import os

def check_encoding(file_path):
    try:
        with open(file_path, 'rb') as f:
            content = f.read()
        content.decode('utf-8')
        # Also check for commonMojibake patterns or literal strings
        # U+FFFD is b'\xef\xbf\xbd' in UTF-8
        if b'\xef\xbf\xbd' in content:
            return "Contains U+FFFD (Replacement Character)"
        return None
    except UnicodeDecodeError as e:
        return f"Invalid UTF-8 at byte {e.start}"
    except Exception as e:
        return str(e)

search_dir = r"d:\Development\SingBox-Gopanel"
extensions = ('.go', '.js', '.jsx', '.ts', '.tsx', '.html', '.css', '.json', '.sql', '.md')
exclude_dirs = {'.git', 'node_modules', 'dist'}

results = []
for root, dirs, files in os.walk(search_dir):
    dirs[:] = [d for d in dirs if d not in exclude_dirs]
    for file in files:
        if file.endswith(extensions):
            full_path = os.path.join(root, file)
            issue = check_encoding(full_path)
            if issue:
                results.append(f"{full_path}: {issue}")

if results:
    print("\n".join(results))
else:
    print("No issues found in source files.")