"""An abstract class common to all Bond entities."""

from abc import abstractmethod
from asyncio import Lock
from datetime import datetime
import logging
from typing import override

from aiohttp import ClientError

from homeassistant.const import (
    ATTR_HW_VERSION,
    ATTR_MODEL,
    ATTR_NAME,
    ATTR_SUGGESTED_AREA,
    ATTR_SW_VERSION,
    ATTR_VIA_DEVICE,
)
from homeassistant.core import CALLBACK_TYPE, HassJob, callback
from homeassistant.helpers.device_registry import DeviceInfo
from homeassistant.helpers.entity import Entity
from homeassistant.helpers.event import async_call_later

from .const import DOMAIN
from .models import BondData
from .utils import BondDevice

_LOGGER = logging.getLogger(__name__)

_FALLBACK_SCAN_INTERVAL = 10
_BPUP_ALIVE_SCAN_INTERVAL = 60


class BondEntity(Entity):
    """Generic Bond entity encapsulating common features of any Bond device."""

    _attr_should_poll = False

    def __init__(
        self,
        data: BondData,
        device: BondDevice,
        sub_device: str | None = None,
        sub_device_id: str | None = None,
    ) -> None:
        """Initialize entity with API and device info."""
        hub = data.hub
        self._hub = hub
        self._bond = hub.bond
        self._device = device
        self._device_id = device.device_id
        self._sub_device = sub_device
        self._attr_available = True
        self._bpup_subs = data.bpup_subs
        self._update_lock = Lock()
        self._initialized = False
        if sub_device_id:
            sub_device_id = f"_{sub_device_id}"
        elif sub_device:
            sub_device_id = f"_{sub_device}"
        else:
            sub_device_id = ""
        self._attr_unique_id = f"{hub.bond_id}_{device.device_id}{sub_device_id}"
        if sub_device:
            sub_device_name = sub_device.replace("_", " ").title()
            self._attr_name = f"{device.name} {sub_device_name}"
        else:
            self._attr_name = device.name
        self._attr_assumed_state = self._hub.is_bridge and not self._device.trust_state
        self._apply_state()
        self._bpup_polling_fallback: CALLBACK_TYPE | None = None
        self._async_update_if_bpup_not_alive_job = HassJob(
            self._async_update_if_bpup_not_alive
        )

    @property
    @override
    def device_info(self) -> DeviceInfo:
        """Get a an HA device representing this Bond controlled device."""
        device_info = DeviceInfo(
            manufacturer=self._hub.make,
            # type ignore: tuple items should not be Optional
            identifiers={(DOMAIN, self._hub.bond_id, self._device_id)},  # type: ignore[arg-type]
            configuration_url=f"http://{self._hub.host}",
        )
        if self.name is not None:
            device_info[ATTR_NAME] = self._device.name
        if self._hub.bond_id is not None:
            device_info[ATTR_VIA_DEVICE] = (DOMAIN, self._hub.bond_id)
        if self._device.location is not None:
            device_info[ATTR_SUGGESTED_AREA] = self._device.location
        if not self._hub.is_bridge:
            if self._hub.model is not None:
                device_info[ATTR_MODEL] = self._hub.model
            if self._hub.fw_ver is not None:
                device_info[ATTR_SW_VERSION] = self._hub.fw_ver
            if self._hub.mcu_ver is not None:
                device_info[ATTR_HW_VERSION] = self._hub.mcu_ver
        else:
            model_data = []
            if self._device.branding_profile:
                model_data.append(self._device.branding_profile)
            if self._device.template:
                model_data.append(self._device.template)
            if model_data:
                device_info[ATTR_MODEL] = " ".join(model_data)

        return device_info

    async def async_update(self) -> None:
        """Perform a manual update from API."""
        await self._async_update_from_api()

    @callback
    def _async_update_if_bpup_not_alive(self, now: datetime) -> None:
        """Fetch via the API if BPUP is not alive."""
        self._async_schedule_bpup_alive_or_poll()
        if self.hass.is_stopping or (
            self._bpup_subs.alive and self._initialized and self.available
        ):
            return
        if self._update_lock.locked():
            _LOGGER.warning(
                "Updating %s took longer than the scheduled update interval %s",
                self.entity_id,
                _FALLBACK_SCAN_INTERVAL,
            )
            return
        self.hass.async_create_background_task(
            self._async_update(), f"{DOMAIN} {self.name} update", eager_start=True
        )

    async def _async_update(self) -> None:
        """Fetch via the API."""
        async with self._update_lock:
            await self._async_update_from_api()
            self.async_write_ha_state()

    async def _async_update_from_api(self) -> None:
        """Fetch via the API."""
        try:
            state: dict = await self._bond.device_state(self._device_id)
        except (ClientError, TimeoutError, OSError) as error:
            if self.available:
                _LOGGER.warning(
                    "Entity %s has become unavailable", self.entity_id, exc_info=error
                )
            self._attr_available = False
        else:
            self._async_state_callback(state)

    @abstractmethod
    def _apply_state(self) -> None:
        raise NotImplementedError

    @callback
    def _async_state_callback(self, state: dict) -> None:
        """Process a state change."""
        self._initialized = True
        if not self.available:
            _LOGGER.info("Entity %s has come back", self.entity_id)
        self._attr_available = True
        _LOGGER.debug(
            "Device state for %s (%s) is:\n%s", self.name, self.entity_id, state
        )
        self._device.state = state
        self._apply_state()

    @callback
    def _async_bpup_callback(self, json_msg: dict) -> None:
        """Process a state change from BPUP."""
        topic = json_msg["t"]
        if topic != f"devices/{self._device_id}/state":
            return

        self._async_state_callback(json_msg["b"])
        self.async_write_ha_state()

    @override
    async def async_added_to_hass(self) -> None:
        """Subscribe to BPUP and start polling."""
        await super().async_added_to_hass()
        self._bpup_subs.subscribe(self._device_id, self._async_bpup_callback)
        self._async_schedule_bpup_alive_or_poll()

    @callback
    def _async_schedule_bpup_alive_or_poll(self) -> None:
        """Schedule the BPUP alive or poll."""
        alive = self._bpup_subs.alive
        self._bpup_polling_fallback = async_call_later(
            self.hass,
            _BPUP_ALIVE_SCAN_INTERVAL if alive else _FALLBACK_SCAN_INTERVAL,
            self._async_update_if_bpup_not_alive_job,
        )

    @override
    async def async_will_remove_from_hass(self) -> None:
        """Unsubscribe from BPUP data on remove."""
        await super().async_will_remove_from_hass()
        self._bpup_subs.unsubscribe(self._device_id, self._async_bpup_callback)
        if self._bpup_polling_fallback:
            self._bpup_polling_fallback()
            self._bpup_polling_fallback = None