"""What every receiver protocol has to provide."""
from __future__ import annotations

from ..devices import Device


class BackendError(Exception):
    pass


class Backend:
    kind = ""
    #: Containers this protocol can be handed, best first.
    containers: tuple[str, ...] = ("webm",)
    #: Does it pull a plain HTTP stream (True) or an HLS playlist (False)?
    progressive = True

    def __init__(self, daemon) -> None:
        self.daemon = daemon

    async def play(self, device: Device, url: str, *, container: str, title: str) -> None:
        raise NotImplementedError

    async def stop(self, device: Device) -> None:
        raise NotImplementedError

    async def set_volume(self, device: Device, volume: float) -> None:
        raise BackendError("this receiver has no volume control")

    async def set_muted(self, device: Device, muted: bool) -> None:
        raise BackendError("this receiver has no mute control")

    async def transport(self, device: Device, action: str) -> None:
        raise BackendError("this receiver has no transport control")

    async def poll(self, device: Device) -> dict:
        """Live status of the session: {state, app, volume, muted, error}."""
        return {}

    async def close(self) -> None:
        return None