Add artist artwork support using album covers from their tracks

src/routes/subsonic.js

@@ -213,7 +213,8 @@ router.get('/getMusicDirectory.view', authenticateSubsonic, async (req, res) =>
 router.get('/getArtists.view', authenticateSubsonic, async (req, res) => {
   try {
     const artists = await all(`
-      SELECT DISTINCT artist, COUNT(DISTINCT album) as album_count
+      SELECT DISTINCT artist, COUNT(DISTINCT album) as album_count,
+             (SELECT artwork_path FROM tracks t2 WHERE t2.artist = tracks.artist AND artwork_path IS NOT NULL LIMIT 1) as artwork_path
       FROM tracks
       GROUP BY artist
       ORDER BY artist
@@ -230,7 +231,8 @@ router.get('/getArtists.view', authenticateSubsonic, async (req, res) => {
       grouped[letter].push({ 
         id: artistId, 
         name: artist.artist, 
-        albumCount: artist.album_count 
+        albumCount: artist.album_count,
+        coverArt: artist.artwork_path ? artistId : ''
       });
     });
 
@@ -239,7 +241,12 @@ router.get('/getArtists.view', authenticateSubsonic, async (req, res) => {
     Object.keys(grouped).sort().forEach(letter => {
       artistsXml += `  <index name="${letter}">\n`;
       grouped[letter].forEach(artist => {
-        artistsXml += `    <artist id="${artist.id}" name="${escapeXml(artist.name)}" albumCount="${artist.albumCount}"/>\n`;
+        artistsXml += `    <artist id="${artist.id}" name="${escapeXml(artist.name)}" `;
+        artistsXml += `albumCount="${artist.albumCount}" `;
+        if (artist.coverArt) {
+          artistsXml += `coverArt="${artist.coverArt}" `;
+        }
+        artistsXml += `/>\n`;
       });
       artistsXml += `  </index>\n`;
     });
@@ -568,9 +575,25 @@ router.get('/getCoverArt.view', authenticateSubsonic, async (req, res) => {
     // First try to find by track ID
     let track = await get('SELECT artwork_path FROM tracks WHERE id = ?', [id]);
     
-    // If not found, the ID might be an album ID - decode it and find a track from that album
+    // If not found, try artist ID
+    if (!track) {
+      const allArtists = await all(`SELECT DISTINCT artist FROM tracks`);
+      
+      for (const artist of allArtists) {
+        const artistId = crypto.createHash('md5').update(`artist-${artist.artist}`).digest('hex');
+        if (artistId === id) {
+          // Found the artist, get artwork from any of their tracks
+          track = await get(
+            'SELECT artwork_path FROM tracks WHERE artist = ? AND artwork_path IS NOT NULL LIMIT 1',
+            [artist.artist]
+          );
+          break;
+        }
+      }
+    }
+    
+    // If still not found, try album ID
     if (!track) {
-      // Try to find which album this ID represents
       const allAlbums = await all(`SELECT DISTINCT album, album_artist FROM tracks`);
       
       for (const album of allAlbums) {