import os
from dataclasses import dataclass

DEFAULT_TAKE_TO_WORK_STAGE_ID = "PREPARATION"


def _required(name: str) -> str:
    value = os.getenv(name)
    if not value:
        raise RuntimeError(f"{name} is not set")
    return value


@dataclass(frozen=True)
class BotConfig:
    """Настройки процесса Telegram-бота."""

    bot_token: str
    database_url: str
    bitrix_client_id: str
    bitrix_client_secret: str
    token_encryption_key: str
    oauth_token_url: str
    take_to_work_stage_id: str = DEFAULT_TAKE_TO_WORK_STAGE_ID

    @classmethod
    def from_env(cls) -> "BotConfig":
        return cls(
            bot_token=_required("BOT_TOKEN"),
            database_url=_required("DATABASE_URL"),
            bitrix_client_id=_required("BITRIX_CLIENT_ID"),
            bitrix_client_secret=_required("BITRIX_CLIENT_SECRET"),
            token_encryption_key=_required("TOKEN_ENCRYPTION_KEY"),
            oauth_token_url=os.getenv(
                "BITRIX_OAUTH_TOKEN_URL",
                "https://oauth.bitrix.info/oauth/token/",
            ),
            take_to_work_stage_id=os.getenv(
                "BITRIX_TAKE_TO_WORK_STAGE_ID",
                DEFAULT_TAKE_TO_WORK_STAGE_ID
            )
        )