from dataclasses import asdict, dataclass
from datetime import datetime


@dataclass(frozen=True, slots=True)
class ExhaustState:
    mqtt_connected: bool = False
    device_online: bool = False

    last_message_at: datetime | None = None

    firmware: str | None = None
    uptime_seconds: int | None = None

    wifi_rssi: int | None = None

    def to_dict(self) -> dict:
        result = asdict(self)

        if result["last_message_at"] is not None:
            result["last_message_at"] = (
                result["last_message_at"].isoformat()
            )

        return result