refactor analyze_chess_image function to accept both file paths and raw bytes, improve error handling for file reading

libs/chess/chess_tools.py

@@ -178,20 +178,38 @@ def analyze_chess_position(position_text: str, max_moves: int = 8) -> str:
 
 
 @tool
-def analyze_chess_image(image_bytes: bytes) -> str:
+def analyze_chess_image(image_input: str) -> str:
     """
     Best-effort: try to extract a FEN string from an image using OCR (if available),
     and then analyze the position. If OCR is unavailable or fails, save the image to a
     temporary file and return a helpful message describing how to use the `analyze_chess_position` tool.
 
     Args:
-        image_bytes: Raw image bytes (PNG/JPEG/etc.)
+        image_input: Either a file path (string) to an image file, or raw image bytes
 
     Returns:
         JSON string. If a FEN was found and parsed, returns the same output as `analyze_chess_position`.
         Otherwise returns a helpful error/message and a temporary path where the image was saved.
     """
     try:
+        # Handle both file path (string) and bytes input
+        if isinstance(image_input, str):
+            # It's a file path
+            try:
+                with open(image_input, "rb") as f:
+                    image_bytes = f.read()
+            except Exception as e:
+                return json.dumps(
+                    {
+                        "status": "error",
+                        "error": f"Could not read image file: {str(e)}",
+                    },
+                    indent=2,
+                )
+        else:
+            # Assume it's bytes
+            image_bytes = image_input
+
         # Validate input early and return a clear error message if image bytes
         # are missing. This prevents opaque failures later when attempting
         # to open or process the bytes.
@@ -199,7 +217,7 @@ def analyze_chess_image(image_bytes: bytes) -> str:
             return json.dumps(
                 {
                     "status": "error",
-                    "error": "image_bytes was not provided or is empty",
+                    "error": "image_input was not provided or is empty",
                 },
                 indent=2,
             )