Upgrade artwork to highest available resolution for Spotify and iTunes

Spotify album art: replace the 4-char size segment after '0000ab67616d'
with '82c1' to request the original uploaded master (up to 2000px+).
Applied via _upgrade_spotify_image_url() in Track, Artist, and Album
dataclass constructors and as a catch-all in _download_cover_art.
Scoped to the ab67616d album art prefix only — artist images use a
different prefix (ab676161) where the trick does not apply.

iTunes/Apple Music: replace '100x100bb' with '3000x3000bb' in all
artworkUrl100 replacements across Track, Artist, Album, and the
get_album images arrays. Also applied as a catch-all in _download_cover_art.

Deezer already uses cover_xl at its maximum — no changes needed there.

core/itunes_client.py

@@ -83,8 +83,8 @@ class Track:
         # Extract album image (highest quality)
         album_image_url = None
         if 'artworkUrl100' in track_data:
-            # Replace 100x100 with 600x600 for higher quality
+            # Replace 100x100 with 3000x3000 for highest available quality
-            album_image_url = track_data['artworkUrl100'].replace('100x100bb', '600x600bb')
+            album_image_url = track_data['artworkUrl100'].replace('100x100bb', '3000x3000bb')
         
         # Get artist name(s) - prefer clean name from ID lookup if available
         if clean_artist_name:
@@ -136,7 +136,7 @@ class Artist:
         # iTunes artist search doesn't reliably return images
         image_url = None
         if 'artworkUrl100' in artist_data:
-            image_url = artist_data['artworkUrl100'].replace('100x100bb', '600x600bb')
+            image_url = artist_data['artworkUrl100'].replace('100x100bb', '3000x3000bb')
         
         # Build external URLs
         external_urls = {}
@@ -173,8 +173,8 @@ class Album:
         # Get highest quality artwork
         image_url = None
         if album_data.get('artworkUrl100'):
-            image_url = album_data['artworkUrl100'].replace('100x100bb', '600x600bb')
+            image_url = album_data['artworkUrl100'].replace('100x100bb', '3000x3000bb')
-        
+
         # Build external URLs
         external_urls = {}
         if 'collectionViewUrl' in album_data:
@@ -633,12 +633,12 @@ class iTunesClient:
             # Reconstruct Spotify-compatible format from cached raw iTunes data
             image_url = None
             if cached.get('artworkUrl100'):
-                image_url = cached['artworkUrl100'].replace('100x100bb', '600x600bb')
+                image_url = cached['artworkUrl100'].replace('100x100bb', '3000x3000bb')
 
             images = []
             if image_url:
                 images = [
-                    {'url': image_url, 'height': 600, 'width': 600},
+                    {'url': image_url, 'height': 3000, 'width': 3000},
                     {'url': cached['artworkUrl100'].replace('100x100bb', '300x300bb'), 'height': 300, 'width': 300},
                     {'url': cached['artworkUrl100'], 'height': 100, 'width': 100}
                 ]
@@ -681,13 +681,13 @@ class iTunesClient:
                 # Normalize to Spotify-compatible format
                 image_url = None
                 if album_data.get('artworkUrl100'):
-                    image_url = album_data['artworkUrl100'].replace('100x100bb', '600x600bb')
+                    image_url = album_data['artworkUrl100'].replace('100x100bb', '3000x3000bb')
 
                 # Build images array like Spotify (multiple sizes)
                 images = []
                 if image_url:
                     images = [
-                        {'url': image_url, 'height': 600, 'width': 600},
+                        {'url': image_url, 'height': 3000, 'width': 3000},
                         {'url': album_data['artworkUrl100'].replace('100x100bb', '300x300bb'), 'height': 300, 'width': 300},
                         {'url': album_data['artworkUrl100'], 'height': 100, 'width': 100}
                     ]

core/spotify_client.py

@@ -1,6 +1,7 @@
 import spotipy
 from spotipy.oauth2 import SpotifyOAuth, SpotifyClientCredentials
 from typing import Dict, List, Optional, Any
+import re
 import time
 import threading
 from functools import wraps
@@ -11,6 +12,21 @@ from core.metadata_cache import get_metadata_cache
 
 logger = get_logger("spotify_client")
 
+def _upgrade_spotify_image_url(url: str) -> str:
+    """Upgrade a Spotify CDN image URL to the highest available resolution.
+
+    Album art URLs use the prefix 'ab67616d' and encode size as the 4-char hex
+    segment following '0000' (e.g. 'b273' = 640x640, '1e02' = 300x300).
+    Replacing it with '82c1' requests the original uploaded master (up to 2000px+).
+
+    This only applies to album art (ab67616d prefix). Artist images use a different
+    prefix (ab676161) and the 82c1 trick does not work for them — those are left
+    as-is since Spotify already returns them sorted largest-first.
+    """
+    if not url or 'i.scdn.co' not in url:
+        return url
+    return re.sub(r'(/image/ab67616d)0000[0-9a-f]{4}', r'\g<1>000082c1', url)
+
 # Global rate limiting variables
 _last_api_call_time = 0
 _api_call_lock = threading.Lock()
@@ -352,7 +368,7 @@ class Track:
         if 'album' in track_data and 'images' in track_data['album']:
             images = track_data['album']['images']
             if images:
-                album_image_url = images[0]['url']
+                album_image_url = _upgrade_spotify_image_url(images[0]['url'])
 
         return cls(
             id=track_data['id'],
@@ -384,7 +400,7 @@ class Artist:
         # Get the largest image URL if available
         image_url = None
         if artist_data.get('images') and len(artist_data['images']) > 0:
-            image_url = artist_data['images'][0]['url']
+            image_url = _upgrade_spotify_image_url(artist_data['images'][0]['url'])
         
         return cls(
             id=artist_data['id'],
@@ -413,7 +429,7 @@ class Album:
         # Get the largest image URL if available
         image_url = None
         if album_data.get('images') and len(album_data['images']) > 0:
-            image_url = album_data['images'][0]['url']
+            image_url = _upgrade_spotify_image_url(album_data['images'][0]['url'])
 
         return cls(
             id=album_data['id'],

web_server.py

@@ -19127,7 +19127,7 @@ def _download_cover_art(album_info: dict, target_dir: str, context: dict = None)
             print(f"CAA upgrade failed — keeping existing cover.jpg")
             return
 
-        # Fallback to Spotify/iTunes/Deezer URL (typically 640x640)
+        # Fallback to Spotify/iTunes/Deezer URL
         if not image_data:
             art_url = album_info.get('album_image_url')
             # If album_info lacks the URL, try the context's spotify_album
@@ -19141,6 +19141,13 @@ def _download_cover_art(album_info: dict, target_dir: str, context: dict = None)
                         art_url = images[0].get('url') if isinstance(images[0], dict) else None
                 if art_url:
                     print(f"Using cover art URL from spotify_album context")
+            # Upgrade to highest available resolution before fetching
+            if art_url and 'i.scdn.co' in art_url:
+                from core.spotify_client import _upgrade_spotify_image_url
+                art_url = _upgrade_spotify_image_url(art_url)
+            elif art_url and 'mzstatic.com' in art_url:
+                import re as _re
+                art_url = _re.sub(r'\d+x\d+bb', '3000x3000bb', art_url)
             if not art_url:
                 print("No cover art URL available for download.")
                 return