"""Support for Daikin AC sensors."""
import logging

from homeassistant.components.daikin import DOMAIN as DAIKIN_DOMAIN
from homeassistant.components.daikin.const import (
    ATTR_INSIDE_TEMPERATURE, ATTR_OUTSIDE_TEMPERATURE, SENSOR_TYPE_TEMPERATURE,
    SENSOR_TYPES)
from homeassistant.const import CONF_ICON, CONF_NAME, CONF_TYPE
from homeassistant.helpers.entity import Entity
from homeassistant.util.unit_system import UnitSystem

_LOGGER = logging.getLogger(__name__)


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Old way of setting up the Daikin sensors.

    Can only be called when a user accidentally mentions the platform in their
    config. But even in that case it would have been ignored.
    """
    pass


async def async_setup_entry(hass, entry, async_add_entities):
    """Set up Daikin climate based on config_entry."""
    daikin_api = hass.data[DAIKIN_DOMAIN].get(entry.entry_id)
    async_add_entities([
        DaikinClimateSensor(daikin_api, sensor, hass.config.units)
        for sensor in SENSOR_TYPES
    ])


class DaikinClimateSensor(Entity):
    """Representation of a Sensor."""

    def __init__(self, api, monitored_state, units: UnitSystem,
                 name=None) -> None:
        """Initialize the sensor."""
        self._api = api
        self._sensor = SENSOR_TYPES.get(monitored_state)
        if name is None:
            name = "{} {}".format(self._sensor[CONF_NAME], api.name)

        self._name = "{} {}".format(name, monitored_state.replace("_", " "))
        self._device_attribute = monitored_state

        if self._sensor[CONF_TYPE] == SENSOR_TYPE_TEMPERATURE:
            self._unit_of_measurement = units.temperature_unit

    @property
    def unique_id(self):
        """Return a unique ID."""
        return "{}-{}".format(self._api.mac, self._device_attribute)

    def get(self, key):
        """Retrieve device settings from API library cache."""
        value = None
        cast_to_float = False

        if key == ATTR_INSIDE_TEMPERATURE:
            value = self._api.device.values.get('htemp')
            cast_to_float = True
        elif key == ATTR_OUTSIDE_TEMPERATURE:
            value = self._api.device.values.get('otemp')

        if value is None:
            _LOGGER.warning("Invalid value requested for key %s", key)
        else:
            if value in ("-", "--"):
                value = None
            elif cast_to_float:
                try:
                    value = float(value)
                except ValueError:
                    value = None

        return value

    @property
    def icon(self):
        """Icon to use in the frontend, if any."""
        return self._sensor[CONF_ICON]

    @property
    def name(self):
        """Return the name of the sensor."""
        return self._name

    @property
    def state(self):
        """Return the state of the sensor."""
        return self.get(self._device_attribute)

    @property
    def unit_of_measurement(self):
        """Return the unit of measurement."""
        return self._unit_of_measurement

    async def async_update(self):
        """Retrieve latest state."""
        await self._api.async_update()

    @property
    def device_info(self):
        """Return a device description for device registry."""
        return self._api.device_info