add eta subscriber callback code

src/services/NotificationService.ts

@@ -3,6 +3,7 @@ import * as crypto from "node:crypto";
 import jwt from "jsonwebtoken";
 import fs from "fs";
 import { TupleKey } from "../types/TupleKey";
+import { IEta } from "../entities/entities";
 
 interface ScheduledNotificationData {
   deviceId: string;
@@ -62,13 +63,29 @@ export class NotificationService {
     return this._lastRefreshedTimeMs && Date.now() - this._lastRefreshedTimeMs < thirtyMinutesMs;
   }
 
-  private sendEtaNotificationImmediately({ deviceId, shuttleId, stopId }: ScheduledNotificationData) {
+  private async sendEtaNotificationImmediately({ deviceId, shuttleId, stopId }: ScheduledNotificationData): Promise<boolean> {
     // Construct the fetch request
 
     // Send the fetch request
 
     // Check whether it was successful
     // Return the result
+    return false;
+  }
+
+  private async etaSubscriberCallback(eta: IEta) {
+    const tuple = new TupleKey(eta.shuttleId, eta.stopId);
+    if (this.deviceIdsToDeliverTo[tuple.toString()] === undefined) {
+      return;
+    }
+
+    await Promise.all(this.deviceIdsToDeliverTo[tuple.toString()].map(async (deviceId) => {
+      await this.sendEtaNotificationImmediately({
+        deviceId,
+        shuttleId: eta.shuttleId,
+        stopId: eta.stopId,
+      });
+    }));
   }
 
   /**
@@ -78,7 +95,6 @@ export class NotificationService {
    * @param stopId Stop ID of ETA object to check.
    */
   public async scheduleNotification({ deviceId, shuttleId, stopId }: ScheduledNotificationData) {
-    // Associate TupleKey(shuttleId, stopId) with array of device IDs
     const tuple = new TupleKey(shuttleId, stopId);
     if (this.deviceIdsToDeliverTo[tuple.toString()] === undefined) {
       this.deviceIdsToDeliverTo[tuple.toString()] = [deviceId];
@@ -87,6 +103,8 @@ export class NotificationService {
     }
 
     // Refresh the subscriber with the updated array if needed
+    this.repository.unsubscribeFromEtaUpdates(this.etaSubscriberCallback);
+    this.repository.subscribeToEtaUpdates(this.etaSubscriberCallback);
 
     // In the subscriber callback:
     // If the ETA matches, call sendNotification with the necessary parameters