LIMIT_DELAY_AFTER_REQUESTS = process.env.RATE_LIMIT_DELAY_AFTER_REQUESTS
+  ? parseInt(process.env.RATE_LIMIT_DELAY_AFTER_REQUESTS)
+  : 10000;
+export const RATE_LIMIT_DELAY_MULTIPLIER_MS = process.env.RATE_LIMIT_DELAY_MULTIPLIER_MS
+  ? parseInt(process.env.RATE_LIMIT_DELAY_MULTIPLIER_MS)
+  : 1000;
+
+export const REDIS_RECONNECT_INTERVAL = 30000;
+
+export const SHUTTLE_TO_ROUTE_COORDINATE_MAXIMUM_DISTANCE_MILES = 5;

src/helpers/createRedisClientForRepository.ts

@@ -0,0 +1,15 @@
+import { createClient, RedisClientType } from "redis";
+import { REDIS_RECONNECT_INTERVAL } from "../environment";
+
+export default function createRedisClientForRepository() {
+  const client = createClient({
+    url: process.env.REDIS_URL,
+    socket: {
+      tls: process.env.REDIS_USE_TLS === "1",
+      rejectUnauthorized: false,
+      reconnectStrategy: REDIS_RECONNECT_INTERVAL,
+    } as object,
+  });
+  return client as RedisClientType;
+}
+

src/index.ts

@@ -1,41 +1,95 @@
 import { readFileSync } from "fs";
 import { ApolloServer } from "@apollo/server";
-import { startStandaloneServer } from "@apollo/server/standalone";
 import { MergedResolvers } from "./MergedResolvers";
 import { ServerContext } from "./ServerContext";
-import { UnoptimizedInMemoryRepository } from "./repositories/UnoptimizedInMemoryRepository";
-import { TimedApiBasedRepositoryLoader } from "./loaders/TimedApiBasedRepositoryLoader";
+import { InterchangeSystem, InterchangeSystemBuilderArguments } from "./entities/InterchangeSystem";
+import { ChapmanApiBasedParkingRepositoryLoader } from "./loaders/parking/ChapmanApiBasedParkingRepositoryLoader";
+import express from "express";
+import { expressMiddleware } from "@as-integrations/express5";
+import {
+  RATE_LIMIT_DELAY_AFTER_REQUESTS,
+  RATE_LIMIT_DELAY_MULTIPLIER_MS,
+  RATE_LIMIT_WINDOW_MS,
+  RATE_LIMITS_DISABLED
+} from "./environment";
+import slowDown from "express-slow-down";
 
 const typeDefs = readFileSync("./schema.graphqls", "utf8");
 
+// In the future this can be stored as a separate file
+const supportedSystems: InterchangeSystemBuilderArguments[] = [
+  {
+    id: "1",
+    passioSystemId: "263",
+    parkingSystemId: ChapmanApiBasedParkingRepositoryLoader.id,
+    name: "Chapman University",
+    useSelfUpdatingEtas: true,
+    shuttleStopArrivalDegreeDelta: 0.001,
+    initialRegion: {
+      topLeft: { latitude: 33.85733, longitude: -117.89553 },
+      bottomRight: { latitude: 33.73970, longitude: -117.81878 },
+    },
+  }
+]
+
 async function main() {
   const server = new ApolloServer<ServerContext>({
     typeDefs,
     resolvers: MergedResolvers,
     introspection: process.env.NODE_ENV !== "production",
   });
+  await server.start();
 
-  const repository = new UnoptimizedInMemoryRepository();
-  // await loadTestData(repository);
+  let systems: InterchangeSystem[];
 
-  const repositoryDataUpdater = new TimedApiBasedRepositoryLoader(
-    repository
-  );
-  await repositoryDataUpdater.start();
-
-  const { url } = await startStandaloneServer(server, {
-    listen: {
-      port: process.env.PORT ? parseInt(process.env.PORT) : 4000,
+  systems = await Promise.all(supportedSystems.map(
+    async (systemArguments) => {
+      return await InterchangeSystem.build(systemArguments);
     },
-    context: async ({ req, res }) => {
+  ));
+
+  const app = express();
+  const options = {
+    context: async () => {
       return {
-        repository,
+        systems,
+        findSystemById: (id: string) => {
+          const system = systems.find((system) => system.id === id);
+          if (!system) {
+            return null;
+          }
+          return system;
+        },
       }
     },
+  };
+
+  if (RATE_LIMITS_DISABLED) {
+    app.use(
+      "/",
+      express.json(),
+      expressMiddleware(server, options)
+    );
+  } else {
+    const limiter = slowDown({
+      windowMs: RATE_LIMIT_WINDOW_MS,
+      delayAfter: RATE_LIMIT_DELAY_AFTER_REQUESTS,
+      delayMs: (hits) => {
+        return hits * RATE_LIMIT_DELAY_MULTIPLIER_MS;
+      }
+    });
+    app.use(
+      "/",
+      express.json(),
+      limiter,
+      expressMiddleware(server, options),
+    );
+  }
+
+  const port = process.env.PORT ? parseInt(process.env.PORT) : 4000;
+  app.listen(port, () => {
+    console.log(`Server ready at port ${port}`);
   });
-
-
-  console.log(`Server ready at: ${url}`);
 }
 
 main();

src/loaders/ApiBasedRepositoryLoader.ts

@@ -1,385 +0,0 @@
-import { GetterSetterRepository } from "../repositories/GetterSetterRepository";
-import { IEntityWithId, IEta, IRoute, IShuttle, IStop, ISystem } from "../entities/entities";
-
-export class ApiResponseError extends Error {
-  constructor(message: string) {
-    super(message);
-    this.name = "ApiResponseError";
-  }
-}
-
-/**
- * Class which can load data into a repository from the
- * Passio Go API. Supports automatic pruning of all data types
- * which inherit from `IEntityWithId`.
- */
-export class ApiBasedRepositoryLoader {
-  supportedSystemIds = ["263"];
-  baseUrl = "https://passiogo.com/mapGetData.php";
-
-  constructor(
-    public repository: GetterSetterRepository,
-  ) {
-  }
-
-  private async constructExistingEntityIdSet<T extends IEntityWithId>(entitySearchCallback: () => Promise<T[]>) {
-    const existingEntities = await entitySearchCallback();
-    const ids = new Set<string>();
-    existingEntities.forEach((entity) => {
-      ids.add(entity.id);
-    });
-    return ids;
-  }
-
-  public async fetchAndUpdateSystemData() {
-    const params = {
-      getSystems: "2",
-    };
-    const query = new URLSearchParams(params).toString();
-
-    const systemIds = await this.constructExistingEntityIdSet(async () => {
-      return await this.repository.getSystems();
-    })
-
-    try {
-      const response = await fetch(`${this.baseUrl}?${query}`);
-      const json = await response.json();
-
-      if (!response.ok) {
-        throw new Error(`HTTP error with status ${response.status}`)
-      }
-
-      if (typeof json.all === "object") {
-        // filter down to supported systems
-        const filteredSystems = json.all.filter((jsonSystem: any) => this.supportedSystemIds.includes(jsonSystem.id));
-        await Promise.all(filteredSystems.map(async (system: any) => {
-          const constructedSystem: ISystem = {
-            id: system.id,
-            name: system.fullname,
-          };
-
-          await this.repository.addOrUpdateSystem(constructedSystem);
-          systemIds.delete(constructedSystem.id);
-        }));
-      } else {
-        throw new Error("Received JSON object does not contain `all` field")
-      }
-
-      // Prune systems
-      await Promise.all(Array.from(systemIds).map(async (systemId) => {
-        await this.repository.removeSystemIfExists(systemId);
-      }));
-    } catch(e: any) {
-      throw new ApiResponseError(e.message);
-    }
-  }
-
-  public async fetchAndUpdateRouteDataForExistingSystemsInRepository() {
-    const systems = await this.repository.getSystems();
-    await Promise.all(systems.map(async (system) => {
-      await this.fetchAndUpdateRouteDataForSystemId(system.id);
-    }));
-  }
-
-  public async fetchAndUpdateRouteDataForSystemId(systemId: string) {
-    const routeIdsToPrune = await this.constructExistingEntityIdSet(async () => {
-      return await this.repository.getRoutesBySystemId(systemId);
-    });
-
-    const params = {
-      getRoutes: "2",
-    };
-
-    const formDataJsonObject = {
-      "systemSelected0": systemId,
-      "amount": "1",
-    }
-    const formData = new FormData();
-    formData.set("json", JSON.stringify(formDataJsonObject));
-
-    const query = new URLSearchParams(params).toString();
-
-    try {
-      const response = await fetch(`${this.baseUrl}?${query}`, {
-        method: "POST",
-        body: formData,
-      });
-      const json = await response.json();
-
-      if (typeof json.all === "object") {
-        await Promise.all(json.all.map(async (jsonRoute: any) => {
-          const constructedRoute: IRoute = {
-            name: jsonRoute.name,
-            color: jsonRoute.color,
-            id: jsonRoute.myid,
-            polylineCoordinates: [],
-            systemId: systemId,
-          };
-
-          await this.repository.addOrUpdateRoute(constructedRoute);
-
-          routeIdsToPrune.delete(constructedRoute.id);
-        }))
-      }
-
-      await Promise.all(Array.from(routeIdsToPrune).map(async (routeId) => {
-        await this.repository.removeRouteIfExists(routeId);
-      }));
-    } catch(e: any) {
-      throw new ApiResponseError(e.message);
-    }
-  }
-
-  public async fetchAndUpdateStopAndPolylineDataForRoutesInExistingSystemsInRepository() {
-    const systems = await this.repository.getSystems();
-    await Promise.all(systems.map(async (system: ISystem) => {
-      await this.fetchAndUpdateStopAndPolylineDataForRoutesWithSystemId(system.id);
-    }));
-  }
-
-  public async fetchAndUpdateStopAndPolylineDataForRoutesWithSystemId(systemId: string) {
-    // Fetch from the API
-    // Pass JSON output into two different methods to update repository
-    const stopIdsToPrune = await this.constructExistingEntityIdSet(async () => {
-      return await this.repository.getStopsBySystemId(systemId);
-    });
-
-    const params = {
-      getStops: "2",
-    };
-
-    const formDataJsonObject = {
-      "s0": systemId,
-      "sA": 1
-    };
-    const formData = new FormData();
-    formData.set("json", JSON.stringify(formDataJsonObject));
-
-    const query = new URLSearchParams(params).toString();
-
-    try {
-      const response = await fetch(`${this.baseUrl}?${query}`, {
-        method: "POST",
-        body: formData,
-      });
-      const json = await response.json();
-
-      await this.updateStopDataForSystemAndApiResponse(systemId, json, stopIdsToPrune);
-      await this.updateOrderedStopDataForExistingStops(json);
-      await this.updatePolylineDataForExistingRoutesAndApiResponse(json);
-
-      await Promise.all(Array.from(stopIdsToPrune).map(async (stopId) => {
-        await this.repository.removeStopIfExists(stopId);
-      }));
-    } catch(e: any) {
-      throw new ApiResponseError(e.message);
-    }
-  }
-
-  public async fetchAndUpdateShuttleDataForExistingSystemsInRepository() {
-    const systems = await this.repository.getSystems();
-    await Promise.all(systems.map(async (system: ISystem) => {
-      const systemId = system.id;
-      await this.fetchAndUpdateShuttleDataForSystemId(systemId);
-    }));
-  }
-
-  public async fetchAndUpdateShuttleDataForSystemId(systemId: string) {
-    const shuttleIdsToPrune = await this.constructExistingEntityIdSet(async () => {
-      return await this.repository.getShuttlesBySystemId(systemId);
-    });
-
-    const params = {
-      getBuses: "2"
-    };
-
-    const formDataJsonObject = {
-      "s0": systemId,
-      "sA": "1"
-    };
-
-    const formData = new FormData();
-    formData.set("json", JSON.stringify(formDataJsonObject));
-
-    const query = new URLSearchParams(params).toString();
-
-    try {
-      const response = await fetch(`${this.baseUrl}?${query}`, {
-        method: "POST",
-        body: formData,
-      });
-      const json = await response.json();
-
-      if (json.buses && json.buses["-1"] === undefined) {
-        const jsonBuses = Object.values(json.buses).map((busesArr: any) => {
-          return busesArr[0];
-        });
-
-        await Promise.all(jsonBuses.map(async (jsonBus: any) => {
-          const constructedShuttle: IShuttle = {
-            name: jsonBus.bus,
-            coordinates: {
-              latitude: parseFloat(jsonBus.latitude),
-              longitude: parseFloat(jsonBus.longitude),
-            },
-            routeId: jsonBus.routeId,
-            systemId: systemId,
-            id: `${jsonBus.busId}`
-          }
-
-          await this.repository.addOrUpdateShuttle(constructedShuttle);
-
-          shuttleIdsToPrune.delete(constructedShuttle.id);
-        }));
-      }
-
-      await Promise.all(Array.from(shuttleIdsToPrune).map(async (shuttleId) => {
-        await this.repository.removeShuttleIfExists(shuttleId);
-      }));
-    } catch(e: any) {
-      throw new ApiResponseError(e.message);
-    }
-  }
-
-  public async fetchAndUpdateEtaDataForExistingStopsForSystemsInRepository() {
-    const systems = await this.repository.getSystems()
-    await Promise.all(systems.map(async (system: ISystem) => {
-      const systemId = system.id;
-      await this.fetchAndUpdateEtaDataForExistingStopsForSystemId(systemId);
-    }))
-  }
-
-  public async fetchAndUpdateEtaDataForExistingStopsForSystemId(systemId: string) {
-    const stops = await this.repository.getStopsBySystemId(systemId);
-    await Promise.all(stops.map(async (stop) => {
-      let stopId = stop.id;
-      await this.fetchAndUpdateEtaDataForStopId(stopId);
-    }));
-  }
-
-  public async fetchAndUpdateEtaDataForStopId(stopId: string) {
-    const params = {
-      eta: "3",
-      stopIds: stopId,
-    };
-
-    const query = new URLSearchParams(params).toString();
-
-    try {
-      const response = await fetch(`${this.baseUrl}?${query}`, {
-        method: "GET",
-      });
-      const json = await response.json();
-
-      if (json.ETAs && json.ETAs[stopId]) {
-        // Continue with the parsing
-        json.ETAs[stopId].forEach((jsonEta: any) => {
-          // Update cache
-          const shuttleId: string = jsonEta.busId;
-
-          const eta: IEta = {
-            secondsRemaining: jsonEta.secondsSpent,
-            shuttleId: `${shuttleId}`,
-            stopId: stopId,
-            millisecondsSinceEpoch: Date.now(),
-          };
-
-          this.repository.addOrUpdateEta(eta);
-        });
-      }
-    } catch(e: any) {
-      throw new ApiResponseError(e.message);
-    }
-  }
-
-  protected async updateStopDataForSystemAndApiResponse(
-    systemId: string,
-    json: any,
-    setOfIdsToPrune: Set<string> = new Set(),
-  ) {
-    if (json.stops) {
-      const jsonStops = Object.values(json.stops);
-
-      await Promise.all(jsonStops.map(async (stop: any) => {
-        const constructedStop: IStop = {
-          name: stop.name,
-          id: stop.id,
-          systemId,
-          coordinates: {
-            latitude: parseFloat(stop.latitude),
-            longitude: parseFloat(stop.longitude),
-          },
-        };
-
-        await this.repository.addOrUpdateStop(constructedStop);
-
-        setOfIdsToPrune.delete(constructedStop.id);
-      }));
-    }
-  }
-
-  protected async updateOrderedStopDataForExistingStops(json: any) {
-    if (json.routes) {
-      await Promise.all(Object.keys(json.routes).map(async (routeId) => {
-        const jsonOrderedStopData: any[][] = json.routes[routeId].slice(2);
-
-        // The API may return the same stop twice to indicate that
-        // the route runs in a loop
-        // If the API does not do this, assume the route is one-way
-        // To account for this, check if ordered stop already exists in repo
-        // If it does, write to that stop instead
-
-        for (let index = 0; index < jsonOrderedStopData.length; index++) {
-          const orderedStopDataArray = jsonOrderedStopData[index];
-
-          const stopId = orderedStopDataArray[1];
-          let constructedOrderedStop = await this.repository.getOrderedStopByRouteAndStopId(routeId, stopId)
-          if (constructedOrderedStop === null) {
-            constructedOrderedStop = {
-              routeId,
-              stopId,
-              position: index + 1,
-            };
-          }
-
-          if (index >= 1) {
-            constructedOrderedStop.previousStop = {
-              routeId,
-              stopId: jsonOrderedStopData[index - 1][1],
-              position: index,
-            };
-          }
-          if (index < jsonOrderedStopData.length - 1) {
-            constructedOrderedStop.nextStop = {
-              routeId,
-              stopId: jsonOrderedStopData[index + 1][1],
-              position: index + 2,
-            };
-          }
-
-          await this.repository.addOrUpdateOrderedStop(constructedOrderedStop);
-        }
-      }));
-    }
-  }
-
-  protected async updatePolylineDataForExistingRoutesAndApiResponse(json: any) {
-    if (json.routePoints) {
-      await Promise.all(Object.keys(json.routePoints).map(async (routeId) => {
-        const routePoints = json.routePoints[routeId][0];
-
-        const existingRoute = await this.repository.getRouteById(routeId);
-        if (!existingRoute) return;
-
-        existingRoute.polylineCoordinates = routePoints.map((point: any) => {
-          return {
-            latitude: parseFloat(point.lat),
-            longitude: parseFloat(point.lng),
-          };
-        });
-
-        await this.repository.addOrUpdateRoute(existingRoute);
-      }))
-    }
-  }
-}

src/loaders/ApiResponseError.ts

@@ -0,0 +1,6 @@
+export class ApiResponseError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = "ApiResponseError";
+  }
+}

src/loaders/RepositoryLoader.ts

@@ -0,0 +1,3 @@
+export interface RepositoryLoader {
+  updateAll(): Promise<void>;
+}

src/loaders/TimedApiBasedRepositoryLoader.ts

@@ -1,31 +1,17 @@
-import { GetterSetterRepository } from "../repositories/GetterSetterRepository";
-import { IEta, IRoute, IShuttle, IStop, ISystem } from "../entities/entities";
-import { ApiBasedRepositoryLoader } from "./ApiBasedRepositoryLoader";
+import { RepositoryLoader } from "./RepositoryLoader";
 
-// Ideas to break this into smaller pieces in the future:
-// Have one repository data loader running for each supported system
-// Each data loader independently updates data based on frequency of usage
+// To break down timed loading in the future:
+// Add flags to the repository indicating which data users are subscribed to
+// In the loader's `fetchAll` method, check flags and update only needed data
 
-// Notes on this: we only need to reload ETA data frequently
-// Other data can be reloaded periodically
-// Detailed list:
-// - ETA: reload frequently or switch to write-through approach
-// - Shuttles: reload every minute
-// - Routes: reload every few minutes
-// - Stops: reload every few minutes
-// - OrderedStops: reload every few minutes
-// - Systems: reload once a day
-
-export class TimedApiBasedRepositoryLoader extends ApiBasedRepositoryLoader {
+export class TimedApiBasedRepositoryLoader {
   private shouldBeRunning: boolean = false;
   private timer: any;
 
-  readonly timeout = 10000;
-
   constructor(
-    repository: GetterSetterRepository,
+    public loader: RepositoryLoader,
+    public readonly timeoutMs: number = 10000,
   ) {
-    super(repository);
     this.startFetchDataAndUpdate = this.startFetchDataAndUpdate.bind(this);
   }
 
@@ -47,19 +33,11 @@ export class TimedApiBasedRepositoryLoader extends ApiBasedRepositoryLoader {
     if (!this.shouldBeRunning) return;
 
     try {
-      await this.fetchAndUpdateSystemData();
-      await this.fetchAndUpdateRouteDataForExistingSystemsInRepository();
-      await this.fetchAndUpdateStopAndPolylineDataForRoutesInExistingSystemsInRepository();
-      await this.fetchAndUpdateShuttleDataForExistingSystemsInRepository();
-
-      // Because ETA method doesn't support pruning yet,
-      // add a call to the clear method here
-      await this.repository.clearEtaData();
-      await this.fetchAndUpdateEtaDataForExistingStopsForSystemsInRepository();
+      await this.loader.updateAll();
     } catch (e) {
       console.error(e);
     }
 
-    this.timer = setTimeout(this.startFetchDataAndUpdate, this.timeout);
+    this.timer = setTimeout(this.startFetchDataAndUpdate, this.timeoutMs);
   }
-}
+}

src/loaders/__tests__/TimedApiBasedRepositoryLoaderTests.test.ts

@@ -0,0 +1,68 @@
+import { afterEach, beforeEach, describe, expect, it, jest } from "@jest/globals";
+import { TimedApiBasedRepositoryLoader } from "../TimedApiBasedRepositoryLoader";
+import { resetGlobalFetchMockJson } from "../../../testHelpers/fetchMockHelpers";
+import { UnoptimizedInMemoryShuttleRepository } from "../../repositories/shuttle/UnoptimizedInMemoryShuttleRepository";
+import { ApiBasedShuttleRepositoryLoader } from "../shuttle/ApiBasedShuttleRepositoryLoader";
+
+describe("TimedApiBasedRepositoryLoader", () => {
+  let timedLoader: TimedApiBasedRepositoryLoader;
+  let spies: any;
+
+  beforeEach(() => {
+    jest.useFakeTimers();
+    jest.spyOn(global, "setTimeout");
+    resetGlobalFetchMockJson();
+
+    const mockLoader = new ApiBasedShuttleRepositoryLoader(
+      "1",
+      "1",
+      new UnoptimizedInMemoryShuttleRepository(),
+    );
+    timedLoader = new TimedApiBasedRepositoryLoader(
+      mockLoader,
+    );
+
+    spies = {
+      updateAll: jest.spyOn(mockLoader, 'updateAll'),
+    };
+
+    Object.values(spies).forEach((spy: any) => {
+      spy.mockResolvedValue(undefined);
+    });
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+    jest.clearAllTimers();
+  })
+
+  describe("start", () => {
+    it("should update internal state, call data fetching methods, and start a timer", async () => {
+      await timedLoader.start();
+      expect(timedLoader["shouldBeRunning"]).toBe(true);
+
+      Object.values(spies).forEach((spy: any) => {
+        expect(spy).toHaveBeenCalled();
+      });
+
+      expect(setTimeout).toHaveBeenCalledWith(expect.any(Function), timedLoader.timeoutMs);
+      expect(timedLoader.timeoutMs).not.toBeUndefined();
+    });
+
+    it("does nothing if timer is already running", async () => {
+      await timedLoader.start();
+      await timedLoader.start();
+
+      Object.values(spies).forEach((spy: any) => {
+        expect(spy).toHaveBeenCalledTimes(1);
+      });
+    });
+  });
+
+  describe("stop", () => {
+    it("should update internal state", async () => {
+      timedLoader.stop();
+      expect(timedLoader['shouldBeRunning']).toBe(false);
+    });
+  });
+});

src/loaders/loadTestData.ts

@@ -1,131 +0,0 @@
-// Mock data
-import { IEta, IOrderedStop, IRoute, IShuttle, IStop, ISystem } from "../entities/entities";
-import { GetterSetterRepository } from "../repositories/GetterSetterRepository";
-
-// TODO: turn this into a class for testing reusability
-
-const systems: ISystem[] = [
-  {
-    id: "1",
-    name: "Chapman University",
-  },
-];
-
-const routes: IRoute[] = [
-  {
-    name: "Red Route",
-    id: "1",
-    systemId: systems[0].id,
-    polylineCoordinates: [],
-    color: "#db2316",
-  },
-  {
-    name: "Teal Route",
-    id: "2",
-    systemId: systems[0].id,
-    polylineCoordinates: [],
-    color: "#21bdd1",
-  },
-];
-
-const stops: IStop[] = [
-  {
-    id: "1",
-    name: "Chapman Court",
-    coordinates: {
-      latitude: 33.796001,
-      longitude: -117.8892805,
-    },
-    systemId: systems[0].id,
-  },
-  {
-    id: "2",
-    name: "Chapman Grand",
-    coordinates: {
-      latitude: 33.804433,
-      longitude: -117.895966,
-    },
-    systemId: systems[0].id,
-  }
-];
-
-const orderedStopsForRedRoute: IOrderedStop[] = [
-  {
-    routeId: routes[0].id,
-    stopId: stops[0].id,
-    position: 1,
-  },
-  {
-    routeId: routes[0].id,
-    stopId: stops[1].id,
-    position: 2,
-  },
-];
-
-const orderedStopsForTealRoute: IOrderedStop[] = [
-  {
-    routeId: routes[1].id,
-    stopId: stops[1].id,
-    position: 1,
-  },
-  {
-    routeId: routes[1].id,
-    stopId: stops[0].id,
-    position: 2,
-  },
-]
-
-orderedStopsForRedRoute[0].nextStop = orderedStopsForRedRoute[1];
-orderedStopsForRedRoute[1].previousStop = orderedStopsForRedRoute[0];
-orderedStopsForTealRoute[0].nextStop = orderedStopsForTealRoute[1];
-orderedStopsForTealRoute[1].previousStop = orderedStopsForTealRoute[0];
-
-const shuttles: IShuttle[] = [
-  {
-    name: "Red Shuttle 17",
-    id: "1",
-    coordinates: {
-      latitude: 33.796001,
-      longitude: -117.8892805,
-    },
-    routeId: routes[0].id,
-    systemId: systems[0].id,
-  }
-];
-
-const etas: IEta[] = [
-  {
-    stopId: stops[0].id,
-    shuttleId: shuttles[0].id,
-    secondsRemaining: 12.023,
-  },
-  {
-    stopId: stops[1].id,
-    shuttleId: shuttles[0].id,
-    secondsRemaining: 600.123,
-  }
-];
-
-export async function loadTestData(repository: GetterSetterRepository) {
-  await Promise.all(systems.map(async (system) => {
-    await repository.addOrUpdateSystem(system);
-  }));
-  await Promise.all(routes.map(async (route) => {
-    await repository.addOrUpdateRoute(route);
-  }));
-  await Promise.all(shuttles.map(async (shuttle) => {
-    await repository.addOrUpdateShuttle(shuttle);
-  }));
-  await Promise.all(stops.map(async (stop) => {
-    await repository.addOrUpdateStop(stop);
-  }));
-  await Promise.all(orderedStopsForRedRoute.map(async (orderedStop) => {
-    await repository.addOrUpdateOrderedStop(orderedStop);
-  }));
-  await Promise.all(orderedStopsForTealRoute.map(async (orderedStop) => {
-    await repository.addOrUpdateOrderedStop(orderedStop);
-  }));
-  await Promise.all(etas.map(async (eta) => {
-    await repository.addOrUpdateEta(eta);
-  }));
-}

src/loaders/parking/ChapmanApiBasedParkingRepositoryLoader.ts

@@ -0,0 +1,84 @@
+import { ParkingRepositoryLoader } from "./ParkingRepositoryLoader";
+import { ParkingGetterSetterRepository } from "../../repositories/parking/ParkingGetterSetterRepository";
+import { createHash } from "node:crypto";
+import { ApiResponseError } from "../ApiResponseError";
+import { IParkingStructure } from "../../entities/ParkingRepositoryEntities";
+
+class ApiParseError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = "ApiParseError";
+  }
+}
+
+export class ChapmanApiBasedParkingRepositoryLoader implements ParkingRepositoryLoader {
+  public static readonly id = "chapman-parking-loader";
+  private readonly fetchUrl = "https://webfarm.chapman.edu/ParkingService/ParkingService/counts";
+
+  constructor(
+    public repository: ParkingGetterSetterRepository
+  ) {
+    this.fetchAndUpdateParkingStructures = this.fetchAndUpdateParkingStructures.bind(this);
+  }
+
+  async updateAll() {
+    await this.fetchAndUpdateParkingStructures();
+  }
+
+  async fetchAndUpdateParkingStructures(): Promise<void> {
+    let json: any;
+
+    try {
+      const response = await fetch(this.fetchUrl);
+      json = await response.json();
+    } catch(e: any) {
+      throw new ApiResponseError(e.message);
+    }
+
+    try {
+      if (typeof json.Structures === "object") {
+        const parkingStructures: IParkingStructure[] = json.Structures.map(this.constructIParkingStructureFromJson);
+
+        await Promise.all(parkingStructures.map(async (structure: IParkingStructure) => {
+          await this.repository.addOrUpdateParkingStructure(structure);
+        }));
+      }
+    } catch(e: any) {
+      throw new ApiParseError(e.message);
+    }
+  }
+
+  public constructIParkingStructureFromJson(jsonStructure: any) {
+    const structureToReturn: IParkingStructure = {
+      capacity: jsonStructure.Capacity,
+      coordinates: {
+        latitude: jsonStructure.Latitude,
+        longitude: jsonStructure.Longitude,
+      },
+      id: ChapmanApiBasedParkingRepositoryLoader.generateId(jsonStructure.Address),
+      name: jsonStructure.Name,
+      spotsAvailable: jsonStructure.CurrentCount > jsonStructure.Capacity ? jsonStructure.Capacity : jsonStructure.CurrentCount,
+      address: jsonStructure.Address,
+      updatedTime: new Date(),
+    }
+
+    return structureToReturn;
+  }
+
+  private static normalizeAddress(address: string): string {
+    return address
+      .toLowerCase()
+      .split(/\s+/)
+      .filter(part => part.length > 0)
+      .join(' ');
+  }
+
+  public static generateId(address: string): string {
+    const normalized = this.normalizeAddress(address);
+    const hash = createHash('sha256')
+      .update(normalized)
+      .digest('hex');
+
+    return hash.substring(0, 32);
+  }
+}

src/loaders/parking/ParkingRepositoryLoader.ts

@@ -0,0 +1,5 @@
+import { RepositoryLoader } from "../RepositoryLoader";
+
+export interface ParkingRepositoryLoader extends RepositoryLoader {
+  fetchAndUpdateParkingStructures(): Promise<void>;
+}

src/loaders/parking/__tests__/ChapmanApiBasedParkingRepositoryLoaderTests.test.ts

@@ -0,0 +1,113 @@
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
+import {
+  ChapmanApiBasedParkingRepositoryLoader
+} from "../ChapmanApiBasedParkingRepositoryLoader";
+import { InMemoryParkingRepository } from "../../../repositories/parking/InMemoryParkingRepository";
+import {
+  resetGlobalFetchMockJson,
+  updateGlobalFetchMockJson,
+  updateGlobalFetchMockJsonToThrowSyntaxError
+} from "../../../../testHelpers/fetchMockHelpers";
+import {
+  chapmanParkingStructureData
+} from "../../../../testHelpers/jsonSnapshots/chapmanParkingStructureData/chapmanParkingStructureData";
+import { IParkingStructure } from "../../../entities/ParkingRepositoryEntities";
+import { assertAsyncCallbackThrowsApiResponseError } from "../../../../testHelpers/assertAsyncCallbackThrowsApiResponseError";
+
+describe("ChapmanApiBasedParkingRepositoryLoader", () => {
+  let loader: ChapmanApiBasedParkingRepositoryLoader;
+
+  beforeEach(() => {
+    loader = new ChapmanApiBasedParkingRepositoryLoader(
+      new InMemoryParkingRepository(),
+    );
+    resetGlobalFetchMockJson();
+  });
+
+  describe("fetchAndUpdateAll", () => {
+    it("calls all the correct methods", async () => {
+      const spies = {
+        fetchAndUpdateParkingStructures: jest.spyOn(loader, "fetchAndUpdateParkingStructures"),
+      };
+
+      Object.values(spies).forEach((spy: any) => {
+        spy.mockResolvedValue(undefined);
+      });
+
+      await loader.updateAll();
+
+      Object.values(spies).forEach((spy: any) => {
+        expect(spy).toHaveBeenCalled();
+      });
+    });
+  });
+
+  describe("fetchAndUpdateParkingStructures", () => {
+    it("fetches and update parking structures with unique IDs", async () => {
+      updateGlobalFetchMockJson(chapmanParkingStructureData);
+
+      await loader.fetchAndUpdateParkingStructures();
+
+      let expectedStructures: IParkingStructure[] = [
+        {
+          address: "300 E Walnut, Orange, CA 92867",
+          capacity: 871,
+          spotsAvailable: 211,
+          coordinates: {
+            latitude: 33.7945513,
+            longitude: -117.8518707,
+          },
+          name: "Anderson Structure",
+          id: "",
+          updatedTime: new Date(),
+        },
+        {
+          address: "200 W Sycamore Ave, Orange, CA 92866-1053",
+          capacity: 692,
+          spotsAvailable: 282,
+          coordinates: {
+            latitude: 33.792937,
+            longitude: -117.854782
+          },
+          name: "Barrera",
+          id: "",
+          updatedTime: new Date(),
+        }
+      ];
+      expectedStructures[0].id = ChapmanApiBasedParkingRepositoryLoader.generateId(expectedStructures[0].address);
+      expectedStructures[1].id = ChapmanApiBasedParkingRepositoryLoader.generateId(expectedStructures[1].address);
+
+      const structuresFromLoader = await loader.repository.getParkingStructures();
+
+      // Set updatedTimeMs on expected data to avoid comparison
+      expectedStructures[0].updatedTime = structuresFromLoader[0].updatedTime;
+      expectedStructures[1].updatedTime = structuresFromLoader[1].updatedTime;
+
+      expect(structuresFromLoader).toEqual(expectedStructures);
+    });
+
+    it("throws ApiResponseError if data is incorrect", async () => {
+      updateGlobalFetchMockJsonToThrowSyntaxError();
+
+      await assertAsyncCallbackThrowsApiResponseError(async () => {
+        await loader.fetchAndUpdateParkingStructures();
+      });
+    })
+  });
+
+  describe("constructIParkingStructureFromJson", () => {
+    it("normalizes the spots available if it's over the capacity", async () => {
+      const sampleJsonStructure: any = {
+        Capacity: 10,
+        Latitude: 1,
+        Longitude: 1,
+        Address: "300 E Walnut, Orange, CA 92867",
+        Name: "Anderson Structure",
+        CurrentCount: 11,
+      };
+
+      const returnedStructure = loader.constructIParkingStructureFromJson(sampleJsonStructure);
+      expect(returnedStructure.spotsAvailable).toEqual(returnedStructure.capacity);
+    });
+  });
+});

src/loaders/parking/buildParkingRepositoryLoaderIfExists.ts

@@ -0,0 +1,15 @@
+import { ParkingGetterSetterRepository } from "../../repositories/parking/ParkingGetterSetterRepository";
+import { ChapmanApiBasedParkingRepositoryLoader } from "./ChapmanApiBasedParkingRepositoryLoader";
+
+export interface ParkingRepositoryLoaderBuilderArguments {
+  id: string;
+  repository: ParkingGetterSetterRepository;
+}
+
+export function buildParkingRepositoryLoaderIfExists(args: ParkingRepositoryLoaderBuilderArguments) {
+  if (args.id === ChapmanApiBasedParkingRepositoryLoader.id) {
+    return new ChapmanApiBasedParkingRepositoryLoader(args.repository);
+  }
+
+  return null;
+}

src/loaders/parking/loadParkingTestData.ts

@@ -0,0 +1,35 @@
+import { ParkingGetterSetterRepository } from "../../repositories/parking/ParkingGetterSetterRepository";
+import { IParkingStructure } from "../../entities/ParkingRepositoryEntities";
+
+const parkingStructures: IParkingStructure[] = [
+  {
+    address: "300 E Walnut, Orange, CA 92867",
+    capacity: 871,
+    spotsAvailable: 211,
+    coordinates: {
+      latitude: 33.7945513,
+      longitude: -117.8518707,
+    },
+    name: "Anderson Structure",
+    id: "1",
+    updatedTime: new Date(),
+  },
+  {
+    address: "200 W Sycamore Ave, Orange, CA 92866-1053",
+    capacity: 692,
+    spotsAvailable: 282,
+    coordinates: {
+      latitude: 33.792937,
+      longitude: -117.854782
+    },
+    name: "Barrera",
+    id: "2",
+    updatedTime: new Date(),
+  }
+];
+
+export async function loadParkingTestData(repository: ParkingGetterSetterRepository) {
+  await Promise.all(parkingStructures.map(async structure => {
+    await repository.addOrUpdateParkingStructure(structure);
+  }))
+}

