"""
Support for Xiaomi Mi Air Quality Monitor (PM2.5).

For more details about this platform, please refer to the documentation
https://home-assistant.io/components/sensor.xiaomi_miio/
"""
import logging

import voluptuous as vol

import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import Entity
from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.const import (CONF_NAME, CONF_HOST, CONF_TOKEN)
from homeassistant.exceptions import PlatformNotReady

_LOGGER = logging.getLogger(__name__)

DEFAULT_NAME = 'Xiaomi Miio Sensor'
DATA_KEY = 'sensor.xiaomi_miio'

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_HOST): cv.string,
    vol.Required(CONF_TOKEN): vol.All(cv.string, vol.Length(min=32, max=32)),
    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
})

REQUIREMENTS = ['python-miio==0.3.9', 'construct==2.9.41']

ATTR_POWER = 'power'
ATTR_CHARGING = 'charging'
ATTR_BATTERY_LEVEL = 'battery_level'
ATTR_TIME_STATE = 'time_state'
ATTR_MODEL = 'model'

SUCCESS = ['ok']


# pylint: disable=unused-argument
async def async_setup_platform(hass, config, async_add_devices,
                               discovery_info=None):
    """Set up the sensor from config."""
    from miio import AirQualityMonitor, DeviceException
    if DATA_KEY not in hass.data:
        hass.data[DATA_KEY] = {}

    host = config.get(CONF_HOST)
    name = config.get(CONF_NAME)
    token = config.get(CONF_TOKEN)

    _LOGGER.info("Initializing with host %s (token %s...)", host, token[:5])

    try:
        air_quality_monitor = AirQualityMonitor(host, token)
        device_info = air_quality_monitor.info()
        model = device_info.model
        unique_id = "{}-{}".format(model, device_info.mac_address)
        _LOGGER.info("%s %s %s detected",
                     model,
                     device_info.firmware_version,
                     device_info.hardware_version)
        device = XiaomiAirQualityMonitor(
            name, air_quality_monitor, model, unique_id)
    except DeviceException:
        raise PlatformNotReady

    hass.data[DATA_KEY][host] = device
    async_add_devices([device], update_before_add=True)


class XiaomiAirQualityMonitor(Entity):
    """Representation of a Xiaomi Air Quality Monitor."""

    def __init__(self, name, device, model, unique_id):
        """Initialize the entity."""
        self._name = name
        self._device = device
        self._model = model
        self._unique_id = unique_id

        self._icon = 'mdi:cloud'
        self._unit_of_measurement = 'AQI'
        self._available = None
        self._state = None
        self._state_attrs = {
            ATTR_POWER: None,
            ATTR_BATTERY_LEVEL: None,
            ATTR_CHARGING: None,
            ATTR_TIME_STATE: None,
            ATTR_MODEL: self._model,
        }

    @property
    def should_poll(self):
        """Poll the miio device."""
        return True

    @property
    def unique_id(self):
        """Return an unique ID."""
        return self._unique_id

    @property
    def name(self):
        """Return the name of this entity, if any."""
        return self._name

    @property
    def unit_of_measurement(self):
        """Return the unit of measurement of this entity, if any."""
        return self._unit_of_measurement

    @property
    def icon(self):
        """Return the icon to use for device if any."""
        return self._icon

    @property
    def available(self):
        """Return true when state is known."""
        return self._available

    @property
    def state(self):
        """Return the state of the device."""
        return self._state

    @property
    def device_state_attributes(self):
        """Return the state attributes of the device."""
        return self._state_attrs

    async def async_update(self):
        """Fetch state from the miio device."""
        from miio import DeviceException

        try:
            state = await self.hass.async_add_job(self._device.status)
            _LOGGER.debug("Got new state: %s", state)

            self._available = True
            self._state = state.aqi
            self._state_attrs.update({
                ATTR_POWER: state.power,
                ATTR_CHARGING: state.usb_power,
                ATTR_BATTERY_LEVEL: state.battery,
                ATTR_TIME_STATE: state.time_state,
            })

        except DeviceException as ex:
            self._available = False
            _LOGGER.error("Got exception while fetching the state: %s", ex)