#!/usr/bin/env python3
"""Entry point for python -m generator."""

import os
import sys
from pathlib import Path

from dotenv import load_dotenv

from .errors import GenerationError, ModelGeneratorError
from .generate import generate_models
from .utils.env import get_db_config, try_env
from .utils.print import error, info, success

# Load environment variables
load_dotenv()


def main() -> int:
    """Enter entry point for the model generator.

    Returns:
        Exit code (0 for success, non-zero for failure)
    """
    try:
        success('Starting SQLAlchemy model generation...')

        info('Checking environment...')
        try_env()

        info('Reading database configuration...')
        db_config = get_db_config()
        info(f'\tDatabase: {db_config}')

        info('Reading output directory...')
        db_vendor = db_config.get_vendor().lower()
        db_name = db_config.database.lower()
        output_dir = os.environ.get(
            'OUTPUT_DIR', f'abacus_models/{db_vendor}/{db_name}'
        )
        output_dir = Path(str(output_dir))
        info(f'\tOutput directory: {output_dir}')

        if output_dir.exists():
            info('Clearing output directory...')
            for file in output_dir.glob('*.py'):
                file.unlink()
        else:
            info('Creating output directory...')
            output_dir.mkdir(parents=True, exist_ok=True)

        info('Creating missing __init__.py files...')
        _create_init_files(output_dir, 'abacus_models')

        info('Creating SQLAlchemy engine....')
        engine = db_config.get_engine()

        try:
            generate_models(engine, output_dir)
        except Exception as e:
            raise GenerationError(f'Failed to generate models: {e}') from e
        finally:
            engine.dispose()

        success('\nSuccessfully generated models!')

        return 0

    except ModelGeneratorError as e:
        error(f'\nError: {e}')
        return 1
    except Exception as e:
        error(f'\nUnexpected error: {e}')
        import traceback

        traceback.print_exc()
        return 1


def _create_init_files(local_dir, root_dir):
    """Create __init__.py files in each directory from local_dir to root_dir (exclusive)."""
    local_dir = os.path.abspath(local_dir)
    root_dir = os.path.abspath(root_dir)

    if not os.path.isdir(local_dir):
        raise ValueError(f"Directory '{local_dir}' does not exist.")

    if not os.path.isdir(root_dir):
        raise ValueError(f"Directory '{root_dir}' does not exist.")

    if not local_dir.startswith(root_dir):
        raise ValueError(f"Directory '{local_dir}' is not a subdirectory '{root_dir}'.")

    current_dir = local_dir
    while current_dir != root_dir:
        # Create a __init__.py file if it does not already exist
        init_file_path = os.path.join(current_dir, '__init__.py')
        if not os.path.exists(init_file_path):
            with open(init_file_path, 'x') as f:
                f.write('"""Generated SQLAlchemy module."""\n')
        current_dir = os.path.dirname(current_dir)


if __name__ == '__main__':
    sys.exit(main())