changed to python312

backend/main.py

@@ -61,18 +61,37 @@ async def serve_local_file(request: Request, path: str = Query(...)):
     """Stream a local file with HTTP Range support (required for video seeking)."""
     file_path = Path(path)
     if not file_path.is_file():
+        logger.warning(f"[serve_file] File not found: {path}")
         raise HTTPException(status_code=404, detail=f"File not found: {path}")
 
     file_size = file_path.stat().st_size
     content_type = MIME_MAP.get(file_path.suffix.lower(), "application/octet-stream")
-
     range_header = request.headers.get("range")
+
+    logger.info(
+        f"[serve_file] {file_path.name} | size={file_size} | "
+        f"type={content_type} | range={range_header or 'none'}"
+    )
+
+    if content_type == "application/octet-stream":
+        logger.warning(
+            f"[serve_file] Unknown MIME type for extension '{file_path.suffix}' — "
+            f"browser may fail to decode audio/video for '{file_path.name}'"
+        )
+
+    if file_size == 0:
+        logger.error(f"[serve_file] File is empty: {path}")
+        raise HTTPException(status_code=422, detail=f"File is empty: {path}")
     if range_header:
-        range_spec = range_header.replace("bytes=", "")
-        range_start_str, range_end_str = range_spec.split("-")
-        range_start = int(range_start_str) if range_start_str else 0
-        range_end = int(range_end_str) if range_end_str else file_size - 1
-        range_end = min(range_end, file_size - 1)
+        try:
+            range_spec = range_header.replace("bytes=", "")
+            range_start_str, range_end_str = range_spec.split("-")
+            range_start = int(range_start_str) if range_start_str else 0
+            range_end = int(range_end_str) if range_end_str else file_size - 1
+            range_end = min(range_end, file_size - 1)
+        except (ValueError, TypeError) as e:
+            logger.error(f"[serve_file] Malformed Range header '{range_header}': {e}")
+            raise HTTPException(status_code=416, detail=f"Invalid Range header: {range_header}")
         content_length = range_end - range_start + 1
 
         def iter_range():