feat(Track): add lyrics and subtitles downloading support

also adds simple tests
resolves #3

tests/test_tidal_async.py

@@ -11,7 +11,7 @@
 #   - [ ] Track
 #       - [x] loading track info
 #       - [x] downloading tracks
-#       - [ ] track lyrics (no lyrics support atm)
+#       - [x] track lyrics
 #       - [ ] track metadata generation
 #   - [x] loading album info
 #       - [x] listing tracks from albums
@@ -62,6 +62,38 @@ async def test_track_title(sess: TidalSession, id_, artist, title):
     assert track.title == title and track.artist_name == artist
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "id_, lyrics_len",
+    (
+        (22563745, None),
+        (22563746, 3079),
+    ),
+)
+async def test_track_lyrics(sess: TidalSession, id_, lyrics_len):
+    track = await sess.track(id_)
+    if lyrics_len is None:
+        assert await track.lyrics() is None
+    else:
+        assert len(await track.lyrics()) == lyrics_len
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "id_, subtitles_len",
+    (
+        (22563745, None),
+        (22563746, 4193),
+    ),
+)
+async def test_track_subtitles(sess: TidalSession, id_, subtitles_len):
+    track = await sess.track(id_)
+    if subtitles_len is None:
+        assert await track.subtitles() is None
+    else:
+        assert len(await track.subtitles()) == subtitles_len
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     "id_, artist, title",

tidal_async/api.py

@@ -6,6 +6,7 @@
 from typing import TYPE_CHECKING, AsyncGenerator, Optional, Tuple
 
 import music_service_async_interface as generic
+from aiohttp import ClientResponseError
 
 from tidal_async.exceptions import InsufficientAudioQuality
 from tidal_async.utils import cacheable, gen_artist, gen_title, id_from_url, snake_to_camel
@@ -104,10 +105,13 @@ class ArtistType(enum.Enum):
     artist = "ARTIST"
 
 
-# TODO [#3]: Downloading lyrics
 class Track(TidalObject, generic.Track):
     urlname = "track"
 
+    def __init__(self, sess: "TidalSession", dict_, id_field_name="id"):
+        super().__init__(sess, dict_, id_field_name)
+        self._lyrics_dict = None
+
     def __repr__(self):
         cls = self.__class__
         return f"<{cls.__module__}.{cls.__qualname__} ({self.get_id()}): {self.artist_name} - {self.title}>"
@@ -184,6 +188,45 @@ async def get_file_url(
 
         return manifest["urls"][0]
 
+    async def _lyrics(self) -> Optional[dict]:
+        if self._lyrics_dict is not None:
+            return self._lyrics_dict
+
+        try:
+            resp = await self.sess.get(
+                f"/v1/tracks/{self.get_id()}/lyrics", params={"countryCode": self.sess.country_code}
+            )
+        except ClientResponseError as e:
+            if e.status == 404:
+                return None
+            else:
+                raise
+
+        self._lyrics_dict = await resp.json()
+        return self._lyrics_dict
+
+    async def lyrics(self) -> Optional[str]:
+        """Gets lyrics for track
+
+        :return: Lyrics string when available, `None` when not
+        """
+        lyrics_dict = await self._lyrics()
+        if lyrics_dict is None or "lyrics" not in lyrics_dict:
+            return None
+
+        return lyrics_dict["lyrics"]
+
+    async def subtitles(self) -> Optional[str]:
+        """Gets subtitles (time-synchronized lyrics) for track
+
+        :return: Subtitles string in LRC format when available, `None` when not
+        """
+        lyrics_dict = await self._lyrics()
+        if lyrics_dict is None or "subtitles" not in lyrics_dict:
+            return None
+
+        return lyrics_dict["subtitles"]
+
     async def get_metadata(self):
         # TODO [#22]: Rewrite Track.get_metadata
         #   - [ ] lyrics