Fix downloading

src/app/utils.py

@@ -0,0 +1,22 @@
+from fastapi import HTTPException, Request, status
+
+from app.models import CachedFile as CachedFileDB
+from app.services.cache_updater import cache_file_by_book_id
+
+
+async def get_cached_file_or_cache(
+    request: Request, object_id: int, object_type: str
+) -> CachedFileDB:
+    cached_file = await CachedFileDB.objects.get_or_none(
+        object_id=object_id, object_type=object_type
+    )
+
+    if not cached_file:
+        cached_file = await cache_file_by_book_id(
+            {"redis": request.app.state.redis_client}, object_id, object_type
+        )
+
+    if not cached_file:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND)
+
+    return cached_file