add get_song_by_mbid

backend/src/song.py

@@ -27,3 +27,17 @@ class Song:
     tags: list[str]
     image_id: str
     youtube_id: str
+
+
+def get_song_by_mbid(mbid: str) -> Song:
+    conn = get_connection()
+    cursor = conn.cursor()
+    cursor.execute("SELECT * FROM songs WHERE mbid = ?", (mbid,))
+    row = cursor.fetchone()
+    conn.close()
+
+    if row is None:
+        raise ValueError(f"Song with MBID {mbid} not found")
+
+    song = Song(mbid=row["mbid"], title=row["title"], artist=row["artist"], tags=row["tags"].split(","), image_id=row["lastfm_image_id"], youtube_id=row["youtube_id"])
+    return song