"""DataUpdateCoordinator for DKN Cloud NA."""

from __future__ import annotations

import asyncio
from datetime import timedelta
from typing import Any

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

from .api import DknAuthError, DknCloudNaClient, DknConnectionError
from .const import CONF_REFRESH_TOKEN, CONF_USER_TOKEN, DEFAULT_SCAN_INTERVAL, DOMAIN, LOGGER


class DknCoordinator(DataUpdateCoordinator[dict[str, dict[str, Any]]]):
    """Coordinator that polls all installations and exposes a flat device map.

    ``data`` is ``{mac_address: device_dict}`` where device_dict matches the
    shape returned by DknCloudNaClient.fetch_installations() device entries.

    The coordinator owns the client instance used across all platforms.
    Per-device asyncio.Lock objects for write serialization are stored in
    ``hass.data[DOMAIN][entry_id]["device_locks"]``.
    """

    client: DknCloudNaClient

    def __init__(
        self,
        hass: HomeAssistant,
        entry: ConfigEntry,
        client: DknCloudNaClient,
    ) -> None:
        scan_interval = int(entry.options.get("scan_interval", DEFAULT_SCAN_INTERVAL))
        super().__init__(
            hass,
            LOGGER,
            name=DOMAIN,
            update_interval=timedelta(seconds=scan_interval),
        )
        self.client = client
        self._entry = entry
        self.entry_id = entry.entry_id

    async def _async_update_data(self) -> dict[str, dict[str, Any]]:
        """Fetch all installations and flatten into {mac: device_dict}."""
        try:
            installations = await self.client.fetch_installations()
            await self.client.ensure_socket_connection(
                installations,
                self.async_handle_socket_device_data,
                self.async_request_refresh,
            )
        except DknAuthError as err:
            # 401 — trigger the reauth UI and mark entities unavailable.
            raise ConfigEntryAuthFailed("Token invalid or expired") from err
        except DknConnectionError as err:
            raise UpdateFailed(f"Cannot reach DKN Cloud NA: {err}") from err
        except asyncio.CancelledError:
            raise
        except Exception as err:  # noqa: BLE001
            raise UpdateFailed(f"Unexpected error: {type(err).__name__}") from err

        self._persist_tokens_if_changed()

        devices: dict[str, dict[str, Any]] = {}
        existing = self.data or {}
        for installation in installations or []:
            inst_id = installation.get("_id", "")
            for device in installation.get("devices", []):
                mac = str(device.get("mac") or "").strip().lower()
                if not mac:
                    continue
                devices[mac] = {
                    **existing.get(mac, {}),
                    **device,
                    "_installation_id": inst_id,
                }

        return devices

    def _persist_tokens_if_changed(self) -> None:
        """Save refreshed tokens back to the config entry so they survive restarts."""
        opts = self._entry.options
        stored_token = opts.get(CONF_USER_TOKEN)
        stored_refresh = opts.get(CONF_REFRESH_TOKEN)
        if (
            self.client.token
            and self.client.refresh_token
            and (
                self.client.token != stored_token
                or self.client.refresh_token != stored_refresh
            )
        ):
            new_opts = dict(opts)
            new_opts[CONF_USER_TOKEN] = self.client.token
            new_opts[CONF_REFRESH_TOKEN] = self.client.refresh_token
            self.hass.config_entries.async_update_entry(self._entry, options=new_opts)
            LOGGER.debug("DKN tokens persisted after refresh")

    async def async_handle_socket_device_data(
        self, mac: str, data: dict[str, Any]
    ) -> None:
        """Merge live device-data from Socket.IO into coordinator state."""
        current = dict(self.data or {})
        current[mac] = {**current.get(mac, {}), **data}
        self.async_set_updated_data(current)