feat(scrobble stats): genre ranking (Top-Genres) — web + android

Play-log now stores each play's genre (from the song tags; web scrobbleLog +
android PlayLogClient capture song.genre). The stats endpoint returns topGenres
(GROUP BY lower(genre), case-insensitive, blanks ignored); web + android render a
Top-Genres section. Schema migrates via ALTER TABLE. Old plays have no genre
(fills going forward, like cover art). SW cache -> ns-v72.

Android compileDebugKotlin + web build green; genre grouping + null-ignore unit-tested.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

android/app/src/main/kotlin/com/novasonic/app/api/model/ScrobbleModels.kt

@@ -11,10 +11,17 @@ data class ScrobbleStats(
     val topArtists: List<StatArtist> = emptyList(),
     val topAlbums: List<StatAlbum> = emptyList(),
     val topTracks: List<StatTrack> = emptyList(),
+    val topGenres: List<StatGenre> = emptyList(),
     val series: List<StatBucket> = emptyList(),
     val byHour: List<StatHour> = emptyList(),
 )
 
+@Serializable
+data class StatGenre(
+    val name: String? = null,
+    val plays: Int = 0,
+)
+
 @Serializable
 data class StatArtist(
     val name: String? = null,

android/app/src/main/kotlin/com/novasonic/app/data/PlayLogClient.kt

@@ -60,6 +60,7 @@ class PlayLogClient(context: Context) {
         val album: String? = null,
         val albumId: String? = null,
         val coverArt: String? = null,
+        val genre: String? = null,
         val duration: Int? = null,
         val playedAt: Long,
         val source: String = "android",
@@ -81,6 +82,7 @@ class PlayLogClient(context: Context) {
             album    = song.album,
             albumId  = song.albumId,
             coverArt = song.coverArt,
+            genre    = song.genre,
             duration = song.duration,
             playedAt = System.currentTimeMillis() / 1000,
         )

android/app/src/main/kotlin/com/novasonic/app/ui/screen/StatsScreen.kt

@@ -159,6 +159,12 @@ private fun StatsContent(
             Spacer(Modifier.height(20.dp))
         }
 
+        if (d.topGenres.isNotEmpty()) {
+            SectionHeader("Top-Genres")
+            d.topGenres.forEachIndexed { i, g -> GenreRow(i + 1, g.name ?: "—", g.plays) }
+            Spacer(Modifier.height(20.dp))
+        }
+
         if (d.byHour.any { it.plays > 0 }) {
             SectionHeader("Hör-Uhr (Stunde)")
             HourClock(d.byHour.map { it.plays })
@@ -166,6 +172,25 @@ private fun StatsContent(
     }
 }
 
+@Composable
+private fun GenreRow(rank: Int, name: String, plays: Int) {
+    Row(
+        verticalAlignment = Alignment.CenterVertically,
+        modifier = Modifier.fillMaxWidth().padding(vertical = 6.dp),
+    ) {
+        Text(
+            rank.toString(), fontFamily = Outfit, fontWeight = FontWeight.Bold, fontSize = 13.sp,
+            color = NsOnSurface2, modifier = Modifier.width(22.dp),
+        )
+        Text(
+            name, fontFamily = Outfit, fontWeight = FontWeight.SemiBold, fontSize = 14.sp,
+            color = NsOnSurface, maxLines = 1, overflow = TextOverflow.Ellipsis,
+            modifier = Modifier.weight(1f).padding(horizontal = 12.dp),
+        )
+        Text("$plays", fontFamily = Outfit, fontWeight = FontWeight.SemiBold, fontSize = 13.sp, color = NsOnSurface2)
+    }
+}
+
 @Composable
 private fun StepArrow(glyph: String, enabled: Boolean, onClick: () -> Unit) {
     Text(

public/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'ns-v71';
+const CACHE = 'ns-v72';
 const PRECACHE = ['/', 'index.html', 'manifest.json', 'icon.svg'];
 const SKIP_PATHS = ['/rest/stream', '/rest/download', '/config.js'];
 // Auth token params stripped from cache keys so artwork survives across sessions/token refreshes.

scrobble/scrobble-server.js

@@ -53,19 +53,21 @@ db.exec(`
     played_at  INTEGER NOT NULL,   -- Unix epoch, UTC
     source     TEXT,               -- 'web' | 'android'
     uuid       TEXT UNIQUE,        -- idempotency for offline-retry
-    cover_art  TEXT                -- Subsonic coverArt token (NOT the entity id) for real covers
+    cover_art  TEXT,               -- Subsonic coverArt token (NOT the entity id) for real covers
+    genre      TEXT                -- per-play genre (from the song's tags) for genre stats
   );
 `);
-// Migration for DBs created before cover_art existed (ALTER throws if the column is already there).
+// Migrations for DBs created before a column existed (ALTER throws if it's already there).
 try { db.exec('ALTER TABLE plays ADD COLUMN cover_art TEXT'); } catch {}
+try { db.exec('ALTER TABLE plays ADD COLUMN genre TEXT'); } catch {}
 db.exec('CREATE INDEX IF NOT EXISTS ix_plays_user_time   ON plays(user, played_at);');
 db.exec('CREATE INDEX IF NOT EXISTS ix_plays_user_artist ON plays(user, artist_id);');
 db.exec('CREATE INDEX IF NOT EXISTS ix_plays_user_song   ON plays(user, song_id);');
 
