Aurora SpotiRip desktop and web app

- Spotify playlist, library, album and artist browsing with in-app playback
- Song, playlist and album downloads via spotdl with YouTube and Bandcamp fallbacks
- Electron desktop app (castLabs Widevine) with a permanent sidebar layout
- Linux and Windows packaging scripts

endpoints/lyrics_POST.ts

@@ -0,0 +1,57 @@
+import superjson from "superjson";
+import { schema, type OutputType } from "./lyrics_POST.schema";
+
+type LrclibResult = {
+  plainLyrics?: string | null;
+  syncedLyrics?: string | null;
+  instrumental?: boolean;
+};
+
+function delay(ms: number) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+export async function handle(request: Request) {
+  try {
+    const input = schema.parse(superjson.parse(await request.text()));
+    const params = new URLSearchParams({
+      artist_name: input.artist,
+      track_name: input.title,
+    });
+    if (input.album) params.set("album_name", input.album);
+    if (input.durationMs) {
+      params.set("duration", String(Math.round(input.durationMs / 1000)));
+    }
+    let response: Response | undefined;
+    for (let attempt = 0; attempt < 2; attempt += 1) {
+      response = await fetch(`https://lrclib.net/api/get?${params.toString()}`, {
+        headers: { "User-Agent": "Aurora-SpotiRip/1.0" },
+      });
+      if (response.status !== 429 || attempt > 0) break;
+      const retryAfter = Number(response.headers.get("retry-after") || 1);
+      await delay(Math.min(5000, Math.max(500, retryAfter * 1000)));
+    }
+    if (!response) {
+      throw new Error("Lyrics service did not respond.");
+    }
+    if (response.status === 404) {
+      return new Response(superjson.stringify({} satisfies OutputType));
+    }
+    if (!response.ok) {
+      return new Response(
+        superjson.stringify({ error: `Lyrics service returned HTTP ${response.status}.` }),
+        { status: 502 },
+      );
+    }
+    const result = (await response.json()) as LrclibResult;
+    const output: OutputType = {
+      plain: result.plainLyrics || undefined,
+      synced: result.syncedLyrics || undefined,
+      instrumental: Boolean(result.instrumental),
+    };
+    return new Response(superjson.stringify(output));
+  } catch (error) {
+    const message = error instanceof Error ? error.message : "Unable to load lyrics.";
+    return new Response(superjson.stringify({ error: message }), { status: 400 });
+  }
+}