"""Feed Entity Manager Sensor support for GDACS Feed."""
from __future__ import annotations

from collections.abc import Callable
from datetime import datetime
import logging
from typing import Any

from aio_georss_client.status_update import StatusUpdate

from homeassistant.components.sensor import SensorEntity
from homeassistant.config_entries import ConfigEntry
from homeassistant.core import HomeAssistant, callback
from homeassistant.helpers.device_registry import DeviceEntryType, DeviceInfo
from homeassistant.helpers.dispatcher import async_dispatcher_connect
from homeassistant.helpers.entity_platform import AddEntitiesCallback
from homeassistant.util import dt as dt_util

from . import GdacsFeedEntityManager
from .const import DEFAULT_ICON, DOMAIN, FEED

_LOGGER = logging.getLogger(__name__)

ATTR_STATUS = "status"
ATTR_LAST_UPDATE = "last_update"
ATTR_LAST_UPDATE_SUCCESSFUL = "last_update_successful"
ATTR_LAST_TIMESTAMP = "last_timestamp"
ATTR_CREATED = "created"
ATTR_UPDATED = "updated"
ATTR_REMOVED = "removed"

DEFAULT_UNIT_OF_MEASUREMENT = "alerts"

# An update of this entity is not making a web request, but uses internal data only.
PARALLEL_UPDATES = 0


async def async_setup_entry(
    hass: HomeAssistant, entry: ConfigEntry, async_add_entities: AddEntitiesCallback
) -> None:
    """Set up the GDACS Feed platform."""
    manager: GdacsFeedEntityManager = hass.data[DOMAIN][FEED][entry.entry_id]
    sensor = GdacsSensor(entry, manager)
    async_add_entities([sensor])


class GdacsSensor(SensorEntity):
    """Status sensor for the GDACS integration."""

    _attr_should_poll = False
    _attr_icon = DEFAULT_ICON
    _attr_native_unit_of_measurement = DEFAULT_UNIT_OF_MEASUREMENT
    _attr_has_entity_name = True
    _attr_name = None

    def __init__(
        self, config_entry: ConfigEntry, manager: GdacsFeedEntityManager
    ) -> None:
        """Initialize entity."""
        assert config_entry.unique_id
        self._config_entry_id = config_entry.entry_id
        self._attr_unique_id = config_entry.unique_id
        self._manager = manager
        self._status: str | None = None
        self._last_update: datetime | None = None
        self._last_update_successful: datetime | None = None
        self._last_timestamp: datetime | None = None
        self._total: int | None = None
        self._created: int | None = None
        self._updated: int | None = None
        self._removed: int | None = None
        self._remove_signal_status: Callable[[], None] | None = None
        self._attr_device_info = DeviceInfo(
            identifiers={(DOMAIN, config_entry.unique_id)},
            entry_type=DeviceEntryType.SERVICE,
            manufacturer="GDACS",
        )

    async def async_added_to_hass(self) -> None:
        """Call when entity is added to hass."""
        self._remove_signal_status = async_dispatcher_connect(
            self.hass,
            f"gdacs_status_{self._config_entry_id}",
            self._update_status_callback,
        )
        _LOGGER.debug("Waiting for updates %s", self._config_entry_id)
        # First update is manual because of how the feed entity manager is updated.
        await self.async_update()

    async def async_will_remove_from_hass(self) -> None:
        """Call when entity will be removed from hass."""
        if self._remove_signal_status:
            self._remove_signal_status()

    @callback
    def _update_status_callback(self) -> None:
        """Call status update method."""
        _LOGGER.debug("Received status update for %s", self._config_entry_id)
        self.async_schedule_update_ha_state(True)

    async def async_update(self) -> None:
        """Update this entity from the data held in the feed manager."""
        _LOGGER.debug("Updating %s", self._config_entry_id)
        if self._manager:
            status_info = self._manager.status_info()
            if status_info:
                self._update_from_status_info(status_info)

    def _update_from_status_info(self, status_info: StatusUpdate) -> None:
        """Update the internal state from the provided information."""
        self._status = status_info.status
        self._last_update = (
            dt_util.as_utc(status_info.last_update) if status_info.last_update else None
        )
        if status_info.last_update_successful:
            self._last_update_successful = dt_util.as_utc(
                status_info.last_update_successful
            )
        else:
            self._last_update_successful = None
        self._last_timestamp = status_info.last_timestamp
        self._total = status_info.total
        self._created = status_info.created
        self._updated = status_info.updated
        self._removed = status_info.removed

    @property
    def native_value(self) -> int | None:
        """Return the state of the sensor."""
        return self._total

    @property
    def extra_state_attributes(self) -> dict[str, Any]:
        """Return the device state attributes."""
        attributes: dict[str, Any] = {}
        for key, value in (
            (ATTR_STATUS, self._status),
            (ATTR_LAST_UPDATE, self._last_update),
            (ATTR_LAST_UPDATE_SUCCESSFUL, self._last_update_successful),
            (ATTR_LAST_TIMESTAMP, self._last_timestamp),
            (ATTR_CREATED, self._created),
            (ATTR_UPDATED, self._updated),
            (ATTR_REMOVED, self._removed),
        ):
            if value or isinstance(value, bool):
                attributes[key] = value
        return attributes