fix: optimize toggle_favourite endpoint performance (#1094)

* fix: optimize toggle_favourite endpoint performance

Related to #977

* fix: guard against invalid metadata JSON

* fix: add docstrings and improve error handling

---------

Co-authored-by: harsh <shah.ha@media.net>

Author: harsh1519

backend/app/database/images.py

@@ -1,6 +1,8 @@
 # Standard library imports
 import sqlite3
 from typing import Any, List, Mapping, Tuple, TypedDict, Union, Optional
+import json
+
 from datetime import datetime
 
 # App-specific imports
@@ -455,6 +457,36 @@ def db_toggle_image_favourite_status(image_id: str) -> bool:
     finally:
         conn.close()
 
+def db_get_image_by_id(image_id: str) -> Optional[dict]:
+    """
+    Get a single image by ID with its favorite status.
+    """
+    conn = _connect()
+    cursor = conn.cursor()
+    try:
+        cursor.execute("""
+            SELECT id, path, folder_id, thumbnailPath, metadata, isTagged, isFavourite
+            FROM images
+            WHERE id = ?
+        """, (image_id,))
+        row = cursor.fetchone()
+        if not row:
+            return None
+        try:
+            metadata = json.loads(row[4]) if row[4] else {}
+        except json.JSONDecodeError:
+            metadata = {}
+        return {
+            "id": row[0],
+            "path": row[1],
+            "folder_id": row[2],
+            "thumbnailPath": row[3],
+            "metadata": metadata,
+            "isTagged": bool(row[5]),
+            "isFavourite": bool(row[6]),
+        }
+    finally:
+        conn.close()
 
 # ============================================================================
 # MEMORIES FEATURE - Location and Time-based Queries

backend/app/routes/images.py

@@ -4,9 +4,10 @@
 from app.schemas.images import ErrorResponse
 from app.utils.images import image_util_parse_metadata
 from pydantic import BaseModel
-from app.database.images import db_toggle_image_favourite_status
+from app.database.images import db_toggle_image_favourite_status, db_get_image_by_id
 from app.logging.setup_logging import get_logger
 
+
 # Initialize logger
 logger = get_logger(__name__)
 router = APIRouter()
@@ -97,27 +98,37 @@ class ToggleFavouriteRequest(BaseModel):
 
 @router.post("/toggle-favourite")
 def toggle_favourite(req: ToggleFavouriteRequest):
+    """
+    Toggle the favorite status of an image.
+    """
     image_id = req.image_id
     try:
         success = db_toggle_image_favourite_status(image_id)
         if not success:
             raise HTTPException(
-                status_code=404, detail="Image not found or failed to toggle"
+                status_code=status.HTTP_404_NOT_FOUND, 
+                detail="Image not found or failed to toggle"
             )
         # Fetch updated status to return
-        image = next(
-            (img for img in db_get_all_images() if img["id"] == image_id), None
-        )
+        image = db_get_image_by_id(image_id)
+        if not image:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND, 
+                detail="Image not found after toggle"
+            )
         return {
             "success": True,
             "image_id": image_id,
             "isFavourite": image.get("isFavourite", False),
         }
-
+    except HTTPException:
+        raise  # Re-raise HTTPExceptions to preserve status codes
     except Exception as e:
         logger.error(f"error in /toggle-favourite route: {e}")
-        raise HTTPException(status_code=500, detail=f"Internal server error: {e}")
-
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, 
+            detail=f"Internal server error: {e}"
+        )
 
 class ImageInfoResponse(BaseModel):
     id: str