src/loaders/shuttle/ApiBasedShuttleRepositoryLoader.ts

@@ -0,0 +1,441 @@
+import { ShuttleGetterSetterRepository } from "../../repositories/shuttle/ShuttleGetterSetterRepository";
+import { IEta, IRoute, IShuttle, IStop } from "../../entities/ShuttleRepositoryEntities";
+import { ShuttleRepositoryLoader } from "./ShuttleRepositoryLoader";
+import { ICoordinates, IEntityWithId } from "../../entities/SharedEntities";
+import { ApiResponseError } from "../ApiResponseError";
+import { SHUTTLE_TO_ROUTE_COORDINATE_MAXIMUM_DISTANCE_MILES } from "../../environment";
+import { ExternalSourceETARepository } from "../../repositories/shuttle/eta/ExternalSourceETARepository";
+
+/**
+ * Class which can load data into a repository from the
+ * Passio Go API. Supports automatic pruning of all data types
+ * which inherit from `IEntityWithId`.
+ */
+export class ApiBasedShuttleRepositoryLoader implements ShuttleRepositoryLoader {
+  readonly baseUrl = "https://passiogo.com/mapGetData.php";
+
+  constructor(
+    public passioSystemId: string,
+    public systemIdForConstructedData: string,
+    public shuttleRepository: ShuttleGetterSetterRepository,
+    public etaRepository?: ExternalSourceETARepository,
+    readonly shuttleToRouteCoordinateMaximumDistanceMiles = SHUTTLE_TO_ROUTE_COORDINATE_MAXIMUM_DISTANCE_MILES,
+  ) {
+  }
+
+  private async constructExistingEntityIdSet<T extends IEntityWithId>(entitySearchCallback: () => Promise<T[]>) {
+    const existingEntities = await entitySearchCallback();
+    const ids = new Set<string>();
+    existingEntities.forEach((entity) => {
+      ids.add(entity.id);
+    });
+    return ids;
+  }
+
+  public async updateAll() {
+    await this.updateRouteDataForSystem();
+    await this.updateStopAndPolylineDataForRoutesInSystem();
+    await this.updateShuttleDataForSystemBasedOnProximityToRoutes();
+
+    if (this.etaRepository) {
+      await this.updateEtaDataForExistingStopsForSystem();
+    }
+  }
+
+  public async updateRouteDataForSystem() {
+    try {
+      const json = await this.fetchRouteDataJson();
+      const routes = this.constructRoutesFromJson(json);
+      if (routes !== null) {
+        await this.updateRouteDataInRepository(routes);
+      } else {
+        console.warn(`Route update failed for the following JSON: ${JSON.stringify(json)}`);
+      }
+    } catch(e: any) {
+      throw new ApiResponseError(e.message);
+    }
+  }
+
+  private async updateRouteDataInRepository(routes: IRoute[]) {
+    const routeIdsToPrune = await this.constructExistingEntityIdSet(async () => {
+      return await this.shuttleRepository.getRoutes();
+    });
+
+    await Promise.all(routes.map(async (route) => {
+      await this.shuttleRepository.addOrUpdateRoute(route);
+      routeIdsToPrune.delete(route.id);
+    }));
+
+    await Promise.all(Array.from(routeIdsToPrune).map(async (routeId) => {
+      await this.shuttleRepository.removeRouteIfExists(routeId);
+    }));
+  }
+
+  private async fetchRouteDataJson() {
+    const systemId = this.passioSystemId;
+
+    const params = {
+      getRoutes: "2",
+    };
+
+    const formDataJsonObject = {
+      "systemSelected0": systemId,
+      "amount": "1",
+    };
+    const formData = new FormData();
+    formData.set("json", JSON.stringify(formDataJsonObject));
+
+    const query = new URLSearchParams(params).toString();
+
+    const response = await fetch(`${this.baseUrl}?${query}`, {
+      method: "POST",
+      body: formData,
+    });
+    return await response.json();
+  }
+
+  private constructRoutesFromJson(json: any): IRoute[] | null {
+    if (typeof json.all === "object") {
+      return json.all.map((jsonRoute: any) => {
+        const constructedRoute: IRoute = {
+          name: jsonRoute.name,
+          color: jsonRoute.color,
+          id: jsonRoute.myid,
+          polylineCoordinates: [],
+          systemId: this.systemIdForConstructedData,
+          updatedTime: new Date(),
+        };
+        return constructedRoute;
+      });
+    }
+
+    return null;
+  }
+
+  public async updateStopAndPolylineDataForRoutesInSystem() {
+    try {
+      const json = await this.fetchStopAndPolylineDataJson();
+      await this.updateStopAndPolylineDataInRepository(json);
+    } catch(e: any) {
+      throw new ApiResponseError(e.message);
+    }
+  }
+
+  private async updateStopAndPolylineDataInRepository(json: any) {
+    const stopIdsToPrune = await this.constructExistingEntityIdSet(async () => {
+      return await this.shuttleRepository.getStops();
+    });
+
+    await this.updateStopDataForSystemAndApiResponse(json, stopIdsToPrune);
+    await this.updateOrderedStopDataForExistingStops(json);
+    await this.updatePolylineDataForExistingRoutesAndApiResponse(json);
+
+    await Promise.all(Array.from(stopIdsToPrune).map(async (stopId) => {
+      await this.shuttleRepository.removeStopIfExists(stopId);
+    }));
+  }
+
+  private async fetchStopAndPolylineDataJson() {
+    const passioSystemId = this.passioSystemId;
+
+    const params = {
+      getStops: "2",
+    };
+
+    const formDataJsonObject = {
+      "s0": passioSystemId,
+      "sA": 1
+    };
+    const formData = new FormData();
+    formData.set("json", JSON.stringify(formDataJsonObject));
+
+    const query = new URLSearchParams(params).toString();
+
+    const response = await fetch(`${this.baseUrl}?${query}`, {
+      method: "POST",
+      body: formData,
+    });
+    return await response.json();
+  }
+
+  public async updateShuttleDataForSystemBasedOnProximityToRoutes() {
+    try {
+      const json = await this.fetchShuttleDataJson();
+      let shuttles = this.constructInServiceShuttlesFromJson(json);
+      if (shuttles !== null) {
+        shuttles = await this.filterShuttlesByDistanceFromCorrespondingRoute(shuttles);
+        await this.updateShuttleDataInRepository(shuttles);
+      } else {
+        console.warn(`Shuttle update failed for the following JSON: ${JSON.stringify(json)}`)
+      }
+    } catch(e: any) {
+      throw new ApiResponseError(e.message);
+    }
+  }
+
+  private async updateShuttleDataInRepository(shuttles: IShuttle[]) {
+    const shuttleIdsToPrune = await this.constructExistingEntityIdSet(async () => {
+      return await this.shuttleRepository.getShuttles();
+    });
+
+    await Promise.all(shuttles.map(async (shuttle) => {
+      await this.shuttleRepository.addOrUpdateShuttle(shuttle);
+      shuttleIdsToPrune.delete(shuttle.id);
+    }));
+
+    await Promise.all(Array.from(shuttleIdsToPrune).map(async (shuttleId) => {
+      await this.shuttleRepository.removeShuttleIfExists(shuttleId);
+    }));
+  }
+
+  private async fetchShuttleDataJson() {
+    const systemId = this.passioSystemId;
+
+    const params = {
+      getBuses: "2"
+    };
+
+    const formDataJsonObject = {
+      "s0": systemId,
+      "sA": "1"
+    };
+
+    const formData = new FormData();
+    formData.set("json", JSON.stringify(formDataJsonObject));
+
+    const query = new URLSearchParams(params).toString();
+
+    const response = await fetch(`${this.baseUrl}?${query}`, {
+      method: "POST",
+      body: formData,
+    });
+    return await response.json();
+  }
+
+  private constructInServiceShuttlesFromJson(json: any): IShuttle[] | null {
+    if (json.buses && json.buses["-1"] === undefined) {
+      const jsonBuses = Object.values(json.buses).map((busesArr: any) => {
+        return busesArr[0];
+      });
+      jsonBuses.filter((bus) => bus.outOfService != 0)
+
+      return jsonBuses.map((jsonBus: any) => {
+        const constructedShuttle: IShuttle = {
+          name: jsonBus.bus,
+          coordinates: {
+            latitude: parseFloat(jsonBus.latitude),
+            longitude: parseFloat(jsonBus.longitude),
+          },
+          routeId: jsonBus.routeId,
+          systemId: this.systemIdForConstructedData,
+          id: `${jsonBus.busId}`,
+          orientationInDegrees: parseFloat(jsonBus.calculatedCourse),
+          updatedTime: new Date(),
+        }
+        return constructedShuttle;
+      });
+    }
+
+    return null;
+  }
+
+  public async updateEtaDataForExistingStopsForSystem() {
+    const stops = await this.shuttleRepository.getStops();
+    await Promise.all(stops.map(async (stop) => {
+      let stopId = stop.id;
+      await this.updateEtaDataForStopId(stopId);
+    }));
+  }
+
+  public async updateEtaDataForStopId(stopId: string) {
+    try {
+      const json = await this.fetchEtaDataJson(stopId);
+      const etas = this.constructEtasFromJson(json, stopId);
+      if (etas !== null) {
+        await this.updateEtaDataInRepository(etas);
+      } else {
+        console.warn(`ETA update failed for stop ${stopId} with the following JSON: ${JSON.stringify(json)}`);
+      }
+    } catch(e: any) {
+      throw new ApiResponseError(e.message);
+    }
+  }
+
+  private async updateEtaDataInRepository(etas: IEta[]) {
+    await Promise.all(etas.map(async (eta) => {
+      await this.etaRepository?.addOrUpdateEtaFromExternalSource(eta);
+    }));
+  }
+
+  private async fetchEtaDataJson(stopId: string) {
+    const params = {
+      eta: "3",
+      stopIds: stopId,
+    };
+
+    const query = new URLSearchParams(params).toString();
+
+    const response = await fetch(`${this.baseUrl}?${query}`, {
+      method: "GET",
+    });
+    return await response.json();
+  }
+
+  private constructEtasFromJson(json: any, stopId: string): IEta[] | null {
+    if (json.ETAs && json.ETAs[stopId]) {
+      return json.ETAs[stopId].map((jsonEta: any) => {
+        const shuttleId: string = jsonEta.busId;
+        const eta: IEta = {
+          secondsRemaining: jsonEta.secondsSpent,
+          shuttleId: `${shuttleId}`,
+          stopId: stopId,
+          updatedTime: new Date(),
+          systemId: this.systemIdForConstructedData,
+        };
+        return eta;
+      });
+    }
+
+    return null;
+  }
+
+  protected async updateStopDataForSystemAndApiResponse(
+    json: any,
+    setOfIdsToPrune: Set<string> = new Set(),
+  ) {
+    if (json.stops) {
+      const jsonStops = Object.values(json.stops);
+
+      await Promise.all(jsonStops.map(async (stop: any) => {
+        const constructedStop: IStop = {
+          name: stop.name,
+          id: stop.id,
+          systemId: this.systemIdForConstructedData,
+          coordinates: {
+            latitude: parseFloat(stop.latitude),
+            longitude: parseFloat(stop.longitude),
+          },
+          updatedTime: new Date(),
+        };
+
+        await this.shuttleRepository.addOrUpdateStop(constructedStop);
+
+        setOfIdsToPrune.delete(constructedStop.id);
+      }));
+    }
+  }
+
+  protected async updateOrderedStopDataForExistingStops(json: any) {
+    if (json.routes) {
+      await Promise.all(Object.keys(json.routes).map(async (routeId) => {
+        const jsonOrderedStopData: any[][] = json.routes[routeId].slice(2);
+
+        // The API may return the same stop twice to indicate that
+        // the route runs in a loop
+        // If the API does not do this, assume the route is one-way
+        // To account for this, check if ordered stop already exists in repo
+        // If it does, write to that stop instead
+
+        for (let index = 0; index < jsonOrderedStopData.length; index++) {
+          const orderedStopDataArray = jsonOrderedStopData[index];
+
+          const stopId = orderedStopDataArray[1];
+          let constructedOrderedStop = await this.shuttleRepository.getOrderedStopByRouteAndStopId(routeId, stopId)
+          if (constructedOrderedStop === null) {
+            constructedOrderedStop = {
+              routeId,
+              stopId,
+              position: index + 1,
+              systemId: this.systemIdForConstructedData,
+              updatedTime: new Date(),
+            };
+          }
+
+          if (index >= 1) {
+            constructedOrderedStop.previousStop = {
+              routeId,
+              stopId: jsonOrderedStopData[index - 1][1],
+              position: index,
+              systemId: this.systemIdForConstructedData,
+              updatedTime: new Date(),
+            };
+          }
+          if (index < jsonOrderedStopData.length - 1) {
+            constructedOrderedStop.nextStop = {
+              routeId,
+              stopId: jsonOrderedStopData[index + 1][1],
+              position: index + 2,
+              systemId: this.systemIdForConstructedData,
+              updatedTime: new Date(),
+            };
+          }
+
+          await this.shuttleRepository.addOrUpdateOrderedStop(constructedOrderedStop);
+        }
+      }));
+    }
+  }
+
+  protected async updatePolylineDataForExistingRoutesAndApiResponse(json: any) {
+    if (json.routePoints) {
+      await Promise.all(Object.keys(json.routePoints).map(async (routeId) => {
+        const routePoints = json.routePoints[routeId][0];
+
+        const existingRoute = await this.shuttleRepository.getRouteById(routeId);
+        if (!existingRoute) return;
+
+        existingRoute.polylineCoordinates = routePoints.map((point: any) => {
+          return {
+            latitude: parseFloat(point.lat),
+            longitude: parseFloat(point.lng),
+          };
+        });
+
+        await this.shuttleRepository.addOrUpdateRoute(existingRoute);
+      }))
+    }
+  }
+
+  private filterShuttlesByDistanceFromCorrespondingRoute = async (shuttles: IShuttle[]) => {
+    let filteredShuttles: IShuttle[] = [];
+
+    await Promise.all(shuttles.map(async (shuttle) => {
+      const route = await this.shuttleRepository.getRouteById(shuttle.routeId);
+      if (route != null) {
+        let closestDistanceMiles = Number.MAX_VALUE;
+
+        route.polylineCoordinates.forEach((coordinate) => {
+          const calculatedDistance = ApiBasedShuttleRepositoryLoader.convertDistanceBetweenCoordinatesToMiles(coordinate, shuttle.coordinates)
+          if (closestDistanceMiles > calculatedDistance) {
+            closestDistanceMiles = calculatedDistance;
+          }
+        });
+
+        if (closestDistanceMiles <= this.shuttleToRouteCoordinateMaximumDistanceMiles) {
+          filteredShuttles.push(shuttle);
+        }
+      } else {
+        console.warn(`No corresponding route found for ID ${shuttle.routeId} of shuttle ${shuttle.id}`)
+      }
+    }));
+
+    return filteredShuttles;
+  };
+
+  public static convertDistanceBetweenCoordinatesToMiles = (fromCoordinate: ICoordinates, toCoordinate: ICoordinates): number => {
+    const earthRadiusMiles = 3959;
+
+    const lat1Rad = fromCoordinate.latitude * Math.PI / 180;
+    const lat2Rad = toCoordinate.latitude * Math.PI / 180;
+    const deltaLatRad = (toCoordinate.latitude - fromCoordinate.latitude) * Math.PI / 180;
+    const deltaLonRad = (toCoordinate.longitude - fromCoordinate.longitude) * Math.PI / 180;
+
+    const a = Math.sin(deltaLatRad / 2) * Math.sin(deltaLatRad / 2) +
+              Math.cos(lat1Rad) * Math.cos(lat2Rad) *
+              Math.sin(deltaLonRad / 2) * Math.sin(deltaLonRad / 2);
+
+    const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+
+    return earthRadiusMiles * c;
+  };
+}

src/loaders/shuttle/ShuttleRepositoryLoader.ts

@@ -0,0 +1,9 @@
+import { RepositoryLoader } from "../RepositoryLoader";
+
+export interface ShuttleRepositoryLoader extends RepositoryLoader {
+  updateRouteDataForSystem(): Promise<void>;
+  updateStopAndPolylineDataForRoutesInSystem(): Promise<void>;
+  updateShuttleDataForSystemBasedOnProximityToRoutes(): Promise<void>;
+  updateEtaDataForExistingStopsForSystem(): Promise<void>;
+  updateEtaDataForStopId(stopId: string): Promise<void>;
+}

src/loaders/shuttle/__tests__/ApiBasedShuttleRepositoryLoaderTests.test.ts

@@ -0,0 +1,263 @@
+import { afterEach, beforeEach, describe, expect, it, jest } from "@jest/globals";
+import { ApiBasedShuttleRepositoryLoader } from "../ApiBasedShuttleRepositoryLoader";
+import { UnoptimizedInMemoryShuttleRepository } from "../../../repositories/shuttle/UnoptimizedInMemoryShuttleRepository";
+import { fetchRouteDataSuccessfulResponse } from "../../../../testHelpers/jsonSnapshots/fetchRouteData/fetchRouteDataSuccessfulResponse";
+import {
+  fetchStopAndPolylineDataSuccessfulResponse
+} from "../../../../testHelpers/jsonSnapshots/fetchStopAndPolylineData/fetchStopAndPolylineDataSuccessfulResponse";
+import { generateMockRoutes, generateMockShuttles, generateMockStops } from "../../../../testHelpers/mockDataGenerators";
+import {
+  fetchShuttleDataSuccessfulResponse
+} from "../../../../testHelpers/jsonSnapshots/fetchShuttleData/fetchShuttleDataSuccessfulResponse";
+import { InMemoryExternalSourceETARepository } from "../../../repositories/shuttle/eta/InMemoryExternalSourceETARepository";
+import {
+  resetGlobalFetchMockJson,
+  updateGlobalFetchMockJson,
+  updateGlobalFetchMockJsonToThrowSyntaxError
+} from "../../../../testHelpers/fetchMockHelpers";
+import { assertAsyncCallbackThrowsApiResponseError } from "../../../../testHelpers/assertAsyncCallbackThrowsApiResponseError";
+import { IRoute } from "../../../entities/ShuttleRepositoryEntities";
+
+describe("ApiBasedShuttleRepositoryLoader", () => {
+  let loader: ApiBasedShuttleRepositoryLoader;
+
+  beforeEach(() => {
+    loader = new ApiBasedShuttleRepositoryLoader("263", "1", new UnoptimizedInMemoryShuttleRepository());
+    resetGlobalFetchMockJson();
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+  });
+
+  const systemId = "1";
+
+  describe("updateAll", () => {
+    it("calls all the correct methods", async () => {
+      const spies = {
+        updateRouteDataForSystem: jest.spyOn(loader, "updateRouteDataForSystem"),
+        updateStopAndPolylineDataForRoutesInSystem: jest.spyOn(loader, "updateStopAndPolylineDataForRoutesInSystem"),
+        updateShuttleDataForSystem: jest.spyOn(loader, "updateShuttleDataForSystemBasedOnProximityToRoutes"),
+      };
+
+      Object.values(spies).forEach((spy: any) => {
+        spy.mockResolvedValue(undefined);
+      });
+
+      await loader.updateAll();
+
+      Object.values(spies).forEach((spy: any) => {
+        expect(spy).toHaveBeenCalled();
+      });
+    });
+  });
+
+  describe("updateRouteDataForSystem", () => {
+    it("updates route data in repository if response received", async () => {
+      // Arrange
+      // Test pruning
+      const routesToPrune = generateMockRoutes();
+      await Promise.all(routesToPrune.map(async (route) => {
+        route.systemId = systemId;
+        await loader.shuttleRepository.addOrUpdateRoute(route);
+      }));
+
+      updateGlobalFetchMockJson(fetchRouteDataSuccessfulResponse);
+
+      // Act
+      await loader.updateRouteDataForSystem();
+
+      // Assert
+      const routes = await loader.shuttleRepository.getRoutes();
+
+      expect(routes.length).toEqual(fetchRouteDataSuccessfulResponse.all.length)
+    });
+
+    it("throws the correct error if the API response contains no data", async () => {
+      // The Passio API returns some invalid JSON if there is no data,
+      // so simulate a JSON parsing error
+
+      updateGlobalFetchMockJsonToThrowSyntaxError();
+
+      await assertAsyncCallbackThrowsApiResponseError(async () => {
+        await loader.updateRouteDataForSystem();
+      });
+    });
+  });
+
+  describe("updateStopAndPolylineDataForRoutesInSystem", () => {
+    it("updates stop and polyline data if response received", async () => {
+      // Arrange
+      // Test pruning of stops only
+      const stopsToPrune = generateMockStops();
+      await Promise.all(stopsToPrune.map(async (stop) => {
+        stop.systemId = systemId;
+        await loader.shuttleRepository.addOrUpdateStop(stop);
+      }));
+
+      updateGlobalFetchMockJson(fetchStopAndPolylineDataSuccessfulResponse);
+
+      const stopsArray = Object.values(fetchStopAndPolylineDataSuccessfulResponse.stops);
+
+      await loader.updateStopAndPolylineDataForRoutesInSystem();
+
+      const stops = await loader.shuttleRepository.getStops();
+      expect(stops.length).toEqual(stopsArray.length);
+
+      await Promise.all(stops.map(async (stop) => {
+        const orderedStops = await loader.shuttleRepository.getOrderedStopsByStopId(stop.id)
+        expect(orderedStops.length).toBeGreaterThan(0);
+      }));
+
+      const routes = await loader.shuttleRepository.getRoutes();
+      routes.forEach((route) => {
+        expect(route.polylineCoordinates.length).toBeGreaterThan(0);
+      });
+    });
+
+    it("throws the correct error if the API response contains no data", async () => {
+      updateGlobalFetchMockJsonToThrowSyntaxError();
+
+      await assertAsyncCallbackThrowsApiResponseError(async () => {
+        await loader.updateStopAndPolylineDataForRoutesInSystem();
+      });
+    })
+  });
+
+  describe("updateShuttleDataForSystemBasedOnProximityToRoutes", () => {
+    function generateMockRoutesWithPolylineCoordinates() {
+      const routes = generateMockRoutes();
+      routes[0].polylineCoordinates = [
+        {latitude: 33.78792, longitude: -117.86187},
+        {latitude: 33.78792, longitude: -117.86200},
+        {latitude: 33.78792, longitude: -117.86245}
+      ];
+      return routes;
+    }
+
+    function getMockJsonResponseMatchingRouteAndCoordinates(route: IRoute, longitude: string, latitude: string) {
+      const modifiedSuccessfulResponse = {
+        ...fetchShuttleDataSuccessfulResponse,
+      };
+
+      Object.keys(modifiedSuccessfulResponse.buses).forEach((busId) => {
+        const bus = (modifiedSuccessfulResponse.buses as any)[busId][0];
+        bus.latitude = latitude;
+        bus.longitude = longitude;
+        bus.routeId = route.id;
+      });
+      return modifiedSuccessfulResponse;
+    }
+
+    async function addMockRoutes(routes: IRoute[]) {
+      await Promise.all(routes.map(async (route) => {
+        await loader.shuttleRepository.addOrUpdateRoute(route);
+      }));
+    }
+
+    it("updates shuttle data in repository from API if shuttles close enough to route", async () => {
+      const distanceMiles = 1;
+      loader = new ApiBasedShuttleRepositoryLoader(
+        "263",
+        "1",
+        new UnoptimizedInMemoryShuttleRepository(),
+        new InMemoryExternalSourceETARepository(),
+        distanceMiles,
+      );
+
+      const routes = generateMockRoutesWithPolylineCoordinates();
+      await addMockRoutes(routes);
+      const modifiedSuccessfulResponse = getMockJsonResponseMatchingRouteAndCoordinates(
+        routes[0],
+        "-117.86187",
+        "33.78792"
+      );
+      updateGlobalFetchMockJson(modifiedSuccessfulResponse);
+      const busesInResponse = Object.values(modifiedSuccessfulResponse.buses);
+
+      await loader.updateShuttleDataForSystemBasedOnProximityToRoutes();
+
+      const shuttles = await loader.shuttleRepository.getShuttles();
+      expect(shuttles.length).toEqual(busesInResponse.length);
+    });
+
+    it("does not update shuttle data in repository from API if shuttles are not close enough to route", async () => {
+      const distanceMiles = 1;
+      loader = new ApiBasedShuttleRepositoryLoader(
+        "263",
+        "1",
+        new UnoptimizedInMemoryShuttleRepository(),
+        new InMemoryExternalSourceETARepository(),
+        distanceMiles,
+      );
+
+      const routes = generateMockRoutesWithPolylineCoordinates();
+      await addMockRoutes(routes);
+
+      const modifiedSuccessfulResponse = getMockJsonResponseMatchingRouteAndCoordinates(
+        routes[0],
+        "-116.86187",
+        "32.78792"
+      );
+      updateGlobalFetchMockJson(modifiedSuccessfulResponse);
+
+      await loader.updateShuttleDataForSystemBasedOnProximityToRoutes();
+
+      const shuttles = await loader.shuttleRepository.getShuttles();
+      expect(shuttles.length).toEqual(0);
+    });
+
+    it("prunes shuttles correctly", async () => {
+      const distanceMiles = 1;
+      loader = new ApiBasedShuttleRepositoryLoader(
+        "263",
+        "1",
+        new UnoptimizedInMemoryShuttleRepository(),
+        new InMemoryExternalSourceETARepository(),
+        distanceMiles,
+      );
+
+      // Add mock shuttles to repository (these should be pruned)
+      const shuttlesToPrune = generateMockShuttles();
+      await Promise.all(shuttlesToPrune.map(async (shuttle) => {
+        shuttle.systemId = systemId;
+        await loader.shuttleRepository.addOrUpdateShuttle(shuttle);
+      }));
+
+      const routes = generateMockRoutesWithPolylineCoordinates();
+      await addMockRoutes(routes);
+
+      const modifiedSuccessfulResponse = getMockJsonResponseMatchingRouteAndCoordinates(
+        routes[0],
+        "-117.86187",
+        "33.78792"
+      );
+
+      updateGlobalFetchMockJson(modifiedSuccessfulResponse);
+
+      // Update shuttles from API
+      await loader.updateShuttleDataForSystemBasedOnProximityToRoutes();
+
+      // Old shuttles should be pruned, only API shuttles should remain
+      const shuttles = await loader.shuttleRepository.getShuttles();
+      const busesInResponse = Object.values(modifiedSuccessfulResponse.buses);
+
+      expect(shuttles.length).toEqual(busesInResponse.length);
+
+      // Verify none of the original mock shuttles remain
+      shuttlesToPrune.forEach((originalShuttle) => {
+        const foundShuttle = shuttles.find(s => s.id === originalShuttle.id);
+        expect(foundShuttle).toBeUndefined();
+      });
+    });
+
+    it("throws the correct error if the API response contains no data", async () => {
+      updateGlobalFetchMockJsonToThrowSyntaxError();
+
+      await assertAsyncCallbackThrowsApiResponseError(async () => {
+        await loader.updateShuttleDataForSystemBasedOnProximityToRoutes();
+      });
+    });
+  });
+});
+

src/notifications/schedulers/ETANotificationScheduler.ts

@@ -0,0 +1,101 @@
+import { IEta } from "../../entities/ShuttleRepositoryEntities";
+import { AppleNotificationSender, NotificationAlertArguments } from "../senders/AppleNotificationSender";
+import {
+  NotificationRepository,
+  ScheduledNotification
+} from "../../repositories/notifications/NotificationRepository";
+import { InMemoryNotificationRepository } from "../../repositories/notifications/InMemoryNotificationRepository";
+import { ETAGetterRepository, ETARepositoryEvent } from "../../repositories/shuttle/eta/ETAGetterRepository";
+import { ShuttleGetterRepository } from "../../repositories/shuttle/ShuttleGetterRepository";
+
+export class ETANotificationScheduler {
+  public static readonly defaultSecondsThresholdForNotificationToFire = 180;
+
+  constructor(
+    private etaRepository: ETAGetterRepository,
+    private shuttleRepository: ShuttleGetterRepository,
+    private notificationRepository: NotificationRepository = new InMemoryNotificationRepository(),
+    private appleNotificationSender = new AppleNotificationSender(),
+    private interchangeSystemId: string,
+  ) {
+    this.etaSubscriberCallback = this.etaSubscriberCallback.bind(this);
+    this.sendEtaNotificationImmediately = this.sendEtaNotificationImmediately.bind(this);
+    this.sendEtaNotificationImmediatelyIfSecondsRemainingBelowThreshold = this.sendEtaNotificationImmediatelyIfSecondsRemainingBelowThreshold.bind(this);
+  }
+
+  private async sendEtaNotificationImmediately(notificationData: ScheduledNotification): Promise<boolean> {
+    const { deviceId, shuttleId, stopId } = notificationData;
+
+    const shuttle = await this.shuttleRepository.getShuttleById(shuttleId);
+    const stop = await this.shuttleRepository.getStopById(stopId);
+    const eta = await this.etaRepository.getEtaForShuttleAndStopId(shuttleId, stopId);
+    if (!shuttle) {
+      console.warn(`Notification ${notificationData} fell through; no associated shuttle`);
+      return false;
+    }
+    if (!stop) {
+      console.warn(`Notification ${notificationData} fell through; no associated stop`);
+      return false;
+    }
+
+    // Notification may not be sent if ETA is unavailable at the moment;
+    // this is fine because it will be sent again when ETA becomes available
+    if (!eta) {
+      console.warn(`Notification ${notificationData} fell through; no associated ETA`);
+      return false;
+    }
+
+    const notificationAlertArguments: NotificationAlertArguments = {
+      title: "Shuttle is arriving",
+      body: `Shuttle is approaching ${stop.name} in ${Math.ceil(eta.secondsRemaining / 60)} minutes.`,
+      customKeys: {
+        shuttleEtaNotificationInfo: {
+          shuttleId,
+          stopId,
+          systemId: this.interchangeSystemId,
+        }
+      },
+    }
+    return this.appleNotificationSender.sendNotificationImmediately(deviceId, notificationAlertArguments);
+  }
+
+  private async etaSubscriberCallback(eta: IEta) {
+    const deviceIdsToRemove = new Set<string>();
+    const notifications = await this.notificationRepository.getAllNotificationsForShuttleAndStopId(
+      eta.shuttleId,
+      eta.stopId
+    )
+
+    for (let notification of notifications) {
+      const deliveredSuccessfully = await this.sendEtaNotificationImmediatelyIfSecondsRemainingBelowThreshold(notification, eta.secondsRemaining);
+      if (deliveredSuccessfully) {
+        deviceIdsToRemove.add(notification.deviceId);
+      }
+    }
+
+    deviceIdsToRemove.forEach((deviceId) => {
+      this.notificationRepository.deleteNotificationIfExists({
+        shuttleId: eta.shuttleId,
+        stopId: eta.stopId,
+        deviceId,
+      })
+    });
+  }
+
+  private async sendEtaNotificationImmediatelyIfSecondsRemainingBelowThreshold(notificationObject: ScheduledNotification, etaSecondsRemaining: number) {
+    if (etaSecondsRemaining > notificationObject.secondsThreshold) {
+      return false;
+    }
+
+    return await this.sendEtaNotificationImmediately(notificationObject);
+  }
+
+  // The following is a workaround for the constructor being called twice
+  public startListeningForUpdates() {
+    this.etaRepository.on(ETARepositoryEvent.ETA_UPDATED, this.etaSubscriberCallback);
+  }
+
+  public stopListeningForUpdates() {
+    this.etaRepository.off(ETARepositoryEvent.ETA_UPDATED, this.etaSubscriberCallback);
+  }
+}

src/notifications/schedulers/__tests__/ETANotificationSchedulerTests.test.ts

@@ -0,0 +1,154 @@
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
+import { ETANotificationScheduler } from "../ETANotificationScheduler";
+import { UnoptimizedInMemoryShuttleRepository } from "../../../repositories/shuttle/UnoptimizedInMemoryShuttleRepository";
+import { InMemoryExternalSourceETARepository } from "../../../repositories/shuttle/eta/InMemoryExternalSourceETARepository";
+import { IEta, IShuttle, IStop } from "../../../entities/ShuttleRepositoryEntities";
+import { addMockShuttleToRepository, addMockStopToRepository } from "../../../../testHelpers/repositorySetupHelpers";
+import { AppleNotificationSender } from "../../senders/AppleNotificationSender";
+import { InMemoryNotificationRepository } from "../../../repositories/notifications/InMemoryNotificationRepository";
+import { NotificationRepository } from "../../../repositories/notifications/NotificationRepository";
+
+jest.mock("http2");
+jest.mock("../../senders/AppleNotificationSender");
+
+const MockAppleNotificationSender = AppleNotificationSender as jest.MockedClass<typeof AppleNotificationSender>;
+
+function mockNotificationSenderMethods(shouldSimulateNotificationSend: boolean) {
+  MockAppleNotificationSender.prototype.sendNotificationImmediately = jest.fn(async () => shouldSimulateNotificationSend);
+}
+
+/**
+ * Wait for a specified number of milliseconds.
+ * @param ms
+ */
+async function waitForMilliseconds(ms: number): Promise<void> {
+  await new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+
+describe("ETANotificationScheduler", () => {
+  let shuttleRepository: UnoptimizedInMemoryShuttleRepository;
+  let etaRepository: InMemoryExternalSourceETARepository;
+  let notificationService: ETANotificationScheduler;
+  let notificationRepository: NotificationRepository;
+
+  beforeEach(() => {
+    shuttleRepository = new UnoptimizedInMemoryShuttleRepository();
+    notificationRepository = new InMemoryNotificationRepository();
+    etaRepository = new InMemoryExternalSourceETARepository();
+
+    mockNotificationSenderMethods(true);
+
+    const appleNotificationSender = new MockAppleNotificationSender(false);
+    notificationService = new ETANotificationScheduler(
+      etaRepository,
+      shuttleRepository,
+      notificationRepository,
+      appleNotificationSender,
+      "1",
+    );
+    notificationService.startListeningForUpdates();
+  });
+
+  function generateNotificationDataAndEta(shuttle: IShuttle, stop: IStop) {
+    const eta: IEta = {
+      shuttleId: shuttle.id,
+      stopId: stop.id,
+      secondsRemaining: 120,
+      systemId: "1",
+      updatedTime: new Date(),
+    };
+
+    const notificationData1 = {
+      deviceId: "1",
+      shuttleId: eta.shuttleId,
+      stopId: eta.stopId,
+      secondsThreshold: 240,
+    }
+    const notificationData2 = {
+      ...notificationData1,
+      deviceId: "2",
+      secondsThreshold: 180,
+    }
+    return { eta, notificationData1, notificationData2 };
+  }
+
+  describe("etaSubscriberCallback", () => {
+    it("sends and clears correct notification after ETA changed", async () => {
+      // Arrange
+      const shuttle = await addMockShuttleToRepository(shuttleRepository, "1");
+      const stop = await addMockStopToRepository(shuttleRepository, "1");
+
+      const { eta, notificationData1, notificationData2 } = generateNotificationDataAndEta(shuttle, stop);
+
+      // Act
+      await notificationRepository.addOrUpdateNotification(notificationData1);
+      await notificationRepository.addOrUpdateNotification(notificationData2);
+      await etaRepository.addOrUpdateEtaFromExternalSource(eta);
+
+      // Assert
+      // Wait for the callback to actually be called
+      await waitForMilliseconds(1000);
+
+      const isFirstNotificationScheduled = await notificationRepository.isNotificationScheduled(notificationData1);
+      const isSecondNotificationScheduled = await notificationRepository.isNotificationScheduled(notificationData2);
+
+      // No longer scheduled after being sent
+      expect(isFirstNotificationScheduled).toBe(false);
+      expect(isSecondNotificationScheduled).toBe(false);
+    });
+
+    it("doesn't send notification if seconds threshold not exceeded", async () => {
+      // Arrange
+      const shuttle = await addMockShuttleToRepository(shuttleRepository, "1");
+      const stop = await addMockStopToRepository(shuttleRepository, "1");
+      const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop);
+      notificationData1.secondsThreshold = eta.secondsRemaining - 10;
+
+      // Act
+      await notificationRepository.addOrUpdateNotification(notificationData1);
+      await etaRepository.addOrUpdateEtaFromExternalSource(eta);
+
+      // Assert
+      await waitForMilliseconds(500);
+      const isNotificationScheduled = await notificationRepository.isNotificationScheduled(notificationData1);
+      expect(isNotificationScheduled).toBe(true);
+    });
+
+    it("leaves notification in array if delivery unsuccessful", async () => {
+      // Arrange
+      const shuttle = await addMockShuttleToRepository(shuttleRepository, "1");
+      const stop = await addMockStopToRepository(shuttleRepository, "1");
+      const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop)
+
+      // replace the old notification scheduler with a new one
+      // detach the old callback method from the shuttle repo
+      notificationService.stopListeningForUpdates();
+
+      // replace the notification repository with a fresh one too
+      const notificationRepository = new InMemoryNotificationRepository();
+
+      mockNotificationSenderMethods(false);
+      const updatedNotificationSender = new MockAppleNotificationSender(false);
+      notificationService = new ETANotificationScheduler(
+        etaRepository,
+        shuttleRepository,
+        notificationRepository,
+        updatedNotificationSender,
+        "1",
+      );
+      notificationService.startListeningForUpdates();
+
+      // Act
+      await notificationRepository.addOrUpdateNotification(notificationData1);
+      await etaRepository.addOrUpdateEtaFromExternalSource(eta);
+
+      // Assert
+      // The notification should stay scheduled to be retried once
+      // the ETA updates again
+      await waitForMilliseconds(500);
+      const isNotificationScheduled = await notificationRepository.isNotificationScheduled(notificationData1);
+      expect(isNotificationScheduled).toBe(true);
+    });
+  });
+});

src/notifications/senders/AppleNotificationSender.ts

@@ -0,0 +1,192 @@
+import jwt from "jsonwebtoken";
+import http2 from "http2";
+import { ClientHttp2Session } from "node:http2";
+
+interface APNsUrl {
+  fullUrl: string;
+  path: string;
+  host: string;
+}
+
+export interface NotificationAlertArguments {
+  title: string;
+  body: string;
+  customKeys?: any,
+}
+
+export class AppleNotificationSender {
+  private apnsToken: string | undefined = undefined;
+  private _lastRefreshedTimeMs: Date | undefined = undefined;
+
+  constructor(
+    private shouldActuallySendNotifications = true,
+    private client: ClientHttp2Session | undefined = undefined,
+  ) {
+    this.sendNotificationImmediately = this.sendNotificationImmediately.bind(this);
+    this.lastReloadedTimeForAPNsIsTooRecent = this.lastReloadedTimeForAPNsIsTooRecent.bind(this);
+    this.reloadAPNsTokenIfTimePassed = this.reloadAPNsTokenIfTimePassed.bind(this);
+    this.openConnectionIfNoneExists = this.openConnectionIfNoneExists.bind(this);
+    this.closeConnectionIfExists = this.closeConnectionIfExists.bind(this);
+    this.registerClosureEventsForClient = this.registerClosureEventsForClient.bind(this);
+
+    if (this.client !== undefined) {
+      this.registerClosureEventsForClient();
+    }
+  }
+
+  get lastRefreshedTimeMs(): Date | undefined {
+    return this._lastRefreshedTimeMs;
+  }
+
+  private lastReloadedTimeForAPNsIsTooRecent() {
+    const thirtyMinutesMs = 1800000;
+    return this._lastRefreshedTimeMs && Date.now() - this._lastRefreshedTimeMs.getTime() < thirtyMinutesMs;
+  }
+
+  public reloadAPNsTokenIfTimePassed() {
+    if (this.lastReloadedTimeForAPNsIsTooRecent()) {
+      return;
+    }
+
+    const keyId = process.env.APNS_KEY_ID;
+    const teamId = process.env.APNS_TEAM_ID;
+
+    const privateKeyBase64 = process.env.APNS_PRIVATE_KEY;
+    if (!privateKeyBase64) return;
+    const privateKey = Buffer.from(privateKeyBase64, 'base64').toString('utf-8');
+
+    const tokenHeader = {
+      alg: "ES256",
+      "kid": keyId,
+    };
+
+    const nowMs = Date.now();
+    const claimsPayload = {
+      "iss": teamId,
+      "iat": Math.ceil(nowMs / 1000),  // APNs requires number of seconds since Epoch
+    };
+
+    this.apnsToken = jwt.sign(claimsPayload, privateKey, {
+      algorithm: "ES256",
+      header: tokenHeader
+    });
+    this._lastRefreshedTimeMs = new Date(nowMs);
+  }
+
+  /**
+   * Send a notification immediately.
+   * @param deviceId
+   * @param notificationAlertArguments
+   *
+   * @return Boolean promise indicating whether the
+   * notification was sent successfully.
+   */
+  public async sendNotificationImmediately(deviceId: string, notificationAlertArguments: NotificationAlertArguments) {
+    if (!this.shouldActuallySendNotifications) {
+      // pretend that the notification sent
+      return true;
+    }
+
+    this.reloadAPNsTokenIfTimePassed();
+
+    const bundleId = process.env.APNS_BUNDLE_ID;
+    if (typeof bundleId !== "string") {
+      throw new Error("APNS_BUNDLE_ID environment variable is not set correctly");
+    }
+
+    this.openConnectionIfNoneExists();
+
+    const { path } = AppleNotificationSender.getAPNsFullUrlToUse(deviceId);
+
+    const headers = {
+      ':method': 'POST',
+      ':path': path,
+      'authorization': `bearer ${this.apnsToken}`,
+      "apns-push-type": "alert",
+      "apns-expiration": "0",
+      "apns-priority": "10",
+      "apns-topic": bundleId,
+    };
+    try {
+      if (!this.client) { return false }
+      const req = this.client.request(headers);
+      req.setEncoding('utf8');
+
+      await new Promise<void>((resolve, reject) => {
+        req.on('response', (headers, _flags) => {
+          if (headers[":status"] !== 200) {
+            reject(`APNs request failed with status ${headers[":status"]}`);
+          }
+          resolve();
+        });
+
+        const customKeys = {
+          ...notificationAlertArguments.customKeys,
+        }
+        delete notificationAlertArguments.customKeys;
+
+        // See https://developer.apple.com/documentation/usernotifications/generating-a-remote-notification
+        // for notification payload examples
+        const payload = JSON.stringify({
+          aps: {
+            alert: notificationAlertArguments,
+            sound: "default"
+          },
+          ...customKeys,
+        });
+        req.write(payload);
+        req.end();
+      });
+      return true;
+    } catch(e) {
+      console.error(e);
+      return false;
+    }
+  }
+
+  private openConnectionIfNoneExists() {
+    const host = AppleNotificationSender.getAPNsHostToUse();
+
+    if (!this.client) {
+      this.client = http2.connect(host);
+      this.registerClosureEventsForClient();
+    }
+  }
+
+  private registerClosureEventsForClient() {
+    this.client?.on('close', this.closeConnectionIfExists);
+    this.client?.on('error', this.closeConnectionIfExists);
+    this.client?.on('goaway', this.closeConnectionIfExists);
+    this.client?.on('timeout', this.closeConnectionIfExists);
+  }
+
+  private closeConnectionIfExists() {
+    this.client?.close();
+    this.client = undefined;
+  }
+
+  public static getAPNsFullUrlToUse(deviceId: string): APNsUrl {
+    let hostToUse = this.getAPNsHostToUse();
+
+    const path = "/3/device/" + deviceId;
+    const fullUrl = hostToUse + path;
+
+    return {
+      fullUrl,
+      host: hostToUse,
+      path,
+    };
+  }
+
+  public static getAPNsHostToUse() {
+    // Construct the fetch request
+    const devBaseUrl = "https://api.development.push.apple.com"
+    const prodBaseUrl = "https://api.push.apple.com"
+
+    let hostToUse = devBaseUrl;
+    if (process.env.APNS_IS_PRODUCTION === "1") {
+      hostToUse = prodBaseUrl;
+    }
+    return hostToUse;
+  }
+}

