from dataclasses import asdict, dataclass


@dataclass
class Config:
    bot_channel: str = 'breadtube-bot'
    bot_role: str = 'BreadTube'
    bot_channel_init_retries: int = 3

    def to_str(self) -> str:
        return '\n'.join(['config', *[f'{k}={v}' for k, v in asdict(self).items()]])

    def from_str(self, text: str):
        lines = text.strip().splitlines()
        if not lines:
            raise RuntimeError('Config cannot load: empty input')
        if lines[0] != 'config':
            raise RuntimeError('Config cannot load: first line is not "config"')
        for line in lines[1:]:
            key, value = line.split('=', maxsplit=1)
            setattr(self, key, self.__annotations__[key](value))