import json
from dataclasses import dataclass
from typing import Any

from .logging import Logging
from .email import Email
from .parse import ConfigParseError, assert_key_of_type


@dataclass
class Config:
    host: str | None
    port: int | None
    logging: Logging
    email: Email

    @classmethod
    def from_dict(cls, config: dict[str, Any]) -> 'Config':
        assert_key_of_type(config, 'logging', dict)
        assert_key_of_type(config, 'email', dict)
        assert_key_of_type(config, 'host', str)
        assert_key_of_type(config, 'port', int)
        try:
            log_config = Logging.from_dict(config['logging'])
        except ConfigParseError as e:
            raise ConfigParseError(['logging', *e.keypath], e.issue) from e

        try:
            email_config = Email.from_dict(config['email'])
        except ConfigParseError as e:
            raise ConfigParseError(['email', *e.keypath], e.issue) from e

        return Config(host=config['host'], port=config['port'], email=email_config, logging=log_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']