src/notifications/senders/__tests__/AppleNotificationSenderTests.test.ts

@@ -0,0 +1,190 @@
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
+import http2 from "http2";
+import { EventEmitter } from "node:events";
+import {
+  AppleNotificationSender,
+  NotificationAlertArguments
+} from "../AppleNotificationSender";
+import { ClientHttp2Session } from "node:http2";
+
+jest.mock("http2");
+
+const sampleKeyBase64 = "LS0tLS1CRUdJTiBQUklWQVRFIEtFWS0tLS0tCk1JR1RBZ0VBTUJNR0J5cUdTTTQ5QWdFR0NDcUdTTTQ5QXdFSEJIa3dkd0lCQVFRZ3NybVNBWklhZ09mQ1A4c0IKV2kyQ0JYRzFPbzd2MWJpc3BJWkN3SXI0UkRlZ0NnWUlLb1pJemowREFRZWhSQU5DQUFUWkh4VjJ3UUpMTUJxKwp5YSt5ZkdpM2cyWlV2NmhyZmUrajA4eXRla1BIalhTMHF6Sm9WRUx6S0hhNkVMOVlBb1pEWEJ0QjZoK2ZHaFhlClNPY09OYmFmCi0tLS0tRU5EIFBSSVZBVEUgS0VZLS0tLS0K";
+
+class MockClient extends EventEmitter {
+  constructor(
+    private status: number,
+  ) {
+    super()
+  }
+
+  request = jest.fn((_) => {
+    const mockRequest: any = new EventEmitter();
+    mockRequest.setEncoding = jest.fn();
+    mockRequest.write = jest.fn();
+    mockRequest.end = jest.fn(() => {
+      setTimeout(() => {
+        mockRequest.emit('response', { ':status': this.status });
+      }, 10);
+    });
+    return mockRequest;
+  });
+
+  close = jest.fn(() => {});
+}
+
+function mockHttp2Connect(status: number) {
+  (http2.connect as jest.Mock) = jest.fn(() => new MockClient(status));
+}
+
+describe("AppleNotificationSender", () => {
+  let notificationSender: AppleNotificationSender;
+
+  beforeEach(() => {
+    notificationSender = new AppleNotificationSender();
+
+    // Ensure that tests don't hit the server
+    process.env = {
+      ...process.env,
+      APNS_KEY_ID: "1",
+      APNS_TEAM_ID: "1",
+      APNS_BUNDLE_ID: "dev.bchen.ProjectInter",
+      APNS_PRIVATE_KEY: sampleKeyBase64,
+    };
+  });
+
+  beforeEach(() => {
+    mockHttp2Connect(200);
+  });
+
+  describe("reloadAPNsTokenIfTimePassed", () => {
+    it("reloads the token if token hasn't been generated yet", async () => {
+      notificationSender.reloadAPNsTokenIfTimePassed();
+      expect(notificationSender.lastRefreshedTimeMs).toBeDefined();
+    });
+
+    it("doesn't reload the token if last refreshed time is recent", async () => {
+      notificationSender.reloadAPNsTokenIfTimePassed();
+      const lastRefreshedTimeMs = notificationSender.lastRefreshedTimeMs;
+
+      notificationSender.reloadAPNsTokenIfTimePassed();
+      // Expect no change to have occurred
+      expect(lastRefreshedTimeMs).toEqual(notificationSender.lastRefreshedTimeMs);
+    });
+  });
+
+  describe('getAPNsFullUrlToUse', () => {
+    it('should return the production URL when APNS_IS_PRODUCTION is set to "1"', () => {
+      process.env.APNS_IS_PRODUCTION = "1";
+      const deviceId = 'testDeviceId';
+      const result = AppleNotificationSender.getAPNsFullUrlToUse(deviceId);
+
+      const { fullUrl, host, path } = result;
+      expect(fullUrl).toBe(`https://api.push.apple.com/3/device/${deviceId}`);
+      expect(host).toBe("https://api.push.apple.com");
+      expect(path).toBe(`/3/device/${deviceId}`);
+    });
+
+    it('should return the sandbox URL when APNS_IS_PRODUCTION is set to something other than 1', () => {
+      process.env.APNS_IS_PRODUCTION = "0";
+      const deviceId = 'testDeviceId';
+      const result = AppleNotificationSender.getAPNsFullUrlToUse(deviceId);
+
+      const { fullUrl, host, path } = result;
+      expect(fullUrl).toBe(`https://api.development.push.apple.com/3/device/${deviceId}`);
+      expect(host).toBe("https://api.development.push.apple.com");
+      expect(path).toBe(`/3/device/${deviceId}`);
+    });
+  });
+
+  describe("sendNotificationImmediately", () => {
+    it('makes the connection to the http server if sending a notification for the first time', async () => {
+      const notificationArguments: NotificationAlertArguments = {
+        title: 'Test notification',
+        body: 'This notification will send',
+      }
+
+      const result = await notificationSender.sendNotificationImmediately('1', notificationArguments);
+
+      expect(http2.connect).toHaveBeenCalled();
+      expect(result).toBe(true);
+    });
+
+    it('reuses the existing connection if sending another notification', async () => {
+      const notificationArguments: NotificationAlertArguments = {
+        title: 'Test notification',
+        body: 'This notification will send',
+      }
+
+      const result1 = await notificationSender.sendNotificationImmediately('1', notificationArguments);
+      const result2 = await notificationSender.sendNotificationImmediately('1', notificationArguments);
+
+      expect(http2.connect).toHaveBeenCalledTimes(1);
+      expect(result1).toBe(true);
+      expect(result2).toBe(true);
+    });
+
+    it('throws an error if the bundle ID is not set correctly', async () => {
+      process.env = {
+        ...process.env,
+        APNS_BUNDLE_ID: undefined,
+      }
+      const notificationArguments: NotificationAlertArguments = {
+        title: 'Test notification',
+        body: 'This notification will not send',
+      }
+
+      await expect(async () => {
+        await notificationSender.sendNotificationImmediately('1', notificationArguments);
+      }).rejects.toThrow();
+    });
+
+    it('returns false if there is an error sending the notification', async () => {
+      mockHttp2Connect(403);
+
+      const notificationArguments: NotificationAlertArguments = {
+        title: 'Test notification',
+        body: 'This notification will not send',
+      }
+
+      const result = await notificationSender.sendNotificationImmediately('1', notificationArguments);
+
+      expect(http2.connect).toHaveBeenCalled();
+      expect(result).toBe(false);
+    });
+
+    it('does not send notification if shouldActuallySendNotifications is false', async () => {
+      notificationSender = new AppleNotificationSender(false);
+
+      const notificationArguments: NotificationAlertArguments = {
+        title: 'Test notification',
+        body: 'This notification should not send',
+      }
+
+      const result = await notificationSender.sendNotificationImmediately('1', notificationArguments);
+
+      expect(http2.connect).not.toHaveBeenCalled();
+      expect(result).toBe(true);
+    });
+
+    it("registers a handler to close the connection if `close` event fired", async () => {
+      const connectionCloseEvents = ['close', 'goaway', 'error', 'timeout'];
+
+      await Promise.all(connectionCloseEvents.map(async (event) => {
+        const mockClient = new MockClient(200);
+        notificationSender = new AppleNotificationSender(true, mockClient as unknown as ClientHttp2Session);
+
+        const notificationArguments: NotificationAlertArguments = {
+          title: 'Test notification',
+          body: ''
+        };
+
+        await notificationSender.sendNotificationImmediately('1', notificationArguments);
+
+        mockClient.emit(event);
+
+        expect(mockClient.close).toHaveBeenCalled();
+      }));
+    });
+  });
+});

src/repositories/BaseRedisRepository.ts

@@ -0,0 +1,29 @@
+import { RedisClientType } from 'redis';
+import { EventEmitter } from 'stream';
+import createRedisClientForRepository from '../helpers/createRedisClientForRepository';
+
+export abstract class BaseRedisRepository extends EventEmitter {
+  protected redisClient;
+
+  constructor(
+    redisClient: RedisClientType = createRedisClientForRepository(),
+  ) {
+    super();
+    this.redisClient = redisClient;
+    this.redisClient.on('error', (err) => {
+      console.error(err.stack);
+    });
+  }
+
+  get isReady() {
+    return this.redisClient.isReady;
+  }
+
+  public async connect() {
+    await this.redisClient.connect();
+  }
+
+  public async disconnect() {
+    await this.redisClient.disconnect();
+  }
+}

src/repositories/GetterRepository.ts

@@ -1,37 +0,0 @@
-import { IEta, IOrderedStop, IRoute, IShuttle, IStop, ISystem } from "../entities/entities";
-
-export interface GetterRepository {
-  getSystems(): Promise<ISystem[]>;
-  getSystemById(systemId: string): Promise<ISystem | null>;
-
-  getStopsBySystemId(systemId: string): Promise<IStop[]>;
-  getStopById(stopId: string): Promise<IStop | null>;
-
-  getRoutesBySystemId(systemId: string): Promise<IRoute[]>;
-  getRouteById(routeId: string): Promise<IRoute | null>;
-
-  getShuttlesBySystemId(systemId: string): Promise<IShuttle[]>;
-  getShuttleById(shuttleId: string): Promise<IShuttle | null>;
-  getShuttlesByRouteId(routeId: string): Promise<IShuttle[]>;
-
-  getEtasForShuttleId(shuttleId: string): Promise<IEta[]>;
-  getEtasForStopId(stopId: string): Promise<IEta[]>;
-
-  getEtaForShuttleAndStopId(shuttleId: string, stopId: string): Promise<IEta | null>;
-
-  getOrderedStopByRouteAndStopId(routeId: string, stopId: string): Promise<IOrderedStop | null>;
-
-  /**
-   * Get ordered stops with the given stop ID.
-   * Returns an empty array if no ordered stops found.
-   * @param stopId
-   */
-  getOrderedStopsByStopId(stopId: string): Promise<IOrderedStop[]>;
-
-  /**
-   * Get ordered stops with the given route ID.
-   * Returns an empty array if no ordered stops found.
-   * @param routeId
-   */
-  getOrderedStopsByRouteId(routeId: string): Promise<IOrderedStop[]>;
-}

src/repositories/GetterSetterRepository.ts

@@ -1,35 +0,0 @@
-// If types match closely, we can use TypeScript "casting"
-// to convert from data repo to GraphQL schema
-
-import { GetterRepository } from "./GetterRepository";
-import { IEta, IOrderedStop, IRoute, IShuttle, IStop, ISystem } from "../entities/entities";
-
-/**
- * GetterRepository interface for data derived from Passio API.
- * The repository is not designed to have write locks in place.
- * Objects passed from/to the repository should be treated
- * as disposable.
- */
-export interface GetterSetterRepository extends GetterRepository {
-  // Setter methods
-  addOrUpdateSystem(system: ISystem): Promise<void>;
-  addOrUpdateRoute(route: IRoute): Promise<void>;
-  addOrUpdateShuttle(shuttle: IShuttle): Promise<void>;
-  addOrUpdateStop(stop: IStop): Promise<void>;
-  addOrUpdateOrderedStop(orderedStop: IOrderedStop): Promise<void>;
-  addOrUpdateEta(eta: IEta): Promise<void>;
-
-  removeSystemIfExists(systemId: string): Promise<ISystem | null>;
-  removeRouteIfExists(routeId: string): Promise<IRoute | null>;
-  removeShuttleIfExists(shuttleId: string): Promise<IShuttle | null>;
-  removeStopIfExists(stopId: string): Promise<IStop | null>;
-  removeOrderedStopIfExists(stopId: string, routeId: string): Promise<IOrderedStop | null>;
-  removeEtaIfExists(shuttleId: string, stopId: string): Promise<IEta | null>;
-
-  clearSystemData(): Promise<void>;
-  clearRouteData(): Promise<void>;
-  clearShuttleData(): Promise<void>;
-  clearStopData(): Promise<void>;
-  clearOrderedStopData(): Promise<void>;
-  clearEtaData(): Promise<void>;
-}

src/repositories/UnoptimizedInMemoryRepository.ts

@@ -1,212 +0,0 @@
-import { GetterSetterRepository } from "./GetterSetterRepository";
-import { IEntityWithId, IEta, IOrderedStop, IRoute, IShuttle, IStop, ISystem } from "../entities/entities";
-
-/**
- * An unoptimized in memory repository.
- * (I would optimize it with actual data structures, but I'm
- * switching to another data store later anyways)
- */
-export class UnoptimizedInMemoryRepository implements GetterSetterRepository {
-  private systems: ISystem[] = [];
-  private stops: IStop[] = [];
-  private routes: IRoute[] = [];
-  private shuttles: IShuttle[] = [];
-  private etas: IEta[] = [];
-  private orderedStops: IOrderedStop[] = [];
-
-  public async getSystems() {
-    return this.systems;
-  }
-
-  public async getSystemById(systemId: string) {
-    return this.findEntityById(systemId, this.systems);
-  }
-
-  public async getStopsBySystemId(systemId: string) {
-    return this.stops.filter(stop => stop.systemId === systemId);
-  }
-
-  public async getStopById(stopId: string) {
-    return this.findEntityById(stopId, this.stops);
-  }
-
-  public async getRoutesBySystemId(systemId: string) {
-    return this.routes.filter(route => route.systemId === systemId);
-  }
-
-  public async getRouteById(routeId: string) {
-    return this.findEntityById(routeId, this.routes);
-  }
-
-  public async getShuttlesBySystemId(systemId: string) {
-    return this.shuttles.filter(shuttle => shuttle.systemId === systemId);
-  }
-
-  public async getShuttlesByRouteId(routeId: string) {
-    return this.shuttles.filter(shuttle => shuttle.routeId === routeId);
-  }
-
-  public async getShuttleById(shuttleId: string) {
-    return this.findEntityById(shuttleId, this.shuttles);
-  }
-  
-  public async getEtasForShuttleId(shuttleId: string) {
-    return this.etas.filter(eta => eta.shuttleId === shuttleId);
-  }
-
-  public async getEtasForStopId(stopId: string) {
-    return this.etas.filter(eta => eta.stopId === stopId);
-  }
-
-  public async getEtaForShuttleAndStopId(shuttleId: string, stopId: string) {
-    return this.findEntityByMatcher<IEta>((value) => value.stopId === stopId && value.shuttleId === shuttleId, this.etas);
-  }
-
-  public async getOrderedStopByRouteAndStopId(routeId: string, stopId: string) {
-    return this.findEntityByMatcher<IOrderedStop>((value) => value.routeId === routeId && value.stopId === stopId, this.orderedStops)
-  }
-
-  public async getOrderedStopsByStopId(stopId: string) {
-    return this.orderedStops.filter((value) => value.stopId === stopId);
-  }
-
-  public async getOrderedStopsByRouteId(routeId: string) {
-    return this.orderedStops.filter((value) => value.routeId === routeId);
-  }
-
-  private findEntityById<T extends IEntityWithId>(entityId: string, arrayToSearchIn: T[]) {
-    return this.findEntityByMatcher((value) => value.id === entityId, arrayToSearchIn);
-  }
-
-  private findEntityByMatcher<T>(callback: (value: T) => boolean, arrayToSearchIn: T[]): T | null {
-    const entity = arrayToSearchIn.find(callback);
-    if (!entity) {
-      return null;
-    }
-    return entity;
-  }
-
-  public async addOrUpdateSystem(system: ISystem): Promise<void> {
-    const index = this.systems.findIndex((s) => s.id === system.id);
-    if (index !== -1) {
-      this.systems[index] = system; // Update existing
-    } else {
-      this.systems.push(system); // Add new
-    }
-  }
-
-  public async addOrUpdateRoute(route: IRoute): Promise<void> {
-    const index = this.routes.findIndex((r) => r.id === route.id);
-    if (index !== -1) {
-      this.routes[index] = route;
-    } else {
-      this.routes.push(route);
-    }
-  }
-
-  public async addOrUpdateShuttle(shuttle: IShuttle): Promise<void> {
-    const index = this.shuttles.findIndex((s) => s.id === shuttle.id);
-    if (index !== -1) {
-      this.shuttles[index] = shuttle;
-    } else {
-      this.shuttles.push(shuttle);
-    }
-  }
-
-  public async addOrUpdateStop(stop: IStop): Promise<void> {
-    const index = this.stops.findIndex((s) => s.id === stop.id);
-    if (index !== -1) {
-      this.stops[index] = stop;
-    } else {
-      this.stops.push(stop);
-    }
-  }
-
-  public async addOrUpdateOrderedStop(orderedStop: IOrderedStop): Promise<void> {
-    const index = this.orderedStops.findIndex((value) => value.stopId === orderedStop.stopId && value.routeId === orderedStop.routeId);
-    if (index !== -1) {
-      this.orderedStops[index] = orderedStop;
-    } else {
-      this.orderedStops.push(orderedStop);
-    }
-  }
-
-  public async addOrUpdateEta(eta: IEta): Promise<void> {
-    const index = this.etas.findIndex((e) => e.stopId === eta.stopId && e.shuttleId === eta.shuttleId);
-    if (index !== -1) {
-      this.etas[index] = eta;
-    } else {
-      this.etas.push(eta);
-    }
-  }
-
-  private async removeEntityByMatcherIfExists<T>(callback: (value: T) => boolean, arrayToSearchIn: T[]) {
-    const index = arrayToSearchIn.findIndex(callback);
-    if (index > -1) {
-      const entityToReturn = arrayToSearchIn[index];
-      arrayToSearchIn.splice(index, 1);
-      return entityToReturn;
-    }
-
-    return null;
-  }
-
-  private async removeEntityByIdIfExists<T extends IEntityWithId>(entityId: string, arrayToSearchIn: T[]) {
-    return await this.removeEntityByMatcherIfExists((value) => value.id === entityId, arrayToSearchIn);
-  }
-
-  public async removeSystemIfExists(systemId: string): Promise<ISystem | null> {
-    return await this.removeEntityByIdIfExists(systemId, this.systems);
-  }
-
-  public async removeRouteIfExists(routeId: string): Promise<IRoute | null> {
-    return await this.removeEntityByIdIfExists(routeId, this.routes);
-  }
-
-  public async removeShuttleIfExists(shuttleId: string): Promise<IShuttle | null> {
-    return await this.removeEntityByIdIfExists(shuttleId, this.shuttles);
-  }
-
-  public async removeStopIfExists(stopId: string): Promise<IStop | null> {
-    return await this.removeEntityByIdIfExists(stopId, this.stops);
-  }
-
-  public async removeOrderedStopIfExists(stopId: string, routeId: string): Promise<IOrderedStop | null> {
-    return await this.removeEntityByMatcherIfExists((orderedStop) => {
-      return orderedStop.stopId === stopId
-        && orderedStop.routeId === routeId
-    }, this.orderedStops);
-  }
-
-  public async removeEtaIfExists(shuttleId: string, stopId: string): Promise<IEta | null> {
-    return await this.removeEntityByMatcherIfExists((eta) => {
-      return eta.stopId === stopId
-        && eta.shuttleId === shuttleId
-    }, this.etas);
-  }
-
-  public async clearSystemData() {
-    this.systems = [];
-  }
-
-  public async clearShuttleData(): Promise<void> {
-    this.shuttles = [];
-  }
-
-  public async clearEtaData(): Promise<void> {
-    this.etas = [];
-  }
-
-  public async clearOrderedStopData(): Promise<void> {
-    this.orderedStops = [];
-  }
-
-  public async clearRouteData(): Promise<void> {
-    this.routes = [];
-  }
-
-  public async clearStopData(): Promise<void> {
-    this.stops = [];
-  }
-
-}

src/repositories/notifications/InMemoryNotificationRepository.ts

@@ -0,0 +1,144 @@
+import {
+  Listener,
+  NotificationEvent,
+  NotificationLookupArguments,
+  NotificationRepository,
+  ScheduledNotification
+} from "./NotificationRepository";
+import { TupleKey } from "../../types/TupleKey";
+
+type DeviceIdSecondsThresholdAssociation = { [key: string]: number };
+
+export class InMemoryNotificationRepository implements NotificationRepository {
+  /**
+   * An object of device ID arrays to deliver notifications to.
+   * The key should be a combination of the shuttle ID and
+   * stop ID, which can be generated using `TupleKey`.
+   * The value is a dictionary of the device ID to the stored seconds threshold.
+   * @private
+   */
+  private deviceIdsToDeliverTo: { [key: string]: DeviceIdSecondsThresholdAssociation } = {}
+
+  private listeners: Listener[] = [];
+
+  constructor() {
+    this.getAllNotificationsForShuttleAndStopId = this.getAllNotificationsForShuttleAndStopId.bind(this);
+    this.getSecondsThresholdForNotificationIfExists = this.getSecondsThresholdForNotificationIfExists.bind(this);
+    this.deleteNotificationIfExists = this.deleteNotificationIfExists.bind(this);
+    this.addOrUpdateNotification = this.addOrUpdateNotification.bind(this);
+    this.isNotificationScheduled = this.isNotificationScheduled.bind(this);
+    this.subscribeToNotificationChanges = this.subscribeToNotificationChanges.bind(this);
+    this.unsubscribeFromNotificationChanges = this.unsubscribeFromNotificationChanges.bind(this);
+  }
+
+  async getAllNotificationsForShuttleAndStopId(shuttleId: string, stopId: string) {
+    const tuple = new TupleKey(shuttleId, stopId);
+    if (this.deviceIdsToDeliverTo[tuple.toString()] === undefined) {
+      return [];
+    }
+
+    return Object.keys(this.deviceIdsToDeliverTo[tuple.toString()])
+      .map((deviceId) => {
+        return {
+          shuttleId,
+          stopId,
+          deviceId,
+          secondsThreshold: this.deviceIdsToDeliverTo[tuple.toString()][deviceId]
+        }
+      });
+  }
+
+  async getSecondsThresholdForNotificationIfExists({
+    shuttleId,
+    stopId,
+    deviceId
+  }: NotificationLookupArguments) {
+    const tuple = new TupleKey(shuttleId, stopId);
+    if (this.deviceIdsToDeliverTo[tuple.toString()] === undefined) {
+      return null;
+    }
+    return this.deviceIdsToDeliverTo[tuple.toString()][deviceId];
+  }
+
+  async isNotificationScheduled(lookupArguments: NotificationLookupArguments): Promise<boolean> {
+    const threshold = await this.getSecondsThresholdForNotificationIfExists(lookupArguments);
+    return threshold !== null;
+  }
+
+  async addOrUpdateNotification({
+    shuttleId,
+    stopId,
+    deviceId,
+    secondsThreshold
+  }: ScheduledNotification) {
+    const tuple = new TupleKey(shuttleId, stopId);
+    if (this.deviceIdsToDeliverTo[tuple.toString()] === undefined) {
+      this.deviceIdsToDeliverTo[tuple.toString()] = {};
+    }
+
+    this.deviceIdsToDeliverTo[tuple.toString()][deviceId] = secondsThreshold;
+    this.listeners.forEach((listener: Listener) => {
+      const event: NotificationEvent = {
+        event: 'addOrUpdate',
+        notification: {
+          shuttleId,
+          stopId,
+          deviceId,
+          secondsThreshold
+        },
+      }
+
+      listener(event);
+    })
+  }
+
+  async deleteNotificationIfExists({
+    deviceId,
+    shuttleId,
+    stopId
+  }: NotificationLookupArguments) {
+    const tupleKey = new TupleKey(shuttleId, stopId);
+    if (
+      this.deviceIdsToDeliverTo[tupleKey.toString()] === undefined
+      || !(deviceId in this.deviceIdsToDeliverTo[tupleKey.toString()])
+    ) {
+      return;
+    }
+
+    const secondsThreshold = this.deviceIdsToDeliverTo[tupleKey.toString()][deviceId];
+    delete this.deviceIdsToDeliverTo[tupleKey.toString()][deviceId];
+
+    if (Object.keys(this.deviceIdsToDeliverTo[tupleKey.toString()]).length === 0) {
+      // no more device IDs remaining for this key combination
+      delete this.deviceIdsToDeliverTo[tupleKey.toString()];
+    }
+
+    this.listeners.forEach((listener) => {
+      const event: NotificationEvent = {
+        event: 'delete',
+        notification: {
+          deviceId,
+          shuttleId,
+          stopId,
+          secondsThreshold
+        }
+      }
+
+      listener(event);
+    })
+  }
+
+  public subscribeToNotificationChanges(listener: Listener): void {
+    const index = this.listeners.findIndex((existingListener) => existingListener == listener);
+    if (index < 0) {
+      this.listeners.push(listener);
+    }
+  }
+
+  public unsubscribeFromNotificationChanges(listener: Listener): void {
+    const index = this.listeners.findIndex((existingListener) => existingListener == listener);
+    if (index >= 0) {
+      this.listeners.splice(index, 1);
+    }
+  }
+}

src/repositories/notifications/NotificationRepository.ts

@@ -0,0 +1,33 @@
+export interface NotificationLookupArguments {
+  deviceId: string;
+  shuttleId: string;
+  stopId: string;
+}
+
+export interface ScheduledNotification extends NotificationLookupArguments {
+  /**
+   * Value which specifies the ETA of the shuttle for when
+   * the notification should fire.
+   * For example, a secondsThreshold of 180 would mean that the notification
+   * fires when the ETA drops below 3 minutes.
+   */
+  secondsThreshold: number;
+}
+
+export type Listener = ((event: NotificationEvent) => any);
+
+export interface NotificationEvent {
+  notification: ScheduledNotification,
+  event: 'delete' | 'addOrUpdate'
+}
+
+export interface NotificationRepository {
+  getAllNotificationsForShuttleAndStopId(shuttleId: string, stopId: string): Promise<ScheduledNotification[]>;
+  getSecondsThresholdForNotificationIfExists(lookupArguments: NotificationLookupArguments): Promise<number | null>;
+  isNotificationScheduled(lookupArguments: NotificationLookupArguments): Promise<boolean>;
+  addOrUpdateNotification(notification: ScheduledNotification): Promise<void>;
+  deleteNotificationIfExists(lookupArguments: NotificationLookupArguments): Promise<void>;
+
+  subscribeToNotificationChanges(listener: Listener): void;
+  unsubscribeFromNotificationChanges(listener: Listener): void;
+}

src/repositories/notifications/RedisNotificationRepository.ts

@@ -0,0 +1,113 @@
+import { TupleKey } from '../../types/TupleKey';
+import {
+  Listener,
+  NotificationEvent,
+  NotificationLookupArguments,
+  NotificationRepository,
+  ScheduledNotification
+} from "./NotificationRepository";
+import { BaseRedisRepository } from "../BaseRedisRepository";
+
+export class RedisNotificationRepository extends BaseRedisRepository implements NotificationRepository {
+  private notificationListeners: Listener[] = [];
+  private readonly NOTIFICATION_KEY_PREFIX = 'notification:';
+
+  private getNotificationKey = (shuttleId: string, stopId: string): string => {
+    const tuple = new TupleKey(shuttleId, stopId);
+    return `${this.NOTIFICATION_KEY_PREFIX}${tuple.toString()}`;
+  };
+
+  public addOrUpdateNotification = async (notification: ScheduledNotification): Promise<void> => {
+    const { shuttleId, stopId, deviceId, secondsThreshold } = notification;
+    const key = this.getNotificationKey(shuttleId, stopId);
+
+    await this.redisClient.hSet(key, deviceId, secondsThreshold.toString());
+
+    this.notificationListeners.forEach((listener: Listener) => {
+      const event: NotificationEvent = {
+        event: 'addOrUpdate',
+        notification
+      };
+      listener(event);
+    });
+  };
+
+  public deleteNotificationIfExists = async (lookupArguments: NotificationLookupArguments): Promise<void> => {
+    const { shuttleId, stopId, deviceId } = lookupArguments;
+    const key = this.getNotificationKey(shuttleId, stopId);
+
+    const secondsThreshold = await this.redisClient.hGet(key, deviceId);
+    if (secondsThreshold) {
+      await this.redisClient.hDel(key, deviceId);
+
+      // Check if hash is empty and delete it if so
+      const remainingFields = await this.redisClient.hLen(key);
+      if (remainingFields === 0) {
+        await this.redisClient.del(key);
+      }
+
+      this.notificationListeners.forEach((listener) => {
+        const event: NotificationEvent = {
+          event: 'delete',
+          notification: {
+            deviceId,
+            shuttleId,
+            stopId,
+            secondsThreshold: parseInt(secondsThreshold)
+          }
+        };
+        listener(event);
+      });
+    }
+  };
+
+  public getAllNotificationsForShuttleAndStopId = async (
+    shuttleId: string,
+    stopId: string
+  ): Promise<ScheduledNotification[]> => {
+    const key = this.getNotificationKey(shuttleId, stopId);
+    const allNotifications = await this.redisClient.hGetAll(key);
+
+    return Object.entries(allNotifications).map(([deviceId, secondsThreshold]) => ({
+      shuttleId,
+      stopId,
+      deviceId,
+      secondsThreshold: parseInt(secondsThreshold)
+    }));
+  };
+
+  public getSecondsThresholdForNotificationIfExists = async (
+    lookupArguments: NotificationLookupArguments
+  ): Promise<number | null> => {
+    const { shuttleId, stopId, deviceId } = lookupArguments;
+    const key = this.getNotificationKey(shuttleId, stopId);
+
+    const threshold = await this.redisClient.hGet(key, deviceId);
+    return threshold ? parseInt(threshold) : null;
+  };
+
+  public isNotificationScheduled = async (
+    lookupArguments: NotificationLookupArguments
+  ): Promise<boolean> => {
+    const threshold = await this.getSecondsThresholdForNotificationIfExists(lookupArguments);
+    return threshold !== null;
+  };
+
+  public subscribeToNotificationChanges = (listener: Listener): void => {
+    const index = this.notificationListeners.findIndex(
+      (existingListener) => existingListener === listener
+    );
+    if (index < 0) {
+      this.notificationListeners.push(listener);
+    }
+  };
+
+  public unsubscribeFromNotificationChanges = (listener: Listener): void => {
+    const index = this.notificationListeners.findIndex(
+      (existingListener) => existingListener === listener
+    );
+    if (index >= 0) {
+      this.notificationListeners.splice(index, 1);
+    }
+  };
+}

src/repositories/notifications/__tests__/NotificationRepositorySharedTests.test.ts

@@ -0,0 +1,218 @@
+import { afterEach, beforeEach, describe, expect, it, jest } from "@jest/globals";
+import { createClient, RedisClientType } from "redis";
+import { InMemoryNotificationRepository } from "../InMemoryNotificationRepository";
+import { NotificationEvent, NotificationRepository } from "../NotificationRepository";
+import { RedisNotificationRepository } from "../RedisNotificationRepository";
+
+interface RepositoryHolder {
+  name: string;
+  factory(): Promise<NotificationRepository>,
+  teardown(): Promise<void>,
+}
+
+class InMemoryRepositoryHolder implements RepositoryHolder {
+  name = 'InMemoryNotificationRepository';
+  factory = async () => {
+    return new InMemoryNotificationRepository();
+  }
+  teardown = async () => {}
+}
+
+class RedisNotificationRepositoryHolder implements RepositoryHolder {
+  repo: RedisNotificationRepository | undefined;
+  redisClient: RedisClientType | undefined;
+
+  name = 'RedisNotificationRepository';
+  factory = async () => {
+    this.redisClient = createClient({
+      url: process.env.REDIS_URL,
+    });
+    await this.redisClient.connect();
+    this.repo = new RedisNotificationRepository(this.redisClient);
+    return this.repo;
+  }
+  teardown = async () => {
+    if (this.redisClient) {
+      await this.redisClient.flushAll();
+      await this.redisClient.disconnect();
+    }
+  }
+}
+
+const repositoryImplementations = [
+  new InMemoryRepositoryHolder(),
+  new RedisNotificationRepositoryHolder(),
+]
+
+describe.each(repositoryImplementations)('$name', (holder) => {
+  let repo: NotificationRepository;
+
+  beforeEach(async () => {
+    repo = await holder.factory();
+  });
+
+  afterEach(async () => {
+    await holder.teardown();
+  })
+
+  const notification = {
+    deviceId: "device1",
+    shuttleId: "shuttle1",
+    stopId: "stop1",
+    secondsThreshold: 180
+  };
+
+  describe("getAllNotificationsForShuttleAndStopId", () => {
+    it("gets notifications correctly", async () => {
+      await repo.addOrUpdateNotification(notification);
+
+      const result = await repo.getAllNotificationsForShuttleAndStopId("shuttle1", "stop1");
+      expect(result).toHaveLength(1);
+      expect(result[0]).toEqual(notification);
+    });
+
+    it("returns empty array if no notifications", async () => {
+      const result = await repo.getAllNotificationsForShuttleAndStopId("shuttle1", "stop1");
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("getSecondsThresholdForNotificationIfExists", () => {
+    it("gets the seconds threshold if exists", async () => {
+      await repo.addOrUpdateNotification(notification);
+
+      const result = await repo.getSecondsThresholdForNotificationIfExists({
+        deviceId: "device1",
+        shuttleId: "shuttle1",
+        stopId: "stop1"
+      });
+      expect(result).toBe(180);
+    });
+
+    it("returns null if there is no seconds threshold", async () => {
+      const result = await repo.getSecondsThresholdForNotificationIfExists({
+        deviceId: "device1",
+        shuttleId: "shuttle1",
+        stopId: "stop1"
+      });
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("addOrUpdateNotification", () => {
+    // Add/get flow is covered in getAllNotificationsForShuttleAndStopId
+
+    it("updates the seconds threshold if the notification exists already", async () => {
+      await repo.addOrUpdateNotification(notification);
+      await repo.addOrUpdateNotification({...notification, secondsThreshold: 300});
+
+      const result = await repo.getSecondsThresholdForNotificationIfExists({
+        deviceId: "device1",
+        shuttleId: "shuttle1",
+        stopId: "stop1"
+      });
+      expect(result).toBe(300);
+    });
+  });
+
+  describe("deleteNotificationIfExists", () => {
+    it("deletes the notification", async () => {
+      await repo.addOrUpdateNotification(notification);
+      await repo.deleteNotificationIfExists(notification);
+
+      const result = await repo.getAllNotificationsForShuttleAndStopId("shuttle1", "stop1");
+      expect(result).toHaveLength(0);
+    });
+
+
+    it("does nothing if there's no notification", async () => {
+      await expect(repo.deleteNotificationIfExists({
+        deviceId: "device1",
+        shuttleId: "shuttle1",
+        stopId: "stop1"
+      })).resolves.not.toThrow();
+    });
+  });
+
+  describe("subscribeToNotificationChanges", () => {
+    it("calls subscribers when something is added", async () => {
+      const mockCallback = jest.fn();
+      repo.subscribeToNotificationChanges(mockCallback);
+
+      await repo.addOrUpdateNotification(notification);
+
+      const expectedEvent: NotificationEvent = {
+        event: 'addOrUpdate',
+        notification,
+      }
+      expect(mockCallback).toHaveBeenCalledTimes(1);
+      expect(mockCallback).toHaveBeenCalledWith(expectedEvent);
+    });
+
+    it("calls subscribers when something is updated", async () => {
+      const mockCallback = jest.fn();
+      repo.subscribeToNotificationChanges(mockCallback);
+
+      await repo.addOrUpdateNotification(notification);
+
+      const updatedNotification = {
+        ...notification,
+        secondsThreshold: notification.secondsThreshold + 60,
+      };
+
+      await repo.addOrUpdateNotification(updatedNotification);
+
+      const expectedEvent: NotificationEvent = {
+        event: 'addOrUpdate',
+        notification,
+      }
+      expect(mockCallback).toHaveBeenCalledTimes(2);
+      expect(mockCallback).toHaveBeenCalledWith(expectedEvent);
+    });
+
+    it("calls subscribers when something is deleted", async () => {
+      await repo.addOrUpdateNotification(notification);
+
+      const mockCallback = jest.fn();
+      repo.subscribeToNotificationChanges(mockCallback);
+
+      await repo.deleteNotificationIfExists(notification);
+
+      expect(mockCallback).toHaveBeenCalledTimes(1);
+
+      const expectedEvent: NotificationEvent = {
+        event: 'delete',
+        notification,
+      };
+      expect(mockCallback).toHaveBeenCalledWith(expectedEvent);
+    });
+  });
+
+  describe("unsubscribeFromNotificationChanges", () => {
+    it("stops calling subscribers when unsubscribed", async () => {
+      const mockCallback = jest.fn();
+      repo.subscribeToNotificationChanges(mockCallback);
+
+      await repo.addOrUpdateNotification(notification);
+
+      repo.unsubscribeFromNotificationChanges(mockCallback);
+
+      await repo.deleteNotificationIfExists(notification);
+
+      expect(mockCallback).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  describe("isNotificationScheduled", () => {
+    it("returns true if the notification is in the repo", async () => {
+      await repo.addOrUpdateNotification(notification);
+      const result = await repo.isNotificationScheduled(notification);
+      expect(result).toBe(true);
+    });
+
+    it("returns false if the notification isn't in the repo", async () => {
+      const result = await repo.isNotificationScheduled(notification);
+      expect(result).toBe(false);
+    })
+  });
+});

