import json
from dataclasses import dataclass
from typing import Any

from .logging import Logging
from .email import Email
from .auth import Auth
from .database import Database
from .parse import assert_key_of_type, parse_nested_config


@dataclass
class Config:
    host: str | None
    port: int | None
    logging: Logging
    email: Email
    database: Database
    auth: Auth

    @classmethod
    def from_dict(cls, config: dict[str, Any]) -> 'Config':
        assert_key_of_type(config, 'host', str)
        assert_key_of_type(config, 'port', int)

        log_config = parse_nested_config(config, 'logging', Logging.from_dict)
        email_config = parse_nested_config(config, 'email', Email.from_dict)
        db_config = parse_nested_config(config, 'database', Database.from_dict)
        auth_config = parse_nested_config(config, 'auth', Auth.from_dict)

        return Config(
            host=config['host'],
            port=config['port'],
            email=email_config,
            logging=log_config,
            database=db_config,
            auth=auth_config,
        )


def parse_config(filename: str) -> Config:
    with open(filename, 'r') as infile:
        config = json.loads(infile.read())
    return Config.from_dict(config)


__all__ = ['Config', 'parse_config']