from __future__ import annotations as _annotations

from dataclasses import asdict, dataclass


@dataclass
class Config:
    bot_channel: str = 'breadtube-bot'
    bot_role: str = 'BreadTube'
    bot_channel_scan_interval: float = 30.
    bot_channel_init_retries: int = 3
    bot_message_duration: float = 150.
    request_timeout: float = 3.

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

    @staticmethod
    def from_str(text: str) -> Config:
        annotations = Config.__annotations__
        global_types = globals()['__builtins__']
        config = Config()
        lines = text.strip().splitlines()
        if not lines:
            raise RuntimeError('Cannot load config: empty input')
        if lines[0] != 'config':
            raise RuntimeError('Cannot load config: first line is not "config"')
        config_dict = {}
        for line_number, line in enumerate(lines[1:]):
            key, value = line.split('=', maxsplit=1)
            if key not in annotations:
                raise RuntimeError(f'Invalid config: invalid key {key} at line {line_number + 1}')
            if key in config_dict:
                raise RuntimeError(f'Invalid config: duplicated key {key} at line {line_number + 1}')
            config_dict[key] = value

        for key, value in config_dict.items():
            setattr(config, key, global_types[annotations[key]](value))
        return config