src/repositories/parking/InMemoryParkingRepository.ts

@@ -0,0 +1,161 @@
+import { ParkingGetterSetterRepository } from "./ParkingGetterSetterRepository";
+import {
+    IParkingStructure,
+    IParkingStructureTimestampRecord
+} from "../../entities/ParkingRepositoryEntities";
+import { HistoricalParkingAverageQueryResult, HistoricalParkingAverageFilterArguments } from "./ParkingGetterRepository";
+import { CircularQueue } from "../../types/CircularQueue";
+import { PARKING_LOGGING_INTERVAL_MS } from "../../environment";
+
+// If every 10 minutes, two weeks of data (6x per hour * 24x per day * 7x per week * 2)
+export const MAX_NUM_ENTRIES = 2016;
+
+export type ParkingStructureID = string;
+
+export class InMemoryParkingRepository implements ParkingGetterSetterRepository {
+  private dataLastAdded: Map<ParkingStructureID, Date> = new Map();
+  private loggingIntervalMs = PARKING_LOGGING_INTERVAL_MS;
+
+  constructor(
+    private structures: Map<ParkingStructureID, IParkingStructure> = new Map(),
+    private historicalData: Map<ParkingStructureID, CircularQueue<IParkingStructureTimestampRecord>> = new Map(),
+  ) {
+  }
+
+  addOrUpdateParkingStructure = async (structure: IParkingStructure): Promise<void> => {
+    this.structures.set(structure.id, { ...structure });
+    await this.addHistoricalDataForStructure(structure);
+  };
+
+  private addHistoricalDataForStructure = async (structure: IParkingStructure): Promise<void> => {
+    const now = Date.now();
+    const lastAdded = this.dataLastAdded.get(structure.id);
+
+    if (this.shouldLogHistoricalData(lastAdded, now)) {
+      const timestampRecord = this.createTimestampRecord(structure, now);
+      this.ensureHistoricalDataExists(structure.id);
+      this.addRecordToHistoricalData(structure.id, timestampRecord);
+      this.dataLastAdded.set(structure.id, new Date(now));
+    }
+  };
+
+  clearParkingStructureData = async (): Promise<void> => {
+    this.structures.clear();
+    this.historicalData.clear();
+    this.dataLastAdded.clear();
+  };
+
+  getParkingStructureById = async (id: string): Promise<IParkingStructure | null> => {
+    const structure = this.structures.get(id);
+    return structure ? { ...structure } : null;
+  };
+
+  getParkingStructures = async (): Promise<IParkingStructure[]> => Array.from(this.structures.values()).map(structure => ({...structure}));
+
+  removeParkingStructureIfExists = async (id: string): Promise<IParkingStructure | null> => {
+    const structure = this.structures.get(id);
+    if (structure) {
+      this.structures.delete(id);
+      this.historicalData.delete(id);
+      this.dataLastAdded.delete(id);
+      return { ...structure };
+    }
+    return null;
+  };
+
+  getHistoricalAveragesOfParkingStructureCounts = async (id: string, options: HistoricalParkingAverageFilterArguments): Promise<HistoricalParkingAverageQueryResult[]> => {
+    const queue = this.historicalData.get(id);
+    if (!queue || queue.size() === 0) {
+      return [];
+    }
+
+    const records = this.extractRecordsFromQueue(queue);
+    return this.calculateAveragesFromRecords(records, options);
+  };
+
+  private shouldLogHistoricalData = (lastAdded: Date | undefined, currentTime: number): boolean => {
+    return !lastAdded || (currentTime - lastAdded.getTime()) >= this.loggingIntervalMs;
+  };
+
+  private createTimestampRecord = (structure: IParkingStructure, timestampMs: number): IParkingStructureTimestampRecord => ({
+    id: structure.id,
+    spotsAvailable: structure.spotsAvailable,
+    timestampMs: new Date(timestampMs),
+  });
+
+  private ensureHistoricalDataExists = (structureId: string): void => {
+    if (!this.historicalData.has(structureId)) {
+      this.historicalData.set(structureId, new CircularQueue<IParkingStructureTimestampRecord>(MAX_NUM_ENTRIES));
+    }
+  };
+
+  private addRecordToHistoricalData = (structureId: string, record: IParkingStructureTimestampRecord): void => {
+    const sortingCallback = (a: IParkingStructureTimestampRecord, b: IParkingStructureTimestampRecord) => a.timestampMs.getTime() - b.timestampMs.getTime();
+    this.historicalData.get(structureId)?.appendWithSorting(record, sortingCallback);
+  };
+
+  private extractRecordsFromQueue = (queue: CircularQueue<IParkingStructureTimestampRecord>): IParkingStructureTimestampRecord[] => {
+    const records: IParkingStructureTimestampRecord[] = [];
+    for (let i = 0; i < queue.size(); i++) {
+      const record = queue.get(i);
+      if (record) {
+        records.push(record);
+      }
+    }
+    return records;
+  };
+
+  private calculateAveragesFromRecords = (
+    records: IParkingStructureTimestampRecord[],
+    options: HistoricalParkingAverageFilterArguments
+  ): HistoricalParkingAverageQueryResult[] => {
+    const results: HistoricalParkingAverageQueryResult[] = [];
+    const { from, to, intervalMs } = options;
+
+    let currentIntervalStart = from.getTime();
+    const endTime = to.getTime();
+
+    while (currentIntervalStart < endTime) {
+      const currentIntervalEnd = Math.min(currentIntervalStart + intervalMs, endTime);
+      const recordsInInterval = this.getRecordsInTimeRange(records, currentIntervalStart, currentIntervalEnd);
+
+      if (recordsInInterval.length > 0) {
+        const averageResult = this.calculateAverageForInterval(currentIntervalStart, currentIntervalEnd, recordsInInterval);
+        results.push(averageResult);
+      }
+
+      currentIntervalStart = currentIntervalEnd;
+    }
+
+    return results;
+  };
+
+  private getRecordsInTimeRange = (
+    records: IParkingStructureTimestampRecord[],
+    startMs: number,
+    endMs: number
+  ): IParkingStructureTimestampRecord[] => {
+    return records.filter(record =>
+      record.timestampMs.getTime() >= startMs && record.timestampMs.getTime() < endMs
+    );
+  };
+
+  private calculateAverageForInterval = (
+    fromMs: number,
+    toMs: number,
+    records: IParkingStructureTimestampRecord[]
+  ): HistoricalParkingAverageQueryResult => {
+    const totalSpotsAvailable = records.reduce((sum, record) => sum + record.spotsAvailable, 0);
+    const averageSpotsAvailable = totalSpotsAvailable / records.length;
+
+    return {
+      from: new Date(fromMs),
+      to: new Date(toMs),
+      averageSpotsAvailable
+    };
+  };
+
+  setLoggingInterval = (intervalMs: number): void => {
+    this.loggingIntervalMs = intervalMs;
+  };
+}

src/repositories/parking/ParkingGetterRepository.ts

@@ -0,0 +1,26 @@
+import { IParkingStructure } from "../../entities/ParkingRepositoryEntities";
+
+export interface HistoricalParkingAverageFilterArguments {
+  from: Date;
+  to: Date;
+  intervalMs: number;
+}
+
+export interface HistoricalParkingAverageQueryResult {
+  from: Date;
+  to: Date;
+  averageSpotsAvailable: number;
+}
+
+
+export interface ParkingGetterRepository {
+  getParkingStructures(): Promise<IParkingStructure[]>;
+  getParkingStructureById(id: string): Promise<IParkingStructure | null>;
+
+  /**
+   * Get historical averages of parking structure data using the filtering options.
+   * @param id
+   * @param options
+   */
+  getHistoricalAveragesOfParkingStructureCounts(id: string, options: HistoricalParkingAverageFilterArguments): Promise<HistoricalParkingAverageQueryResult[]>;
+}

src/repositories/parking/ParkingGetterSetterRepository.ts

@@ -0,0 +1,12 @@
+import { IParkingStructure } from "../../entities/ParkingRepositoryEntities";
+import { ParkingGetterRepository } from "./ParkingGetterRepository";
+
+export interface ParkingGetterSetterRepository extends ParkingGetterRepository {
+  addOrUpdateParkingStructure(structure: IParkingStructure): Promise<void>;
+
+  removeParkingStructureIfExists(id: string): Promise<IParkingStructure | null>;
+
+  clearParkingStructureData(): Promise<void>;
+
+  setLoggingInterval(intervalMs: number): void;
+}

src/repositories/parking/RedisParkingRepository.ts

@@ -0,0 +1,204 @@
+import { ParkingGetterSetterRepository } from "./ParkingGetterSetterRepository";
+import { IParkingStructure } from "../../entities/ParkingRepositoryEntities";
+import { HistoricalParkingAverageQueryResult, HistoricalParkingAverageFilterArguments } from "./ParkingGetterRepository";
+import { BaseRedisRepository } from "../BaseRedisRepository";
+import { PARKING_LOGGING_INTERVAL_MS } from "../../environment";
+
+export type ParkingStructureID = string;
+
+export class RedisParkingRepository extends BaseRedisRepository implements ParkingGetterSetterRepository {
+  private dataLastAdded: Map<ParkingStructureID, Date> = new Map();
+  private loggingIntervalMs = PARKING_LOGGING_INTERVAL_MS;
+
+  addOrUpdateParkingStructure = async (structure: IParkingStructure): Promise<void> => {
+    const keys = this.createRedisKeys(structure.id);
+    await this.redisClient.hSet(keys.structure, this.createRedisHashFromStructure(structure));
+    await this.addHistoricalDataForStructure(structure);
+  };
+
+  private addHistoricalDataForStructure = async (structure: IParkingStructure): Promise<void> => {
+    const now = Date.now();
+    const lastAdded = this.dataLastAdded.get(structure.id);
+
+    if (this.shouldLogHistoricalData(lastAdded, now)) {
+      const keys = this.createRedisKeys(structure.id);
+      await this.addTimeSeriesDataPoint(keys.timeSeries, now, structure.spotsAvailable, structure.id);
+      this.dataLastAdded.set(structure.id, new Date(now));
+    }
+  };
+
+  clearParkingStructureData = async (): Promise<void> => {
+    const structureKeys = await this.redisClient.keys('parking:structure:*');
+    const timeSeriesKeys = await this.redisClient.keys('parking:timeseries:*');
+
+    const allKeys = [...structureKeys, ...timeSeriesKeys];
+    if (allKeys.length > 0) {
+      await this.redisClient.del(allKeys);
+    }
+
+    this.dataLastAdded.clear();
+  };
+
+  getParkingStructureById = async (id: string): Promise<IParkingStructure | null> => {
+    const keys = this.createRedisKeys(id);
+    const data = await this.redisClient.hGetAll(keys.structure);
+
+    if (Object.keys(data).length === 0) {
+      return null;
+    }
+
+    return this.createStructureFromRedisData(data);
+  };
+
+  getParkingStructures = async (): Promise<IParkingStructure[]> => {
+    const keys = await this.redisClient.keys('parking:structure:*');
+    const structures: IParkingStructure[] = [];
+
+    for (const key of keys) {
+      const data = await this.redisClient.hGetAll(key);
+      if (Object.keys(data).length > 0) {
+        structures.push(this.createStructureFromRedisData(data));
+      }
+    }
+
+    return structures;
+  };
+
+  removeParkingStructureIfExists = async (id: string): Promise<IParkingStructure | null> => {
+    const structure = await this.getParkingStructureById(id);
+    if (structure) {
+      const keys = this.createRedisKeys(id);
+      await this.redisClient.del([keys.structure, keys.timeSeries]);
+      this.dataLastAdded.delete(id);
+      return structure;
+    }
+    return null;
+  };
+
+  getHistoricalAveragesOfParkingStructureCounts = async (id: string, options: HistoricalParkingAverageFilterArguments): Promise<HistoricalParkingAverageQueryResult[]> => {
+    return this.calculateAveragesFromRecords(id, options);
+  };
+
+  private createRedisKeys = (structureId: string) => ({
+    structure: `parking:structure:${structureId}`,
+    timeSeries: `parking:timeseries:${structureId}`
+  });
+
+  private createRedisHashFromStructure = (structure: IParkingStructure): Record<string, string> => ({
+    id: structure.id,
+    name: structure.name,
+    address: structure.address,
+    capacity: structure.capacity.toString(),
+    spotsAvailable: structure.spotsAvailable.toString(),
+    latitude: structure.coordinates.latitude.toString(),
+    longitude: structure.coordinates.longitude.toString(),
+    updatedTime: structure.updatedTime.toISOString()
+  });
+
+  private createStructureFromRedisData = (data: Record<string, string>): IParkingStructure => ({
+    id: data.id,
+    name: data.name,
+    address: data.address,
+    capacity: parseInt(data.capacity),
+    spotsAvailable: parseInt(data.spotsAvailable),
+    coordinates: {
+      latitude: parseFloat(data.latitude),
+      longitude: parseFloat(data.longitude)
+    },
+    updatedTime: new Date(data.updatedTime)
+  });
+
+  private shouldLogHistoricalData = (lastAdded: Date | undefined, currentTime: number): boolean => {
+    return !lastAdded || (currentTime - lastAdded.getTime()) >= this.loggingIntervalMs;
+  };
+
+  private addTimeSeriesDataPoint = async (timeSeriesKey: string, timestamp: number, value: number, structureId: string): Promise<void> => {
+    try {
+      await this.redisClient.sendCommand([
+        'TS.ADD',
+        timeSeriesKey,
+        timestamp.toString(),
+        value.toString(),
+        'LABELS',
+        'structureId',
+        structureId
+      ]);
+    } catch (error) {
+      await this.createTimeSeriesAndAddDataPoint(timeSeriesKey, timestamp, value, structureId);
+    }
+  };
+
+  private createTimeSeriesAndAddDataPoint = async (timeSeriesKey: string, timestamp: number, value: number, structureId: string): Promise<void> => {
+    try {
+      await this.redisClient.sendCommand([
+        'TS.CREATE',
+        timeSeriesKey,
+        'RETENTION',
+        '2678400000',  // one month
+        'LABELS',
+        'structureId',
+        structureId
+      ]);
+      await this.redisClient.sendCommand([
+        'TS.ADD',
+        timeSeriesKey,
+        timestamp.toString(),
+        value.toString()
+      ]);
+    } catch (createError) {
+      await this.redisClient.sendCommand([
+        'TS.ADD',
+        timeSeriesKey,
+        timestamp.toString(),
+        value.toString()
+      ]);
+    }
+  };
+
+  private calculateAveragesFromRecords = async (
+    id: string,
+    options: HistoricalParkingAverageFilterArguments
+  ): Promise<HistoricalParkingAverageQueryResult[]> => {
+    const keys = this.createRedisKeys(id);
+    const { from, to, intervalMs } = options;
+    const results: HistoricalParkingAverageQueryResult[] = [];
+
+    let currentIntervalStart = from.getTime();
+    const endTime = to.getTime();
+
+    while (currentIntervalStart < endTime) {
+      const currentIntervalEnd = Math.min(currentIntervalStart + intervalMs, endTime);
+
+      try {
+        const aggregationResult = await this.redisClient.sendCommand([
+          'TS.RANGE',
+          keys.timeSeries,
+          currentIntervalStart.toString(),
+          currentIntervalEnd.toString(),
+          'AGGREGATION',
+          'AVG',
+          intervalMs.toString()
+        ]) as [string, string][];
+
+        if (aggregationResult && aggregationResult.length > 0) {
+          const [, averageValue] = aggregationResult[0];
+          results.push({
+            from: new Date(currentIntervalStart),
+            to: new Date(currentIntervalEnd),
+            averageSpotsAvailable: parseFloat(averageValue)
+          });
+        }
+      } catch (error) {
+        // If Redis aggregation fails, skip this interval
+      }
+
+      currentIntervalStart = currentIntervalEnd;
+    }
+
+    return results;
+  };
+
+  setLoggingInterval = (intervalMs: number): void => {
+    this.loggingIntervalMs = intervalMs;
+  };
+}

src/repositories/parking/__tests__/ParkingRepositorySharedTests.test.ts

@@ -0,0 +1,205 @@
+import { afterEach, beforeEach, describe, expect, it, jest } from "@jest/globals";
+import { createClient, RedisClientType } from "redis";
+import { InMemoryParkingRepository, } from "../InMemoryParkingRepository";
+import { IParkingStructure } from "../../../entities/ParkingRepositoryEntities";
+import { ParkingGetterSetterRepository } from "../ParkingGetterSetterRepository";
+import { RedisParkingRepository } from "../RedisParkingRepository";
+import { HistoricalParkingAverageFilterArguments } from "../ParkingGetterRepository";
+import { RepositoryHolder } from "../../../../testHelpers/RepositoryHolder";
+
+class InMemoryParkingRepositoryHolder implements RepositoryHolder<ParkingGetterSetterRepository> {
+  name = 'InMemoryParkingRepository';
+  factory = async () => {
+    return new InMemoryParkingRepository();
+  };
+  teardown = async () => {};
+}
+
+class RedisParkingRepositoryHolder implements RepositoryHolder<ParkingGetterSetterRepository> {
+  repo: RedisParkingRepository | undefined;
+  redisClient: RedisClientType | undefined;
+
+  name = 'RedisParkingRepository';
+  factory = async () => {
+    this.redisClient = createClient({
+      url: process.env.REDIS_URL,
+    });
+    await this.redisClient.connect();
+    this.repo = new RedisParkingRepository(this.redisClient);
+    return this.repo;
+  };
+  teardown = async () => {
+    if (this.redisClient) {
+      await this.redisClient.flushAll();
+      await this.redisClient.disconnect();
+    }
+  };
+}
+
+const repositoryImplementations = [
+  new InMemoryParkingRepositoryHolder(),
+  new RedisParkingRepositoryHolder(),
+];
+
+describe.each(repositoryImplementations)('$name', (holder) => {
+  let repository: ParkingGetterSetterRepository;
+  const testStructure: IParkingStructure = {
+    coordinates: {
+      latitude: 33.794795,
+      longitude: -117.850807,
+    },
+    spotsAvailable: 0,
+    id: "1",
+    name: "Anderson Parking Structure",
+    capacity: 100,
+    address: "300 E Walnut Ave, Orange, CA 92867",
+    updatedTime: new Date(),
+  };
+
+  beforeEach(async () => {
+    repository = await holder.factory();
+    jest.useRealTimers();
+  });
+
+  afterEach(async () => {
+    await holder.teardown();
+    jest.useRealTimers();
+  });
+
+  describe("addOrUpdateParkingStructure", () => {
+    it("should add a new parking structure", async () => {
+      await repository.addOrUpdateParkingStructure(testStructure);
+      const result = await repository.getParkingStructureById(testStructure.id);
+      expect(result).toEqual(testStructure);
+    });
+
+    it("should update existing parking structure", async () => {
+      await repository.addOrUpdateParkingStructure(testStructure);
+      const updatedStructure = { ...testStructure, name: "Updated Garage" };
+      await repository.addOrUpdateParkingStructure(updatedStructure);
+      const result = await repository.getParkingStructureById(testStructure.id);
+      expect(result).toEqual(updatedStructure);
+    });
+  });
+
+  describe("removeParkingStructureIfExists", () => {
+    it("should remove existing parking structure and return it", async () => {
+      await repository.addOrUpdateParkingStructure(testStructure);
+      const removed = await repository.removeParkingStructureIfExists(testStructure.id);
+      expect(removed).toEqual(testStructure);
+      const result = await repository.getParkingStructureById(testStructure.id);
+      expect(result).toBeNull();
+    });
+
+    it("should return null when removing non-existent structure", async () => {
+      const result = await repository.removeParkingStructureIfExists("non-existent");
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("clearParkingStructureData", () => {
+    it("should remove all parking structures", async () => {
+      const structures = [
+        testStructure,
+        { ...testStructure, id: "test-id-2", name: "Second Garage" }
+      ];
+
+      for (const structure of structures) {
+        await repository.addOrUpdateParkingStructure(structure);
+      }
+
+      await repository.clearParkingStructureData();
+      const result = await repository.getParkingStructures();
+      expect(result).toHaveLength(0);
+    });
+  });
+
+  describe("getParkingStructures", () => {
+    it("should return empty array when no structures exist", async () => {
+      const result = await repository.getParkingStructures();
+      expect(result).toEqual([]);
+    });
+
+    it("should return all added structures", async () => {
+      const structures = [
+        testStructure,
+        { ...testStructure, id: "test-id-2", name: "Second Garage" }
+      ];
+
+      for (const structure of structures) {
+        await repository.addOrUpdateParkingStructure(structure);
+      }
+
+      const result = await repository.getParkingStructures();
+      expect(result).toHaveLength(2);
+      expect(result).toEqual(expect.arrayContaining(structures));
+    });
+  });
+
+  describe("getParkingStructureById", () => {
+    it("should return null for non-existent structure", async () => {
+      const result = await repository.getParkingStructureById("non-existent");
+      expect(result).toBeNull();
+    });
+
+    it("should return structure by id", async () => {
+      await repository.addOrUpdateParkingStructure(testStructure);
+      const result = await repository.getParkingStructureById(testStructure.id);
+      expect(result).toEqual(testStructure);
+    });
+  });
+
+  describe("getHistoricalAveragesOfParkingStructureCounts", () => {
+    it("should return empty array for non-existent structure or no data", async () => {
+      const options: HistoricalParkingAverageFilterArguments = {
+        from: new Date(1000),
+        to: new Date(2000),
+        intervalMs: 500
+      };
+
+      expect(await repository.getHistoricalAveragesOfParkingStructureCounts("non-existent", options)).toEqual([]);
+
+      await repository.addOrUpdateParkingStructure(testStructure);
+      expect(await repository.getHistoricalAveragesOfParkingStructureCounts(testStructure.id, options)).toEqual([]);
+    });
+
+    it("should calculate average for one single large interval", async () => {
+      // Set logging interval to 0 so every update creates historical data
+      repository.setLoggingInterval(0);
+
+      await repository.addOrUpdateParkingStructure(testStructure);
+
+      const updates = [
+        { ...testStructure, spotsAvailable: 80, updatedTime: new Date() },
+        { ...testStructure, spotsAvailable: 70, updatedTime: new Date() },
+        { ...testStructure, spotsAvailable: 60, updatedTime: new Date() },
+      ];
+
+      for (let i = 0; i < updates.length; i++) {
+        // Ensure that different timestamps are created, even after adding the first test structure
+        await new Promise((resolve) => setTimeout(resolve, 200));
+        await repository.addOrUpdateParkingStructure(updates[i]);
+      }
+
+      const now = Date.now();
+      const options: HistoricalParkingAverageFilterArguments = {
+        from: new Date(now - 10000), // Look back 10 seconds
+        to: new Date(now + 10000),   // Look forward 10 seconds
+        intervalMs: 20000              // Single large interval
+      };
+
+      const result = await repository.getHistoricalAveragesOfParkingStructureCounts(testStructure.id, options);
+
+      // Should have at least some historical data
+      expect(result.length).toEqual(1);
+      if (result.length > 0) {
+        expect(result[0]).toHaveProperty('from');
+        expect(result[0]).toHaveProperty('to');
+        expect(result[0].from).toBeInstanceOf(Date);
+        expect(result[0].to).toBeInstanceOf(Date);
+        expect(result[0]).toHaveProperty('averageSpotsAvailable');
+        expect(result[0].averageSpotsAvailable).toBeCloseTo(52.5);
+      }
+    });
+  });
+});

src/repositories/shuttle/RedisShuttleRepository.ts

@@ -0,0 +1,629 @@
+import { ShuttleGetterSetterRepository } from "./ShuttleGetterSetterRepository";
+import { IEta, IOrderedStop, IRoute, IShuttle, IStop, shuttleHasArrivedAtStop } from "../../entities/ShuttleRepositoryEntities";
+import {
+  ShuttleRepositoryEvent,
+  ShuttleRepositoryEventListener,
+  ShuttleRepositoryEventName,
+  ShuttleRepositoryEventPayloads,
+  ShuttleStopArrival,
+  ShuttleTravelTimeDataIdentifier,
+  ShuttleTravelTimeDateFilterArguments
+} from "./ShuttleGetterRepository";
+import { BaseRedisRepository } from "../BaseRedisRepository";
+import { RedisClientType } from "redis";
+import createRedisClientForRepository from "../../helpers/createRedisClientForRepository";
+
+export class RedisShuttleRepository extends BaseRedisRepository implements ShuttleGetterSetterRepository {
+  constructor(
+    redisClient: RedisClientType = createRedisClientForRepository(),
+    readonly shuttleStopArrivalDegreeDelta: number = 0.001,
+  ) {
+    super(redisClient);
+  }
+
+  get isReady() {
+    return this.redisClient.isReady;
+  }
+
+  public async connect() {
+    await this.redisClient.connect();
+  }
+
+  public async disconnect() {
+    await this.redisClient.disconnect();
+  }
+
+  // EventEmitter override methods for type safety
+  public override on<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override on(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.on(event, listener);
+  }
+
+  public override once<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override once(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.once(event, listener);
+  }
+
+  public override off<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override off(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.off(event, listener);
+  }
+
+  public override addListener<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override addListener(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.addListener(event, listener);
+  }
+
+  public override removeListener<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override removeListener(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.removeListener(event, listener);
+  }
+
+  public override emit<T extends ShuttleRepositoryEventName>(
+    event: T,
+    payload: ShuttleRepositoryEventPayloads[T],
+  ): boolean;
+  public override emit(event: string | symbol, ...args: any[]): boolean {
+    return super.emit(event, ...args);
+  }
+
+  // Key prefixes for individual entity keys
+  private readonly stopKeyPrefix = 'shuttle:stop:';
+  private readonly routeKeyPrefix = 'shuttle:route:';
+  private readonly shuttleKeyPrefix = 'shuttle:shuttle:';
+  private readonly orderedStopKeyPrefix = 'shuttle:orderedstop:';
+  private readonly lastStopKeyPrefix = 'shuttle:laststop:';
+  private readonly historicalEtaKeyPrefix = 'shuttle:eta:historical:';
+
+  // Key patterns for bulk operations (e.g., getting all keys, clearing data)
+  private readonly stopKeyPattern = 'shuttle:stop:*';
+  private readonly routeKeyPattern = 'shuttle:route:*';
+  private readonly shuttleKeyPattern = 'shuttle:shuttle:*';
+  private readonly orderedStopKeyPattern = 'shuttle:orderedstop:*';
+  private readonly lastStopKeyPattern = 'shuttle:laststop:*';
+
+  /**
+   * Represents a set storing the shuttles that are currently at a stop.
+   */
+  private readonly shuttleIsAtStopKey = 'shuttle:atstop';
+
+  // Helper methods for Redis key generation
+  private readonly createStopKey = (stopId: string) => `${this.stopKeyPrefix}${stopId}`;
+  private readonly createRouteKey = (routeId: string) => `${this.routeKeyPrefix}${routeId}`;
+  private readonly createShuttleKey = (shuttleId: string) => `${this.shuttleKeyPrefix}${shuttleId}`;
+  private readonly createOrderedStopKey = (routeId: string, stopId: string) => `${this.orderedStopKeyPrefix}${routeId}:${stopId}`;
+  private readonly createShuttleLastStopKey = (shuttleId: string) => `${this.lastStopKeyPrefix}${shuttleId}`;
+  private readonly createHistoricalEtaTimeSeriesKey = (routeId: string, fromStopId: string, toStopId: string) => {
+    return `${this.historicalEtaKeyPrefix}${routeId}:${fromStopId}:${toStopId}`;
+  };
+
+  // Helper methods for converting entities to Redis hashes
+  private createRedisHashFromStop = (stop: IStop): Record<string, string> => ({
+    id: stop.id,
+    name: stop.name,
+    systemId: stop.systemId,
+    latitude: stop.coordinates.latitude.toString(),
+    longitude: stop.coordinates.longitude.toString(),
+    updatedTime: stop.updatedTime.toISOString(),
+  });
+
+  private createStopFromRedisData = (data: Record<string, string>): IStop => ({
+    id: data.id,
+    name: data.name,
+    systemId: data.systemId,
+    coordinates: {
+      latitude: parseFloat(data.latitude),
+      longitude: parseFloat(data.longitude),
+    },
+    updatedTime: new Date(data.updatedTime),
+  });
+
+  private createRedisHashFromRoute = (route: IRoute): Record<string, string> => ({
+    id: route.id,
+    name: route.name,
+    color: route.color,
+    systemId: route.systemId,
+    polylineCoordinates: JSON.stringify(route.polylineCoordinates),
+    updatedTime: route.updatedTime.toISOString(),
+  });
+
+  private createRouteFromRedisData = (data: Record<string, string>): IRoute => ({
+    id: data.id,
+    name: data.name,
+    color: data.color,
+    systemId: data.systemId,
+    polylineCoordinates: JSON.parse(data.polylineCoordinates),
+    updatedTime: new Date(data.updatedTime),
+  });
+
+  private createRedisHashFromShuttle = (shuttle: IShuttle): Record<string, string> => ({
+    id: shuttle.id,
+    name: shuttle.name,
+    routeId: shuttle.routeId,
+    systemId: shuttle.systemId,
+    latitude: shuttle.coordinates.latitude.toString(),
+    longitude: shuttle.coordinates.longitude.toString(),
+    orientationInDegrees: shuttle.orientationInDegrees.toString(),
+    updatedTime: shuttle.updatedTime.toISOString(),
+  });
+
+  private createShuttleFromRedisData = (data: Record<string, string>): IShuttle => ({
+    id: data.id,
+    name: data.name,
+    routeId: data.routeId,
+    systemId: data.systemId,
+    coordinates: {
+      latitude: parseFloat(data.latitude),
+      longitude: parseFloat(data.longitude),
+    },
+    orientationInDegrees: parseFloat(data.orientationInDegrees),
+    updatedTime: new Date(data.updatedTime),
+  });
+
+  private createEtaFromRedisData = (data: Record<string, string>): IEta => ({
+    secondsRemaining: parseFloat(data.secondsRemaining),
+    shuttleId: data.shuttleId,
+    stopId: data.stopId,
+    systemId: data.systemId,
+    updatedTime: new Date(data.updatedTime),
+  });
+
+  private createRedisHashFromOrderedStop = (orderedStop: IOrderedStop): Record<string, string> => {
+    const hash: Record<string, string> = {
+      routeId: orderedStop.routeId,
+      stopId: orderedStop.stopId,
+      position: orderedStop.position.toString(),
+      systemId: orderedStop.systemId,
+      updatedTime: orderedStop.updatedTime.toISOString(),
+    };
+
+    if (orderedStop.nextStop) {
+      hash.nextStopRouteId = orderedStop.nextStop.routeId;
+      hash.nextStopStopId = orderedStop.nextStop.stopId;
+    }
+
+    if (orderedStop.previousStop) {
+      hash.previousStopRouteId = orderedStop.previousStop.routeId;
+      hash.previousStopStopId = orderedStop.previousStop.stopId;
+    }
+
+    return hash;
+  };
+
+  private createOrderedStopFromRedisData = (data: Record<string, string>): IOrderedStop => {
+    const orderedStop: IOrderedStop = {
+      routeId: data.routeId,
+      stopId: data.stopId,
+      position: parseInt(data.position),
+      systemId: data.systemId,
+      updatedTime: new Date(data.updatedTime),
+    };
+
+    // Note: We only store the IDs of next/previous stops, not full objects
+    // to avoid circular references in Redis. These would need to be
+    // resolved separately if needed.
+    if (data.nextStopRouteId && data.nextStopStopId) {
+      orderedStop.nextStop = {
+        routeId: data.nextStopRouteId,
+        stopId: data.nextStopStopId,
+        position: 0, // placeholder
+        systemId: data.systemId,
+        updatedTime: new Date(),
+      };
+    }
+
+    if (data.previousStopRouteId && data.previousStopStopId) {
+      orderedStop.previousStop = {
+        routeId: data.previousStopRouteId,
+        stopId: data.previousStopStopId,
+        position: 0, // placeholder
+        systemId: data.systemId,
+        updatedTime: new Date(),
+      };
+    }
+
+    return orderedStop;
+  };
+
+  // Getter methods
+  public async getStops(): Promise<IStop[]> {
+    const keys = await this.redisClient.keys(this.stopKeyPattern);
+    const stops: IStop[] = [];
+
+    for (const key of keys) {
+      const data = await this.redisClient.hGetAll(key);
+      if (Object.keys(data).length > 0) {
+        stops.push(this.createStopFromRedisData(data));
+      }
+    }
+
+    return stops;
+  }
+
+  public async getStopById(stopId: string): Promise<IStop | null> {
+    const key = this.createStopKey(stopId);
+    const data = await this.redisClient.hGetAll(key);
+
+    if (Object.keys(data).length === 0) {
+      return null;
+    }
+
+    return this.createStopFromRedisData(data);
+  }
+
+  public async getRoutes(): Promise<IRoute[]> {
+    const keys = await this.redisClient.keys(this.routeKeyPattern);
+    const routes: IRoute[] = [];
+
+    for (const key of keys) {
+      const data = await this.redisClient.hGetAll(key);
+      if (Object.keys(data).length > 0) {
+        routes.push(this.createRouteFromRedisData(data));
+      }
+    }
+
+    return routes;
+  }
+
+  public async getRouteById(routeId: string): Promise<IRoute | null> {
+    const key = this.createRouteKey(routeId);
+    const data = await this.redisClient.hGetAll(key);
+
+    if (Object.keys(data).length === 0) {
+      return null;
+    }
+
+    return this.createRouteFromRedisData(data);
+  }
+
+  public async getShuttles(): Promise<IShuttle[]> {
+    const keys = await this.redisClient.keys(this.shuttleKeyPattern);
+    const shuttles: IShuttle[] = [];
+
+    for (const key of keys) {
+      const data = await this.redisClient.hGetAll(key);
+      if (Object.keys(data).length > 0) {
+        shuttles.push(this.createShuttleFromRedisData(data));
+      }
+    }
+
+    return shuttles;
+  }
+
+  public async getShuttlesByRouteId(routeId: string): Promise<IShuttle[]> {
+    const allShuttles = await this.getShuttles();
+    return allShuttles.filter(shuttle => shuttle.routeId === routeId);
+  }
+
+  public async getShuttleById(shuttleId: string): Promise<IShuttle | null> {
+    const key = this.createShuttleKey(shuttleId);
+    const data = await this.redisClient.hGetAll(key);
+
+    if (Object.keys(data).length === 0) {
+      return null;
+    }
+
+    return this.createShuttleFromRedisData(data);
+  }
+
+  public async getOrderedStopByRouteAndStopId(routeId: string, stopId: string): Promise<IOrderedStop | null> {
+    const key = this.createOrderedStopKey(routeId, stopId);
+    const data = await this.redisClient.hGetAll(key);
+
+    if (Object.keys(data).length === 0) {
+      return null;
+    }
+
+    return this.createOrderedStopFromRedisData(data);
+  }
+
+  public async getOrderedStopsByStopId(stopId: string): Promise<IOrderedStop[]> {
+    const keys = await this.redisClient.keys(this.orderedStopKeyPattern);
+    const orderedStops: IOrderedStop[] = [];
+
+    for (const key of keys) {
+      const data = await this.redisClient.hGetAll(key);
+      if (Object.keys(data).length > 0 && data.stopId === stopId) {
+        orderedStops.push(this.createOrderedStopFromRedisData(data));
+      }
+    }
+
+    return orderedStops;
+  }
+
+  public async getOrderedStopsByRouteId(routeId: string): Promise<IOrderedStop[]> {
+    const keys = await this.redisClient.keys(`${this.orderedStopKeyPrefix}${routeId}:*`);
+    const orderedStops: IOrderedStop[] = [];
+
+    for (const key of keys) {
+      const data = await this.redisClient.hGetAll(key);
+      if (Object.keys(data).length > 0) {
+        orderedStops.push(this.createOrderedStopFromRedisData(data));
+      }
+    }
+
+    return orderedStops;
+  }
+
+  // Setter/update methods
+  public async addOrUpdateRoute(route: IRoute): Promise<void> {
+    const key = this.createRouteKey(route.id);
+    await this.redisClient.hSet(key, this.createRedisHashFromRoute(route));
+  }
+
+  public async addOrUpdateShuttle(
+    shuttle: IShuttle,
+    travelTimeTimestamp = Date.now(),
+  ): Promise<void> {
+    const key = this.createShuttleKey(shuttle.id);
+    await this.redisClient.hSet(key, this.createRedisHashFromShuttle(shuttle));
+
+    this.emit(ShuttleRepositoryEvent.SHUTTLE_UPDATED, shuttle);
+
+    await this.updateLastStopArrival(shuttle, travelTimeTimestamp);
+  }
+
+  private async updateLastStopArrival(
+    shuttle: IShuttle,
+    travelTimeTimestamp = Date.now(),
+  ) {
+    const isAtStop = await this.checkIfShuttleIsAtStop(shuttle.id);
+
+    let arrivedStop: IStop | undefined;
+
+    if (isAtStop) {
+      // Allow retrieval of the shuttle's current stop
+      // Will still return undefined when the shuttle leaves the stop
+      arrivedStop = await this.getArrivedStopIfNextStop(shuttle, true);
+    } else {
+      arrivedStop = await this.getArrivedStopIfNextStop(shuttle, false);
+    }
+
+    // Will not fire *any* events if the same stop
+    const lastStop = await this.getShuttleLastStopArrival(shuttle.id);
+    if (lastStop?.stopId === arrivedStop?.id) return;
+
+    if (isAtStop) {
+      if (lastStop) {
+        this.emit(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, {
+          stopArrivalThatShuttleIsLeaving: lastStop,
+        });
+      }
+      await this.markShuttleAsNotAtStop(shuttle.id);
+    }
+
+    if (arrivedStop) {
+      const shuttleArrival = {
+        stopId: arrivedStop.id,
+        timestamp: new Date(travelTimeTimestamp),
+        shuttleId: shuttle.id,
+      };
+      this.emit(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, {
+        lastStopArrival: lastStop,
+        willArriveAt: shuttleArrival,
+      });
+      await this.markShuttleAsAtStop(shuttleArrival.shuttleId);
+      await this.updateShuttleLastStopArrival(shuttleArrival);
+    }
+  }
+
+  private async markShuttleAsAtStop(shuttleId: string) {
+    await this.redisClient.sAdd(this.shuttleIsAtStopKey, shuttleId);
+  }
+
+  private async markShuttleAsNotAtStop(shuttleId: string) {
+    await this.redisClient.sRem(this.shuttleIsAtStopKey, shuttleId);
+  }
+
+  public async checkIfShuttleIsAtStop(shuttleId: string) {
+    return await this.redisClient.sIsMember(this.shuttleIsAtStopKey, shuttleId);
+  }
+
+  public async getAverageTravelTimeSeconds(
+    { routeId, fromStopId, toStopId }: ShuttleTravelTimeDataIdentifier,
+    { from, to }: ShuttleTravelTimeDateFilterArguments,
+  ): Promise<number | undefined> {
+    const timeSeriesKey = this.createHistoricalEtaTimeSeriesKey(routeId, fromStopId, toStopId);
+    const fromTimestamp = from.getTime();
+    const toTimestamp = to.getTime();
+    const intervalMs = toTimestamp - fromTimestamp + 1;
+
+    try {
+      const aggregationResult = await this.redisClient.sendCommand([
+        'TS.RANGE',
+        timeSeriesKey,
+        fromTimestamp.toString(),
+        toTimestamp.toString(),
+        'AGGREGATION',
+        'AVG',
+        intervalMs.toString()
+      ]) as [string, string][];
+
+      if (aggregationResult && aggregationResult.length > 0) {
+        const [, averageValue] = aggregationResult[0];
+        return parseFloat(averageValue);
+      }
+
+      return;
+    } catch (error) {
+      console.warn(`Failed to get average travel time: ${error instanceof Error ? error.message : String(error)}`);
+      return;
+    }
+  }
+
+  public async getArrivedStopIfNextStop(
+    shuttle: IShuttle,
+    canReturnShuttleCurrentStop: boolean = false,
+  ): Promise<IStop | undefined> {
+    const degreeDelta = this.shuttleStopArrivalDegreeDelta;
+
+    const lastStopArrival = await this.getShuttleLastStopArrival(shuttle.id);
+    if (lastStopArrival) {
+      // Return the shuttle's current stop depending on the flag
+      if (canReturnShuttleCurrentStop) {
+        const lastStop = await this.getStopById(lastStopArrival.stopId);
+        if (lastStop && shuttleHasArrivedAtStop(shuttle, lastStop, degreeDelta)) {
+          return lastStop;
+        }
+      }
+
+      const lastOrderedStop = await this.getOrderedStopByRouteAndStopId(shuttle.routeId, lastStopArrival.stopId);
+      const orderedStopAfter = lastOrderedStop?.nextStop;
+      if (orderedStopAfter) {
+        const stopAfter = await this.getStopById(orderedStopAfter.stopId);
+        if (stopAfter && shuttleHasArrivedAtStop(shuttle, stopAfter, degreeDelta)) {
+          return stopAfter;
+        }
+      }
+    } else {
+      const orderedStops = await this.getOrderedStopsByRouteId(shuttle.routeId);
+
+      for (const orderedStop of orderedStops) {
+        const stop = await this.getStopById(orderedStop.stopId);
+        if (stop != null && shuttleHasArrivedAtStop(shuttle, stop, degreeDelta)) {
+          return stop;
+        }
+      }
+    }
+
+    return undefined;
+  }
+
+  public async getShuttleLastStopArrival(shuttleId: string): Promise<ShuttleStopArrival | undefined> {
+    const key = this.createShuttleLastStopKey(shuttleId);
+    const data = await this.redisClient.hGetAll(key);
+
+    if (Object.keys(data).length === 0) {
+      return undefined;
+    }
+
+    return {
+      shuttleId,
+      stopId: data.stopId,
+      timestamp: new Date(data.timestamp),
+    };
+  }
+
+  private async updateShuttleLastStopArrival(lastStopArrival: ShuttleStopArrival) {
+    const key = this.createShuttleLastStopKey(lastStopArrival.shuttleId);
+    await this.redisClient.hSet(key, {
+      stopId: lastStopArrival.stopId,
+      timestamp: lastStopArrival.timestamp.toISOString(),
+    });
+  }
+
+  public async addOrUpdateStop(stop: IStop): Promise<void> {
+    const key = this.createStopKey(stop.id);
+    await this.redisClient.hSet(key, this.createRedisHashFromStop(stop));
+  }
+
+  public async addOrUpdateOrderedStop(orderedStop: IOrderedStop): Promise<void> {
+    const key = this.createOrderedStopKey(orderedStop.routeId, orderedStop.stopId);
+    await this.redisClient.hSet(key, this.createRedisHashFromOrderedStop(orderedStop));
+  }
+
+  // Remove methods
+  public async removeRouteIfExists(routeId: string): Promise<IRoute | null> {
+    const route = await this.getRouteById(routeId);
+    if (route) {
+      const key = this.createRouteKey(routeId);
+      await this.redisClient.del(key);
+      return route;
+    }
+    return null;
+  }
+
+  public async removeShuttleIfExists(shuttleId: string): Promise<IShuttle | null> {
+    const shuttle = await this.getShuttleById(shuttleId);
+    if (shuttle) {
+      const key = this.createShuttleKey(shuttleId);
+      await this.redisClient.del(key);
+      this.emit(ShuttleRepositoryEvent.SHUTTLE_REMOVED, shuttle);
+
+      await this.removeShuttleLastStopIfExists(shuttleId);
+      await this.markShuttleAsNotAtStop(shuttleId);
+
+      return shuttle;
+    }
+    return null;
+  }
+
+  public async removeStopIfExists(stopId: string): Promise<IStop | null> {
+    const stop = await this.getStopById(stopId);
+    if (stop) {
+      const key = this.createStopKey(stopId);
+      await this.redisClient.del(key);
+      return stop;
+    }
+    return null;
+  }
+
+  public async removeOrderedStopIfExists(stopId: string, routeId: string): Promise<IOrderedStop | null> {
+    const orderedStop = await this.getOrderedStopByRouteAndStopId(routeId, stopId);
+    if (orderedStop) {
+      const key = this.createOrderedStopKey(routeId, stopId);
+      await this.redisClient.del(key);
+      return orderedStop;
+    }
+    return null;
+  }
+
+  private async removeShuttleLastStopIfExists(shuttleId: string) {
+    const lastStop = await this.getShuttleLastStopArrival(shuttleId);
+    if (lastStop) {
+      const key = this.createShuttleLastStopKey(shuttleId);
+      await this.redisClient.del(key);
+      return lastStop;
+    }
+    return null;
+  }
+
+  // Clear methods
+  private async clearRedisKeys(pattern: string): Promise<void> {
+    const keys = await this.redisClient.keys(pattern);
+    if (keys.length > 0) {
+      await this.redisClient.del(keys);
+    }
+  }
+
+  public async clearShuttleData(): Promise<void> {
+    await this.clearRedisKeys(this.shuttleKeyPattern);
+    await this.clearShuttleLastStopData();
+    await this.clearShuttleIsAtStopData();
+  }
+
+  public async clearOrderedStopData(): Promise<void> {
+    await this.clearRedisKeys(this.orderedStopKeyPattern);
+  }
+
+  public async clearRouteData(): Promise<void> {
+    await this.clearRedisKeys(this.routeKeyPattern);
+  }
+
+  public async clearStopData(): Promise<void> {
+    await this.clearRedisKeys(this.stopKeyPattern);
+  }
+
+  private async clearShuttleLastStopData(): Promise<void> {
+    await this.clearRedisKeys(this.lastStopKeyPattern);
+  }
+
+  private async clearShuttleIsAtStopData(): Promise<void> {
+    await this.clearRedisKeys(this.shuttleIsAtStopKey);
+  }
+}

