support multiple artists for spotify and improve multiartist support for lastgenre

beetsplug/lastgenre/__init__.py

@@ -302,23 +302,76 @@ class LastGenrePlugin(plugins.BeetsPlugin):
 
     def fetch_album_genre(self, obj):
         """Return raw album genres from Last.fm for this Item or Album."""
-        return self._last_lookup(
+        genre = self._last_lookup(
             "album", LASTFM.get_album, obj.albumartist, obj.album
         )
+        if genre:
+            return genre
+
+        # If no genres found for the joint 'albumartist', try the individual
+        # album artists if available in 'albumartists'.
+        if obj.albumartists and len(obj.albumartists) > 1:
+            for albumartist in obj.albumartists:
+                genre = self._last_lookup(
+                    "album", LASTFM.get_album, albumartist, obj.album
+                )
+
+                if genre:
+                    return genre
+
+        return genre
 
     def fetch_album_artist_genre(self, obj):
         """Return raw album artist genres from Last.fm for this Item or Album."""
-        return self._last_lookup("artist", LASTFM.get_artist, obj.albumartist)
+        genres = self._last_lookup("artist", LASTFM.get_artist, obj.albumartist)
+        if genres:
+            return genres
 
-    def fetch_artist_genre(self, item):
+        # If not genres found for the joint 'albumartist', try the individual
+        # album artists if available in 'albumartists'.
+        if obj.ablumartists and len(obj.albumartists) > 1:
+            for albumartist in obj.albumartists:
+                genre = self._last_lookup(
+                    "artist", LASTFM.get_artist, albumartist
+                )
+
+                if genre:
+                    return genre
+        return genres
+
+    def fetch_artist_genre(self, obj):
         """Returns raw track artist genres from Last.fm for this Item."""
-        return self._last_lookup("artist", LASTFM.get_artist, item.artist)
+        genres = self._last_lookup("artist", LASTFM.get_artist, obj.artist)
+        if genres:
+            return genres
+
+        # If not genres found for the joint 'artist', try the individual
+        # album artists if available in 'artists'.
+        if obj.artists and len(obj.artists) > 1:
+            for artist in obj.artists:
+                genre = self._last_lookup("artist", LASTFM.get_artist, artist)
+                if genre:
+                    return genre
+        return genres
 
     def fetch_track_genre(self, obj):
         """Returns raw track genres from Last.fm for this Item."""
-        return self._last_lookup(
+        genres = self._last_lookup(
             "track", LASTFM.get_track, obj.artist, obj.title
         )
+        if genres:
+            return genres
+
+        # If not genres found for the joint 'artist', try the individual
+        # album artists if available in 'artists'.
+        if obj.artists and len(obj.artists) > 1:
+            for artist in obj.artists:
+                genre = self._last_lookup(
+                    "track", LASTFM.get_track, artist, obj.title
+                )
+                if genre:
+                    return genre
+        return genres
 
     # Main processing: _get_genre() and helpers.
 

beetsplug/spotify.py

@@ -302,6 +302,21 @@ class SpotifyPlugin(
                 self._log.error("Request failed. Error: {}", e)
                 raise APIError("Request failed.")
 
+    def _multi_artist_credit(
+        self, artists: list[dict[str | int, str]]
+    ) -> tuple[list[str], list[str]]:
+        """Given a list representing an ``artist``, accumulate data into a pair
+        of lists: the first being the artist names, and the second being the
+        artist IDs.
+        """
+        artist_names = []
+        artist_ids = []
+        for artist in artists:
+            name, id = self.get_artist([artist])
+            artist_names.append(name)
+            artist_ids.append(id)
+        return artist_names, artist_ids
+
     def album_for_id(self, album_id: str) -> AlbumInfo | None:
         """Fetch an album by its Spotify ID or URL and return an
         AlbumInfo object or None if the album is not found.
@@ -321,7 +336,8 @@ class SpotifyPlugin(
         if album_data["name"] == "":
             self._log.debug("Album removed from Spotify: {}", album_id)
             return None
-        artist, artist_id = self.get_artist(album_data["artists"])
+        artists_names, artists_ids = self._multi_artist_credit(album_data["artists"])
+        artist = ", ".join(artists_names)
 
         date_parts = [
             int(part) for part in album_data["release_date"].split("-")
@@ -364,8 +380,10 @@ class SpotifyPlugin(
             album_id=spotify_id,
             spotify_album_id=spotify_id,
             artist=artist,
-            artist_id=artist_id,
-            spotify_artist_id=artist_id,
+            artist_id=artists_ids[0],
+            spotify_artist_id=artists_ids[0],
+            artists=artists_names,
+            artists_ids=artists_ids,
             tracks=tracks,
             albumtype=album_data["album_type"],
             va=len(album_data["artists"]) == 1
@@ -388,7 +406,8 @@ class SpotifyPlugin(
         :returns: TrackInfo object for track
 
         """
-        artist, artist_id = self.get_artist(track_data["artists"])
+        artists_names, artists_ids = self._multi_artist_credit(track_data["artists"])
+        artist = ", ".join(artists_names)
 
         # Get album information for spotify tracks
         try:
@@ -401,8 +420,10 @@ class SpotifyPlugin(
             spotify_track_id=track_data["id"],
             artist=artist,
             album=album,
-            artist_id=artist_id,
-            spotify_artist_id=artist_id,
+            artist_id=artists_ids[0],
+            spotify_artist_id=artists_ids[0],
+            artists=artists_names,
+            artists_ids=artists_ids,
             length=track_data["duration_ms"] / 1000,
             index=track_data["track_number"],
             medium=track_data["disc_number"],