 const _insert = db.prepare(`
   INSERT OR IGNORE INTO plays
-    (user, song_id, title, artist, artist_id, album, album_id, duration, played_at, source, uuid, cover_art)
+    (user, song_id, title, artist, artist_id, album, album_id, duration, played_at, source, uuid, cover_art, genre)
-  VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+  VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
 `);
 const _history = db.prepare(`
   SELECT id, song_id, title, artist, artist_id, album, album_id, duration, played_at, source
@@ -145,7 +147,8 @@ app.post('/scrobble/plays', async (req, res) => {
         _toEpochSec(p.playedAt),
         p.source === 'android' ? 'android' : 'web',
         uuid,
-        p.coverArt ?? null
+        p.coverArt ?? null,
+        p.genre ?? null
       );
       if (r.changes > 0) accepted++; else duplicates++;
     } catch { invalid++; }
@@ -220,6 +223,12 @@ app.get('/scrobble/stats', async (req, res) => {
     GROUP BY song_id ORDER BY plays DESC LIMIT :limit
   `).all(winL);
 
+  const topGenres = db.prepare(`
+    SELECT MAX(genre) AS name, COUNT(*) AS plays
+    FROM plays WHERE ${WHERE} AND genre IS NOT NULL AND genre <> ''
+    GROUP BY lower(genre) ORDER BY plays DESC LIMIT :limit
+  `).all(winL);
+
   const series = db.prepare(`
     SELECT strftime('${fmt}', played_at + :tz, 'unixepoch') AS bucket, COUNT(*) AS plays, COALESCE(SUM(duration),0) AS seconds
     FROM plays WHERE ${WHERE} GROUP BY bucket ORDER BY bucket
@@ -238,7 +247,7 @@ app.get('/scrobble/stats', async (req, res) => {
     firstPlayedAt,
     totalPlays: totals.plays,
     totalSeconds: totals.seconds,
-    topArtists, topAlbums, topTracks, series, byHour,
+    topArtists, topAlbums, topTracks, topGenres, series, byHour,
   });
 });
 

src/player/scrobbleLog.js

@@ -41,6 +41,7 @@ export function logPlay(song, source = 'web') {
     album:    song.album    ?? null,
     albumId:  song.albumId  ?? null,
     coverArt: song.coverArt ?? null,   // Subsonic coverArt token — what getCoverArt actually needs
+    genre:    song.genre    ?? null,
     duration: Number.isFinite(Number(song.duration)) ? Math.floor(Number(song.duration)) : null,
     playedAt: Math.floor(Date.now() / 1000),   // Unix seconds, UTC
     source,

src/ui/stats.js

@@ -207,6 +207,7 @@ function _render(body, d) {
       t => t.albumId ? { type: 'album', id: t.albumId, name: t.album, artist: t.artist } : null),
     _topList('Top-Alben', d.topAlbums, a => `${a.name}${a.artist ? ' · ' + a.artist : ''}`, a => a.plays, a => a.coverArt || a.albumId, false,
       a => a.albumId ? { type: 'album', id: a.albumId, name: a.name, artist: a.artist } : null),
+    _topList('Top-Genres', d.topGenres, g => g.name, g => g.plays),
     _hourClock(d.byHour),
   ].join('');
 }
@@ -249,9 +250,11 @@ function _topList(title, items, labelFn, valFn, idFn = null, circular = false, n
   const rows = items.map((it, i) => {
     const val = valFn(it);
     const cover = idFn ? coverUrl(idFn(it), 80) : null;
-    const thumb = `<div style="width:40px;height:40px;border-radius:${radius};background:var(--surface2);flex-shrink:0;overflow:hidden">
+    const thumb = idFn
+      ? `<div style="width:40px;height:40px;border-radius:${radius};background:var(--surface2);flex-shrink:0;overflow:hidden">
         ${cover ? `<img src="${esc(cover)}" loading="lazy" style="width:100%;height:100%;object-fit:cover" onerror="this.style.display='none'">` : ''}
-      </div>`;
+      </div>`
+      : '';
     const nav = navFn ? navFn(it) : null;
     const navAttrs = nav
       ? `data-nav-type="${nav.type}" data-nav-id="${esc(nav.id)}" data-nav-name="${esc(nav.name || '')}" data-nav-artist="${esc(nav.artist || '')}"`