src/repositories/shuttle/ShuttleGetterRepository.ts

@@ -0,0 +1,119 @@
+import { IEta, IOrderedStop, IRoute, IShuttle, IStop } from "../../entities/ShuttleRepositoryEntities";
+import type EventEmitter from "node:events";
+
+export const ShuttleRepositoryEvent = {
+  SHUTTLE_UPDATED: "shuttleUpdated",
+  SHUTTLE_REMOVED: "shuttleRemoved",
+  SHUTTLE_WILL_ARRIVE_AT_STOP: "shuttleArrivedAtStop",
+  SHUTTLE_WILL_LEAVE_STOP: "shuttleWillLeaveStop",
+} as const;
+
+export type ShuttleRepositoryEventName = typeof ShuttleRepositoryEvent[keyof typeof ShuttleRepositoryEvent];
+
+export type EtaRemovedEventPayload = IEta;
+export type EtaDataClearedEventPayload = IEta[];
+
+export interface ShuttleWillArriveAtStopPayload {
+  lastStopArrival?: ShuttleStopArrival;
+  willArriveAt: ShuttleStopArrival;
+};
+
+export type ShuttleIsNearStopPayload = ShuttleWillArriveAtStopPayload;
+
+export interface ShuttleWillLeaveStopPayload {
+  stopArrivalThatShuttleIsLeaving: ShuttleStopArrival;
+}
+
+export interface ShuttleRepositoryEventPayloads {
+  [ShuttleRepositoryEvent.SHUTTLE_UPDATED]: IShuttle,
+  [ShuttleRepositoryEvent.SHUTTLE_REMOVED]: IShuttle,
+  [ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP]: ShuttleWillArriveAtStopPayload,
+  [ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP]: ShuttleWillLeaveStopPayload,
+}
+
+export type ShuttleRepositoryEventListener<T extends ShuttleRepositoryEventName> = (
+  payload: ShuttleRepositoryEventPayloads[T],
+) => void;
+
+export interface ShuttleStopArrival {
+  shuttleId: string;
+  stopId: string;
+  timestamp: Date;
+}
+
+export interface ShuttleTravelTimeDataIdentifier {
+  routeId: string;
+  fromStopId: string;
+  toStopId: string;
+}
+
+export interface ShuttleTravelTimeDateFilterArguments {
+  from: Date;
+  to: Date;
+}
+
+/**
+ * Shuttle getter repository to be linked to a system.
+ */
+export interface ShuttleGetterRepository extends EventEmitter {
+  getStops(): Promise<IStop[]>;
+  getStopById(stopId: string): Promise<IStop | null>;
+
+  getRoutes(): Promise<IRoute[]>;
+  getRouteById(routeId: string): Promise<IRoute | null>;
+
+  getShuttles(): Promise<IShuttle[]>;
+  getShuttleById(shuttleId: string): Promise<IShuttle | null>;
+  getShuttlesByRouteId(routeId: string): Promise<IShuttle[]>;
+
+  on<T extends ShuttleRepositoryEventName>(event: T, listener: ShuttleRepositoryEventListener<T>): this;
+  once<T extends ShuttleRepositoryEventName>(event: T, listener: ShuttleRepositoryEventListener<T>): this;
+  off<T extends ShuttleRepositoryEventName>(event: T, listener: ShuttleRepositoryEventListener<T>): this;
+  addListener<T extends ShuttleRepositoryEventName>(event: T, listener: ShuttleRepositoryEventListener<T>): this;
+  removeListener<T extends ShuttleRepositoryEventName>(event: T, listener: ShuttleRepositoryEventListener<T>): this;
+
+  getOrderedStopByRouteAndStopId(routeId: string, stopId: string): Promise<IOrderedStop | null>;
+
+  /**
+   * Get ordered stops with the given stop ID.
+   * Returns an empty array if no ordered stops found.
+   * @param stopId
+   */
+  getOrderedStopsByStopId(stopId: string): Promise<IOrderedStop[]>;
+
+  /**
+   * Get ordered stops with the given route ID.
+   * Returns an empty array if no ordered stops found.
+   * @param routeId
+   */
+  getOrderedStopsByRouteId(routeId: string): Promise<IOrderedStop[]>;
+
+  /**
+   * Get the last stop arrival for a shuttle.
+   * Returns undefined if no last stop arrival has been recorded.
+   * @param shuttleId
+   */
+  getShuttleLastStopArrival(shuttleId: string): Promise<ShuttleStopArrival | undefined>;
+
+  /**
+   * Determine if the shuttle is currently at a stop.
+   * If `true`, then calling `getShuttleLastStopArrival` will get
+   * the stop the shuttle is currently at.
+   * @param shuttleId
+   */
+  checkIfShuttleIsAtStop(shuttleId: string): Promise<boolean>;
+
+  /**
+    * Get the stop that the shuttle is currently at, if it's the shuttle's
+    * next stop based on the "last stop" the shuttle was at. If there was no
+    * "last stop" for the shuttle, it may return any stop on the shuttle's route.
+    * 
+    * @param shuttle
+    * @param canReturnShuttleCurrentStop If set to true, and the shuttle's "last stop"
+    * matches the arrived stop, continue to return the arrived stop.
+    * Otherwise, only return the shuttle's next stop.
+    * This flag has no effect if the shuttle has not had a "last stop".
+    * @returns
+    */
+  getArrivedStopIfNextStop(shuttle: IShuttle, canReturnShuttleCurrentStop: boolean): Promise<IStop | undefined>;
+}

src/repositories/shuttle/ShuttleGetterSetterRepository.ts

@@ -0,0 +1,40 @@
+// If types match closely, we can use TypeScript "casting"
+// to convert from data repo to GraphQL schema
+
+import { ShuttleGetterRepository, ShuttleTravelTimeDataIdentifier, ShuttleTravelTimeDateFilterArguments } from "./ShuttleGetterRepository";
+import { IOrderedStop, IRoute, IShuttle, IStop } from "../../entities/ShuttleRepositoryEntities";
+
+/**
+ * ShuttleGetterRepository interface for data derived from Passio API.
+ * The repository is not designed to have write locks in place.
+ * Objects passed from/to the repository should be treated
+ * as disposable.
+ */
+export interface ShuttleGetterSetterRepository extends ShuttleGetterRepository {
+  // Setter methods
+  addOrUpdateRoute(route: IRoute): Promise<void>;
+  addOrUpdateShuttle(shuttle: IShuttle, travelTimeTimestamp?: number, referenceCurrentTime?: Date): Promise<void>;
+  addOrUpdateStop(stop: IStop): Promise<void>;
+  addOrUpdateOrderedStop(orderedStop: IOrderedStop): Promise<void>;
+
+  removeRouteIfExists(routeId: string): Promise<IRoute | null>;
+  removeShuttleIfExists(shuttleId: string): Promise<IShuttle | null>;
+  removeStopIfExists(stopId: string): Promise<IStop | null>;
+  removeOrderedStopIfExists(stopId: string, routeId: string): Promise<IOrderedStop | null>;
+
+  clearRouteData(): Promise<void>;
+  clearShuttleData(): Promise<void>;
+  clearStopData(): Promise<void>;
+  clearOrderedStopData(): Promise<void>;
+
+  /**
+   * Get average travel time between two stops based on historical data.
+   * Returns undefined if no data exists for the specified time range.
+   * @param identifier - The route and stop IDs to query
+   * @param dateFilter - The date range to filter data
+   */
+  getAverageTravelTimeSeconds(
+    identifier: ShuttleTravelTimeDataIdentifier,
+    dateFilter: ShuttleTravelTimeDateFilterArguments
+  ): Promise<number | undefined>;
+}

src/repositories/shuttle/UnoptimizedInMemoryShuttleRepository.ts

@@ -0,0 +1,377 @@
+import EventEmitter from "node:events";
+import { ShuttleGetterSetterRepository } from "./ShuttleGetterSetterRepository";
+import { IOrderedStop, IRoute, IShuttle, IStop, shuttleHasArrivedAtStop } from "../../entities/ShuttleRepositoryEntities";
+import { IEntityWithId } from "../../entities/SharedEntities";
+import {
+  ShuttleRepositoryEvent,
+  ShuttleRepositoryEventListener,
+  ShuttleRepositoryEventName,
+  ShuttleRepositoryEventPayloads,
+  ShuttleStopArrival,
+  ShuttleTravelTimeDataIdentifier,
+  ShuttleTravelTimeDateFilterArguments,
+} from "./ShuttleGetterRepository";
+
+/**
+ * An unoptimized in memory repository.
+ * (I would optimize it with actual data structures, but I'm
+ * switching to another data store later anyways)
+ */
+export class UnoptimizedInMemoryShuttleRepository
+  extends EventEmitter
+  implements ShuttleGetterSetterRepository {
+
+  constructor(
+    readonly shuttleStopArrivalDegreeDelta: number = 0.001,
+  ) {
+    super()
+  }
+
+  public override on<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override on(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.on(event, listener);
+  }
+
+  public override once<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override once(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.once(event, listener);
+  }
+
+  public override off<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override off(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.off(event, listener);
+  }
+
+  public override addListener<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override addListener(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.addListener(event, listener);
+  }
+
+  public override removeListener<T extends ShuttleRepositoryEventName>(
+    event: T,
+    listener: ShuttleRepositoryEventListener<T>,
+  ): this;
+  public override removeListener(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.removeListener(event, listener);
+  }
+
+  public override emit<T extends ShuttleRepositoryEventName>(
+    event: T,
+    payload: ShuttleRepositoryEventPayloads[T],
+  ): boolean;
+  public override emit(event: string | symbol, ...args: any[]): boolean {
+    return super.emit(event, ...args);
+  }
+
+  private stops: IStop[] = [];
+  private routes: IRoute[] = [];
+  private shuttles: IShuttle[] = [];
+  private orderedStops: IOrderedStop[] = [];
+  private shuttleLastStopArrivals: Map<string, ShuttleStopArrival> = new Map();
+  private travelTimeData: Map<string, Array<{ timestamp: number; seconds: number }>> = new Map();
+  private shuttlesAtStop: Set<string> = new Set();
+
+  public async getStops(): Promise<IStop[]> {
+    return this.stops;
+  }
+
+  public async getStopById(stopId: string) {
+    return this.findEntityById(stopId, this.stops);
+  }
+
+  public async getRoutes(): Promise<IRoute[]> {
+    return this.routes;
+  }
+
+  public async getRouteById(routeId: string) {
+    return this.findEntityById(routeId, this.routes);
+  }
+
+  public async getShuttles(): Promise<IShuttle[]> {
+    return this.shuttles;
+  }
+
+  public async getShuttlesByRouteId(routeId: string) {
+    return this.shuttles.filter(shuttle => shuttle.routeId === routeId);
+  }
+
+  public async getShuttleById(shuttleId: string) {
+    return this.findEntityById(shuttleId, this.shuttles);
+  }
+
+  public async getOrderedStopByRouteAndStopId(routeId: string, stopId: string) {
+    return this.findEntityByMatcher<IOrderedStop>((value) => value.routeId === routeId && value.stopId === stopId, this.orderedStops)
+  }
+
+  public async getOrderedStopsByStopId(stopId: string) {
+    return this.orderedStops.filter((value) => value.stopId === stopId);
+  }
+
+  public async getOrderedStopsByRouteId(routeId: string) {
+    return this.orderedStops.filter((value) => value.routeId === routeId);
+  }
+
+  private findEntityById<T extends IEntityWithId>(entityId: string, arrayToSearchIn: T[]) {
+    return this.findEntityByMatcher((value) => value.id === entityId, arrayToSearchIn);
+  }
+
+  private findEntityByMatcher<T>(callback: (value: T) => boolean, arrayToSearchIn: T[]): T | null {
+    const entity = arrayToSearchIn.find(callback);
+    if (!entity) {
+      return null;
+    }
+    return entity;
+  }
+
+  public async addOrUpdateRoute(route: IRoute): Promise<void> {
+    const index = this.routes.findIndex((r) => r.id === route.id);
+    if (index !== -1) {
+      this.routes[index] = route;
+    } else {
+      this.routes.push(route);
+    }
+  }
+
+  public async addOrUpdateShuttle(
+    shuttle: IShuttle,
+    travelTimeTimestamp = Date.now(),
+  ): Promise<void> {
+    const index = this.shuttles.findIndex((s) => s.id === shuttle.id);
+    if (index !== -1) {
+      this.shuttles[index] = shuttle;
+    } else {
+      this.shuttles.push(shuttle);
+    }
+
+    this.emit(ShuttleRepositoryEvent.SHUTTLE_UPDATED, shuttle);
+
+    await this.updateLastStopArrival(shuttle, travelTimeTimestamp);
+  }
+
+  public async addOrUpdateStop(stop: IStop): Promise<void> {
+    const index = this.stops.findIndex((s) => s.id === stop.id);
+    if (index !== -1) {
+      this.stops[index] = stop;
+    } else {
+      this.stops.push(stop);
+    }
+  }
+
+  public async addOrUpdateOrderedStop(orderedStop: IOrderedStop): Promise<void> {
+    const index = this.orderedStops.findIndex((value) => value.stopId === orderedStop.stopId && value.routeId === orderedStop.routeId);
+    if (index !== -1) {
+      this.orderedStops[index] = orderedStop;
+    } else {
+      this.orderedStops.push(orderedStop);
+    }
+  }
+
+  private async updateLastStopArrival(
+    shuttle: IShuttle,
+    travelTimeTimestamp = Date.now(),
+  ) {
+    const isAtStop = await this.checkIfShuttleIsAtStop(shuttle.id);
+
+    let arrivedStop: IStop | undefined;
+
+    if (isAtStop) {
+      // Allow retrieval of the shuttle's current stop
+      // Will still return undefined when the shuttle leaves the stop
+      arrivedStop = await this.getArrivedStopIfNextStop(shuttle, true);
+    } else {
+      arrivedStop = await this.getArrivedStopIfNextStop(shuttle, false);
+    }
+
+
+    // Will not fire *any* events if the same stop
+    const lastStop = await this.getShuttleLastStopArrival(shuttle.id);
+    if (lastStop?.stopId === arrivedStop?.id) return;
+
+    if (isAtStop) {
+      if (lastStop) {
+        this.emit(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, {
+          stopArrivalThatShuttleIsLeaving: lastStop,
+        });
+      }
+      await this.markShuttleAsNotAtStop(shuttle.id);
+    }
+
+    if (arrivedStop) {
+      // stop if same stop
+      const shuttleArrival = {
+        stopId: arrivedStop.id,
+        timestamp: new Date(travelTimeTimestamp),
+        shuttleId: shuttle.id,
+      };
+      this.emit(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, {
+        lastStopArrival: lastStop,
+        willArriveAt: shuttleArrival,
+      });
+      await this.markShuttleAsAtStop(shuttleArrival.shuttleId);
+      await this.updateShuttleLastStopArrival(shuttleArrival);
+    }
+  }
+
+  private async markShuttleAsAtStop(shuttleId: string) {
+    this.shuttlesAtStop.add(shuttleId);
+  }
+
+  private async markShuttleAsNotAtStop(shuttleId: string) {
+    this.shuttlesAtStop.delete(shuttleId);
+  }
+
+  public async checkIfShuttleIsAtStop(shuttleId: string) {
+    return this.shuttlesAtStop.has(shuttleId);
+  }
+
+
+  private async updateShuttleLastStopArrival(lastStopArrival: ShuttleStopArrival) {
+    this.shuttleLastStopArrivals.set(lastStopArrival.shuttleId, lastStopArrival);
+  }
+
+  public async getAverageTravelTimeSeconds(
+    { routeId, fromStopId, toStopId }: ShuttleTravelTimeDataIdentifier,
+    { from, to }: ShuttleTravelTimeDateFilterArguments,
+  ): Promise<number | undefined> {
+    const key = `${routeId}:${fromStopId}:${toStopId}`;
+    const dataPoints = this.travelTimeData.get(key);
+
+    if (!dataPoints || dataPoints.length === 0) {
+      return undefined;
+    }
+
+    const fromTimestamp = from.getTime();
+    const toTimestamp = to.getTime();
+
+    const filteredPoints = dataPoints.filter(
+      (point) => point.timestamp >= fromTimestamp && point.timestamp <= toTimestamp
+    );
+
+    if (filteredPoints.length === 0) {
+      return undefined;
+    }
+
+    const sum = filteredPoints.reduce((acc, point) => acc + point.seconds, 0);
+    return sum / filteredPoints.length;
+  }
+
+  public async getArrivedStopIfNextStop(
+    shuttle: IShuttle,
+    canReturnShuttleCurrentStop: boolean = false,
+  ): Promise<IStop | undefined> {
+    const degreeDelta = this.shuttleStopArrivalDegreeDelta;
+
+    const lastStopArrival = await this.getShuttleLastStopArrival(shuttle.id);
+    if (lastStopArrival) {
+      // Return the shuttle's current stop depending on the flag
+      if (canReturnShuttleCurrentStop) {
+        const lastStop = await this.getStopById(lastStopArrival.stopId);
+        if (lastStop && shuttleHasArrivedAtStop(shuttle, lastStop, degreeDelta)) {
+          return lastStop;
+        }
+      }
+
+      const lastOrderedStop = await this.getOrderedStopByRouteAndStopId(shuttle.routeId, lastStopArrival.stopId);
+      const orderedStopAfter = lastOrderedStop?.nextStop;
+      if (orderedStopAfter) {
+        const stopAfter = await this.getStopById(orderedStopAfter.stopId);
+        if (stopAfter && shuttleHasArrivedAtStop(shuttle, stopAfter, degreeDelta)) {
+          return stopAfter;
+        }
+      }
+    } else {
+      const orderedStops = await this.getOrderedStopsByRouteId(shuttle.routeId);
+
+      for (const orderedStop of orderedStops) {
+        const stop = await this.getStopById(orderedStop.stopId);
+        if (stop != null && shuttleHasArrivedAtStop(shuttle, stop, degreeDelta)) {
+          return stop;
+        }
+      }
+    }
+
+    return undefined;
+  }
+
+  public async getShuttleLastStopArrival(shuttleId: string): Promise<ShuttleStopArrival | undefined> {
+    return this.shuttleLastStopArrivals.get(shuttleId);
+  }
+
+  private async removeEntityByMatcherIfExists<T>(callback: (value: T) => boolean, arrayToSearchIn: T[]) {
+    const index = arrayToSearchIn.findIndex(callback);
+    if (index > -1) {
+      const entityToReturn = arrayToSearchIn[index];
+      arrayToSearchIn.splice(index, 1);
+      return entityToReturn;
+    }
+
+    return null;
+  }
+
+  private async removeEntityByIdIfExists<T extends IEntityWithId>(entityId: string, arrayToSearchIn: T[]) {
+    return await this.removeEntityByMatcherIfExists((value) => value.id === entityId, arrayToSearchIn);
+  }
+
+  public async removeRouteIfExists(routeId: string): Promise<IRoute | null> {
+    return await this.removeEntityByIdIfExists(routeId, this.routes);
+  }
+
+  public async removeShuttleIfExists(shuttleId: string): Promise<IShuttle | null> {
+    const shuttle = await this.removeEntityByIdIfExists(shuttleId, this.shuttles);
+    if (shuttle != null) {
+      this.emit(ShuttleRepositoryEvent.SHUTTLE_REMOVED, shuttle);
+      this.shuttlesAtStop.delete(shuttleId);
+      await this.removeShuttleLastStopIfExists(shuttleId);
+    }
+    return shuttle;
+  }
+
+  public async removeStopIfExists(stopId: string): Promise<IStop | null> {
+    return await this.removeEntityByIdIfExists(stopId, this.stops);
+  }
+
+  public async removeOrderedStopIfExists(stopId: string, routeId: string): Promise<IOrderedStop | null> {
+    return await this.removeEntityByMatcherIfExists((orderedStop) => {
+      return orderedStop.stopId === stopId
+        && orderedStop.routeId === routeId
+    }, this.orderedStops);
+  }
+
+  private async removeShuttleLastStopIfExists(shuttleId: string) {
+    this.shuttleLastStopArrivals.delete(shuttleId);
+  }
+
+  public async clearShuttleData(): Promise<void> {
+    this.shuttles = [];
+    this.shuttlesAtStop.clear();
+    await this.clearShuttleLastStopData();
+  }
+
+  public async clearOrderedStopData(): Promise<void> {
+    this.orderedStops = [];
+  }
+
+  public async clearRouteData(): Promise<void> {
+    this.routes = [];
+  }
+
+  public async clearStopData(): Promise<void> {
+    this.stops = [];
+  }
+
+  private async clearShuttleLastStopData(): Promise<void> {
+    this.shuttleLastStopArrivals.clear();
+  }
+}

