from pathlib import Path
import re
import os

def convert_paths_in_file(file_path, root_folder, base_dir):
    """
    Convert absolute paths to relative paths in a single file.
    
    Args:
        file_path (Path): Path to the file being processed
        root_folder (str): Root folder path to check against
        base_dir (Path): Base directory for calculating relative paths
        
    Returns:
        bool: True if modifications were made, False otherwise
    """
    try:
        # Read the file contents
        with open(file_path, 'r', encoding='utf-8') as f:
            content = f.read()
        
        # Find all href attributes starting with root_folder
        pattern = r'href=[\'"]([^\'"]+)[\'"]'
        matches = re.finditer(pattern, content)
        
        modified = False
        offset = 0
        
        for match in matches:
            href = match.group(1)
            
            # Check if href starts with root_folder
            if href.startswith(root_folder):
                # Calculate relative path
                rel_path = os.path.relpath(href, str(base_dir))
                
                # Create replacement string preserving quotes
                quote_char = '"' if match.group(0)[5] == '"' else "'"
                replacement = f'href={quote_char}{rel_path}{quote_char}'
                
                # Perform replacement
                content = content[:match.start() + offset] + \
                         replacement + \
                         content[match.end() + offset:]
                offset += len(replacement) - len(match.group(0))
                modified = True
                
        # Write back modified content if changes were made
        if modified:
            with open(file_path, 'w', encoding='utf-8') as f:
                f.write(content)
                
        return modified
        
    except Exception as e:
        print(f"Error processing {file_path}: {str(e)}")
        return False

def scan_and_convert(root_folder, base_dir=None):
    """
    Scan all files in the specified root folder and convert absolute paths to relative paths.
    Only processes HTML, JS, and CSS files.
    
    Args:
        root_folder (str): Root folder path to scan
        base_dir (str, optional): Base directory for calculating relative paths.
                                Defaults to the root_folder if not specified.
    """
    # Convert inputs to Path objects
    root_path = Path(root_folder)
    base_dir = Path(base_dir or root_folder)
    
    # Validate inputs
    if not root_path.exists():
        raise FileNotFoundError(f"Root folder '{root_folder}' does not exist")
        
    print(f"Scanning folder: {root_folder}")
    print(f"Base directory: {base_dir}")
    
    total_files = 0
    modified_files = 0
    
    # Define allowed file extensions
    allowed_extensions = {'.html'}
    
    # Scan all files recursively
    for file_path in root_path.rglob('*'):
        if file_path.is_file():
            # Check if file has an allowed extension
            if file_path.suffix.lower() in allowed_extensions:
                total_files += 1
                if convert_paths_in_file(file_path, str(root_path), base_dir):
                    modified_files += 1
    
    print(f"\nProcessing complete:")
    print(f"Total files scanned: {total_files}")
    print(f"Files modified: {modified_files}")

def main():
    import argparse
    parser = argparse.ArgumentParser(description='Convert absolute href paths to relative paths')
    parser.add_argument('root_folder', help='Root folder to scan')
    parser.add_argument('--base-dir', help='Base directory for calculating relative paths')
    
    args = parser.parse_args()
    
    try:
        scan_and_convert(args.root_folder, args.base_dir)
    except Exception as e:
        print(f"Error: {str(e)}")

if __name__ == "__main__":
    main()