subsonic: Implement getSong API endpoint

The getSong API endpoint is used by, e.g., the subsonic plugin to mopidy.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>

api/funkwhale_api/subsonic/serializers.py

@@ -130,6 +130,14 @@ class GetAlbumSerializer(serializers.Serializer):
         return payload
 
 
+class GetSongSerializer(serializers.Serializer):
+    def to_representation(self, track):
+        tf = track.files.all()
+        if not len(tf):
+            return {}
+        return get_track_data(track.album, track, tf[0])
+
+
 def get_starred_tracks_data(favorites):
     by_track_id = {f.track_id: f for f in favorites}
     tracks = (

api/funkwhale_api/subsonic/views.py

@@ -147,6 +147,15 @@ class SubsonicViewSet(viewsets.GenericViewSet):
 
         return response.Response(payload, status=200)
 
+    @list_route(methods=["get", "post"], url_name="get_song", url_path="getSong")
+    @find_object(music_models.Track.objects.all())
+    def get_song(self, request, *args, **kwargs):
+        track = kwargs.pop("obj")
+        data = serializers.GetSongSerializer(track).data
+        payload = {"song": data}
+
+        return response.Response(payload, status=200)
+
     @list_route(
         methods=["get", "post"], url_name="get_artist_info2", url_path="getArtistInfo2"
     )

api/tests/subsonic/test_views.py

@@ -140,6 +140,20 @@ def test_get_album(f, db, logged_in_api_client, factories):
     assert response.data == expected
 
 
+@pytest.mark.parametrize("f", ["xml", "json"])
+def test_get_song(f, db, logged_in_api_client, factories):
+    url = reverse("api:subsonic-get-song")
+    assert url.endswith("getSong") is True
+    artist = factories["music.Artist"]()
+    album = factories["music.Album"](artist=artist)
+    track = factories["music.Track"](album=album)
+    tf = factories["music.TrackFile"](track=track)
+    response = logged_in_api_client.get(url, {"f": f, "id": track.pk})
+
+    assert response.status_code == 200
+    assert response.data == {"song": serializers.get_track_data(track.album, track, tf)}
+
+
 @pytest.mark.parametrize("f", ["xml", "json"])
 def test_stream(f, db, logged_in_api_client, factories, mocker):
     url = reverse("api:subsonic-stream")