Update app.py

app.py

@@ -162,7 +162,7 @@ class MetaData(BaseModel):
     rating: Optional[int] = None
     genre: Optional[str] = None
     last_played: Optional[str] = None  # ISO timestamp
-
+    tags: List[str] = Field(default_factory=list)   # ← ADD THIS
 # --- GCS I/O HELPERS ---
 
 
@@ -866,7 +866,58 @@ async def update_music_metadata(music_id: str, payload: SampleMetaUpdatePayload)
 
 # --- 5. SMART SYNC (The "Magic" Button) ---
 
+from pydantic import Field
+from typing import Optional, List
+
+class MetaPatch(BaseModel):
+    name: Optional[str] = None
+    rating: Optional[int] = Field(None, ge=0, le=10)
+    genre: Optional[str] = None
+    tags: Optional[List[str]] = None      # full list (replace)
+    last_played: Optional[str] = None     # ISO string
+
+@app.patch("/api/songs/{item_id}")
+async def patch_song(item_id: str, patch: MetaPatch):
+    config = STORAGE_MAP["songs"]         # ← JSON index only
+    index_path = config["index"]
+
+    async with INDEX_LOCK:
+        try:
+            index: list = await run_io(_read_json_sync, index_path)
+            if not isinstance(index, list):
+                index = []
+
+            # Find by id
+            entry = next((e for e in index if e.get("id") == item_id), None)
+            if not entry:
+                raise HTTPException(status_code=404, detail="Song not found")
+
+            changes = patch.model_dump(exclude_unset=True)
+            if not changes:
+                return {"status": "no-op", "message": "Nothing to update"}
+
+            updated = {}
+            for field, value in changes.items():
+                if field == "tags":
+                    entry["tags"] = value if value is not None else []
+                else:
+                    entry[field] = value
+                updated[field] = entry[field]
+
+            await run_io(_write_json_sync, index_path, index)
+            await cache.clear()   # or cache.delete("library:songs") for precision
 
+            return {
+                "status": "success",
+                "item_id": item_id,
+                "updated": updated
+            }
+
+        except Exception as e:
+            logging.error(f"PATCH /songs/{item_id} failed: {e}")
+            raise HTTPException(status_code=500, detail=str(e))
+
+            
 @app.post("/api/admin/sync")
 async def sync_gcs_storage():
     """