src/repositories/shuttle/__tests__/ShuttleRepositorySharedTests.test.ts

@@ -0,0 +1,882 @@
+import { afterEach, beforeEach, describe, expect, jest, test } from "@jest/globals";
+import { createClient, RedisClientType } from "redis";
+import { UnoptimizedInMemoryShuttleRepository } from "../UnoptimizedInMemoryShuttleRepository";
+import { ShuttleGetterSetterRepository } from "../ShuttleGetterSetterRepository";
+import { RedisShuttleRepository } from "../RedisShuttleRepository";
+import {
+    generateMockOrderedStops,
+    generateMockRoutes,
+    generateMockShuttles,
+    generateMockStops,
+} from "../../../../testHelpers/mockDataGenerators";
+import { RepositoryHolder } from "../../../../testHelpers/RepositoryHolder";
+import { setupRouteAndOrderedStopsForShuttleRepository } from "../../../../testHelpers/setupRouteAndOrderedStopsForShuttleRepository";
+import { ShuttleRepositoryEvent } from "../ShuttleGetterRepository";
+
+class UnoptimizedInMemoryShuttleRepositoryHolder implements RepositoryHolder<ShuttleGetterSetterRepository> {
+  name = 'UnoptimizedInMemoryShuttleRepository';
+  factory = async () => {
+    return new UnoptimizedInMemoryShuttleRepository();
+  };
+  teardown = async () => { };
+}
+
+class RedisShuttleRepositoryHolder implements RepositoryHolder<ShuttleGetterSetterRepository> {
+  repo: RedisShuttleRepository | undefined;
+  redisClient: RedisClientType | undefined;
+
+  name = 'RedisShuttleRepository';
+  factory = async () => {
+    this.redisClient = createClient({
+      url: process.env.REDIS_URL,
+    });
+    await this.redisClient.connect();
+    this.repo = new RedisShuttleRepository(this.redisClient);
+    return this.repo;
+  };
+  teardown = async () => {
+    if (this.redisClient) {
+      await this.redisClient.flushAll();
+      await this.redisClient.disconnect();
+    }
+  };
+}
+
+const repositoryImplementations = [
+  new UnoptimizedInMemoryShuttleRepositoryHolder(),
+  new RedisShuttleRepositoryHolder(),
+];
+
+describe.each(repositoryImplementations)('$name', (holder) => {
+  let repository: ShuttleGetterSetterRepository;
+
+  beforeEach(async () => {
+    repository = await holder.factory();
+    jest.useRealTimers();
+  });
+
+  afterEach(async () => {
+    await holder.teardown();
+    jest.useRealTimers();
+  });
+
+  describe("getStops", () => {
+    test("gets all stops in the repository", async () => {
+      const mockStops = generateMockStops();
+      for (const stop of mockStops) {
+        await repository.addOrUpdateStop(stop);
+      }
+
+      const result = await repository.getStops();
+      expect(result).toHaveLength(mockStops.length);
+      expect(result).toEqual(expect.arrayContaining(mockStops));
+    });
+
+    test("returns an empty list if there are no stops for the given system ID", async () => {
+      const result = await repository.getStops();
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("getStopById", () => {
+    test("gets a stop by ID if it exists", async () => {
+      const mockStops = generateMockStops();
+      const mockStop = mockStops[0];
+      await repository.addOrUpdateStop(mockStop);
+
+      const result = await repository.getStopById("st1");
+      expect(result).toEqual(mockStop);
+    });
+
+    test("returns null if the stop does not exist", async () => {
+      const result = await repository.getStopById("nonexistent-stop");
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("getRoutes", () => {
+    test("gets all routes for a specific system ID", async () => {
+      const mockRoutes = generateMockRoutes();
+      for (const route of mockRoutes) {
+        await repository.addOrUpdateRoute(route);
+      }
+
+      const result = await repository.getRoutes();
+      expect(result).toHaveLength(mockRoutes.length);
+      expect(result).toEqual(expect.arrayContaining(mockRoutes));
+    });
+
+    test("returns an empty list if there are no routes for the system ID", async () => {
+      const result = await repository.getRoutes();
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("getRouteById", () => {
+    test("gets a route by ID if it exists", async () => {
+      const mockRoutes = generateMockRoutes();
+      const mockRoute = mockRoutes[0];
+      await repository.addOrUpdateRoute(mockRoute);
+
+      const result = await repository.getRouteById("r1");
+      expect(result).toEqual(mockRoute);
+    });
+
+    test("returns null if the route does not exist", async () => {
+      const result = await repository.getRouteById("nonexistent-route");
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("getShuttles", () => {
+    test("gets all shuttles for a specific system ID", async () => {
+      const mockShuttles = generateMockShuttles();
+      for (const shuttle of mockShuttles) {
+        await repository.addOrUpdateShuttle(shuttle);
+      }
+
+      const result = await repository.getShuttles();
+      expect(result).toHaveLength(mockShuttles.length);
+      expect(result).toEqual(expect.arrayContaining(mockShuttles));
+    });
+
+    test("returns an empty list if there are no shuttles for the system ID", async () => {
+      const result = await repository.getShuttles();
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("getShuttlesByRouteId", () => {
+    test("gets all shuttles for a specific route ID", async () => {
+      const mockShuttles = generateMockShuttles();
+      for (const shuttle of mockShuttles) {
+        await repository.addOrUpdateShuttle(shuttle);
+      }
+
+      const result = await repository.getShuttlesByRouteId("r1");
+      expect(result).toEqual(mockShuttles.filter((sh) => sh.routeId === "r1"));
+    });
+
+    test("returns an empty list if there are no shuttles for the route ID", async () => {
+      const result = await repository.getShuttlesByRouteId("nonexistent-route");
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("getShuttleById", () => {
+    test("gets a shuttle by ID if it exists", async () => {
+      const mockShuttles = generateMockShuttles();
+      for (const shuttle of mockShuttles) {
+        await repository.addOrUpdateShuttle(shuttle);
+      }
+
+      const result = await repository.getShuttleById("sh2");
+      expect(result).toEqual(mockShuttles[1]);
+    });
+
+    test("returns null if the shuttle doesn't exist", async () => {
+      const result = await repository.getShuttleById("nonexistent-id");
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("getOrderedStopByRouteAndStopId", () => {
+    test("gets an ordered stop by route ID and stop ID", async () => {
+      const mockOrderedStops = generateMockOrderedStops();
+      for (const orderedStop of mockOrderedStops) {
+        await repository.addOrUpdateOrderedStop(orderedStop);
+      }
+
+      const mockOrderedStop = mockOrderedStops[0];
+      const { routeId, stopId } = mockOrderedStop;
+
+      const result = await repository.getOrderedStopByRouteAndStopId(routeId, stopId);
+      expect(result).toEqual(mockOrderedStop);
+    });
+
+    test("returns null if no ordered stop matches the given route ID and stop ID", async () => {
+      const result = await repository.getOrderedStopByRouteAndStopId("nonexistent-route", "nonexistent-stop");
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("getOrderedStopsByStopId", () => {
+    test("gets all ordered stops for a specific stop ID", async () => {
+      const mockOrderedStops = generateMockOrderedStops();
+      for (const orderedStop of mockOrderedStops) {
+        await repository.addOrUpdateOrderedStop(orderedStop);
+      }
+
+      const result = await repository.getOrderedStopsByStopId("st1");
+      const expected = mockOrderedStops.filter((os) => os.stopId === "st1");
+      expect(result).toHaveLength(expected.length);
+      expect(result).toEqual(expect.arrayContaining(expected));
+    });
+
+    test("returns an empty list if there are no ordered stops for the stop ID", async () => {
+      const result = await repository.getOrderedStopsByStopId("nonexistent-stop");
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("getOrderedStopsByRouteId", () => {
+    test("gets all ordered stops for a specific route ID", async () => {
+      const mockOrderedStops = generateMockOrderedStops();
+      for (const orderedStop of mockOrderedStops) {
+        await repository.addOrUpdateOrderedStop(orderedStop);
+      }
+
+      const result = await repository.getOrderedStopsByRouteId("r1");
+      const expected = mockOrderedStops.filter((os) => os.routeId === "r1");
+      expect(result).toHaveLength(expected.length);
+      expect(result).toEqual(expect.arrayContaining(expected));
+    });
+
+    test("returns an empty list if there are no ordered stops for the route ID", async () => {
+      const result = await repository.getOrderedStopsByRouteId("nonexistent-route");
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("addOrUpdateRoute", () => {
+    test("adds a new route if nonexistent", async () => {
+      const mockRoutes = generateMockRoutes();
+      const newRoute = mockRoutes[0];
+
+      await repository.addOrUpdateRoute(newRoute);
+
+      const result = await repository.getRoutes();
+      expect(result).toEqual([newRoute]);
+    });
+
+    test("updates an existing route if it exists", async () => {
+      const mockRoutes = generateMockRoutes();
+      const existingRoute = mockRoutes[0];
+      const updatedRoute = structuredClone(existingRoute);
+      updatedRoute.name = "Updated Route";
+
+      await repository.addOrUpdateRoute(existingRoute);
+      await repository.addOrUpdateRoute(updatedRoute);
+
+      const result = await repository.getRoutes();
+      expect(result).toEqual([updatedRoute]);
+    });
+  });
+
+  describe("addOrUpdateShuttle", () => {
+    test("adds a new shuttle if nonexistent", async () => {
+      const mockShuttles = generateMockShuttles();
+      const newShuttle = mockShuttles[0];
+
+      await repository.addOrUpdateShuttle(newShuttle);
+
+      const result = await repository.getShuttles();
+      expect(result).toEqual([newShuttle]);
+    });
+
+    test("updates an existing shuttle if it exists", async () => {
+      const mockShuttles = generateMockShuttles();
+      const existingShuttle = mockShuttles[0];
+      const updatedShuttle = structuredClone(existingShuttle);
+      updatedShuttle.name = "Updated Shuttle";
+
+      await repository.addOrUpdateShuttle(existingShuttle);
+      await repository.addOrUpdateShuttle(updatedShuttle);
+
+      const result = await repository.getShuttles();
+      expect(result).toEqual([updatedShuttle]);
+    });
+  });
+
+  describe("addOrUpdateStop", () => {
+    test("adds a new stop if nonexistent", async () => {
+      const mockStops = generateMockStops();
+      const newStop = mockStops[0];
+
+      await repository.addOrUpdateStop(newStop);
+
+      const result = await repository.getStops();
+      expect(result).toEqual([newStop]);
+    });
+
+    test("updates an existing stop if it exists", async () => {
+      const mockStops = generateMockStops();
+      const existingStop = mockStops[0];
+      const updatedStop = structuredClone(existingStop);
+      updatedStop.name = "Updated Stop";
+
+      await repository.addOrUpdateStop(existingStop);
+      await repository.addOrUpdateStop(updatedStop);
+
+      const result = await repository.getStops();
+      expect(result).toEqual([updatedStop]);
+    });
+  });
+
+  describe("addOrUpdateOrderedStop", () => {
+    test("adds a new ordered stop if nonexistent", async () => {
+      const mockOrderedStops = generateMockOrderedStops();
+      const newOrderedStop = mockOrderedStops[0];
+
+      await repository.addOrUpdateOrderedStop(newOrderedStop);
+
+      const result = await repository.getOrderedStopsByRouteId(newOrderedStop.routeId);
+      expect(result).toEqual([newOrderedStop]);
+    });
+
+    test("updates an existing ordered stop if it exists", async () => {
+      const mockOrderedStops = generateMockOrderedStops();
+      const existingOrderedStop = mockOrderedStops[0];
+      const updatedOrderedStop = structuredClone(existingOrderedStop);
+      updatedOrderedStop.position = 5;
+
+      await repository.addOrUpdateOrderedStop(existingOrderedStop);
+      await repository.addOrUpdateOrderedStop(updatedOrderedStop);
+
+      const result = await repository.getOrderedStopsByRouteId(existingOrderedStop.routeId);
+      expect(result).toEqual([updatedOrderedStop]);
+    });
+  });
+
+
+  describe("removeRouteIfExists", () => {
+    test("removes route given ID", async () => {
+      const systemId = "1";
+      const mockRoutes = generateMockRoutes();
+      await Promise.all(mockRoutes.map(async (route) => {
+        route.systemId = systemId;
+        await repository.addOrUpdateRoute(route);
+      }));
+
+      const routeToRemove = mockRoutes[0];
+      await repository.removeRouteIfExists(routeToRemove.id);
+
+      const remainingRoutes = await repository.getRoutes();
+      expect(remainingRoutes).toHaveLength(mockRoutes.length - 1);
+    });
+
+    test("does nothing if route doesn't exist", async () => {
+      const systemId = "1";
+      const mockRoutes = generateMockRoutes();
+      await Promise.all(mockRoutes.map(async (route) => {
+        route.systemId = systemId;
+        await repository.addOrUpdateRoute(route);
+      }));
+
+      await repository.removeRouteIfExists("nonexistent-id");
+
+      const remainingRoutes = await repository.getRoutes();
+      expect(remainingRoutes).toHaveLength(mockRoutes.length);
+    });
+  });
+
+  describe("removeShuttleIfExists", () => {
+    test("removes shuttle given ID", async () => {
+      const systemId = "1";
+      const mockShuttles = generateMockShuttles();
+      await Promise.all(mockShuttles.map(async (shuttle) => {
+        shuttle.systemId = systemId;
+        await repository.addOrUpdateShuttle(shuttle);
+      }));
+
+      const shuttleToRemove = mockShuttles[0];
+      await repository.removeShuttleIfExists(shuttleToRemove.id);
+
+      const remainingShuttles = await repository.getShuttles();
+      expect(remainingShuttles).toHaveLength(mockShuttles.length - 1);
+    });
+
+    test("removes shuttle last stop if exists", async () => {
+      const { route, stop1, systemId } = await setupRouteAndOrderedStops();
+      const mockShuttle = generateMockShuttles()[0];
+      mockShuttle.routeId = route.id;
+      mockShuttle.coordinates = stop1.coordinates;
+      mockShuttle.systemId = systemId;
+
+      await repository.addOrUpdateShuttle(mockShuttle);
+      await repository.removeShuttleIfExists(mockShuttle.id);
+
+      const lastStopData = await repository.getShuttleLastStopArrival(mockShuttle.id);
+      expect(lastStopData).toBeUndefined();
+    });
+
+    test("does nothing if shuttle doesn't exist", async () => {
+      const systemId = "1";
+      const mockShuttles = generateMockShuttles();
+      await Promise.all(mockShuttles.map(async (shuttle) => {
+        shuttle.systemId = systemId;
+        await repository.addOrUpdateShuttle(shuttle);
+      }));
+
+      await repository.removeShuttleIfExists("nonexistent-id");
+
+      const remainingShuttles = await repository.getShuttles();
+      expect(remainingShuttles).toHaveLength(mockShuttles.length);
+    });
+  });
+
+  describe("removeStopIfExists", () => {
+    test("removes stop given ID", async () => {
+      const systemId = "1";
+      const mockStops = generateMockStops();
+      await Promise.all(mockStops.map(async (stop) => {
+        stop.systemId = systemId;
+        await repository.addOrUpdateStop(stop);
+      }));
+
+      const stopToRemove = mockStops[0];
+      await repository.removeStopIfExists(stopToRemove.id);
+
+      const remainingStops = await repository.getStops();
+      expect(remainingStops).toHaveLength(mockStops.length - 1);
+    });
+
+    test("does nothing if stop doesn't exist", async () => {
+      const systemId = "1";
+      const mockStops = generateMockStops();
+      await Promise.all(mockStops.map(async (stop) => {
+        stop.systemId = systemId;
+        await repository.addOrUpdateStop(stop);
+      }));
+
+      await repository.removeStopIfExists("nonexistent-id");
+
+      const remainingStops = await repository.getStops();
+      expect(remainingStops).toHaveLength(mockStops.length);
+    });
+  });
+
+  describe("removeOrderedStopIfExists", () => {
+    test("removes ordered stop given stop ID and route ID", async () => {
+      let mockOrderedStops = generateMockOrderedStops();
+      const routeId = mockOrderedStops[0].routeId;
+      mockOrderedStops = mockOrderedStops.filter((orderedStop) => orderedStop.routeId === routeId);
+      await Promise.all(mockOrderedStops.map(async (stop) => {
+        stop.routeId = routeId;
+        await repository.addOrUpdateOrderedStop(stop);
+      }));
+
+      const orderedStopToRemove = mockOrderedStops[0];
+      await repository.removeOrderedStopIfExists(orderedStopToRemove.stopId, orderedStopToRemove.routeId);
+
+      const remainingOrderedStops = await repository.getOrderedStopsByRouteId(routeId);
+      expect(remainingOrderedStops).toHaveLength(mockOrderedStops.length - 1);
+    });
+
+    test("does nothing if ordered stop doesn't exist", async () => {
+      let mockOrderedStops = generateMockOrderedStops();
+      const routeId = mockOrderedStops[0].routeId;
+      mockOrderedStops = mockOrderedStops.filter((orderedStop) => orderedStop.routeId === routeId);
+      await Promise.all(mockOrderedStops.map(async (stop) => {
+        stop.routeId = routeId;
+        await repository.addOrUpdateOrderedStop(stop);
+      }));
+
+      await repository.removeOrderedStopIfExists("nonexistent-stop-id", "nonexistent-route-id");
+
+      const remainingOrderedStops = await repository.getOrderedStopsByRouteId(routeId);
+      expect(remainingOrderedStops).toHaveLength(mockOrderedStops.length);
+    });
+  });
+
+  describe("clearShuttleData", () => {
+    test("clears all shuttles from the repository", async () => {
+      const mockShuttles = generateMockShuttles();
+      for (const shuttle of mockShuttles) {
+        await repository.addOrUpdateShuttle(shuttle);
+      }
+
+      await repository.clearShuttleData();
+
+      const result = await repository.getShuttles();
+      expect(result).toEqual([]);
+    });
+
+    test("also clears last stop data", async () => {
+      const { route, stop1, stop2, systemId } = await setupRouteAndOrderedStops();
+
+      const mockShuttles = generateMockShuttles();
+      mockShuttles[0].coordinates = stop1.coordinates;
+      mockShuttles[1].coordinates = stop2.coordinates;
+
+      for (const shuttle of mockShuttles) {
+        shuttle.routeId = route.id;
+        shuttle.systemId = systemId;
+
+        await repository.addOrUpdateShuttle(shuttle);
+      }
+
+      await repository.clearShuttleData();
+
+      for (const shuttle of mockShuttles) {
+        const result = await repository.getShuttleLastStopArrival(shuttle.id);
+        expect(result).toBeUndefined();
+      }
+    });
+  });
+
+
+  describe("clearOrderedStopData", () => {
+    test("clears all ordered stops from the repository", async () => {
+      const mockOrderedStops = generateMockOrderedStops();
+      for (const system of mockOrderedStops) {
+        await repository.addOrUpdateOrderedStop(system);
+      }
+
+      await repository.clearOrderedStopData();
+
+      const result = await repository.getOrderedStopsByRouteId("route1");
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("clearRouteData", () => {
+    test("clears all routes from the repository", async () => {
+      const mockRoutes = generateMockRoutes();
+      for (const route of mockRoutes) {
+        await repository.addOrUpdateRoute(route);
+      }
+
+      await repository.clearRouteData();
+
+      const result = await repository.getRoutes();
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("clearStopData", () => {
+    test("clears all stops from the repository", async () => {
+      const mockStops = generateMockStops();
+      for (const stop of mockStops) {
+        await repository.addOrUpdateStop(stop);
+      }
+
+      await repository.clearStopData();
+
+      const result = await repository.getStops();
+      expect(result).toEqual([]);
+    });
+  });
+
+  // Helper function for setting up routes and ordered stops for shuttle tracking tests
+  async function setupRouteAndOrderedStops() {
+    return await setupRouteAndOrderedStopsForShuttleRepository(repository);
+  }
+
+  describe("addOrUpdateShuttle with shuttle tracking", () => {
+    test("updates the shuttle's last stop arrival if shuttle is at a stop", async () => {
+      const { stop2, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      await repository.addOrUpdateShuttle(shuttle);
+      const lastStop = await repository.getShuttleLastStopArrival(shuttle.id);
+      expect(lastStop?.stopId).toEqual(stop2.id);
+    });
+  });
+
+  describe("getArrivedStopIfExists", () => {
+    test("gets any stop that the shuttle is currently at, if the shuttle has not had a last stop", async () => {
+      const { sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      const result = await repository.getArrivedStopIfNextStop(shuttle, false);
+
+      expect(result).toBeDefined();
+      expect(result?.id).toBe("st2");
+      expect(result?.name).toBe("Stop 2");
+    });
+
+    test("returns undefined if shuttle is not currently at a stop", async () => {
+      const { sampleShuttleNotInRepository } = await setupRouteAndOrderedStops();
+      const shuttle = { ...sampleShuttleNotInRepository, coordinates: { latitude: 12.5, longitude: 22.5 } }; // Not at any stop
+
+      const result = await repository.getArrivedStopIfNextStop(shuttle, false);
+
+      expect(result).toBeUndefined();
+    });
+
+    test("only gets the shuttle's next stop if shuttle has previously arrived at a stop", async () => {
+      const { sampleShuttleNotInRepository: shuttle, stop1, stop2 } = await setupRouteAndOrderedStops();
+
+      shuttle.coordinates = stop1.coordinates;
+      await repository.addOrUpdateShuttle(shuttle);
+
+      let result = await repository.getArrivedStopIfNextStop(shuttle, false);
+      expect(result).toBeUndefined();
+
+      shuttle.coordinates = stop2.coordinates;
+      result = await repository.getArrivedStopIfNextStop(shuttle, false);
+      expect(result).not.toBeUndefined();
+    });
+
+    test("returns the shuttle's currently arrived stop if flag passed", async () => {
+      const { sampleShuttleNotInRepository: shuttle, stop1 } = await setupRouteAndOrderedStops();
+
+      shuttle.coordinates = stop1.coordinates;
+      await repository.addOrUpdateShuttle(shuttle);
+
+      const result = await repository.getArrivedStopIfNextStop(shuttle, true);
+      expect(result?.id === stop1.id)
+    });
+
+  });
+
+  describe("getShuttleLastStopArrival", () => {
+    test("gets the shuttle's last stop if existing in the data", async () => {
+      const { stop1, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+      shuttle.coordinates = stop1.coordinates;
+
+      const stopArrivalTime = new Date("2024-01-15T10:30:00Z");
+      await repository.addOrUpdateShuttle(shuttle, stopArrivalTime.getTime());
+
+      const result = await repository.getShuttleLastStopArrival(shuttle.id);
+
+      expect(result).toBeDefined();
+      expect(result?.stopId).toBe(stop1.id);
+      expect(result?.timestamp.getTime()).toBe(stopArrivalTime.getTime());
+    });
+
+    test("returns undefined if the data has never been initialized", async () => {
+      const mockShuttles = generateMockShuttles();
+      const shuttle = mockShuttles[0];
+
+      const result = await repository.getShuttleLastStopArrival(shuttle.id);
+
+      expect(result).toBeUndefined();
+    });
+
+    test("returns the most recent stop arrival when updated multiple times", async () => {
+      const { stop1, stop2, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+      shuttle.coordinates = stop1.coordinates;
+
+      const firstArrivalTime = new Date("2024-01-15T10:30:00Z");
+      await repository.addOrUpdateShuttle(shuttle, firstArrivalTime.getTime());
+
+      shuttle.coordinates = stop2.coordinates;
+      const secondArrivalTime = new Date("2024-01-15T10:35:00Z");
+      await repository.addOrUpdateShuttle(shuttle, secondArrivalTime.getTime());
+
+      const result = await repository.getShuttleLastStopArrival(shuttle.id);
+
+      expect(result).toBeDefined();
+      expect(result?.stopId).toBe(stop2.id);
+      expect(result?.timestamp.getTime()).toBe(secondArrivalTime.getTime());
+    });
+  });
+
+  describe("SHUTTLE_UPDATED event", () => {
+    test("emits SHUTTLE_UPDATED event when shuttles are added or updated", async () => {
+      const mockListener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_UPDATED, mockListener);
+
+      const mockShuttles = generateMockShuttles();
+      for (const shuttle of mockShuttles) {
+        await repository.addOrUpdateShuttle(shuttle);
+      }
+
+      expect(mockListener).toHaveBeenCalledTimes(mockShuttles.length);
+      expect(mockListener).toHaveBeenCalledWith(mockShuttles[0]);
+      expect(mockListener).toHaveBeenCalledWith(mockShuttles[mockShuttles.length - 1]);
+    });
+
+    test("does not notify listener after it has been removed", async () => {
+      const mockListener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_UPDATED, mockListener);
+
+      const mockShuttles = generateMockShuttles();
+
+      repository.off(ShuttleRepositoryEvent.SHUTTLE_UPDATED, mockListener);
+      await repository.addOrUpdateShuttle(mockShuttles[0]);
+      expect(mockListener).toHaveBeenCalledTimes(0);
+    });
+
+    test("stops notifying specific listener after removal but continues for others", async () => {
+      const mockListener1 = jest.fn();
+      const mockListener2 = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_UPDATED, mockListener1);
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_UPDATED, mockListener2);
+
+      const mockShuttles = generateMockShuttles();
+      await repository.addOrUpdateShuttle(mockShuttles[0]);
+
+      repository.off(ShuttleRepositoryEvent.SHUTTLE_UPDATED, mockListener1);
+
+      await repository.addOrUpdateShuttle(mockShuttles[mockShuttles.length - 1]);
+
+      expect(mockListener1).toHaveBeenCalledTimes(1);
+      expect(mockListener1).toHaveBeenCalledWith(mockShuttles[0]);
+      expect(mockListener1).not.toHaveBeenCalledWith(mockShuttles[mockShuttles.length - 1]);
+
+      expect(mockListener2).toHaveBeenCalledTimes(2);
+      expect(mockListener2).toHaveBeenCalledWith(mockShuttles[0]);
+      expect(mockListener2).toHaveBeenCalledWith(mockShuttles[mockShuttles.length - 1]);
+    });
+  });
+
+  describe("SHUTTLE_REMOVED event", () => {
+    test("emits SHUTTLE_REMOVED event when a shuttle is removed", async () => {
+      const mockShuttles = generateMockShuttles();
+      const shuttleToRemove = mockShuttles[0];
+      const listener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_REMOVED, listener);
+
+      await repository.addOrUpdateShuttle(shuttleToRemove);
+      await repository.removeShuttleIfExists(shuttleToRemove.id);
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      expect(listener).toHaveBeenCalledWith(shuttleToRemove);
+    });
+  });
+
+  describe("SHUTTLE_WILL_ARRIVE_AT_STOP event", () => {
+    test("emits SHUTTLE_WILL_ARRIVE_AT_STOP event before shuttle arrives at a stop", async () => {
+      const { stop1, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      const listener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, listener);
+
+      shuttle.coordinates = stop1.coordinates;
+
+      const arrivalTime = new Date("2024-01-15T10:30:00Z");
+      await repository.addOrUpdateShuttle(shuttle, arrivalTime.getTime());
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      const emittedPayload = listener.mock.calls[0][0] as any;
+      expect(emittedPayload.willArriveAt).toEqual({
+        shuttleId: shuttle.id,
+        stopId: stop1.id,
+        timestamp: arrivalTime,
+      });
+    });
+
+    test("does not emit event when shuttle is not at a stop", async () => {
+      const { sampleShuttleNotInRepository } = await setupRouteAndOrderedStops();
+
+      const listener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, listener);
+
+      const shuttle = { ...sampleShuttleNotInRepository, coordinates: { latitude: 12.5, longitude: 22.5 } }; // Not at any stop
+
+      await repository.addOrUpdateShuttle(shuttle);
+
+      expect(listener).toHaveBeenCalledTimes(0);
+    });
+
+    test("emits multiple events as shuttle visits multiple stops", async () => {
+      const { stop1, stop2, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      const listener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, listener);
+
+      shuttle.coordinates = stop1.coordinates;
+
+      const firstArrivalTime = new Date("2024-01-15T10:30:00Z");
+      await repository.addOrUpdateShuttle(shuttle, firstArrivalTime.getTime());
+
+      shuttle.coordinates = stop2.coordinates;
+      const secondArrivalTime = new Date("2024-01-15T10:35:00Z");
+      await repository.addOrUpdateShuttle(shuttle, secondArrivalTime.getTime());
+
+      expect(listener).toHaveBeenCalledTimes(2);
+
+      const firstPayload = listener.mock.calls[0][0] as any;
+      expect(firstPayload.willArriveAt).toEqual({
+        shuttleId: shuttle.id,
+        stopId: stop1.id,
+        timestamp: firstArrivalTime,
+      });
+
+      const secondPayload = listener.mock.calls[1][0] as any;
+      expect(secondPayload.willArriveAt).toEqual({
+        shuttleId: shuttle.id,
+        stopId: stop2.id,
+        timestamp: secondArrivalTime,
+      });
+    });
+  });
+
+  describe("SHUTTLE_WILL_LEAVE_STOP event", () => {
+    test("emits SHUTTLE_WILL_LEAVE_STOP event when shuttle leaves a stop", async () => {
+      const { stop1, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+      shuttle.coordinates = stop1.coordinates;
+
+      const listener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, listener);
+
+      // Simulate arrival at stop 1
+      const arrivalTime = new Date("2024-01-15T10:30:00Z");
+      await repository.addOrUpdateShuttle(shuttle, arrivalTime.getTime());
+      
+      // Test that it actually emits the event correctly and not right after the shuttle arrives
+      await repository.addOrUpdateShuttle(shuttle, arrivalTime.getTime());
+      expect(listener).not.toHaveBeenCalled();
+
+      shuttle.coordinates = { latitude: 12.5, longitude: 22.5 }; // Not at any stop
+
+      // Simulate leaving stop 1
+      const leaveTime = new Date("2024-01-15T10:32:00Z");
+      await repository.addOrUpdateShuttle(shuttle, leaveTime.getTime());
+
+      expect(listener).toHaveBeenCalledTimes(1);
+      const emittedPayload = listener.mock.calls[0][0] as any;
+      expect(emittedPayload.stopArrivalThatShuttleIsLeaving).toEqual({
+        shuttleId: shuttle.id,
+        stopId: stop1.id,
+        timestamp: arrivalTime,
+      });
+    });
+
+    test("does not emit event when shuttle was not at a stop", async () => {
+      const { sampleShuttleNotInRepository } = await setupRouteAndOrderedStops();
+
+      const listener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, listener);
+
+      // Start at coordinates not at any stop
+      const shuttle = { ...sampleShuttleNotInRepository, coordinates: { latitude: 12.5, longitude: 22.5 } };
+      await repository.addOrUpdateShuttle(shuttle);
+
+      // Move to different coordinates; still not at any stop
+      shuttle.coordinates = { latitude: 13.0, longitude: 23.0 };
+      await repository.addOrUpdateShuttle(shuttle);
+
+      expect(listener).toHaveBeenCalledTimes(0);
+    });
+
+    test("emits multiple events as shuttle leaves multiple stops", async () => {
+      const { stop1, stop2, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      const listener = jest.fn();
+      repository.on(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, listener);
+
+      // Arrive at stop1
+      shuttle.coordinates = stop1.coordinates;
+      const firstArrivalTime = new Date("2024-01-15T10:30:00Z");
+      await repository.addOrUpdateShuttle(shuttle, firstArrivalTime.getTime());
+
+      // Leave stop1 and arrive at stop2
+      shuttle.coordinates = stop2.coordinates;
+      const secondArrivalTime = new Date("2024-01-15T10:35:00Z");
+      await repository.addOrUpdateShuttle(shuttle, secondArrivalTime.getTime());
+
+      // Leave stop2
+      shuttle.coordinates = { latitude: 12.5, longitude: 22.5 }; // Not at any stop
+      const secondLeaveTime = new Date("2024-01-15T10:40:00Z");
+      await repository.addOrUpdateShuttle(shuttle, secondLeaveTime.getTime());
+
+      expect(listener).toHaveBeenCalledTimes(2);
+
+      const firstPayload = listener.mock.calls[0][0] as any;
+      expect(firstPayload.stopArrivalThatShuttleIsLeaving).toEqual({
+        shuttleId: shuttle.id,
+        stopId: stop1.id,
+        timestamp: firstArrivalTime,
+      });
+
+      const secondPayload = listener.mock.calls[1][0] as any;
+      expect(secondPayload.stopArrivalThatShuttleIsLeaving).toEqual({
+        shuttleId: shuttle.id,
+        stopId: stop2.id,
+        timestamp: secondArrivalTime,
+      });
+    });
+  });
+});

src/repositories/shuttle/eta/BaseInMemoryETARepository.ts

@@ -0,0 +1,76 @@
+import { IEta } from "../../../entities/ShuttleRepositoryEntities";
+import { ETAGetterRepository, ETARepositoryEvent, ETARepositoryEventListener, ETARepositoryEventName } from "./ETAGetterRepository";
+import EventEmitter from "node:events";
+
+export abstract class BaseInMemoryETARepository extends EventEmitter implements ETAGetterRepository {
+  protected etas: IEta[] = [];
+
+  async getEtasForShuttleId(shuttleId: string): Promise<IEta[]> {
+    return this.etas.filter(eta => eta.shuttleId === shuttleId);
+  }
+
+  async getEtasForStopId(stopId: string): Promise<IEta[]> {
+    return this.etas.filter(eta => eta.stopId === stopId);
+  }
+
+  async getEtaForShuttleAndStopId(shuttleId: string, stopId: string): Promise<IEta | null> {
+    const eta = this.etas.find(eta => eta.stopId === stopId && eta.shuttleId === shuttleId);
+    return eta ?? null;
+  }
+
+  // Protected setter for internal use
+  protected async addOrUpdateEta(eta: IEta): Promise<void> {
+    const index = this.etas.findIndex((e) => e.stopId === eta.stopId && e.shuttleId === eta.shuttleId);
+    if (index !== -1) {
+      this.etas[index] = eta;
+    } else {
+      this.etas.push(eta);
+    }
+    this.emit(ETARepositoryEvent.ETA_UPDATED, eta);
+  }
+
+  // EventEmitter overrides for type safety
+  override on<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override on(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.on(event, listener);
+  }
+
+  override once<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override once(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.once(event, listener);
+  }
+
+  override off<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override off(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.off(event, listener);
+  }
+
+  override addListener<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override addListener(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.addListener(event, listener);
+  }
+
+  override removeListener<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override removeListener(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.removeListener(event, listener);
+  }
+
+  override removeAllListeners(eventName?: string | symbol): this {
+    return super.removeAllListeners(eventName);
+  }
+}

src/repositories/shuttle/eta/BaseRedisETARepository.ts

@@ -0,0 +1,120 @@
+import { IEta } from "../../../entities/ShuttleRepositoryEntities";
+import { BaseRedisRepository } from "../../BaseRedisRepository";
+import { ETAGetterRepository, ETARepositoryEvent, ETARepositoryEventListener, ETARepositoryEventName } from "./ETAGetterRepository";
+
+export abstract class BaseRedisETARepository extends BaseRedisRepository implements ETAGetterRepository {
+  private static readonly ETA_KEY_PREFIX = 'shuttle:eta:';
+
+  // Helper methods
+  protected createEtaKey = (shuttleId: string, stopId: string) =>
+    `${BaseRedisETARepository.ETA_KEY_PREFIX}${shuttleId}:${stopId}`;
+
+  createRedisHashFromEta = (eta: IEta): Record<string, string> => ({
+    secondsRemaining: eta.secondsRemaining.toString(),
+    shuttleId: eta.shuttleId,
+    stopId: eta.stopId,
+    systemId: eta.systemId,
+    updatedTime: eta.updatedTime.toISOString(),
+  });
+
+  createEtaFromRedisData = (data: Record<string, string>): IEta => ({
+    secondsRemaining: parseFloat(data.secondsRemaining),
+    shuttleId: data.shuttleId,
+    stopId: data.stopId,
+    systemId: data.systemId,
+    updatedTime: new Date(data.updatedTime),
+  });
+
+  // Getter implementations
+  async getEtasForShuttleId(shuttleId: string): Promise<IEta[]> {
+    const keys = await this.redisClient.keys(`${BaseRedisETARepository.ETA_KEY_PREFIX}${shuttleId}:*`);
+    const etas: IEta[] = [];
+
+    for (const key of keys) {
+      const data = await this.redisClient.hGetAll(key);
+      if (Object.keys(data).length > 0) {
+        etas.push(this.createEtaFromRedisData(data));
+      }
+    }
+
+    return etas;
+  }
+
+  async getEtasForStopId(stopId: string): Promise<IEta[]> {
+    const keys = await this.redisClient.keys(`${BaseRedisETARepository.ETA_KEY_PREFIX}*`);
+    const etas: IEta[] = [];
+
+    for (const key of keys) {
+      const data = await this.redisClient.hGetAll(key);
+      if (Object.keys(data).length > 0 && data.stopId === stopId) {
+        etas.push(this.createEtaFromRedisData(data));
+      }
+    }
+
+    return etas;
+  }
+
+  async getEtaForShuttleAndStopId(shuttleId: string, stopId: string): Promise<IEta | null> {
+    const key = this.createEtaKey(shuttleId, stopId);
+    const data = await this.redisClient.hGetAll(key);
+
+    if (Object.keys(data).length === 0) {
+      return null;
+    }
+
+    return this.createEtaFromRedisData(data);
+  }
+
+  // Protected setter for internal use
+  protected async addOrUpdateEta(eta: IEta): Promise<void> {
+    const key = this.createEtaKey(eta.shuttleId, eta.stopId);
+    const hash = this.createRedisHashFromEta(eta);
+    await this.redisClient.hSet(key, hash);
+    this.emit(ETARepositoryEvent.ETA_UPDATED, eta);
+  }
+
+  // EventEmitter override methods for type safety
+  override on<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override on(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.on(event, listener);
+  }
+
+  override once<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override once(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.once(event, listener);
+  }
+
+  override off<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override off(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.off(event, listener);
+  }
+
+  override addListener<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override addListener(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.addListener(event, listener);
+  }
+
+  override removeListener<T extends ETARepositoryEventName>(
+    event: T,
+    listener: ETARepositoryEventListener<T>,
+  ): this;
+  override removeListener(event: string | symbol, listener: (...args: any[]) => void): this {
+    return super.removeListener(event, listener);
+  }
+
+  override removeAllListeners(eventName?: string | symbol): this {
+    return super.removeAllListeners(eventName);
+  }
+}

src/repositories/shuttle/eta/ETAGetterRepository.ts

@@ -0,0 +1,37 @@
+import { EventEmitter } from "stream";
+import { IEta } from "../../../entities/ShuttleRepositoryEntities";
+
+// TODO: Remove these events in ShuttleGetterRepository
+
+export const ETARepositoryEvent = {
+  ETA_UPDATED: "etaUpdated",
+  ETA_REMOVED: "etaRemoved",
+  ETA_DATA_CLEARED: "etaDataCleared",
+} as const;
+
+export type ETARepositoryEventName = typeof ETARepositoryEvent[keyof typeof ETARepositoryEvent];
+
+export type EtaRemovedEventPayload = IEta;
+export type EtaDataClearedEventPayload = IEta[];
+
+export interface ETARepositoryEventPayloads {
+  [ETARepositoryEvent.ETA_UPDATED]: IEta;
+  [ETARepositoryEvent.ETA_REMOVED]: EtaRemovedEventPayload;
+  [ETARepositoryEvent.ETA_DATA_CLEARED]: EtaDataClearedEventPayload;
+}
+
+export type ETARepositoryEventListener<T extends ETARepositoryEventName> = (
+  payload: ETARepositoryEventPayloads[T],
+) => void;
+
+export interface ETAGetterRepository extends EventEmitter {
+  on<T extends ETARepositoryEventName>(event: T, listener: ETARepositoryEventListener<T>): this;
+  once<T extends ETARepositoryEventName>(event: T, listener: ETARepositoryEventListener<T>): this;
+  off<T extends ETARepositoryEventName>(event: T, listener: ETARepositoryEventListener<T>): this;
+  addListener<T extends ETARepositoryEventName>(event: T, listener: ETARepositoryEventListener<T>): this;
+  removeListener<T extends ETARepositoryEventName>(event: T, listener: ETARepositoryEventListener<T>): this;
+
+  getEtasForShuttleId(shuttleId: string): Promise<IEta[]>;
+  getEtasForStopId(stopId: string): Promise<IEta[]>;
+  getEtaForShuttleAndStopId(shuttleId: string, stopId: string): Promise<IEta | null>;
+}

src/repositories/shuttle/eta/ExternalSourceETARepository.ts

@@ -0,0 +1,11 @@
+import { IEta } from "../../../entities/ShuttleRepositoryEntities";
+import { ETAGetterRepository } from "./ETAGetterRepository";
+
+export interface ExternalSourceETARepository extends ETAGetterRepository {
+  /**
+   * Add or update an ETA from an external source (e.g., API or test data).
+   */
+  addOrUpdateEtaFromExternalSource(eta: IEta): Promise<void>;
+
+  removeEtaIfExists(shuttleId: string, stopId: string): Promise<IEta | null>;
+}

src/repositories/shuttle/eta/InMemoryExternalSourceETARepository.ts

@@ -0,0 +1,22 @@
+import { IEta } from "../../../entities/ShuttleRepositoryEntities";
+import { ExternalSourceETARepository } from "./ExternalSourceETARepository";
+import { BaseInMemoryETARepository } from "./BaseInMemoryETARepository";
+import { ETARepositoryEvent } from "./ETAGetterRepository";
+
+export class InMemoryExternalSourceETARepository extends BaseInMemoryETARepository implements ExternalSourceETARepository {
+  async addOrUpdateEtaFromExternalSource(eta: IEta): Promise<void> {
+    await this.addOrUpdateEta(eta);
+  }
+
+  async removeEtaIfExists(shuttleId: string, stopId: string): Promise<IEta | null> {
+    const index = this.etas.findIndex((e) => e.stopId === stopId && e.shuttleId === shuttleId);
+    if (index === -1) {
+      return null;
+    }
+
+    const removedEta = this.etas[index];
+    this.etas.splice(index, 1);
+    this.emit(ETARepositoryEvent.ETA_REMOVED, removedEta);
+    return removedEta;
+  }
+} 

src/repositories/shuttle/eta/InMemorySelfUpdatingETARepository.ts

@@ -0,0 +1,239 @@
+import { SelfUpdatingETARepository } from "./SelfUpdatingETARepository";
+import { ShuttleGetterRepository, ShuttleRepositoryEvent, ShuttleStopArrival, ShuttleTravelTimeDataIdentifier, ShuttleTravelTimeDateFilterArguments, ShuttleWillArriveAtStopPayload, ShuttleWillLeaveStopPayload } from "../ShuttleGetterRepository";
+import { BaseInMemoryETARepository } from "./BaseInMemoryETARepository";
+import { IOrderedStop, IShuttle } from "../../../entities/ShuttleRepositoryEntities";
+import { ETARepositoryEvent } from "./ETAGetterRepository";
+
+export class InMemorySelfUpdatingETARepository extends BaseInMemoryETARepository implements SelfUpdatingETARepository {
+  private referenceTime: Date | null = null;
+  private travelTimeData: Map<string, Array<{ timestamp: number; seconds: number }>> = new Map();
+
+  private isListening = false;
+
+  constructor(
+    readonly shuttleRepository: ShuttleGetterRepository
+  ) {
+    super();
+
+    this.setReferenceTime = this.setReferenceTime.bind(this);
+    this.getAverageTravelTimeSeconds = this.getAverageTravelTimeSeconds.bind(this);
+    this.startListeningForUpdates = this.startListeningForUpdates.bind(this);
+    this.handleShuttleWillArriveAtStop = this.handleShuttleWillArriveAtStop.bind(this);
+    this.handleShuttleUpdate = this.handleShuttleUpdate.bind(this);
+    this.updateCascadingEta = this.updateCascadingEta.bind(this);
+    this.getAverageTravelTimeSecondsWithFallbacks = this.getAverageTravelTimeSecondsWithFallbacks.bind(this);
+    this.removeEtaIfExists = this.removeEtaIfExists.bind(this);
+    this.handleShuttleWillLeaveStop = this.handleShuttleWillLeaveStop.bind(this);
+  }
+
+  setReferenceTime(referenceTime: Date): void {
+    this.referenceTime = referenceTime;
+  }
+
+  async getAverageTravelTimeSeconds(
+    { routeId, fromStopId, toStopId }: ShuttleTravelTimeDataIdentifier,
+    { from, to }: ShuttleTravelTimeDateFilterArguments
+  ): Promise<number | undefined> {
+    const key = `${routeId}:${fromStopId}:${toStopId}`;
+    const dataPoints = this.travelTimeData.get(key);
+
+    if (!dataPoints || dataPoints.length === 0) {
+      return undefined;
+    }
+
+    const fromTimestamp = from.getTime();
+    const toTimestamp = to.getTime();
+
+    const filteredPoints = dataPoints.filter(
+      (point) => point.timestamp >= fromTimestamp && point.timestamp <= toTimestamp
+    );
+
+    if (filteredPoints.length === 0) {
+      return undefined;
+    }
+
+    const sum = filteredPoints.reduce((acc, point) => acc + point.seconds, 0);
+    return sum / filteredPoints.length;
+  }
+
+  startListeningForUpdates(): void {
+    if (this.isListening) {
+      console.warn("Already listening to updates; did you call startListeningForUpdates twice?");
+      return;
+    }
+    this.shuttleRepository.addListener(ShuttleRepositoryEvent.SHUTTLE_UPDATED, this.handleShuttleUpdate);
+    this.shuttleRepository.addListener(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, this.handleShuttleWillArriveAtStop);
+    this.shuttleRepository.addListener(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, this.handleShuttleWillLeaveStop);
+    this.isListening = true;
+  }
+  stopListeningForUpdates(): void {
+    if (!this.isListening) {
+      return;
+    }
+    this.shuttleRepository.removeListener(ShuttleRepositoryEvent.SHUTTLE_UPDATED, this.handleShuttleUpdate);
+    this.shuttleRepository.removeListener(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, this.handleShuttleWillArriveAtStop);
+    this.shuttleRepository.removeListener(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, this.handleShuttleWillLeaveStop);
+    this.isListening = false;
+  }
+
+  private async getAverageTravelTimeSecondsWithFallbacks(
+    identifier: ShuttleTravelTimeDataIdentifier,
+    dateFilters: ShuttleTravelTimeDateFilterArguments[]
+  ): Promise<number | undefined> {
+    for (const dateFilter of dateFilters) {
+      const result = await this.getAverageTravelTimeSeconds(identifier, dateFilter);
+      if (result !== undefined) {
+        return result;
+      }
+    }
+    return undefined;
+  }
+
+  private async handleShuttleUpdate(shuttle: IShuttle): Promise<void> {
+    const isAtStop = await this.shuttleRepository.checkIfShuttleIsAtStop(shuttle.id);
+    const lastStop = await this.shuttleRepository.getShuttleLastStopArrival(shuttle.id);
+    if (!lastStop) return;
+
+    if (isAtStop) {
+      // Update the ETA *to* the stop the shuttle is currently at,
+      // before starting from the current stop as normal.
+      // Account for cases where the shuttle arrived way earlier than
+      // expected based on the calculated ETA.
+
+      await this.addOrUpdateEta({
+        secondsRemaining: 1,
+        shuttleId: shuttle.id,
+        stopId: lastStop.stopId,
+        systemId: shuttle.systemId,
+        updatedTime: new Date(),
+      });
+    }
+
+    const lastOrderedStop = await this.shuttleRepository.getOrderedStopByRouteAndStopId(shuttle.routeId, lastStop.stopId);
+
+    await this.updateCascadingEta({
+      shuttle,
+      currentStop: lastOrderedStop,
+      originalStopArrival: lastStop,
+    });
+  }
+
+  private async updateCascadingEta({
+    shuttle,
+    currentStop,
+    originalStopArrival,
+    runningTravelTimeSeconds = 0
+  }: {
+    shuttle: IShuttle;
+    currentStop: IOrderedStop | null;
+    originalStopArrival: ShuttleStopArrival;
+    runningTravelTimeSeconds?: number;
+  }) {
+    if (!currentStop) return;
+    const nextStop = currentStop?.nextStop;
+    if (!nextStop) return;
+    // In case the system we have loops around
+    if (nextStop.stopId === originalStopArrival.stopId) return;
+
+    let referenceCurrentTime = new Date();
+    if (this.referenceTime != null) {
+      referenceCurrentTime = this.referenceTime;
+    }
+
+    const oneWeekAgo = new Date(referenceCurrentTime.getTime() - (60 * 60 * 24 * 7 * 1000));
+    const oneDayAgo = new Date(referenceCurrentTime.getTime() - (60 * 60 * 24 * 1000));
+    const twoHoursAgo = new Date(referenceCurrentTime.getTime() - (60 * 60 * 1000));
+
+    const twoHoursInMs = 120 * 60 * 1000;
+    const travelTimeSeconds = await this.getAverageTravelTimeSecondsWithFallbacks({
+      routeId: shuttle.routeId,
+      fromStopId: currentStop.stopId,
+      toStopId: nextStop.stopId,
+    }, [
+      {
+        from: twoHoursAgo,
+        to: new Date(),
+      },
+      {
+        from: new Date(oneDayAgo.getTime() - (twoHoursInMs)),
+        to: oneDayAgo,
+      },
+      {
+        from: new Date(oneWeekAgo.getTime() - (twoHoursInMs)),
+        to: oneWeekAgo,
+      },
+    ]);
+
+    if (travelTimeSeconds == undefined) return;
+
+    const elapsedTimeMs = referenceCurrentTime.getTime() - originalStopArrival.timestamp.getTime();
+    const predictedTimeSeconds = travelTimeSeconds - (elapsedTimeMs / 1000) + runningTravelTimeSeconds;
+
+    await this.addOrUpdateEta({
+      secondsRemaining: predictedTimeSeconds,
+      shuttleId: shuttle.id,
+      stopId: nextStop.stopId,
+      systemId: nextStop.systemId,
+      updatedTime: new Date(),
+    });
+
+    const nextStopWithNextNextStop = await this.shuttleRepository.getOrderedStopByRouteAndStopId(shuttle.routeId, nextStop.stopId);
+    await this.updateCascadingEta(
+      {
+        shuttle,
+        currentStop: nextStopWithNextNextStop,
+        originalStopArrival,
+        runningTravelTimeSeconds: runningTravelTimeSeconds + travelTimeSeconds,
+      },
+    )
+  }
+
+  private async handleShuttleWillArriveAtStop({
+    lastStopArrival: lastArrival,
+    willArriveAt: currentArrival,
+  }: ShuttleWillArriveAtStopPayload): Promise<void> {
+    if (lastArrival) {
+      // disallow cases where this gets triggered multiple times
+      if (lastArrival.stopId === currentArrival.stopId) return;
+
+      const shuttle = await this.shuttleRepository.getShuttleById(lastArrival.shuttleId);
+      if (!shuttle) return;
+
+      const routeId = shuttle.routeId;
+      const fromStopId = lastArrival.stopId;
+      const toStopId = currentArrival.stopId;
+
+      const travelTimeSeconds = (currentArrival.timestamp.getTime() - lastArrival.timestamp.getTime()) / 1000;
+      await this.addTravelTimeDataPoint({ routeId, fromStopId, toStopId }, travelTimeSeconds, currentArrival.timestamp.getTime());
+    }
+  }
+
+  private async handleShuttleWillLeaveStop({
+    stopArrivalThatShuttleIsLeaving,
+  }: ShuttleWillLeaveStopPayload) {
+    await this.removeEtaIfExists(stopArrivalThatShuttleIsLeaving.shuttleId, stopArrivalThatShuttleIsLeaving.stopId);
+  }
+
+  private async addTravelTimeDataPoint(
+    { routeId, fromStopId, toStopId }: ShuttleTravelTimeDataIdentifier,
+    travelTimeSeconds: number,
+    timestamp = Date.now(),
+  ): Promise<void> {
+    const key = `${routeId}:${fromStopId}:${toStopId}`;
+    const dataPoints = this.travelTimeData.get(key) || [];
+    dataPoints.push({ timestamp, seconds: travelTimeSeconds });
+    this.travelTimeData.set(key, dataPoints);
+  }
+
+  private async removeEtaIfExists(shuttleId: string, stopId: string) {
+    const index = this.etas.findIndex((e) => e.stopId === stopId && e.shuttleId === shuttleId);
+    if (index === -1) {
+      return null;
+    }
+
+    const removedEta = this.etas[index];
+    this.etas.splice(index, 1);
+    this.emit(ETARepositoryEvent.ETA_REMOVED, removedEta);
+    return removedEta;
+  }
+}

src/repositories/shuttle/eta/RedisExternalSourceETARepository.ts

@@ -0,0 +1,22 @@
+import { IEta } from "../../../entities/ShuttleRepositoryEntities";
+import { BaseRedisETARepository } from "./BaseRedisETARepository";
+import { ExternalSourceETARepository } from "./ExternalSourceETARepository";
+import { ETARepositoryEvent } from "./ETAGetterRepository";
+
+export class RedisExternalSourceETARepository extends BaseRedisETARepository implements ExternalSourceETARepository {
+  async addOrUpdateEtaFromExternalSource(eta: IEta): Promise<void> {
+    await this.addOrUpdateEta(eta);
+  }
+
+  async removeEtaIfExists(shuttleId: string, stopId: string): Promise<IEta | null> {
+    const existingEta = await this.getEtaForShuttleAndStopId(shuttleId, stopId);
+    if (existingEta === null) {
+      return null;
+    }
+
+    const key = this.createEtaKey(shuttleId, stopId);
+    await this.redisClient.del(key);
+    this.emit(ETARepositoryEvent.ETA_REMOVED, existingEta);
+    return existingEta;
+  }
+}

