avoid incorrect thumbnails

backend/app/services/scanner.py

@@ -8,6 +8,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 from app.models import MediaItem
 from app.database import SessionLocal
+from app.services.thumbnails import thumbnail_path
 
 log = logging.getLogger(__name__)
 
@@ -86,6 +87,11 @@ async def _do_scan(library_id: int, library_path: str, db: AsyncSession) -> None
 
             if rel in db_items:
                 item = db_items[rel]
+                new_hash = await loop.run_in_executor(None, hash_file, file_path)
+                if item.file_hash != new_hash:
+                    item.file_hash = new_hash
+                    item.updated_at = datetime.utcnow()
+                    thumbnail_path(item.id).unlink(missing_ok=True)
                 if item.missing:
                     item.missing = False
                     item.updated_at = datetime.utcnow()
@@ -93,6 +99,7 @@ async def _do_scan(library_id: int, library_path: str, db: AsyncSession) -> None
                 file_hash = await loop.run_in_executor(None, hash_file, file_path)
                 moved = await _find_by_hash(library_id, file_hash, db)
                 if moved:
+                    thumbnail_path(moved.id).unlink(missing_ok=True)
                     moved.rel_path = rel
                     moved.filename = file_path.name
                     moved.missing = False
@@ -131,4 +138,5 @@ async def _find_by_hash(library_id: int, file_hash: str, db: AsyncSession) -> Me
             MediaItem.missing == True,  # noqa: E712
         )
     )
-    return result.scalars().first()
+    rows = result.scalars().all()
+    return rows[0] if len(rows) == 1 else None

backend/app/services/watcher.py

@@ -9,6 +9,7 @@ from sqlalchemy import select
 from app.database import SessionLocal
 from app.models import Library, MediaItem
 from app.services.scanner import classify, hash_file
+from app.services.thumbnails import thumbnail_path
 
 log = logging.getLogger(__name__)
 
@@ -59,6 +60,7 @@ class LibraryEventHandler(FileSystemEventHandler):
                 )
                 item = result.scalars().first()
                 if item:
+                    thumbnail_path(item.id).unlink(missing_ok=True)
                     item.rel_path = dest_rel
                     item.filename = Path(event.dest_path).name
                     item.missing = False