import { beforeEach, describe, expect, it } from "@jest/globals";
import { ApolloServer } from "@apollo/server";
import { UnoptimizedInMemoryRepository } from "../../src/repositories/UnoptimizedInMemoryRepository";
import { ServerContext } from "../../src/ServerContext";
import { setUpTestServer } from "../testHelpers/apolloSetupHelpers";
import { IRoute, IStop, ISystem } from "../../src/entities/entities";
import {
  generateMockOrderedStops,
  generateMockRoutes,
  generateMockShuttles,
  generateMockStops,
  generateMockSystems
} from "../generators";
import assert = require("node:assert");

describe("OrderedStopResolvers", () => {
  let testServer: ApolloServer<ServerContext>;
  let repository: UnoptimizedInMemoryRepository;

  beforeEach(async () => {
    testServer = setUpTestServer();
    repository = new UnoptimizedInMemoryRepository();
  });

  let mockSystem: ISystem;
  let mockRoute: IRoute;
  let mockStops: IStop[];

  beforeEach(async () => {
    const mockSystems = generateMockSystems();
    mockSystem = mockSystems[0];
    mockSystem.id = "1";
    await repository.addOrUpdateSystem(mockSystem);

    const mockRoutes = generateMockRoutes();
    mockRoute = mockRoutes[0];
    mockRoute.id = "1";
    await repository.addOrUpdateRoute(mockRoute);

    mockStops = generateMockStops();

    await Promise.all(mockStops.map(async (mockStop) => {
      await repository.addOrUpdateStop(mockStop);
    }));
  });

  async function setUpOrderedStopsInRepository() {
    const orderedStops = generateMockOrderedStops();

    // Set up IDs and link stops together to work with the test query
    orderedStops[0].routeId = mockRoute.id;
    orderedStops[1].routeId = mockRoute.id;

    // Ensure that there is no duplication
    orderedStops[0].stopId = mockStops[0].id;
    orderedStops[1].stopId = mockStops[1].id;

    // Link the stops together
    orderedStops[0].nextStop = orderedStops[1];
    orderedStops[1].previousStop = orderedStops[0];
    await repository.addOrUpdateOrderedStop(orderedStops[0]);
    await repository.addOrUpdateOrderedStop(orderedStops[1]);
    return orderedStops;
  }

  describe("nextStop", () => {
    async function getResponseForQuery(stopId: string) {
      const query = `
      query GetNextStop($systemId: ID!, $routeId: ID!, $stopId: ID!) {
        system(id: $systemId) {
          route(id: $routeId) {
            orderedStop(forStopId: $stopId) {
              nextStop {
                routeId
                stopId
              }
            }
          }
        }
      }
      `;

      return await testServer.executeOperation({
        query,
        variables: {
          systemId: mockSystem.id,
          routeId: mockRoute.id,
          stopId,
        },
      }, {
        contextValue: {
          repository,
        }
      });
    }


    it("returns the next stop if it exists", async () => {
      // Arrange
      const orderedStops = await setUpOrderedStopsInRepository();

      // Act
      const response = await getResponseForQuery(orderedStops[0].stopId);

      // Assert
      assert(response.body.kind === "single");
      expect(response.body.singleResult.errors).toBeUndefined();

      const nextStop = (response.body.singleResult.data?.system as any).route.orderedStop.nextStop;
      expect(nextStop.stopId).toEqual(orderedStops[1].stopId);
      expect(nextStop.routeId).toEqual(orderedStops[1].routeId);
    });

    it("returns null if there is no next stop in the repository", async () => {
      const orderedStops = await setUpOrderedStopsInRepository();
      orderedStops[0].nextStop = undefined;
      await repository.addOrUpdateOrderedStop(orderedStops[0]);

      const response = await getResponseForQuery(orderedStops[0].stopId);

      assert(response.body.kind === "single");
      const nonexistentNextStop = (response.body.singleResult.data?.system as any).route.orderedStop.nextStop;
      expect(nonexistentNextStop).toBeNull();
    });

    it("returns null if the next stop object no longer exists", async () => {
      const orderedStops = await setUpOrderedStopsInRepository();
      await repository.removeStopIfExists(orderedStops[1].stopId);

      const response = await getResponseForQuery(orderedStops[0].stopId);

      assert(response.body.kind === "single");
      const nonexistentNextStop = (response.body.singleResult.data?.system as any).route.orderedStop.nextStop;
      expect(nonexistentNextStop).toBeNull();
    });
  });

  describe("previousStop", () => {
    const query = `
    query GetNextStop($systemId: ID!, $routeId: ID!, $stopId: ID!) {
      system(id: $systemId) {
        route(id: $routeId) {
          orderedStop(forStopId: $stopId) {
            previousStop {
              routeId
              stopId
            }
          }
        }
      }
    }
    `;

    it("returns the previous stop if it exists", async () => {

    });

    it("returns null if there is no previous stop in the repository", async () => {

    });

    it("returns null if the current stop no longer exists", async () => {

    });
  });

  describe("route", () => {
    // Note that there is no `orderedStop(forRouteId)` resolver,
    // so fetch all ordered stops for a stop instead
    const query = `
    query GetNextStop($systemId: ID!, $stopId: ID!) {
      system(id: $systemId) {
        stop(id: $stopId) {
          orderedStops {
            route {
              id
              name
            }
          }
        }
      }
    }
    `;
  });

  it("returns the associated route if it exists", async () => {

  });

  it("returns null if the route doesn't exist", async () => {

  });

  describe("stop", () => {
    const query = `
    query GetNextStop($systemId: ID!, $routeId: ID!, $stopId: ID!) {
      system(id: $systemId) {
        route(id: $routeId) {
          orderedStop(forStopId: $stopId) {
            stop {
              name
              id
            }
          }
        }
      }
    }
    `;

    it("returns the associated stop if it exists", async () => {

    });

    it("returns null if the stop doesn't exist", async () => {

    });
  });
});