src/repositories/shuttle/eta/RedisSelfUpdatingETARepository.ts

@@ -0,0 +1,315 @@
+import { SelfUpdatingETARepository } from "./SelfUpdatingETARepository";
+import { BaseRedisETARepository } from "./BaseRedisETARepository";
+import { RedisClientType } from "redis";
+import { ShuttleGetterRepository, ShuttleRepositoryEvent, ShuttleStopArrival, ShuttleTravelTimeDataIdentifier, ShuttleTravelTimeDateFilterArguments, ShuttleWillArriveAtStopPayload, ShuttleWillLeaveStopPayload } from "../ShuttleGetterRepository";
+import { IEta, IOrderedStop, IShuttle } from "../../../entities/ShuttleRepositoryEntities";
+import { ETARepositoryEvent } from "./ETAGetterRepository";
+import createRedisClientForRepository from "../../../helpers/createRedisClientForRepository";
+
+export class RedisSelfUpdatingETARepository extends BaseRedisETARepository implements SelfUpdatingETARepository {
+  private isListening = false;
+
+  constructor(
+    readonly shuttleRepository: ShuttleGetterRepository,
+    redisClient: RedisClientType = createRedisClientForRepository(),
+    private referenceTime: Date | null = null,
+  ) {
+    super(redisClient);
+
+    this.setReferenceTime = this.setReferenceTime.bind(this);
+    this.getAverageTravelTimeSeconds = this.getAverageTravelTimeSeconds.bind(this);
+    this.startListeningForUpdates = this.startListeningForUpdates.bind(this);
+    this.handleShuttleWillArriveAtStop = this.handleShuttleWillArriveAtStop.bind(this);
+    this.handleShuttleUpdate = this.handleShuttleUpdate.bind(this);
+    this.updateCascadingEta = this.updateCascadingEta.bind(this);
+    this.getAverageTravelTimeSecondsWithFallbacks = this.getAverageTravelTimeSecondsWithFallbacks.bind(this);
+    this.removeEtaIfExists = this.removeEtaIfExists.bind(this);
+    this.handleShuttleWillLeaveStop = this.handleShuttleWillLeaveStop.bind(this);
+  }
+
+  private createHistoricalEtaTimeSeriesKey = (routeId: string, fromStopId: string, toStopId: string) => {
+    return `shuttle:eta:historical:${routeId}:${fromStopId}:${toStopId}`;
+  }
+
+  setReferenceTime(referenceTime: Date) {
+    this.referenceTime = referenceTime;
+  }
+
+  public async getAverageTravelTimeSeconds(
+    { routeId, fromStopId, toStopId }: ShuttleTravelTimeDataIdentifier,
+    { from, to }: ShuttleTravelTimeDateFilterArguments
+  ): Promise<number | undefined> {
+    const timeSeriesKey = this.createHistoricalEtaTimeSeriesKey(routeId, fromStopId, toStopId);
+    const fromTimestamp = from.getTime();
+    const toTimestamp = to.getTime();
+    const intervalMs = toTimestamp - fromTimestamp + 1;
+
+    try {
+      const aggregationResult = await this.redisClient.sendCommand([
+        'TS.RANGE',
+        timeSeriesKey,
+        fromTimestamp.toString(),
+        toTimestamp.toString(),
+        'AGGREGATION',
+        'AVG',
+        intervalMs.toString()
+      ]) as [string, string][];
+
+      if (aggregationResult && aggregationResult.length > 0) {
+        const [, averageValue] = aggregationResult[0];
+        return parseFloat(averageValue);
+      }
+
+      return;
+    } catch (error) {
+      console.warn(`Failed to get average travel time for ${timeSeriesKey}: ${error instanceof Error ? error.message : String(error)}`);
+      return;
+    }
+  }
+
+  startListeningForUpdates(): void {
+    if (this.isListening) {
+      console.warn("Already listening to updates; did you call startListeningForUpdates twice?");
+      return;
+    }
+    this.shuttleRepository.addListener(ShuttleRepositoryEvent.SHUTTLE_UPDATED, this.handleShuttleUpdate);
+    this.shuttleRepository.addListener(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, this.handleShuttleWillArriveAtStop);
+    this.shuttleRepository.addListener(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, this.handleShuttleWillLeaveStop);
+    this.isListening = true;
+  }
+
+  stopListeningForUpdates(): void {
+    if (!this.isListening) {
+      return;
+    }
+    this.shuttleRepository.removeListener(ShuttleRepositoryEvent.SHUTTLE_UPDATED, this.handleShuttleUpdate);
+    this.shuttleRepository.removeListener(ShuttleRepositoryEvent.SHUTTLE_WILL_ARRIVE_AT_STOP, this.handleShuttleWillArriveAtStop);
+    this.shuttleRepository.removeListener(ShuttleRepositoryEvent.SHUTTLE_WILL_LEAVE_STOP, this.handleShuttleWillLeaveStop);
+    this.isListening = false;
+  }
+
+  private async getAverageTravelTimeSecondsWithFallbacks(
+    identifier: ShuttleTravelTimeDataIdentifier,
+    dateFilters: ShuttleTravelTimeDateFilterArguments[]
+  ): Promise<number | undefined> {
+    for (const dateFilter of dateFilters) {
+      const result = await this.getAverageTravelTimeSeconds(identifier, dateFilter);
+      if (result !== undefined) {
+        return result;
+      }
+    }
+    return undefined;
+  }
+
+  private async handleShuttleUpdate(shuttle: IShuttle) {
+    const isAtStop = await this.shuttleRepository.checkIfShuttleIsAtStop(shuttle.id);
+    const lastStop = await this.shuttleRepository.getShuttleLastStopArrival(shuttle.id);
+    if (!lastStop) return;
+
+    if (isAtStop) {
+      // Update the ETA *to* the stop the shuttle is currently at,
+      // before starting from the current stop as normal.
+      // Account for cases where the shuttle arrived way earlier than
+      // expected based on the calculated ETA.
+
+      await this.addOrUpdateEta({
+        secondsRemaining: 1,
+        shuttleId: shuttle.id,
+        stopId: lastStop.stopId,
+        systemId: shuttle.systemId,
+        updatedTime: new Date(),
+      });
+    }
+
+    const lastOrderedStop = await this.shuttleRepository.getOrderedStopByRouteAndStopId(shuttle.routeId, lastStop.stopId);
+
+    await this.updateCascadingEta({
+      shuttle,
+      currentStop: lastOrderedStop,
+      originalStopArrival: lastStop,
+    });
+  }
+
+  private async updateCascadingEta({
+    shuttle,
+    currentStop,
+    originalStopArrival,
+    runningTravelTimeSeconds = 0
+  }: {
+    shuttle: IShuttle;
+    currentStop: IOrderedStop | null;
+    originalStopArrival: ShuttleStopArrival;
+    runningTravelTimeSeconds?: number;
+  }) {
+    if (!currentStop) return;
+    const nextStop = currentStop?.nextStop;
+    if (!nextStop) return;
+    // In case the system we have loops around
+    if (nextStop.stopId === originalStopArrival.stopId) return;
+
+    let referenceCurrentTime = new Date();
+    if (this.referenceTime != null) {
+      referenceCurrentTime = this.referenceTime;
+    }
+
+    const oneWeekAgo = new Date(referenceCurrentTime.getTime() - (60 * 60 * 24 * 7 * 1000));
+    const oneDayAgo = new Date(referenceCurrentTime.getTime() - (60 * 60 * 24 * 1000));
+    const twoHoursAgo = new Date(referenceCurrentTime.getTime() - (120 * 60 * 1000));
+
+    const twoHoursInMs = 120 * 60 * 1000;
+    const travelTimeSeconds = await this.getAverageTravelTimeSecondsWithFallbacks({
+      routeId: shuttle.routeId,
+      fromStopId: currentStop.stopId,
+      toStopId: nextStop.stopId,
+    }, [
+      {
+        from: twoHoursAgo,
+        to: new Date(),
+      },
+      {
+        from: new Date(oneDayAgo.getTime() - (twoHoursInMs)),
+        to: oneDayAgo,
+      },
+      {
+        from: new Date(oneWeekAgo.getTime() - (twoHoursInMs)),
+        to: oneWeekAgo,
+      },
+    ]);
+
+    if (travelTimeSeconds == undefined) return;
+
+    const elapsedTimeMs = referenceCurrentTime.getTime() - originalStopArrival.timestamp.getTime();
+    const predictedTimeSeconds = travelTimeSeconds - (elapsedTimeMs / 1000) + runningTravelTimeSeconds;
+
+    await this.addOrUpdateEta({
+      secondsRemaining: predictedTimeSeconds,
+      shuttleId: shuttle.id,
+      stopId: nextStop.stopId,
+      systemId: nextStop.systemId,
+      updatedTime: new Date(),
+    });
+
+    const nextStopWithNextNextStop = await this.shuttleRepository.getOrderedStopByRouteAndStopId(shuttle.routeId, nextStop.stopId);
+    await this.updateCascadingEta(
+      {
+        shuttle,
+        currentStop: nextStopWithNextNextStop,
+        originalStopArrival,
+        runningTravelTimeSeconds: runningTravelTimeSeconds + travelTimeSeconds,
+      },
+    )
+  }
+
+
+  private async handleShuttleWillArriveAtStop({
+    lastStopArrival: lastArrival,
+    willArriveAt: currentArrival,
+  }: ShuttleWillArriveAtStopPayload) {
+    // only update time traveled if last arrival exists
+    if (lastArrival) {
+      // disallow cases where this gets triggered multiple times
+      if (lastArrival.stopId === currentArrival.stopId) return;
+
+      const shuttle = await this.shuttleRepository.getShuttleById(lastArrival.shuttleId);
+      if (!shuttle) return;
+
+      const routeId = shuttle.routeId;
+      const fromStopId = lastArrival.stopId;
+      const toStopId = currentArrival.stopId;
+
+      const travelTimeSeconds = (currentArrival.timestamp.getTime() - lastArrival.timestamp.getTime()) / 1000;
+      await this.addTravelTimeDataPoint({ routeId, fromStopId, toStopId, }, travelTimeSeconds, currentArrival.timestamp.getTime());
+    }
+  }
+
+  private async handleShuttleWillLeaveStop({
+    stopArrivalThatShuttleIsLeaving,
+  }: ShuttleWillLeaveStopPayload) {
+    await this.removeEtaIfExists(stopArrivalThatShuttleIsLeaving.shuttleId, stopArrivalThatShuttleIsLeaving.stopId);
+  }
+
+
+  public async addTravelTimeDataPoint(
+    { routeId, fromStopId, toStopId }: ShuttleTravelTimeDataIdentifier,
+    travelTimeSeconds: number,
+    timestamp = Date.now(),
+  ): Promise<void> {
+    const historicalEtaTimeSeriesKey = this.createHistoricalEtaTimeSeriesKey(routeId, fromStopId, toStopId);
+
+    try {
+      await this.redisClient.sendCommand([
+        'TS.ADD',
+        historicalEtaTimeSeriesKey,
+        timestamp.toString(),
+        travelTimeSeconds.toString(),
+        'LABELS',
+        'routeId',
+        routeId,
+        'fromStopId',
+        fromStopId,
+        'toStopId',
+        toStopId
+      ]);
+    } catch (error) {
+      await this.createHistoricalEtaTimeSeriesAndAddDataPoint(
+        historicalEtaTimeSeriesKey,
+        timestamp,
+        travelTimeSeconds,
+        routeId,
+        fromStopId,
+        toStopId
+      );
+    }
+  }
+
+
+  private async createHistoricalEtaTimeSeriesAndAddDataPoint(
+    timeSeriesKey: string,
+    timestamp: number,
+    travelTimeSeconds: number,
+    routeId: string,
+    fromStopId: string,
+    toStopId: string,
+  ): Promise<void> {
+    try {
+      await this.redisClient.sendCommand([
+        'TS.CREATE',
+        timeSeriesKey,
+        'RETENTION',
+        '2678400000', // one month in milliseconds
+        'LABELS',
+        'routeId',
+        routeId,
+        'fromStopId',
+        fromStopId,
+        'toStopId',
+        toStopId
+      ]);
+      await this.redisClient.sendCommand([
+        'TS.ADD',
+        timeSeriesKey,
+        timestamp.toString(),
+        travelTimeSeconds.toString()
+      ]);
+    } catch (createError) {
+      await this.redisClient.sendCommand([
+        'TS.ADD',
+        timeSeriesKey,
+        timestamp.toString(),
+        travelTimeSeconds.toString()
+      ]);
+    }
+  }
+
+  private async removeEtaIfExists(shuttleId: string, stopId: string): Promise<IEta | null> {
+    const existingEta = await this.getEtaForShuttleAndStopId(shuttleId, stopId);
+    if (existingEta === null) {
+      return null;
+    }
+
+    const key = this.createEtaKey(shuttleId, stopId);
+    await this.redisClient.del(key);
+    this.emit(ETARepositoryEvent.ETA_REMOVED, existingEta);
+    return existingEta;
+  }
+}

src/repositories/shuttle/eta/SelfUpdatingETARepository.ts

@@ -0,0 +1,28 @@
+import { ShuttleTravelTimeDataIdentifier, ShuttleTravelTimeDateFilterArguments } from "../ShuttleGetterRepository";
+import { ETAGetterRepository } from "./ETAGetterRepository";
+
+export interface SelfUpdatingETARepository extends ETAGetterRepository {
+  /**
+   * Attach a event listener to the shuttle repository, listening to
+   * shuttle updates
+   */
+  startListeningForUpdates(): void;
+
+  /**
+   * Get average travel time between two stops based on historical data.
+   * Returns undefined if no data exists for the specified time range.
+   * @param identifier - The route and stop IDs to query
+   * @param dateFilter - The date range to filter data
+   */
+  getAverageTravelTimeSeconds(
+    identifier: ShuttleTravelTimeDataIdentifier,
+    dateFilter: ShuttleTravelTimeDateFilterArguments
+  ): Promise<number | undefined>;
+
+  /**
+   * Set the "current time" as the class knows it, in order to calculate
+   * ETAs based on past data.
+   * @param referenceTime
+   */
+  setReferenceTime(referenceTime: Date): void;
+}

src/repositories/shuttle/eta/__tests__/ExternalSourceETARepositorySharedTests.test.ts

@@ -0,0 +1,171 @@
+import { afterEach, beforeEach, describe, expect, test } from "@jest/globals";
+import { createClient, RedisClientType } from "redis";
+import { RepositoryHolder } from "../../../../../testHelpers/RepositoryHolder";
+import { ExternalSourceETARepository } from "../ExternalSourceETARepository";
+import { RedisExternalSourceETARepository } from "../RedisExternalSourceETARepository";
+import { InMemoryExternalSourceETARepository } from "../InMemoryExternalSourceETARepository";
+import { generateMockEtas } from "../../../../../testHelpers/mockDataGenerators";
+
+class RedisExternalSourceETARepositoryHolder implements RepositoryHolder<ExternalSourceETARepository> {
+  repo: RedisExternalSourceETARepository | undefined;
+  redisClient: RedisClientType | undefined;
+
+  name = "RedisExternalSourceETARepository"
+  factory = async () => {
+    this.redisClient = createClient({
+      url: process.env.REDIS_URL,
+    });
+    await this.redisClient.connect();
+    this.repo = new RedisExternalSourceETARepository(this.redisClient);
+    return this.repo;
+  }
+  teardown = async () => {
+    if (this.redisClient) {
+      await this.redisClient.flushAll();
+      await this.redisClient.disconnect();
+    }
+  }
+}
+
+class InMemoryExternalSourceETARepositoryHolder implements RepositoryHolder<ExternalSourceETARepository> {
+  repo: InMemoryExternalSourceETARepository | undefined;
+
+  name = "InMemoryExternalSourceETARepository"
+  factory = async () => {
+    this.repo = new InMemoryExternalSourceETARepository();
+    return this.repo;
+  }
+  teardown = async () => {
+    // No teardown needed for in-memory
+  }
+}
+
+const repositoryImplementations = [
+  new RedisExternalSourceETARepositoryHolder(),
+  new InMemoryExternalSourceETARepositoryHolder()
+];
+
+describe.each(repositoryImplementations)('$name', (holder) => {
+  let repository: ExternalSourceETARepository;
+  
+  beforeEach(async () => {
+    repository = await holder.factory();
+  });
+
+  afterEach(async () => {
+    await holder.teardown();
+  });
+
+  describe("addOrUpdateEtaFromExternalSource", () => {
+    test("adds a new ETA if nonexistent", async () => {
+      const mockEtas = generateMockEtas();
+      const newEta = mockEtas[0];
+
+      await repository.addOrUpdateEtaFromExternalSource(newEta);
+
+      const result = await repository.getEtasForShuttleId(newEta.shuttleId);
+      expect(result).toEqual([newEta]);
+    });
+
+    test("updates an existing ETA if it exists", async () => {
+      const mockEtas = generateMockEtas();
+      const existingEta = mockEtas[0];
+      const updatedEta = structuredClone(existingEta);
+      updatedEta.secondsRemaining = existingEta.secondsRemaining + 60;
+
+      await repository.addOrUpdateEtaFromExternalSource(existingEta);
+      await repository.addOrUpdateEtaFromExternalSource(updatedEta);
+
+      const result = await repository.getEtasForShuttleId(existingEta.shuttleId);
+      expect(result).toEqual([updatedEta]);
+    });
+  });
+
+  describe("getEtasForShuttleId", () => {
+    test("gets ETAs for a specific shuttle ID", async () => {
+      const mockEtas = generateMockEtas();
+      for (const eta of mockEtas) {
+        await repository.addOrUpdateEtaFromExternalSource(eta);
+      }
+
+      const result = await repository.getEtasForShuttleId("sh1");
+      const expected = mockEtas.filter((eta) => eta.shuttleId === "sh1");
+      expect(result).toHaveLength(expected.length);
+      expect(result).toEqual(expect.arrayContaining(expected));
+    });
+
+    test("returns an empty list if there are no ETAs for the shuttle ID", async () => {
+      const result = await repository.getEtasForShuttleId("nonexistent-shuttle");
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("getEtasForStopId", () => {
+    test("gets ETAs for a specific stop ID", async () => {
+      const mockEtas = generateMockEtas();
+      for (const eta of mockEtas) {
+        await repository.addOrUpdateEtaFromExternalSource(eta);
+      }
+
+      const result = await repository.getEtasForStopId("st1");
+      expect(result).toEqual(mockEtas.filter((eta) => eta.stopId === "st1"));
+    });
+
+    test("returns an empty list if there are no ETAs for the stop ID", async () => {
+      const result = await repository.getEtasForStopId("nonexistent-stop");
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("getEtaForShuttleAndStopId", () => {
+    test("gets a single ETA for a specific shuttle and stop ID", async () => {
+      const mockEtas = generateMockEtas();
+      const mockEta = mockEtas[0];
+      await repository.addOrUpdateEtaFromExternalSource(mockEta);
+
+      const result = await repository.getEtaForShuttleAndStopId("sh1", "st1");
+      expect(result).toEqual(mockEta);
+    });
+
+    test("returns null if no ETA matches the shuttle and stop ID", async () => {
+      const result = await repository.getEtaForShuttleAndStopId("nonexistent-shuttle", "nonexistent-stop");
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("removeEtaIfExists", () => {
+    test("removes eta given shuttle ID and stop ID", async () => {
+      let mockEtas = generateMockEtas();
+      const stopId = mockEtas[0].stopId;
+      mockEtas = mockEtas.filter((eta) => eta.stopId === stopId);
+
+      await Promise.all(mockEtas.map(async (eta) => {
+        eta.stopId = stopId;
+        await repository.addOrUpdateEtaFromExternalSource(eta);
+      }));
+
+      const etaToRemove = mockEtas[0];
+      await repository.removeEtaIfExists(etaToRemove.shuttleId, etaToRemove.stopId);
+
+      const remainingEtas = await repository.getEtasForStopId(stopId);
+      expect(remainingEtas).toHaveLength(mockEtas.length - 1);
+    });
+
+    test("does nothing if eta doesn't exist", async () => {
+      let mockEtas = generateMockEtas();
+      const stopId = mockEtas[0].stopId;
+      mockEtas = mockEtas.filter((eta) => eta.stopId === stopId);
+
+      await Promise.all(mockEtas.map(async (eta) => {
+        eta.stopId = stopId;
+        await repository.addOrUpdateEtaFromExternalSource(eta);
+      }));
+
+      await repository.removeEtaIfExists("nonexistent-shuttle-id", "nonexistent-stop-id");
+
+      const remainingEtas = await repository.getEtasForStopId(stopId);
+      expect(remainingEtas).toHaveLength(mockEtas.length);
+    });
+  });
+})
+

src/repositories/shuttle/eta/__tests__/SelfUpdatingETARepositorySharedTests.test.ts

@@ -0,0 +1,362 @@
+import { afterEach, beforeEach, describe, expect, test } from "@jest/globals";
+import { createClient, RedisClientType } from "redis";
+import { RepositoryHolder } from "../../../../../testHelpers/RepositoryHolder";
+import { SelfUpdatingETARepository } from "../SelfUpdatingETARepository";
+import { RedisSelfUpdatingETARepository } from "../RedisSelfUpdatingETARepository";
+import { InMemorySelfUpdatingETARepository } from "../InMemorySelfUpdatingETARepository";
+import { RedisShuttleRepository } from "../../RedisShuttleRepository";
+import { UnoptimizedInMemoryShuttleRepository } from "../../UnoptimizedInMemoryShuttleRepository";
+import { setupRouteAndOrderedStopsForShuttleRepository } from "../../../../../testHelpers/setupRouteAndOrderedStopsForShuttleRepository";
+import { ShuttleGetterSetterRepository } from "../../ShuttleGetterSetterRepository";
+import { IShuttle, IStop } from "../../../../entities/ShuttleRepositoryEntities";
+
+class RedisSelfUpdatingETARepositoryHolder implements RepositoryHolder<SelfUpdatingETARepository> {
+  repo: RedisSelfUpdatingETARepository | undefined;
+  shuttleRepo: RedisShuttleRepository | undefined;
+  redisClient: RedisClientType | undefined;
+
+  name = "RedisSelfUpdatingETARepository"
+  factory = async () => {
+    this.redisClient = createClient({
+      url: process.env.REDIS_URL,
+    });
+    await this.redisClient.connect();
+    await this.redisClient.flushAll();
+    this.shuttleRepo = new RedisShuttleRepository(this.redisClient);
+    this.repo = new RedisSelfUpdatingETARepository(
+      this.shuttleRepo,
+      this.redisClient,
+    );
+    return this.repo;
+  }
+  teardown = async () => {
+    if (this.redisClient) {
+      await this.redisClient.flushAll();
+      await this.redisClient.disconnect();
+    }
+  }
+}
+
+class InMemorySelfUpdatingETARepositoryHolder implements RepositoryHolder<SelfUpdatingETARepository> {
+  repo: InMemorySelfUpdatingETARepository | undefined;
+  shuttleRepo: UnoptimizedInMemoryShuttleRepository | undefined;
+
+  name = "InMemorySelfUpdatingETARepository"
+  factory = async () => {
+    this.shuttleRepo = new UnoptimizedInMemoryShuttleRepository();
+    this.repo = new InMemorySelfUpdatingETARepository(this.shuttleRepo);
+    return this.repo;
+  }
+  teardown = async () => {
+    // No teardown needed for in-memory
+  }
+}
+
+const repositoryImplementations = [
+  new RedisSelfUpdatingETARepositoryHolder(),
+  new InMemorySelfUpdatingETARepositoryHolder(),
+];
+
+describe.each(repositoryImplementations)('$name', (holder) => {
+  let repository: SelfUpdatingETARepository;
+  let shuttleRepository: ShuttleGetterSetterRepository;
+
+  beforeEach(async () => {
+    repository = await holder.factory();
+    shuttleRepository = holder.shuttleRepo!;
+  });
+
+  afterEach(async () => {
+    await holder.teardown();
+  });
+
+  // Helper function for setting up routes and ordered stops
+  async function setupRouteAndOrderedStops() {
+    return await setupRouteAndOrderedStopsForShuttleRepository(shuttleRepository);
+  }
+
+  async function populateTravelTimeDataForStops({
+    currentTime,
+    shuttle,
+    stop1,
+    stop2,
+    stop3,
+    firstStopArrivalTime = new Date(2025, 0, 1, 11, 0, 0),
+    secondStopArrivalTime = new Date(2025, 0, 1, 11, 15, 0),
+    thirdStopArrivalTime = new Date(2025, 0, 1, 11, 20, 0),
+  }: {
+    currentTime: Date;
+    shuttle: IShuttle;
+    stop1: IStop;
+    stop2: IStop;
+    stop3: IStop;
+    firstStopArrivalTime?: Date;
+    secondStopArrivalTime?: Date;
+    thirdStopArrivalTime?: Date;
+  }) {
+    repository.setReferenceTime(currentTime);
+    repository.startListeningForUpdates();
+
+    shuttle.coordinates = stop1.coordinates;
+    await shuttleRepository.addOrUpdateShuttle(shuttle, firstStopArrivalTime.getTime());
+
+    shuttle.coordinates = stop2.coordinates;
+    await shuttleRepository.addOrUpdateShuttle(shuttle, secondStopArrivalTime.getTime());
+
+    shuttle.coordinates = stop3.coordinates;
+    await shuttleRepository.addOrUpdateShuttle(shuttle, thirdStopArrivalTime.getTime());
+  }
+
+  describe("handleShuttleWillArriveAtStop", () => {
+    test("updates how long the shuttle took to get from one stop to another", async () => {
+      const { route, stop2, stop1, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      repository.startListeningForUpdates();
+
+      shuttle.coordinates = stop1.coordinates;
+
+      const firstStopArrivalTime = new Date(2025, 0, 1, 12, 0, 0);
+      await shuttleRepository.addOrUpdateShuttle(shuttle, firstStopArrivalTime.getTime());
+
+      shuttle.coordinates = stop2.coordinates;
+      const secondStopArrivalTime = new Date(2025, 0, 1, 12, 15, 0);
+      await shuttleRepository.addOrUpdateShuttle(shuttle, secondStopArrivalTime.getTime());
+
+      // Necessary to wait for the event emitter subscriber to execute
+      await new Promise((resolve) => setTimeout(resolve, 1000));
+
+      const travelTime = await repository.getAverageTravelTimeSeconds({
+        routeId: route.id,
+        fromStopId: stop1.id,
+        toStopId: stop2.id,
+      }, {
+        from: new Date(2025, 0, 1, 11, 0, 0),
+        to: new Date(2025, 0, 1, 13, 0, 0),
+      });
+      expect(travelTime).toEqual(15 * 60);
+    });
+
+  });
+
+  describe("handleShuttleUpdate", () => {
+    async function assertEtaIsValidGivenCurrentTimeAndSecondArrivalTime(
+      currentTime: Date,
+      shuttleSecondArrivalTimeAtFirstStop: Date
+    ) {
+      const { stop1, stop2, stop3, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      // Populating travel time data
+      await populateTravelTimeDataForStops({ currentTime, shuttle, stop1, stop2, stop3 });
+
+      // Populating ETA data
+      shuttle.coordinates = stop1.coordinates;
+      await shuttleRepository.addOrUpdateShuttle(
+        shuttle,
+        shuttleSecondArrivalTimeAtFirstStop.getTime()
+      );
+
+      shuttle.coordinates = { latitude: 12.5, longitude: 22.5 };
+      await shuttleRepository.addOrUpdateShuttle(
+        shuttle,
+        currentTime.getTime()
+      );
+
+      await new Promise((resolve) => setTimeout(resolve, 1000));
+
+      const secondStopEta = await repository.getEtaForShuttleAndStopId(shuttle.id, stop2.id);
+      expect(secondStopEta?.secondsRemaining).toEqual(8 * 60);
+
+      const thirdStopEta = await repository.getEtaForShuttleAndStopId(shuttle.id, stop3.id);
+      expect(thirdStopEta?.secondsRemaining).toEqual(13 * 60);
+    }
+
+    test("adds ETA entries for stops based on historical data", async () => {
+      const shuttleSecondArrivalTimeAtFirstStop = new Date(2025, 0, 8, 12, 0, 0);
+      const currentTime = new Date(shuttleSecondArrivalTimeAtFirstStop.getTime() + 7 * 60 * 1000);
+
+      await assertEtaIsValidGivenCurrentTimeAndSecondArrivalTime(
+        currentTime, shuttleSecondArrivalTimeAtFirstStop
+      );
+    }, 60000);
+
+    test("uses previous day fallback calculation when no data available from one week ago", async () => {
+      const shuttleSecondArrivalTimeAtFirstStop = new Date(2025, 0, 2, 12, 0, 0);
+      const currentTime = new Date(shuttleSecondArrivalTimeAtFirstStop.getTime() + 7 * 60 * 1000);
+      await assertEtaIsValidGivenCurrentTimeAndSecondArrivalTime(
+        currentTime, shuttleSecondArrivalTimeAtFirstStop
+      );
+    }, 60000);
+
+    test("uses previous two-hour fallback calculation when no data available from one day ago", async () => {
+      const shuttleSecondArrivalTimeAtFirstStop = new Date(2025, 0, 1, 12, 5, 0);
+      const currentTime = new Date(shuttleSecondArrivalTimeAtFirstStop.getTime() + 7 * 60 * 1000);
+      await assertEtaIsValidGivenCurrentTimeAndSecondArrivalTime(
+        currentTime, shuttleSecondArrivalTimeAtFirstStop
+      );
+    });
+
+    test("adds a 'stopgap' entry of 1 second when the shuttle arrives at a stop", async () => {
+      const { stop1, stop2, stop3, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      const shuttleSecondArrivalTimeAtFirstStop = new Date(2025, 0, 1, 12, 5, 0);
+      const currentTime = new Date(shuttleSecondArrivalTimeAtFirstStop.getTime() + 7 * 60 * 1000);
+
+      // Populating travel time data
+      await populateTravelTimeDataForStops({ currentTime, shuttle, stop1, stop2, stop3 });
+
+      // Populate ETA data
+      // Simulate shuttle running early for second stop
+      shuttle.coordinates = stop1.coordinates;
+      await shuttleRepository.addOrUpdateShuttle(
+        shuttle,
+        shuttleSecondArrivalTimeAtFirstStop.getTime()
+      );
+
+      shuttle.coordinates = stop2.coordinates;
+      // Call twice to get the ETA repository to read the correct flag
+      await shuttleRepository.addOrUpdateShuttle(
+        shuttle,
+        currentTime.getTime(),
+      );
+      await new Promise((resolve) => setTimeout(resolve, 500));
+
+      await shuttleRepository.addOrUpdateShuttle(
+        shuttle,
+        currentTime.getTime(),  // ~8 minutes early
+      );
+      await new Promise((resolve) => setTimeout(resolve, 500));
+
+      const eta = await repository.getEtaForShuttleAndStopId(shuttle.id, stop2.id);
+      expect(eta?.secondsRemaining).toEqual(1);
+    });
+  });
+
+  describe("handleShuttleWillLeaveStop", () => {
+    test("clears ETA of correct stop on leaving stop", async () => {
+      const { stop1, stop2, stop3, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      const shuttleSecondArrivalTimeAtFirstStop = new Date(2025, 0, 8, 12, 0, 0);
+      const shuttleSecondArrivalTimeAtSecondStop = new Date(2025, 0, 8, 12, 15, 0);
+      const currentTime = new Date(shuttleSecondArrivalTimeAtSecondStop.getTime() + 3 * 60 * 1000);
+
+      await populateTravelTimeDataForStops({ currentTime, shuttle, stop1, stop2, stop3 });
+
+      // Populating ETA data
+      shuttle.coordinates = stop1.coordinates;
+      await shuttleRepository.addOrUpdateShuttle(shuttle, shuttleSecondArrivalTimeAtFirstStop.getTime());
+
+      shuttle.coordinates = stop2.coordinates;
+      await shuttleRepository.addOrUpdateShuttle(shuttle, shuttleSecondArrivalTimeAtSecondStop.getTime());
+
+      shuttle.coordinates = { latitude: 12.5, longitude: 12.5 }
+      await shuttleRepository.addOrUpdateShuttle(shuttle, currentTime.getTime());
+
+      await new Promise((resolve) => setTimeout(resolve, 1000));
+
+      const etaForStop3 = await repository.getEtaForShuttleAndStopId(shuttle.id, stop3.id);
+      expect(etaForStop3).not.toBeNull();
+      const etaForStop2 = await repository.getEtaForShuttleAndStopId(shuttle.id, stop2.id);
+      expect(etaForStop2).toBeNull();
+    }, 60000);
+  });
+
+  describe("getAverageTravelTimeSeconds", () => {
+    test("returns the average travel time when historical data exists", async () => {
+      const { route, stop1, stop2, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      repository.startListeningForUpdates();
+
+      shuttle.coordinates = stop1.coordinates;
+
+      const firstStopTime = new Date(2025, 0, 1, 12, 0, 0);
+      await shuttleRepository.addOrUpdateShuttle(shuttle, firstStopTime.getTime());
+
+      shuttle.coordinates = stop2.coordinates;
+      const secondStopTime = new Date(2025, 0, 1, 12, 15, 0);
+      await shuttleRepository.addOrUpdateShuttle(shuttle, secondStopTime.getTime());
+
+      await new Promise((resolve) => setTimeout(resolve, 1000));
+
+      const travelTime = await repository.getAverageTravelTimeSeconds({
+        routeId: route.id,
+        fromStopId: stop1.id,
+        toStopId: stop2.id,
+      }, {
+        from: new Date(2025, 0, 1, 11, 0, 0),
+        to: new Date(2025, 0, 1, 13, 0, 0),
+      });
+
+      expect(travelTime).toEqual(15 * 60);
+    });
+
+    test("returns average of multiple data points", async () => {
+      const { route, stop1, stop2, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      repository.startListeningForUpdates();
+
+      shuttle.coordinates = stop1.coordinates;
+
+      // First trip: 10 minutes travel time
+      await shuttleRepository.addOrUpdateShuttle(shuttle, new Date(2025, 0, 1, 12, 0, 0).getTime());
+      shuttle.coordinates = stop2.coordinates;
+      await shuttleRepository.addOrUpdateShuttle(shuttle, new Date(2025, 0, 1, 12, 10, 0).getTime());
+
+      // Second trip: 20 minutes travel time
+      shuttle.coordinates = stop1.coordinates;
+      await shuttleRepository.addOrUpdateShuttle(shuttle, new Date(2025, 0, 1, 12, 30, 0).getTime());
+      shuttle.coordinates = stop2.coordinates;
+      await shuttleRepository.addOrUpdateShuttle(shuttle, new Date(2025, 0, 1, 12, 50, 0).getTime());
+
+      const averageTravelTime = await repository.getAverageTravelTimeSeconds({
+        routeId: route.id,
+        fromStopId: stop1.id,
+        toStopId: stop2.id,
+      }, {
+        from: new Date(2025, 0, 1, 11, 0, 0),
+        to: new Date(2025, 0, 1, 14, 0, 0),
+      });
+
+      // Average of 10 minutes and 20 minutes = 15 minutes = 900 seconds
+      expect(averageTravelTime).toBeDefined();
+    });
+
+    test("returns undefined when no data exists", async () => {
+      const { route, stop1, stop2 } = await setupRouteAndOrderedStops();
+
+      repository.startListeningForUpdates();
+
+      const averageTravelTime = await repository.getAverageTravelTimeSeconds({
+        routeId: route.id,
+        fromStopId: stop1.id,
+        toStopId: stop2.id,
+      }, {
+        from: new Date(2025, 0, 1, 11, 0, 0),
+        to: new Date(2025, 0, 1, 14, 0, 0),
+      });
+
+      expect(averageTravelTime).toBeUndefined();
+    });
+
+    test("returns undefined when querying outside the time range of data", async () => {
+      const { route, stop1, stop2, sampleShuttleNotInRepository: shuttle } = await setupRouteAndOrderedStops();
+
+      repository.startListeningForUpdates();
+
+      shuttle.coordinates = stop1.coordinates;
+
+      await shuttleRepository.addOrUpdateShuttle(shuttle, new Date(2025, 0, 1, 12, 0, 0).getTime());
+      shuttle.coordinates = stop2.coordinates;
+      await shuttleRepository.addOrUpdateShuttle(shuttle, new Date(2025, 0, 1, 12, 15, 0).getTime());
+
+      const averageTravelTime = await repository.getAverageTravelTimeSeconds({
+        routeId: route.id,
+        fromStopId: stop1.id,
+        toStopId: stop2.id,
+      }, {
+        from: new Date(2025, 0, 2, 11, 0, 0),
+        to: new Date(2025, 0, 2, 13, 0, 0),
+      });
+      expect(averageTravelTime).toBeUndefined();
+    });
+  });
+})

src/resolvers/EtaResolvers.ts

@@ -4,10 +4,16 @@ import { ServerContext } from "../ServerContext";
 export const EtaResolvers: Resolvers<ServerContext> = {
   ETA: {
     stop: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getStopById(parent.stopId);
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      return await system.shuttleRepository.getStopById(parent.stopId);
     },
     shuttle: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getShuttleById(parent.shuttleId);
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      return await system.shuttleRepository.getShuttleById(parent.shuttleId);
     },
   },
-}
+}

src/resolvers/MutationResolvers.ts

@@ -0,0 +1,94 @@
+import { MutationScheduleNotificationArgs, NotificationResponse, Resolvers } from "../generated/graphql";
+import { ServerContext } from "../ServerContext";
+import {
+  ETANotificationScheduler,
+} from "../notifications/schedulers/ETANotificationScheduler";
+import { ScheduledNotification } from "../repositories/notifications/NotificationRepository";
+import { InterchangeSystem } from "../entities/InterchangeSystem";
+
+async function temp_findMatchingSystemBasedOnShuttleId(context: ServerContext, args: Omit<MutationScheduleNotificationArgs, "input"> & {
+  input: NonNullable<MutationScheduleNotificationArgs["input"]>
+}) {
+  let matchingSystem: InterchangeSystem | undefined;
+  await Promise.all(context.systems.map(async (system) => {
+    const shuttle = await system.shuttleRepository.getShuttleById(args.input.shuttleId);
+    // Theoretically, there should only be one
+    if (shuttle !== null) {
+      matchingSystem = system;
+    }
+    return shuttle;
+  }));
+  return matchingSystem;
+}
+
+export const MutationResolvers: Resolvers<ServerContext> = {
+  // TODO: Require system ID on these endpoints
+  Mutation: {
+    scheduleNotification: async (_parent, args, context, _info) => {
+      let matchingSystem = await temp_findMatchingSystemBasedOnShuttleId(context, args);
+
+      if (!matchingSystem) {
+        return {
+          message: "Shuttle ID doesn't exist",
+          success: false,
+        }
+      }
+
+      const shuttle = await matchingSystem.shuttleRepository.getShuttleById(args.input.shuttleId);
+      if (!shuttle) {
+        return {
+          message: "Shuttle ID doesn't exist",
+          success: false,
+        }
+      }
+      const stop = await matchingSystem.shuttleRepository.getStopById(args.input.stopId);
+      if (!stop) {
+        return {
+          message: "Stop ID doesn't exist",
+          success: false,
+        }
+      }
+
+      const notificationData: ScheduledNotification = {
+        ...args.input,
+        secondsThreshold: typeof args.input.secondsThreshold === 'number'
+          ? args.input.secondsThreshold
+          : ETANotificationScheduler.defaultSecondsThresholdForNotificationToFire,
+      }
+
+      await matchingSystem.notificationRepository.addOrUpdateNotification(notificationData);
+
+      const response: NotificationResponse = {
+        message: "Notification scheduled",
+        success: true,
+        data: args.input,
+      }
+      return response;
+    },
+    cancelNotification: async (_parent, args, context, _info) => {
+      const matchingSystem = await temp_findMatchingSystemBasedOnShuttleId(context, args);
+      if (!matchingSystem) {
+        return {
+          success: false,
+          message: "Unable to find correct system",
+          data: args.input,
+        }
+      }
+
+      const isScheduled = await matchingSystem.notificationRepository.isNotificationScheduled(args.input)
+      if (isScheduled) {
+        await matchingSystem.notificationRepository.deleteNotificationIfExists(args.input);
+        return {
+          success: true,
+          message: "Notification cancelled",
+          data: args.input,
+        }
+      }
+
+      return {
+        success: false,
+        message: "Notification doesn't exist"
+      }
+    },
+  },
+}

src/resolvers/OrderedStopResolvers.ts

@@ -3,50 +3,66 @@ import { ServerContext } from "../ServerContext";
 
 export const OrderedStopResolvers: Resolvers<ServerContext> = {
   OrderedStop: {
-    nextStop: async (parent, args, contextValue, info): Promise<OrderedStop | null> => {
+    nextStop: async (parent, args, contextValue, _info): Promise<OrderedStop | null> => {
       const routeId = parent.routeId;
       const stopId = parent.stopId;
 
-      const currentOrderedStop = await contextValue.repository.getOrderedStopByRouteAndStopId(routeId, stopId);
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      const currentOrderedStop = await system.shuttleRepository.getOrderedStopByRouteAndStopId(routeId, stopId);
       if (!currentOrderedStop) return null;
 
       const nextOrderedStop = currentOrderedStop.nextStop;
       if (!nextOrderedStop) return null;
 
-      const nextOrderedStopObject = await contextValue.repository.getStopById(nextOrderedStop.stopId);
+      const nextOrderedStopObject = await system.shuttleRepository.getStopById(nextOrderedStop.stopId);
       if (!nextOrderedStopObject) return null;
 
       return {
         route: parent.route,
         routeId: parent.routeId,
         stopId: nextOrderedStopObject.id,
+        systemId: system.id,
+        updatedTime: nextOrderedStopObject.updatedTime
       }
     },
-    previousStop: async (parent, args, contextValue, info): Promise<OrderedStop | null> => {
+    previousStop: async (parent, args, contextValue, _info): Promise<OrderedStop | null> => {
       const routeId = parent.routeId;
       const stopId = parent.stopId;
 
-      const currentOrderedStop = await contextValue.repository.getOrderedStopByRouteAndStopId(routeId, stopId);
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      const currentOrderedStop = await system.shuttleRepository.getOrderedStopByRouteAndStopId(routeId, stopId);
       if (!currentOrderedStop) return null;
 
       const previousOrderedStop = currentOrderedStop.previousStop;
       if (!previousOrderedStop) return null;
 
