"""Configuration module - loads settings from .env file."""

import os
from dataclasses import dataclass
from typing import Optional


@dataclass
class Config:
    """Bot configuration."""

    bot_token: str
    db_url: str
    log_level: str
    timezone: str
    polling_skip_updates: bool

    @classmethod
    def from_env(cls) -> "Config":
        """Load configuration from environment variables."""
        bot_token = os.getenv("BOT_TOKEN")
        if not bot_token:
            raise ValueError("BOT_TOKEN environment variable is required")

        return cls(
            bot_token=bot_token,
            db_url=os.getenv("DB_URL", "sqlite+aiosqlite:///data/reminder.db"),
            log_level=os.getenv("LOG_LEVEL", "INFO"),
            timezone=os.getenv("TZ", "Europe/Moscow"),
            polling_skip_updates=os.getenv("POLLING_SKIP_UPDATES", "true").lower() == "true",
        )


# Global config instance
config: Optional[Config] = None


def get_config() -> Config:
    """Get global config instance."""
    global config
    if config is None:
        config = Config.from_env()
    return config