implement sse

src/homepage/service.ts

@@ -2,6 +2,7 @@ import {
 	BaseService,
 	FullInformation,
 	HomeAssistantDeskPositionResult,
+	SseClientChangeEvent,
 	SseService,
 	TidalGetCurrent,
 	type ServiceResult,
@@ -14,33 +15,135 @@ export class HomepageService extends BaseService<null> {
 	private haService: HomeAssistantService;
 	private tidalService: TidalService;
 	private sseService: SseService;
+	private pollingInterval: ReturnType<typeof setInterval> | null = null;
+	private songEndTimeout: ReturnType<typeof setTimeout> | null = null;
+	private lastPoll: FullInformation | null = null;
 
-	constructor(haService: HomeAssistantService, tidalService: TidalService, sseService: SseService) {
+	constructor(
+		haService: HomeAssistantService,
+		tidalService: TidalService,
+		sseService: SseService,
+	) {
 		super(null);
 		this.haService = haService;
 		this.tidalService = tidalService;
 		this.sseService = sseService;
+		this.listenForClientChange();
 	}
 
 	async getFullInformation(): Promise<ServiceResult<FullInformation | string>> {
 		try {
 			const [desk, temp, song] = await Promise.all([
-			  this.haService.getDeskPosition(),
-			  this.haService.getTemperatureText(),
-			  this.tidalService.getSong()
+				this.haService.getDeskPosition(),
+				this.haService.getTemperatureText(),
+				this.tidalService.getSong(),
 			]);
 
 			const result = {
-				ha_desk_position: desk.successful ? this.haService.convertPosResultToApiAnswer(desk.result as HomeAssistantDeskPositionResult) : null,
+				ha_desk_position: desk.successful
+					? this.haService.convertPosResultToApiAnswer(
+							desk.result as HomeAssistantDeskPositionResult,
+						)
+					: null,
 				ha_temp: temp.successful ? temp.result : null,
-				tidal_current: song ? song.result as TidalGetCurrent : null,
-			}
+				tidal_current: song ? (song.result as TidalGetCurrent) : null,
+			};
 
-			return this.getSuccessfulResult(result);
+			return this.getSuccessfulResult(this.updateLastPoll(result));
 		} catch {
 			const error_message = "error getting all information";
 			logWarning(error_message);
 			return this.getErrorResult(error_message);
 		}
 	}
+
+	updateLastPoll(newPoll: FullInformation) {
+		const updates = [];
+		if (
+			this.lastPoll?.ha_desk_position?.is_standing !==
+			newPoll.ha_desk_position?.is_standing
+		) {
+			updates.push({
+				component: "ha_desk_position",
+				data: newPoll.ha_desk_position,
+			});
+		}
+
+		if (this.lastPoll?.ha_temp !== newPoll.ha_temp) {
+			updates.push({
+				component: "ha_temp",
+				data: newPoll.ha_temp,
+			});
+		}
+
+		if (
+			this.lastPoll?.tidal_current?.title !== newPoll.tidal_current?.title ||
+			this.lastPoll?.tidal_current?.status !== newPoll.tidal_current?.status
+		) {
+			updates.push({
+				component: "tidal_current",
+				data: newPoll.tidal_current,
+			});
+		}
+
+		this.sseService.notifyClients({
+			type: "update",
+			data: updates,
+		});
+
+		this.lastPoll = newPoll;
+		this.scheduleSongEndPoll(newPoll.tidal_current);
+		return newPoll;
+	}
+
+	private scheduleSongEndPoll(tidal: TidalGetCurrent | null): void {
+		this.clearSongEndPoll();
+
+		if (!tidal || tidal.status === "paused") {
+			return;
+		}
+
+		const remainingSeconds = tidal.durationInSeconds - tidal.currentInSeconds;
+		if (remainingSeconds > 0) {
+			this.songEndTimeout = setTimeout(
+				() => {
+					this.songEndTimeout = null;
+					this.getFullInformation();
+				},
+				(remainingSeconds + 1) * 1000,
+			);
+		}
+	}
+
+	private clearSongEndPoll(): void {
+		if (this.songEndTimeout) {
+			clearTimeout(this.songEndTimeout);
+			this.songEndTimeout = null;
+		}
+	}
+
+	listenForClientChange(): void {
+		this.sseService.onClientChange((clientChange: SseClientChangeEvent) => {
+			if (clientChange.clientCount === 0) {
+				this.stopPolling();
+			} else {
+				if (!this.pollingInterval) {
+					this.startPolling();
+				}
+			}
+		});
+	}
+
+	startPolling(): void {
+		this.pollingInterval = setInterval(() => {
+			this.getFullInformation();
+		}, 30000);
+	}
+
+	stopPolling(): void {
+		if (this.pollingInterval) {
+			clearInterval(this.pollingInterval);
+		}
+		this.clearSongEndPoll();
+	}
 }