db: Give Tracks a Decade property and genres() function

For accessing a Track's Decade playlist or list of genres

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

db/test_track.py

@@ -16,6 +16,7 @@ class TestTrack(unittest.TestCase):
         self.assertIsInstance(track.artist, db.artist.Artist)
         self.assertIsInstance(track.album, db.album.Album)
         self.assertIsInstance(track.disc, db.disc.Disc)
+        self.assertIsInstance(track.decade, db.decade.Decade)
         self.assertIsInstance(track.year, db.year.Year)
         self.assertEqual(track.number, 1)
         self.assertEqual(track.playcount, 0)
@@ -23,6 +24,14 @@ class TestTrack(unittest.TestCase):
         self.assertEqual(track.length, 1.234)
         self.assertEqual(track.title, "Test Title")
 
+    def test_genres(self):
+        track = db.make_fake_track(1, 1.234, "Test Title", "/a/b/c/1.ogg")
+        self.assertEqual(track.genres(), [ ])
+
+        genre = db.genre.Table.find("Test Genre")
+        genre.add_track(track)
+        self.assertEqual(track.genres(), [ genre ])
+
     def test_played(self):
         track = db.make_fake_track(1, 1.234, "Test Title", "/a/b/c/1.ogg")
         track.played()

db/track.py

@@ -18,6 +18,7 @@ from . import artist
 from . import album
 from . import decade
 from . import disc
+from . import genre
 from . import library
 from . import sql
 from . import table
@@ -32,6 +33,7 @@ class Track(GObject.GObject):
         self._artist = artist.Table.get(row["artistid"])
         self._album = album.Table.get(row["albumid"])
         self._disc = disc.Table.get(row["discid"])
+        self._decade = decade.Table.get(row["decadeid"])
         self._year = year.Table.get(row["yearid"])
         self._number = row["number"]
         self._playcount = row["playcount"]
@@ -55,6 +57,9 @@ class Track(GObject.GObject):
     @GObject.Property
     def disc(self): return self._disc
 
+    @GObject.Property
+    def decade(self): return self._decade
+
     @GObject.Property
     def year(self): return self._year
 
@@ -84,6 +89,11 @@ class Track(GObject.GObject):
     @GObject.Property
     def path(self): return self._path
 
+    def genres(self):
+        rows = sql.execute(f"SELECT genreid FROM genre_map WHERE trackid=?",
+                           [ self.rowid ]).fetchall()
+        return [ genre.Table.get(row[0]) for row in rows ]
+
     def update(self, column, newval):
         sql.execute(f"UPDATE tracks SET {column}=? WHERE trackid=?",
                     [ newval, self.rowid ])