refactor(lyrics): convert to singleton

js/app.js

@@ -106,8 +106,6 @@ let settingsModule = null;
 let downloadsModule = null;
 let metadataModule = null;
 
-export const managers = {};
-
 async function loadSettingsModule() {
     if (!settingsModule) {
         settingsModule = await import('./settings.js');
@@ -654,9 +652,9 @@ document.addEventListener('DOMContentLoaded', async () => {
 
     const scrobbler = new MultiScrobbler();
     window.monochromeScrobbler = scrobbler;
-    const lyricsManager = new LyricsManager(MusicAPI.instance);
+
+    const lyricsManager = await LyricsManager.initialize(MusicAPI.instance);
     ui.lyricsManager = lyricsManager;
-    managers.lyricsManager = lyricsManager;
 
     // Check browser support for local files
     const selectLocalBtn = document.getElementById('select-local-folder-btn');

js/lyrics.js

@@ -151,6 +151,16 @@ class GeniusManager {
 }
 
 export class LyricsManager {
+    static #instance = null;
+
+    static get instance() {
+        if (!LyricsManager.#instance) {
+            throw new Error('LyricsManager is not initialized. Call LyricsManager.initialize() first.');
+        }
+        return LyricsManager.#instance;
+    }
+
+    /** @private */
     constructor(api) {
         this.api = api;
         this.currentLyrics = null;
@@ -174,6 +184,13 @@ export class LyricsManager {
         this.timingOffset = 0; // Offset in milliseconds (positive = delay lyrics, negative = advance lyrics)
     }
 
+    static async initialize(api) {
+        if (LyricsManager.#instance) {
+            throw new Error('LyricsManager is already initialized');
+        }
+        return (LyricsManager.#instance = new LyricsManager(api));
+    }
+
     // Get timing offset for current track
     getTimingOffset(trackId) {
         try {

js/metadata.js

@@ -1,7 +1,7 @@
 import { getCoverBlob, getTrackTitle, getFullArtistString, getMimeType, getTrackCoverId } from './utils.js';
 import { addMetadataWithTagLib, getMetadataWithTagLib } from './taglib.ts';
 import { doTimed, doTimedAsync } from './doTimed.ts';
-import { managers } from './app.js';
+import { LyricsManager } from './lyrics.js';
 
 export function prefetchMetadataObjects(track, api, coverBlob = null) {
     const coverId = getTrackCoverId(track);
@@ -10,7 +10,7 @@ export function prefetchMetadataObjects(track, api, coverBlob = null) {
         : coverId
           ? getCoverBlob(api, coverId).catch(console.error)
           : Promise.resolve(null);
-    const lyricsFetch = managers?.lyricsManager?.fetchLyrics?.(track.id, track)?.catch(console.error);
+    const lyricsFetch = LyricsManager.initialize.fetchLyrics?.(track.id, track)?.catch(console.error);
 
     return { coverFetch, lyricsFetch };
 }