import argparse
import os
from typing import Sequence
"""
This is always the entry point so you don't technically need to do the
__name__ == "__main__" check, but its still common practice to show that
this is the entry point.

You would start your project/app by first installing it.
You can install it as an editable package during development as this symlinks it instead.
Example (in venv):
    pip install -e .
    python -m ajusta_bling args...
"""

class EnvDefault(argparse.Action):
    def __init__(self, envvar, required=False, default=None, **kwargs):
        if not default and envvar:
            if envvar in os.environ:
                default = os.environ[envvar]

        if required and default:
            required = False
        super(EnvDefault, self).__init__(default=default, required=required, 
                                         **kwargs)

    def __call__(self, parser, namespace, values, option_string=None):
        setattr(namespace, self.dest, values)

def main(argv: Sequence[str] | None = None) -> int:
    """
    This is where I would put argparse (if you want to use this as a callable package with args)
    If not then I use this as setup.
    """
    parser = argparse.ArgumentParser(
        prog=__package__ or "ajusta_bling",
        
    )
    parser.add_argument(
        "--dbuser", "-du",
        type=str,
        action=EnvDefault,
        required=True,
        envvar="POSTGRES_USER",
        help="PostgreSQL User",
    )

    parser.add_argument(
        "--dbpassword", "-dP",
        type=str,
        action=EnvDefault,
        envvar="POSTGRES_PASSWORD",
        help="PostgreSQL Password",
    )

    parser.add_argument(
        "--dbhost", "-dh",
        type=str,
        required=False,
        default='db',
        help="PostgreSQL Host",
    )

    parser.add_argument(
        "--dbport", "-dp",
        type=int,
        default=5432,
        help="PostgreSQL Port",
    )

    parser.add_argument(
        "--dbname", "-db",
        type=str,
        action=EnvDefault,
        required=True,
        envvar="POSTGRES_DB",
        help="PostgreSQL Database",
    )

    parser.add_argument(
        "--webhost", "-wh",
        type=str,
        action=EnvDefault,
        required=True,
        envvar="FLASK_HOST",
        help="Web server host",
    )

    parser.add_argument(
        "--webport", "-wp",
        type=int,
        default=5000,
        help="Web server port",
    )

    parser.add_argument(
        "--env",
        type=str,
        action=EnvDefault,
        envvar="FLASK_ENV",
        default=False,
        help="Changes flask environment",
    )
    
    args = parser.parse_args(argv)
    from . import app
    from .app import Args

    args = Args(**vars(args))

    app.main(args)

    return 0

if __name__ == "__main__":
    raise SystemExit(main())