-      const previousOrderedStopObject = await contextValue.repository.getStopById(previousOrderedStop.stopId);
+      const previousOrderedStopObject = await system.shuttleRepository.getStopById(previousOrderedStop.stopId);
       if (!previousOrderedStopObject) return null;
 
       return {
         route: parent.route,
         routeId: parent.routeId,
         stopId: previousOrderedStopObject.id,
+        systemId: system.id,
+        updatedTime: previousOrderedStopObject.updatedTime,
       }
     },
-    stop: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getStopById(parent.stopId);
+    stop: async (parent, args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      return await system.shuttleRepository.getStopById(parent.stopId);
     },
-    route: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getRouteById(parent.routeId);
+    route: async (parent, args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      return await system.shuttleRepository.getRouteById(parent.routeId);
     },
   },
 
-}
+}

src/resolvers/ParkingStructureResolvers.ts

@@ -0,0 +1,59 @@
+import { Resolvers } from "../generated/graphql";
+import { ServerContext } from "../ServerContext";
+import { HistoricalParkingAverageFilterArguments } from "../repositories/parking/ParkingGetterRepository";
+import { GraphQLError } from "graphql/error";
+import {
+    PARKING_HISTORICAL_AVERAGE_MAXIMUM_TIMESPAN,
+    PARKING_HISTORICAL_AVERAGE_MINIMUM_INTERVAL
+} from "../environment";
+
+export const ParkingStructureResolvers: Resolvers<ServerContext> = {
+  ParkingStructure: {
+    historicalAverages: async (parent, args, contextValue, _info) => {
+      /**
+       * @param errorMessage
+       */
+      function throwBadUserInputError(errorMessage: string) {
+        throw new GraphQLError(errorMessage, {
+          extensions: {
+            code: 'BAD_USER_INPUT',
+          }
+        });
+      }
+
+      const system = contextValue.findSystemById(parent.systemId);
+
+      if (!args.input?.intervalMs) {
+        throwBadUserInputError('No interval provided');
+        return null;
+      }
+      const queryArguments: HistoricalParkingAverageFilterArguments = {
+        from: new Date(args.input.from),
+        intervalMs: args.input.intervalMs,
+        to: new Date(args.input.to),
+      }
+      if (Number.isNaN(queryArguments.from.getTime()
+        || Number.isNaN(queryArguments.to.getTime()))) {
+        throwBadUserInputError('One or more incorrect dates provided');
+      }
+      if (queryArguments.from.getTime() > queryArguments.to.getTime()) {
+        throwBadUserInputError("`from` date can't be greater than the `to` date");
+      }
+
+      // Limit queries for improved performance
+      if (queryArguments.to.getTime() - queryArguments.from.getTime() > PARKING_HISTORICAL_AVERAGE_MAXIMUM_TIMESPAN) {
+        throwBadUserInputError('Maximum timespan exceeded');
+      }
+      if (queryArguments.intervalMs < PARKING_HISTORICAL_AVERAGE_MINIMUM_INTERVAL) {
+        throwBadUserInputError('Provided interval is less than minimum interval');
+      }
+
+      const parkingAverages = await system?.parkingRepository?.getHistoricalAveragesOfParkingStructureCounts(parent.id, queryArguments);
+      if (!parkingAverages) {
+        return null;
+      }
+
+      return parkingAverages;
+    }
+  }
+}

src/resolvers/ParkingSystemResolvers.ts

@@ -0,0 +1,42 @@
+import { Resolvers } from "../generated/graphql";
+import { ServerContext } from "../ServerContext";
+
+export const ParkingSystemResolvers: Resolvers<ServerContext> = {
+  ParkingSystem: {
+    parkingStructures: async (parent, _args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) {
+        return [];
+      }
+      const parkingRepository = system.parkingRepository;
+      if (!parkingRepository) return [];
+
+      const parkingStructures = await parkingRepository.getParkingStructures();
+      return parkingStructures
+        .slice()
+        .sort((a, b) => a.name.localeCompare(b.name))
+        .map((structure) => {
+        return {
+          ...structure,
+          systemId: parent.systemId
+        };
+      });
+    },
+    parkingStructure: async (parent, args, contextValue, _info) => {
+      if (!args.id) return null;
+
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) {
+        return null;
+      }
+      const parkingRepository = system.parkingRepository;
+      if (!parkingRepository) return null;
+
+      const parkingStructure = await parkingRepository.getParkingStructureById(args.id);
+      return parkingStructure ? {
+        ...parkingStructure,
+        systemId: parent.systemId,
+      } : null;
+    },
+  }
+}

src/resolvers/QueryResolvers.ts

@@ -1,20 +1,62 @@
 import { ServerContext } from "../ServerContext";
 import { Resolvers } from "../generated/graphql";
 
+const GRAPHQL_SCHEMA_MIN_VERSION = 1;
+const GRAPHQL_SCHEMA_CURRENT_VERSION = 1;
+
 export const QueryResolvers: Resolvers<ServerContext> = {
   Query: {
-    systems: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getSystems();
+    systems: async (_parent, args, contextValue, _info) => {
+      return contextValue.systems
+        .slice()
+        .sort((a, b) => a.name.localeCompare(b.name))
+        .map((system) => {
+          return {
+            name: system.name,
+            id: system.id,
+          };
+        })
     },
-    system: async (parent, args, contextValue, info) => {
+    system: async (_parent, args, contextValue, _info) => {
       if (!args.id) return null;
-      const system = await contextValue.repository.getSystemById(args.id);
+      const system = contextValue.findSystemById(args.id);
       if (system === null) return null;
 
       return {
         name: system.name,
         id: system.id,
       };
-    }
+    },
+    // TODO: Update the GraphQL schema to require a system ID
+    isNotificationScheduled: async (_parent, args, contextValue, _info) => {
+      const notificationData = args.input;
+
+      for (let system of contextValue.systems) {
+        const isScheduled = await system.notificationRepository.isNotificationScheduled(notificationData);
+        if (isScheduled) {
+          return true;
+        }
+      }
+
+      return false;
+    },
+    secondsThresholdForNotification: async (_parent, args, contextValue, _info) => {
+      const notificationData = args.input;
+
+      for (let system of contextValue.systems) {
+        const isScheduled = await system.notificationRepository.isNotificationScheduled(notificationData);
+        if (isScheduled) {
+          return await system.notificationRepository.getSecondsThresholdForNotificationIfExists(args.input);
+        }
+      }
+
+      return null;
+    },
+    schemaMinVersion: async (_parent, _args, _contextValue, _info) => {
+      return GRAPHQL_SCHEMA_MIN_VERSION;
+    },
+    schemaCurrentVersion: async (_parent, _args, _contextValue, _info) => {
+      return GRAPHQL_SCHEMA_CURRENT_VERSION;
+    },
   },
-}
+}

src/resolvers/RouteResolvers.ts

@@ -3,34 +3,67 @@ import { ServerContext } from "../ServerContext";
 
 export const RouteResolvers: Resolvers<ServerContext> = {
   Route: {
-    shuttles: async (parent, args, contextValue, info) => {
-      const shuttles = await contextValue.repository.getShuttlesByRouteId(parent.id);
+    shuttles: async (parent, args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
 
-      return shuttles.map(({
+      const shuttles = await system.shuttleRepository.getShuttlesByRouteId(parent.id);
+
+      return shuttles
+        .slice()
+        .sort((a, b) => a.name.localeCompare(b.name))
+        .map(({
         coordinates,
         name,
         id,
+        orientationInDegrees,
+        updatedTime
       }) => ({
         coordinates: coordinates as Coordinates,
         name,
         route: parent,
         routeId: parent.id,
         id,
+        orientationInDegrees,
+        systemId: parent.systemId,
+        updatedTime,
       }));
     },
-    orderedStop: async (parent, args, contextValue, info) => {
+    orderedStop: async (parent, args, contextValue, _info) => {
       if (!args.forStopId) return null;
-      const orderedStop = await contextValue.repository.getOrderedStopByRouteAndStopId(parent.id, args.forStopId);
+
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      const orderedStop = await system.shuttleRepository.getOrderedStopByRouteAndStopId(parent.id, args.forStopId);
       if (!orderedStop) return null;
 
-      const stop = await contextValue.repository.getStopById(orderedStop.stopId);
+      const stop = await system.shuttleRepository.getStopById(orderedStop.stopId);
       if (!stop) return null;
 
       return {
         stopId: args.forStopId,
         routeId: parent.id,
         route: parent,
+        systemId: system.id,
+        updatedTime: orderedStop.updatedTime,
       }
     },
+    orderedStops: async (parent, args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      const orderedStops = await system.shuttleRepository.getOrderedStopsByRouteId(parent.id);
+      return orderedStops
+        .slice()
+        .sort((a, b) => a.position - b.position)
+        .map(({ routeId, stopId, position, systemId, updatedTime }) => ({
+        routeId,
+        stopId,
+        position,
+        systemId,
+        updatedTime,
+      }));
+    }
   },
-}
+}

src/resolvers/ShuttleResolvers.ts

@@ -3,9 +3,13 @@ import { ServerContext } from "../ServerContext";
 
 export const ShuttleResolvers: Resolvers<ServerContext> = {
   Shuttle: {
-    eta: async (parent, args, contextValue, info) => {
+    eta: async (parent, args, contextValue, _) => {
       if (!args.forStopId) return null;
-      const etaForStopId = await contextValue.repository.getEtaForShuttleAndStopId(parent.id, args.forStopId);
+
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      const etaForStopId = await system.etaRepository.getEtaForShuttleAndStopId(parent.id, args.forStopId);
       if (etaForStopId === null) return null;
 
       return {
@@ -13,32 +17,46 @@ export const ShuttleResolvers: Resolvers<ServerContext> = {
         secondsRemaining: etaForStopId.secondsRemaining,
         shuttleId: parent.id,
         shuttle: parent,
+        systemId: system.id,
+        updatedTimeMs: etaForStopId.updatedTime,
       };
     },
-    etas: async (parent, args, contextValue, info) => {
-      const etasForShuttle = await contextValue.repository.getEtasForShuttleId(parent.id);
+    etas: async (parent, args, contextValue, _) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      const etasForShuttle = await system.etaRepository.getEtasForShuttleId(parent.id);
       if (!etasForShuttle) return null;
 
-      const computedEtas = await Promise.all(etasForShuttle.map(async ({
-                                                                         secondsRemaining,
-                                                                         stopId,
-                                                                       }): Promise<Eta | null> => {
-        return {
+      const computedEtas = await Promise.all(
+        etasForShuttle.map(async ({
           secondsRemaining,
           stopId,
-          shuttle: parent,
-          shuttleId: parent.id,
-        }
+          updatedTime
+        }): Promise<Eta | null> => {
+          return {
+            secondsRemaining,
+            stopId,
+            shuttle: parent,
+            shuttleId: parent.id,
+            systemId: system.id,
+            updatedTime: updatedTime,
+          }
       }));
 
       if (computedEtas.every((eta) => eta !== null)) {
-        return computedEtas;
+        return computedEtas
+          .slice()
+          .sort((a, b) => (a!.secondsRemaining - b!.secondsRemaining));
       }
 
       return [];
     },
-    route: async (parent, args, contextValue, info) => {
-      const route = await contextValue.repository.getRouteById(parent.routeId);
+    route: async (parent, args, contextValue, _) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) return null;
+
+      const route = await system.shuttleRepository.getRouteById(parent.routeId);
       if (route === null) return null;
 
       return {
@@ -46,7 +64,9 @@ export const ShuttleResolvers: Resolvers<ServerContext> = {
         id: route.id,
         name: route.name,
         polylineCoordinates: route.polylineCoordinates,
+        systemId: system.id,
+        updatedTimeMs: route.updatedTime
       }
     }
   },
-}
+}

src/resolvers/StopResolvers.ts

@@ -3,11 +3,21 @@ import { ServerContext } from "../ServerContext";
 
 export const StopResolvers: Resolvers<ServerContext> = {
   Stop: {
-    orderedStops: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getOrderedStopsByStopId(parent.id);
+    orderedStops: async (parent, args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) {
+        return [];
+      }
+      const orderedStops = await system.shuttleRepository.getOrderedStopsByStopId(parent.id);
+      return orderedStops.slice().sort((a, b) => a.position - b.position);
     },
-    etas: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getEtasForStopId(parent.id);
+    etas: async (parent, args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.systemId);
+      if (!system) {
+        return [];
+      }
+      const etas = await system.etaRepository.getEtasForStopId(parent.id);
+      return etas.slice().sort((a, b) => a.secondsRemaining - b.secondsRemaining);
     },
   },
-}
+}

src/resolvers/SystemResolvers.ts

@@ -3,15 +3,32 @@ import { ServerContext } from "../ServerContext";
 
 export const SystemResolvers: Resolvers<ServerContext> = {
   System: {
-    routes: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getRoutesBySystemId(parent.id);
+    routes: async (parent, _args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return [];
+      }
+
+      const routes = await system.shuttleRepository.getRoutes();
+      return routes.slice().sort((a, b) => a.name.localeCompare(b.name));
     },
-    stops: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getStopsBySystemId(parent.id);
+    stops: async (parent, _args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return [];
+      }
+
+      const stops = await system.shuttleRepository.getStops();
+      return stops.slice().sort((a, b) => a.name.localeCompare(b.name));
     },
-    stop: async (parent, args, contextValue, info) => {
+    stop: async (parent, args, contextValue, _info) => {
       if (!args.id) return null;
-      const stop = await contextValue.repository.getStopById(args.id);
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return null;
+      }
+
+      const stop = await system.shuttleRepository.getStopById(args.id);
       if (stop === null) return null;
 
       if (stop.systemId !== parent.id) return null;
@@ -20,11 +37,17 @@ export const SystemResolvers: Resolvers<ServerContext> = {
         id: stop.id,
         name: stop.name,
         coordinates: stop.coordinates as Coordinates,
+        systemId: parent.id,
+        updatedTimeMs: stop.updatedTime,
       };
     },
-    route: async (parent, args, contextValue, info) => {
+    route: async (parent, args, contextValue, _info) => {
       if (!args.id) return null;
-      const route = await contextValue.repository.getRouteById(args.id);
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return null;
+      }
+      const route = await system.shuttleRepository.getRouteById(args.id);
       if (route === null) return null;
 
       if (route.systemId !== parent.id) return null;
@@ -34,19 +57,51 @@ export const SystemResolvers: Resolvers<ServerContext> = {
         id: route.id,
         name: route.name,
         polylineCoordinates: route.polylineCoordinates as Coordinates[],
+        systemId: parent.id,
+        updatedTimeMs: route.updatedTime,
       };
     },
-    shuttle: async (parent, args, contextValue, info) => {
+    shuttle: async (parent, args, contextValue, _info) => {
       if (!args.id) return null;
-      const shuttle = await contextValue.repository.getShuttleById(args.id);
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return null;
+      }
+      const shuttle = await system.shuttleRepository.getShuttleById(args.id);
       if (shuttle === null) return null;
 
       if (shuttle.systemId !== parent.id) return null;
 
       return shuttle;
     },
-    shuttles: async (parent, args, contextValue, info) => {
-      return await contextValue.repository.getShuttlesBySystemId(parent.id);
-    }
+    shuttles: async (parent, _args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return [];
+      }
+
+      const shuttles = await system.shuttleRepository.getShuttles();
+      return shuttles.slice().sort((a, b) => a.name.localeCompare(b.name));
+    },
+    initialRegion: async (parent, _args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return null;
+      }
+
+      return system.initialRegion;
+    },
+    parkingSystem: async (parent, _args, contextValue, _info) => {
+      const system = contextValue.findSystemById(parent.id);
+      if (!system) {
+        return null;
+      }
+
+      if (!system.parkingRepository) return null;
+
+      return {
+        systemId: parent.id,
+      };
+    },
   },
-}
+}

src/resolvers/__tests__/EtaResolverTests.test.ts

@@ -1,41 +1,39 @@
 import { beforeEach, describe, expect, it } from "@jest/globals";
-import { setupTestServerContext } from "../testHelpers/apolloTestServerHelpers";
-import { IEta, IShuttle, IStop, ISystem } from "../../src/entities/entities";
+import { setupTestServerContext, setupTestServerHolder } from "../../../testHelpers/apolloTestServerHelpers";
+import { IEta, IShuttle, IStop } from "../../entities/ShuttleRepositoryEntities";
 import {
-  addMockEtaToRepository, addMockShuttleToRepository,
+  addMockEtaToRepository,
+  addMockShuttleToRepository,
   addMockStopToRepository,
-  addMockSystemToRepository
-} from "../testHelpers/repositorySetupHelpers";
-import assert = require("node:assert");
+} from "../../../testHelpers/repositorySetupHelpers";
+import { ExternalSourceETARepository } from "../../repositories/shuttle/eta/ExternalSourceETARepository";
+import assert from "node:assert";
 
 describe("EtaResolvers", () => {
+  const holder = setupTestServerHolder();
   const context = setupTestServerContext();
 
-  let mockSystem: ISystem;
   let mockShuttle: IShuttle;
   let mockStop: IStop;
   let expectedEta: IEta;
 
   beforeEach(async () => {
-    mockSystem = await addMockSystemToRepository(context.repository);
-    mockShuttle = await addMockShuttleToRepository(context.repository, mockSystem.id);
-    mockStop = await addMockStopToRepository(context.repository, mockSystem.id);
-    expectedEta = await addMockEtaToRepository(context.repository, mockStop.id, mockShuttle.id);
+    mockShuttle = await addMockShuttleToRepository(context.systems[0].shuttleRepository, context.systems[0].id);
+    mockStop = await addMockStopToRepository(context.systems[0].shuttleRepository, context.systems[0].id);
+    expectedEta = await addMockEtaToRepository(context.systems[0].etaRepository as ExternalSourceETARepository, mockStop.id, mockShuttle.id);
   });
 
   async function getResponseForEtaQuery(query: string) {
-    const response = await context.testServer.executeOperation({
+    return await holder.testServer.executeOperation({
       query,
       variables: {
-        systemId: mockSystem.id,
+        systemId: context.systems[0].id,
         shuttleId: mockShuttle.id,
       },
     }, {
-      contextValue: {
-        repository: context.repository,
-      }
+      contextValue: context
+
     });
-    return response;
   }
 
   describe("stop", () => {
@@ -87,4 +85,4 @@ describe("EtaResolvers", () => {
       expect(eta.shuttle.id).toEqual(expectedEta.shuttleId);
     });
   });
-});
+});

src/resolvers/__tests__/MutationResolverTests.test.ts

@@ -0,0 +1,187 @@
+import { describe, expect, it } from "@jest/globals";
+import { setupTestServerContext, setupTestServerHolder } from "../../../testHelpers/apolloTestServerHelpers";
+import {
+  addMockShuttleToRepository,
+  addMockStopToRepository,
+} from "../../../testHelpers/repositorySetupHelpers";
+import assert = require("node:assert");
+import { NotificationInput } from "../../generated/graphql";
+
+describe("MutationResolvers", () => {
+  const holder = setupTestServerHolder()
+  const context = setupTestServerContext();
+
+  async function getServerResponse(query: string, notificationInput: { deviceId: string; shuttleId: string; stopId: string }) {
+    return await holder.testServer.executeOperation({
+      query,
+      variables: {
+        input: notificationInput,
+      }
+    }, {
+      contextValue: context
+    });
+  }
+
+  describe("scheduleNotification", () => {
+    const query = `
+    mutation ScheduleNotification($input: NotificationInput!) {
+      scheduleNotification(input: $input) {
+         success
+         message
+         data {
+           deviceId
+           shuttleId
+           stopId
+         }
+      }
+    }
+    `
+
+    async function assertFailedResponse(response: any, notificationInput: NotificationInput) {
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+      const notificationResponse = response.body.singleResult.data?.scheduleNotification as any;
+      expect(notificationResponse.success).toBe(false);
+
+      expect(await context.systems[0].notificationRepository.isNotificationScheduled(notificationInput)).toBe(false);
+    }
+
+
+    it("adds a notification to the notification service", async () => {
+      const system = context.systems[0];
+      const shuttle = await addMockShuttleToRepository(context.systems[0].shuttleRepository, system.id);
+      const stop = await addMockStopToRepository(context.systems[0].shuttleRepository, system.id);
+
+      const notificationInput = {
+        deviceId: "1",
+        shuttleId: shuttle.id,
+        stopId: stop.id,
+        secondsThreshold: 240,
+      };
+      const response = await getServerResponse(query, notificationInput);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const expectedNotificationData: any = {
+        ...notificationInput,
+      }
+      delete expectedNotificationData.secondsThreshold;
+      const notificationResponse = response.body.singleResult.data?.scheduleNotification as any;
+      expect(notificationResponse?.success).toBe(true);
+      expect(notificationResponse?.data).toEqual(expectedNotificationData);
+
+      expect(await context.systems[0].notificationRepository.getSecondsThresholdForNotificationIfExists(expectedNotificationData)).toBe(240);
+    });
+
+    it("adds a notification with the default seconds threshold if none is provided", async () => {
+      const system = context.systems[0];
+      const shuttle = await addMockShuttleToRepository(context.systems[0].shuttleRepository, system.id);
+      const stop = await addMockStopToRepository(context.systems[0].shuttleRepository, system.id);
+
+      const notificationInput = {
+        deviceId: "1",
+        shuttleId: shuttle.id,
+        stopId: stop.id,
+      };
+      const response = await getServerResponse(query, notificationInput);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const notificationResponse = response.body.singleResult.data?.scheduleNotification as any;
+      expect(notificationResponse?.success).toBe(true);
+
+      expect(await context.systems[0].notificationRepository.getSecondsThresholdForNotificationIfExists(notificationInput)).toBe(180);
+    });
+
+    it("fails if the shuttle ID doesn't exist", async () => {
+      const system = context.systems[0];
+      const stop = await addMockStopToRepository(context.systems[0].shuttleRepository, system.id);
+
+      const notificationInput = {
+        deviceId: "1",
+        shuttleId: "1",
+        stopId: stop.id,
+      }
+      const response = await getServerResponse(query, notificationInput);
+      await assertFailedResponse(response, notificationInput);
+    });
+
+    it("fails if the stop ID doesn't exist", async () => {
+      const system = context.systems[0];
+      const shuttle = await addMockShuttleToRepository(context.systems[0].shuttleRepository, system.id);
+
+      const notificationInput = {
+        deviceId: "1",
+        shuttleId: shuttle.id,
+        stopId: "1",
+      }
+      const response = await getServerResponse(query, notificationInput);
+
+      await assertFailedResponse(response, notificationInput);
+    });
+  });
+
+  describe("cancelNotification", () => {
+    const query = `
+    mutation CancelNotification($input: NotificationInput!) {
+      cancelNotification(input: $input) {
+        success
+        message
+        data {
+          deviceId
+          shuttleId
+          stopId
+        }
+      }
+    }
+    `
+
+    it("removes the notification from the notification service", async () => {
+      const system = context.systems[0];
+      const shuttle = await addMockShuttleToRepository(context.systems[0].shuttleRepository, system.id);
+      const stop = await addMockStopToRepository(context.systems[0].shuttleRepository, system.id);
+
+      const notificationInput: any = {
+        deviceId: "1",
+        shuttleId: shuttle.id,
+        stopId: stop.id,
+        secondsThreshold: 180,
+      }
+      await context.systems[0].notificationRepository.addOrUpdateNotification(notificationInput);
+
+      const notificationLookup = {
+        ...notificationInput
+      }
+      delete notificationLookup.secondsThreshold;
+
+      const response = await getServerResponse(query, notificationLookup);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const notificationResponse = response.body.singleResult.data?.cancelNotification as any;
+      expect(notificationResponse.success).toBe(true);
+      expect(notificationResponse.data).toEqual(notificationLookup);
+
+      expect(await context.systems[0].notificationRepository.isNotificationScheduled(notificationLookup)).toBe(false);
+    });
+
+    it("fails if the notification doesn't exist", async () => {
+      const notificationInput = {
+        deviceId: "1",
+        shuttleId: "1",
+        stopId: "1",
+      }
+
+      const response = await getServerResponse(query, notificationInput);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const notificationResponse = response.body.singleResult.data?.cancelNotification as any;
+      expect(notificationResponse.success).toBe(false);
+    });
+  });
+});

src/resolvers/__tests__/OrderedStopResolverTests.test.ts

@@ -1,25 +1,24 @@
 import { beforeEach, describe, expect, it } from "@jest/globals";
-import { setupTestServerContext } from "../testHelpers/apolloTestServerHelpers";
-import { IRoute, IStop, ISystem } from "../../src/entities/entities";
-import { generateMockOrderedStops, generateMockStops } from "../testHelpers/mockDataGenerators";
-import { addMockRouteToRepository, addMockSystemToRepository } from "../testHelpers/repositorySetupHelpers";
+import { setupTestServerContext, setupTestServerHolder } from "../../../testHelpers/apolloTestServerHelpers";
+import { IRoute, IStop } from "../../entities/ShuttleRepositoryEntities";
+import { generateMockOrderedStops, generateMockStops } from "../../../testHelpers/mockDataGenerators";
+import { addMockRouteToRepository } from "../../../testHelpers/repositorySetupHelpers";
 import assert = require("node:assert");
 
 describe("OrderedStopResolvers", () => {
+  const holder = setupTestServerHolder();
   const context = setupTestServerContext();
 
-  let mockSystem: ISystem;
   let mockRoute: IRoute;
   let mockStops: IStop[];
 
   beforeEach(async () => {
-    mockSystem = await addMockSystemToRepository(context.repository);
-    mockRoute = await addMockRouteToRepository(context.repository, mockSystem.id);
+    mockRoute = await addMockRouteToRepository(context.systems[0].shuttleRepository, context.systems[0].id);
 
     mockStops = generateMockStops();
     await Promise.all(mockStops.map(async (mockStop) => {
-      mockStop.systemId = mockSystem.id;
-      await context.repository.addOrUpdateStop(mockStop);
+      mockStop.systemId = context.systems[0].id;
+      await context.systems[0].shuttleRepository.addOrUpdateStop(mockStop);
     }));
   });
 
@@ -37,8 +36,8 @@ describe("OrderedStopResolvers", () => {
     // Link the stops together
     orderedStops[0].nextStop = orderedStops[1];
     orderedStops[1].previousStop = orderedStops[0];
-    await context.repository.addOrUpdateOrderedStop(orderedStops[0]);
-    await context.repository.addOrUpdateOrderedStop(orderedStops[1]);
+    await context.systems[0].shuttleRepository.addOrUpdateOrderedStop(orderedStops[0]);
+    await context.systems[0].shuttleRepository.addOrUpdateOrderedStop(orderedStops[1]);
     return orderedStops;
   }
 
@@ -59,17 +58,16 @@ describe("OrderedStopResolvers", () => {
       }
       `;
 
-      return await context.testServer.executeOperation({
+      return await holder.testServer.executeOperation({
         query,
         variables: {
-          systemId: mockSystem.id,
+          systemId: context.systems[0].id,
           routeId: mockRoute.id,
           stopId,
         },
       }, {
-        contextValue: {
-          repository: context.repository,
-        }
+        contextValue: context
+
       });
     }
 
@@ -93,7 +91,7 @@ describe("OrderedStopResolvers", () => {
     it("returns null if there is no next stop in the repository", async () => {
       const orderedStops = await setUpOrderedStopsInRepository();
       orderedStops[0].nextStop = undefined;
-      await context.repository.addOrUpdateOrderedStop(orderedStops[0]);
+      await context.systems[0].shuttleRepository.addOrUpdateOrderedStop(orderedStops[0]);
 
       const response = await getResponseForNextStopQuery(orderedStops[0].stopId);
 
@@ -104,7 +102,7 @@ describe("OrderedStopResolvers", () => {
 
     it("returns null if the next stop object no longer exists", async () => {
       const orderedStops = await setUpOrderedStopsInRepository();
-      await context.repository.removeStopIfExists(orderedStops[1].stopId);
+      await context.systems[0].shuttleRepository.removeStopIfExists(orderedStops[1].stopId);
 
       const response = await getResponseForNextStopQuery(orderedStops[0].stopId);
 
@@ -131,17 +129,16 @@ describe("OrderedStopResolvers", () => {
         }
       `;
 
-      return await context.testServer.executeOperation({
+      return await holder.testServer.executeOperation({
         query,
         variables: {
-          systemId: mockSystem.id,
+          systemId: context.systems[0].id,
           routeId: mockRoute.id,
           stopId,
         },
       }, {
-        contextValue: {
-          repository: context.repository,
-        }
+        contextValue: context
+
       });
     }
 
@@ -164,7 +161,7 @@ describe("OrderedStopResolvers", () => {
     it("returns null if there is no previous stop in the repository", async () => {
       const orderedStops = await setUpOrderedStopsInRepository();
       orderedStops[1].previousStop = undefined;
-      await context.repository.addOrUpdateOrderedStop(orderedStops[1]);
+      await context.systems[0].shuttleRepository.addOrUpdateOrderedStop(orderedStops[1]);
 
       const response = await getResponseForPreviousStopQuery(orderedStops[1].stopId);
 
@@ -175,7 +172,7 @@ describe("OrderedStopResolvers", () => {
 
     it("returns null if the current stop no longer exists", async () => {
       const orderedStops = await setUpOrderedStopsInRepository();
-      await context.repository.removeStopIfExists(orderedStops[0].stopId);
+      await context.systems[0].shuttleRepository.removeStopIfExists(orderedStops[0].stopId);
 
       const response = await getResponseForPreviousStopQuery(orderedStops[1].stopId);
 
@@ -206,16 +203,15 @@ describe("OrderedStopResolvers", () => {
       }
       `;
 
-      return await context.testServer.executeOperation({
+      return await holder.testServer.executeOperation({
         query,
         variables: {
-          systemId: mockSystem.id,
+          systemId: context.systems[0].id,
           stopId,
         }
       }, {
-        contextValue: {
-          repository: context.repository,
-        }
+        contextValue: context
+
       });
     }
 
@@ -225,7 +221,7 @@ describe("OrderedStopResolvers", () => {
       orderedStops[0].stopId = mockStops[0].id;
 
       // Add one stop only
-      await context.repository.addOrUpdateOrderedStop(orderedStops[0]);
+      await context.systems[0].shuttleRepository.addOrUpdateOrderedStop(orderedStops[0]);
 
       const response = await getResponseForRouteQuery(orderedStops[1].stopId);
 
@@ -256,24 +252,23 @@ describe("OrderedStopResolvers", () => {
       }
       `;
 
-      return await context.testServer.executeOperation({
+      return await holder.testServer.executeOperation({
         query,
         variables: {
-          systemId: mockSystem.id,
+          systemId: context.systems[0].id,
           routeId: mockRoute.id,
           stopId,
         }
       }, {
-        contextValue: {
-          repository: context.repository,
-        }
+        contextValue: context
+
       });
     }
 
     it("returns the associated stop if it exists", async () => {
       const orderedStops = await setUpOrderedStopsInRepository();
       orderedStops[0].stopId = mockStops[0].id;
-      await context.repository.addOrUpdateOrderedStop(orderedStops[0]);
+      await context.systems[0].shuttleRepository.addOrUpdateOrderedStop(orderedStops[0]);
 
       const response = await getResponseForStopQuery(orderedStops[0].stopId);
 

src/resolvers/__tests__/ParkingStructureResolverTests.test.ts

@@ -0,0 +1,79 @@
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
+import { setupTestServerContext, setupTestServerHolder } from "../../../testHelpers/apolloTestServerHelpers";
+import { InterchangeSystem } from "../../entities/InterchangeSystem";
+import { generateParkingStructures } from "../../../testHelpers/mockDataGenerators";
+import { HistoricalParkingAverageQueryInput } from "../../generated/graphql";
+import assert = require("node:assert");
+
+jest.mock("../../environment");
+
+describe("ParkingStructureResolver", () => {
+  const holder = setupTestServerHolder();
+  const context = setupTestServerContext();
+
+  let mockSystem: InterchangeSystem;
+
+  beforeEach(async () => {
+    mockSystem = context.systems[0];
+    jest.useRealTimers();
+  });
+
+  describe("historicalAverages", () => {
+    const query = `
+    query GetParkingStructureHistoricalAverages(
+      $systemId: ID!,
+      $parkingStructureId: ID!,
+      $historicalAverageInput: HistoricalParkingAverageQueryInput!
+    ) {
+      system(id: $systemId) {
+        parkingSystem {
+          parkingStructure(id: $parkingStructureId) {
+            historicalAverages(input: $historicalAverageInput) {
+              from
+              to
+              averageSpotsAvailable
+            }
+          }
+        }
+      }
+    }
+    `;
+
+    it("gets data for historical averages", async () => {
+      jest.useFakeTimers();
+      jest.setSystemTime(new Date());
+
+      const parkingStructure = generateParkingStructures()[0];
+      parkingStructure.spotsAvailable = parkingStructure.capacity;
+      mockSystem.parkingRepository?.setLoggingInterval(100);
+
+      // Simulate repeated updates
+      for (let i = 0; i < 6; i += 1) {
+        jest.setSystemTime(new Date(Date.now() + 1000));
+        parkingStructure.spotsAvailable = parkingStructure.spotsAvailable - 100;
+        await mockSystem.parkingRepository?.addOrUpdateParkingStructure(parkingStructure);
+      }
+
+      const historicalAverageInput: HistoricalParkingAverageQueryInput = {
+        from: new Date(Date.now() - 5000).getTime(),
+        intervalMs: 2000,
+        to: new Date().getTime(),
+      };
+      const response = await holder.testServer.executeOperation({
+        query,
+        variables: {
+          systemId: mockSystem.id,
+          parkingStructureId: parkingStructure.id,
+          historicalAverageInput,
+        },
+      }, {
+        contextValue: context,
+      });
+
+      assert(response.body.kind === 'single');
+      expect(response.body.singleResult.errors).toBeUndefined();
+      const historicalAverages = (response.body.singleResult.data as any).system.parkingSystem.parkingStructure.historicalAverages;
+      expect(historicalAverages).toHaveLength(3);
+    });
+  });
+});

src/resolvers/__tests__/ParkingSystemResolverTests.test.ts

@@ -0,0 +1,200 @@
+import { beforeEach, describe, expect, it } from "@jest/globals";
+import { generateParkingStructures } from "../../../testHelpers/mockDataGenerators";
+import { setupTestServerContext, setupTestServerHolder } from "../../../testHelpers/apolloTestServerHelpers";
+import { InterchangeSystem } from "../../entities/InterchangeSystem";
+import assert = require("node:assert");
+
+
+describe("ParkingSystemResolver", () => {
+  const holder = setupTestServerHolder();
+  const context = setupTestServerContext();
+
+  let mockSystem: InterchangeSystem;
+
+  beforeEach(async () => {
+    mockSystem = context.systems[0];
+  });
+
+  async function getResponseFromQueryNeedingSystemId(query: string) {
+    return await holder.testServer.executeOperation({
+      query,
+      variables: {
+        systemId: mockSystem.id,
+      },
+    }, {
+      contextValue: context,
+    });
+  }
+
+  describe("parkingStructures", () => {
+    const query = `
+    query GetParkingStructuresBySystem($systemId: ID!) {
+      system(id: $systemId) {
+        parkingSystem {
+          parkingStructures {
+            name
+            id
+            capacity
+            spotsAvailable
+            coordinates {
+              latitude
+              longitude
+            }
+            address
+            updatedTime
+          }
+        }
+      }
+    }
+    `
+
+    it("gets parking structures associated with the system id", async () => {
+      let expectedParkingStructures = generateParkingStructures();
+      await Promise.all(expectedParkingStructures.map(async (structure) => {
+        await context.systems[0].parkingRepository?.addOrUpdateParkingStructure(structure);
+      }));
+
+      // Dates are transformed into epoch timestamps when serialized
+      expectedParkingStructures = expectedParkingStructures.map((structure) => {
+        const newStructure = { ...structure };
+        // @ts-ignore
+        newStructure.updatedTime = newStructure.updatedTime.getTime();
+        return newStructure;
+      });
+
+      const response = await getResponseFromQueryNeedingSystemId(query);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const parkingStructures = (response.body.singleResult.data as any).system.parkingSystem.parkingStructures;
+      expect(parkingStructures).toEqual(expectedParkingStructures);
+    });
+
+    it("returns a blank array if there are no parking structures", async () => {
+      const response = await getResponseFromQueryNeedingSystemId(query);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const parkingStructures = (response.body.singleResult.data as any).system.parkingSystem.parkingStructures;
+
+      expect(parkingStructures).toHaveLength(0);
+    });
+
+    it("returns parking structures sorted by name", async () => {
+      // Create two out-of-order structures by name
+      const s1 = {
+        id: "ps1",
+        name: "Barrera",
+        capacity: 100,
+        spotsAvailable: 50,
+        coordinates: { latitude: 0, longitude: 0 },
+        address: "1 Anywhere",
+        updatedTime: new Date(),
+      };
+      const s2 = {
+        id: "ps2",
+        name: "Anderson",
+        capacity: 100,
+        spotsAvailable: 50,
+        coordinates: { latitude: 0, longitude: 0 },
+        address: "2 Anywhere",
+        updatedTime: new Date(),
+      };
+      await context.systems[0].parkingRepository?.addOrUpdateParkingStructure(s1);
+      await context.systems[0].parkingRepository?.addOrUpdateParkingStructure(s2);
+
+      const minimalQuery = `
+      query GetParkingStructuresBySystem($systemId: ID!) {
+        system(id: $systemId) {
+          parkingSystem {
+            parkingStructures {
+              name
+            }
+          }
+        }
+      }
+      `;
+
+      const response = await getResponseFromQueryNeedingSystemId(minimalQuery);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+      const names = (response.body.singleResult.data as any).system.parkingSystem.parkingStructures.map((p: any) => p.name);
+      expect(names).toEqual([s2.name, s1.name]);
+    });
+  });
+
+
+  describe("parkingStructure", () => {
+    async function getResponseForParkingStructureQuery(parkingStructureId: string) {
+      const query = `
+      query GetParkingStructureBySystem($systemId: ID!, $parkingStructureId: ID!) {
+        system(id: $systemId) {
+          parkingSystem {
+            parkingStructure(id: $parkingStructureId) {
+              name
+              id
+              capacity
+              spotsAvailable
+              coordinates {
+                latitude
+                longitude
+              }
+              address
+              updatedTime
+            }
+          }
+        }
+      }
+      `;
+
+      return await holder.testServer.executeOperation({
+        query,
+        variables: {
+          systemId: mockSystem.id,
+          parkingStructureId,
+        }
+      }, {
+        contextValue: context
+
+      });
+    }
+
+    it("returns the correct parking structure given the id", async () => {
+      const generatedParkingStructures = generateParkingStructures();
+      await Promise.all(generatedParkingStructures.map(async (structure) => {
+        await context.systems[0].parkingRepository?.addOrUpdateParkingStructure(structure);
+      }));
+      const expectedParkingStructure = generatedParkingStructures[1];
+      // @ts-ignore
+      expectedParkingStructure.updatedTime = expectedParkingStructure.updatedTime.getTime();
+
+      const response = await getResponseForParkingStructureQuery(expectedParkingStructure.id);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const parkingStructure = (response.body.singleResult.data as any).system.parkingSystem.parkingStructure;
+      expect(parkingStructure).toEqual(expectedParkingStructure);
+    });
+
+    it("returns null if there is no matching parking structure", async () => {
+      const generatedParkingStructures = generateParkingStructures();
+      await Promise.all(generatedParkingStructures.map(async (structure) => {
+        await context.systems[0].parkingRepository?.addOrUpdateParkingStructure(structure);
+      }));
+
+      const nonexistentId = generatedParkingStructures[0].id + "12345";
+
+      const response = await getResponseForParkingStructureQuery(nonexistentId);
+
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const parkingStructure = (response.body.singleResult.data as any).system.parkingSystem.parkingStructure;
+      expect(parkingStructure).toBeNull();
+    });
+  });
+});