Add bulk import of a YouTube playlist URL

server/server.js

@@ -15,6 +15,7 @@
  *   GET  /api/user/data?fp=<fp>        retrieve stored playlists + history
  *   POST /api/playlist/share           share a single playlist → { ok, code }
  *   GET  /api/playlist/shared?code=<code> retrieve shared playlist → { ok, code, playlist, createdAt }
+ *   GET  /api/playlist/expand?url=<url> expand YouTube playlist → { ok, title, entries, truncated? }
  *   GET  /*                            serve frontend/public static files
  *
  * JSON shapes mirror the Tauri (Rust) bridge exactly so the existing app.js
@@ -730,6 +731,62 @@ app.get('/api/playlist/shared', async (c) => {
   }
 });
 
+function isYoutubeHost(hostname) {
+  const h = (hostname || '').toLowerCase();
+  return h === 'youtube.com' || h.endsWith('.youtube.com') ||
+         h === 'youtu.be' || h.endsWith('.youtu.be');
+}
+
+function isValidYoutubeUrl(rawUrl) {
+  if (typeof rawUrl !== 'string' || !rawUrl.trim()) return false;
+  try {
+    const u = new URL(rawUrl.trim());
+    return (u.protocol === 'http:' || u.protocol === 'https:') && isYoutubeHost(u.hostname);
+  } catch {
+    return false;
+  }
+}
+
+// GET /api/playlist/expand?url=<youtube playlist url>
+// Expands a YouTube playlist URL into slim video cards without resolving streams.
+app.get('/api/playlist/expand', async (c) => {
+  const url = (c.req.query('url') || '').trim();
+  if (!url || !isValidYoutubeUrl(url)) {
+    return c.json({ ok: false, error: 'invalid YouTube URL' }, 400);
+  }
+
+  try {
+    const out = await runYtdlp([
+      url,
+      '--dump-json', '--flat-playlist',
+      '--no-warnings', '--ignore-errors',
+      '--playlist-end', '201',
+    ]);
+    const parsed = parseCards(out);
+    let title = '';
+    for (const line of out.split('\n')) {
+      const t = line.trim();
+      if (!t) continue;
+      try {
+        const j = JSON.parse(t);
+        title = title || pick(j, 'playlist_title', 'playlist');
+        if (title) break;
+      } catch { /* skip */ }
+    }
+    const truncated = parsed.length > 200;
+    const entries = parsed.slice(0, 200);
+    const resp = {
+      ok: true,
+      title: title || '',
+      entries,
+    };
+    if (truncated) resp.truncated = true;
+    return c.json(resp);
+  } catch (err) {
+    return c.json({ ok: false, error: err.message }, 502);
+  }
+});
+
 // POST /api/user/sync
 // Body: { fingerprint, playlists?, recentVideo?, appVersion? }
 app.post('/api/user/sync', async (c) => {