Switch to MusicBrainz for song verification, YouTube Music for playback links

backend/app/services/recommender.py

@@ -216,34 +216,46 @@ Return ONLY the JSON array, no other text."""
     except json.JSONDecodeError:
         return [], remaining
 
-    # Verify each recommendation exists on YouTube Music before saving
+    # Verify recommendations exist using MusicBrainz, get YouTube Music links
     import asyncio
-    from app.services.youtube_music import search_track
-    from difflib import SequenceMatcher
+    from app.services.musicbrainz import verify_track as mb_verify
+    from app.services.youtube_music import search_track as yt_search
 
-    def _normalize(s: str) -> str:
-        import re
-        return re.sub(r'[^a-z0-9\s]', '', s.lower()).strip()
+    def verify_and_link(artist: str, title: str) -> dict | None:
+        """Verify track on MusicBrainz, then get YouTube Music link."""
+        # Step 1: Verify on MusicBrainz
+        mb_result = mb_verify(artist, title)
+        if not mb_result:
+            return None
 
-    def _sim(a: str, b: str) -> float:
-        return SequenceMatcher(None, _normalize(a), _normalize(b)).ratio()
+        real_artist = mb_result["artist"]
+        real_title = mb_result["title"]
+        album = mb_result.get("album")
 
-    def verify_track(artist: str, title: str) -> dict | None:
-        """Search YouTube Music to verify a track exists and get the real data."""
+        # Step 2: Get YouTube Music link for listening
+        youtube_url = None
+        image_url = None
         try:
-            results = search_track(f"{artist} {title}")
-            for r in results[:3]:
-                r_artist = r.get("artist", "")
-                r_title = r.get("title", "")
-                # Check artist similarity (>0.5) and title similarity (>0.4)
-                if _sim(r_artist, artist) >= 0.5 and _sim(r_title, title) >= 0.4:
-                    return r
-                # Or very strong artist match with any title
-                if _sim(r_artist, artist) >= 0.8:
-                    return r
+            yt_results = yt_search(f"{real_artist} {real_title}")
+            if yt_results:
+                yt = yt_results[0]
+                yt_id = yt.get("youtube_id")
+                if yt_id:
+                    youtube_url = f"https://music.youtube.com/watch?v={yt_id}"
+                image_url = yt.get("image_url")
         except Exception:
             pass
-        return None
+
+        if not youtube_url:
+            youtube_url = f"https://www.youtube.com/results?search_query={quote_plus(f'{real_artist} {real_title}')}"
+
+        return {
+            "artist": real_artist,
+            "title": real_title,
+            "album": album,
+            "youtube_url": youtube_url,
+            "image_url": image_url,
+        }
 
     # Save to DB — only keep verified tracks
     recommendations = []
@@ -255,35 +267,23 @@ Return ONLY the JSON array, no other text."""
         title = rec.get("title", "Unknown")
         reason = rec.get("reason", "")
 
-        # Verify on YouTube Music (run sync in thread)
-        verified = await asyncio.to_thread(verify_track, artist, title)
+        # Verify on MusicBrainz + get YouTube link (sync, run in thread)
+        verified = await asyncio.to_thread(verify_and_link, artist, title)
 
         if not verified:
-            continue  # Skip hallucinated songs
-
-        # Use verified data (correct artist/title from YouTube Music)
-        real_artist = verified.get("artist", artist)
-        real_title = verified.get("title", title)
-        youtube_id = verified.get("youtube_id")
-        image_url = verified.get("image_url")
-
-        # Direct YouTube link if we have a video ID, otherwise search
-        if youtube_id:
-            youtube_url = f"https://music.youtube.com/watch?v={youtube_id}"
-        else:
-            youtube_url = f"https://www.youtube.com/results?search_query={quote_plus(f'{real_artist} {real_title} official music video')}"
+            continue  # Song doesn't exist — AI hallucinated it
 
         r = Recommendation(
             user_id=user.id,
             playlist_id=playlist_id,
-            title=real_title,
-            artist=real_artist,
-            album=rec.get("album"),
-            image_url=image_url,
+            title=verified["title"],
+            artist=verified["artist"],
+            album=verified.get("album") or rec.get("album"),
+            image_url=verified.get("image_url"),
             reason=reason,
             score=rec.get("score"),
             query=query,
-            youtube_url=youtube_url,
+            youtube_url=verified["youtube_url"],
         )
         db.add(r)
         recommendations.append(r)