Verify Bandcamp results match the actual artist/track before including

backend/app/services/bandcamp.py

@@ -1,4 +1,5 @@
 import re
+from difflib import SequenceMatcher
 
 import httpx
 
@@ -11,6 +12,46 @@ HEADERS = {
 }
 
 
+def _normalize(s: str) -> str:
+    """Normalize string for comparison."""
+    return re.sub(r'[^a-z0-9\s]', '', s.lower()).strip()
+
+
+def _similarity(a: str, b: str) -> float:
+    """Return similarity ratio between two strings."""
+    return SequenceMatcher(None, _normalize(a), _normalize(b)).ratio()
+
+
+async def search_bandcamp_verified(artist: str, title: str) -> dict | None:
+    """Search Bandcamp and only return a result if the artist actually matches.
+
+    Returns the best matching result or None if no good match found.
+    """
+    # Try track search first: "artist title"
+    results = await search_bandcamp(f"{artist} {title}", item_type="t")
+    for r in results:
+        artist_sim = _similarity(r.get("artist", ""), artist)
+        title_sim = _similarity(r.get("title", ""), title)
+        # Require artist to be a strong match (>0.6) and title reasonable (>0.4)
+        if artist_sim >= 0.6 and title_sim >= 0.4:
+            return r
+        # Or if artist is very close, accept even if title differs (different track by same artist)
+        if artist_sim >= 0.8:
+            return r
+
+    # Try artist/band search as fallback
+    results = await search_bandcamp(artist, item_type="b")
+    for r in results:
+        artist_sim = _similarity(r.get("title", ""), artist)  # For band results, title IS the band name
+        if artist_sim >= 0.6:
+            return r
+        artist_sim = _similarity(r.get("artist", ""), artist)
+        if artist_sim >= 0.6:
+            return r
+
+    return None
+
+
 async def search_bandcamp(query: str, item_type: str = "t") -> list[dict]:
     """Search Bandcamp for tracks, albums, or artists.