Cache music as mp3 files on startup

src/routes/api/music/+server.ts

@@ -1,8 +1,9 @@
 import { json } from '@sveltejs/kit';
 import { getPlaylistTracks } from '#lib/server/music';
+import { isSongCached } from '#lib/server/musicCache';
 import type { RequestHandler } from './$types';
 
 export const GET: RequestHandler = async () => {
-	const tracks = await getPlaylistTracks();
+	const tracks = (await getPlaylistTracks()).map((track) => ({ ...track, cached: isSongCached(track.id) }));
 	return json(tracks, { headers: { 'Cache-Control': 'no-store' } });
 };

src/routes/api/music/[id]/+server.ts

@@ -1,10 +1,19 @@
 import { error } from '@sveltejs/kit';
 import { isPlaylistVideo, streamTrackAsMp3 } from '#lib/server/music';
+import { isSongCached, serveCachedSong } from '#lib/server/musicCache';
 import type { RequestHandler } from './$types';
 
-export const GET: RequestHandler = ({ params, url }) => {
+export const GET: RequestHandler = async ({ params, url, request }) => {
 	if (!isPlaylistVideo(params.id)) error(404, 'Song not found');
 
+	if (isSongCached(params.id)) {
+		try {
+			return await serveCachedSong(params.id, request.headers.get('range'));
+		} catch (cacheError) {
+			console.error(`Cached song unavailable for ${params.id}:`, cacheError);
+		}
+	}
+
 	const requestedStart = Number(url.searchParams.get('start') ?? 0);
 	const startSeconds = Number.isFinite(requestedStart) && requestedStart > 0 ? Math.floor(requestedStart) : 0;