import re
from pathlib import Path

def get_file_extension_and_default_name(attributes: str, code: str) -> tuple[str, str]:
    """Determine file extension and default name based on attributes and content."""
    # Extract language from attributes (e.g., language=bash)
    language_match = re.search(r'language=(\w+)', attributes)
    language = language_match.group(1).lower() if language_match else 'unknown'

    if language == 'bash' or 'incus' in code.lower():
        return '.sh', 'incus_script'
    elif language == 'yaml':
        return '.yaml', 'netplan_config'
    elif language == 'python':
        return '.py', 'python_script'
    else:
        # Assume .conf for blocks without language or resembling config
        return '.conf', 'dnsmasq_config'

def generate_unique_filename(base_dir: Path, base_name: str, extension: str) -> Path:
    """Generate a unique filename by appending a number if the file exists."""
    counter = 1
    while True:
        filename = f"{base_name}_{counter}{extension}"
        file_path = base_dir / filename
        if not file_path.exists():
            return file_path
        counter += 1

def extract_listings():
    """Extract lstlisting code blocks from main.tex and save to scripts folder."""
    # Define paths
    base_dir = Path(__file__).parent.parent  # ~/edu/paso/dnsmasq
    tex_file = base_dir / 'doc' / 'main.tex'
    scripts_dir = base_dir / 'scripts'

    # Ensure scripts directory exists
    scripts_dir.mkdir(exist_ok=True)

    # Read the LaTeX file
    try:
        with open(tex_file, 'r', encoding='utf-8') as f:
            content = f.read()
    except FileNotFoundError:
        print(f"Error: {tex_file} not found")
        return
    except Exception as e:
        print(f"Error reading {tex_file}: {str(e)}")
        return

    # Regex to match lstlisting environments
    # Captures optional attributes [language=...,label=...] and code block content
    pattern = r'\\begin\{lstlisting\}(\[(.*?)\])?(.*?)\\end\{lstlisting\}'
    matches = re.finditer(pattern, content, re.DOTALL)

    extracted_count = 0

    for match in matches:
        # Extract attributes (if any) and code
        attributes = match.group(2) or ''  # Empty string if no attributes
        code = match.group(3).strip()

        # Extract label from attributes (e.g., label={setup_container})
        label_match = re.search(r'label=\{([^}]+)\}', attributes)
        label = label_match.group(1) if label_match else None

        # Get file extension and default name
        extension, default_name = get_file_extension_and_default_name(attributes, code)

        # Use label if available, otherwise use default name
        base_name = label if label else default_name

        # Generate unique filename
        file_path = generate_unique_filename(scripts_dir, base_name, extension)

        # Save the code block to a file
        try:
            with open(file_path, 'w', encoding='utf-8') as f:
                f.write(code)
            print(f"Saved code block to {file_path}")
            extracted_count += 1
        except Exception as e:
            print(f"Error saving {file_path}: {str(e)}")

    if extracted_count == 0:
        print("No lstlisting code blocks found in main.tex")
    else:
        print(f"Completed: Extracted {extracted_count} code block(s) to {scripts_dir}")

if __name__ == "__main__":
    extract_listings()