Fix ampache compatibility

Ampache returns strings where integers are normally expected and full
URLs instead of IDs for some album art.

Fixes #272

sublime_music/adapters/subsonic/adapter.py

@@ -592,8 +592,12 @@ class SubsonicAdapter(Adapter):
     def delete_playlist(self, playlist_id: str):
         self._get_json(self._make_url("deletePlaylist"), id=playlist_id)
 
-    def get_cover_art_uri(self, cover_art_id: str, scheme: str, size: int) -> str:
-        params = {"id": cover_art_id, "size": size, **self._get_params()}
+    def get_cover_art_uri(self, cover_art: str, scheme: str, size: int) -> str:
+        # Some servers return a full URL instead of an ID
+        if cover_art.startswith("http://") or cover_art.startswith("https://"):
+            return cover_art
+
+        params = {"id": cover_art, "size": size, **self._get_params()}
         return self._make_url("getCoverArt") + "?" + urlencode(params)
 
     def get_song_file_uri(self, song_id: str, schemes: Iterable[str]) -> str:

sublime_music/adapters/subsonic/api_objects.py

@@ -17,10 +17,12 @@ from dateutil import parser
 
 from .. import api_objects as SublimeAPI
 
-# Translation map
+# Translation map for encoding/decoding API results. For instance some servers
+# may return a string where an integer is required.
 decoder_functions = {
     datetime: (lambda s: parser.parse(s) if s else None),
-    timedelta: (lambda s: timedelta(seconds=s) if s else None),
+    timedelta: (lambda s: timedelta(seconds=float(s)) if s else None),
+    int: (lambda s: int(s) if s else None),
 }
 encoder_functions = {
     datetime: (lambda d: datetime.strftime(d, "%Y-%m-%dT%H:%M:%S.%f%z") if d else None),