"""Data coordinator for one ninlight lamp."""

from __future__ import annotations

import asyncio
from collections.abc import Awaitable, Callable
from dataclasses import dataclass
from datetime import timedelta
import logging
from typing import Any

from homeassistant.config_entries import ConfigEntry
from homeassistant.core import HomeAssistant
from homeassistant.exceptions import ConfigEntryAuthFailed, HomeAssistantError
from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed

from .api import (
    NinlightAuthError,
    NinlightBusyError,
    NinlightClient,
    NinlightError,
    NinlightRequestError,
)
from .const import CONF_SCAN_INTERVAL, DEFAULT_SCAN_INTERVAL, DOMAIN, MAX_POLL_FAILURES

_LOGGER = logging.getLogger(__name__)

type NinlightConfigEntry = ConfigEntry[NinlightCoordinator]


@dataclass(frozen=True, slots=True)
class NinlightData:
    """Last known lamp state and system info."""

    state: dict[str, Any]
    info: dict[str, Any]


class NinlightCoordinator(DataUpdateCoordinator[NinlightData]):
    """Polls one lamp; every request to the lamp goes through `lock`."""

    config_entry: NinlightConfigEntry

    def __init__(
        self, hass: HomeAssistant, entry: NinlightConfigEntry, client: NinlightClient
    ) -> None:
        super().__init__(
            hass,
            _LOGGER,
            config_entry=entry,
            name=f"{DOMAIN} {client.host}",
            update_interval=timedelta(
                seconds=entry.options.get(CONF_SCAN_INTERVAL, DEFAULT_SCAN_INTERVAL)
            ),
        )
        self.client = client
        # The W600 web server has a listen backlog of 4: never talk to one lamp concurrently.
        self.lock = asyncio.Lock()
        # While a firmware update runs, the update entity watches the lamp itself.
        self.ota_in_progress = False
        # Consecutive poll failures; a short outage should not flip the lamp unavailable.
        self._consecutive_poll_failures = 0

    async def _async_update_data(self) -> NinlightData:
        if self.ota_in_progress and self.data is not None:
            return self.data
        try:
            async with self.lock:
                state = await self.client.get_state()
                info = await self.client.get_info()
        except NinlightAuthError as err:
            raise ConfigEntryAuthFailed(f"{self.client.host}: token rejected") from err
        except NinlightError as err:
            self._consecutive_poll_failures += 1
            if self.data is not None and self._consecutive_poll_failures < MAX_POLL_FAILURES:
                _LOGGER.debug(
                    "%s: poll failed (%d/%d), keeping last known state: %s",
                    self.client.host,
                    self._consecutive_poll_failures,
                    MAX_POLL_FAILURES,
                    err,
                )
                return self.data
            raise UpdateFailed(f"{self.client.host}: {err}") from err
        self._consecutive_poll_failures = 0
        return NinlightData(state, info)

    async def async_call[T](self, action: Callable[[NinlightClient], Awaitable[T]]) -> T:
        """Run one request under the lock and translate lamp errors for the UI."""
        try:
            async with self.lock:
                return await action(self.client)
        except NinlightAuthError as err:
            self.config_entry.async_start_reauth(self.hass)
            raise HomeAssistantError(
                translation_domain=DOMAIN, translation_key="auth_failed"
            ) from err
        except NinlightBusyError as err:
            raise HomeAssistantError(
                translation_domain=DOMAIN, translation_key="update_busy"
            ) from err
        except NinlightRequestError as err:
            raise HomeAssistantError(
                translation_domain=DOMAIN,
                translation_key="request_failed",
                translation_placeholders={"message": err.message},
            ) from err
        except NinlightError as err:
            raise HomeAssistantError(
                translation_domain=DOMAIN, translation_key="cannot_connect"
            ) from err

    async def async_set_state(self, **fields: Any) -> None:
        """Write and adopt the lamp's complete answer directly - no debounced refresh."""
        state = await self.async_call(lambda client: client.set_state(**fields))
        self._consecutive_poll_failures = 0
        self.async_set_updated_data(NinlightData(state, self.data.info))