"""
Support for functionality to use a ZigBee device as a sensor.

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

import voluptuous as vol

from homeassistant.components import zigbee
from homeassistant.components.zigbee import PLATFORM_SCHEMA
from homeassistant.const import TEMP_CELSIUS
from homeassistant.helpers.entity import Entity

_LOGGER = logging.getLogger(__name__)

CONF_TYPE = 'type'
CONF_MAX_VOLTS = 'max_volts'

DEFAULT_VOLTS = 1.2
DEPENDENCIES = ['zigbee']

TYPES = ['analog', 'temperature']

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_TYPE): vol.In(TYPES),
    vol.Optional(CONF_MAX_VOLTS, default=DEFAULT_VOLTS): vol.Coerce(float),
})


def setup_platform(hass, config, add_devices, discovery_info=None):
    """Setup the ZigBee platform.

    Uses the 'type' config value to work out which type of ZigBee sensor we're
    dealing with and instantiates the relevant classes to handle it.
    """
    typ = config.get(CONF_TYPE)

    try:
        sensor_class, config_class = TYPE_CLASSES[typ]
    except KeyError:
        _LOGGER.exception("Unknown ZigBee sensor type: %s", typ)
        return

    add_devices([sensor_class(hass, config_class(config))])


class ZigBeeTemperatureSensor(Entity):
    """Representation of XBee Pro temperature sensor."""

    def __init__(self, hass, config):
        """Initialize the sensor."""
        self._config = config
        self._temp = None
        # Get initial state
        self.schedule_update_ha_state(True)

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

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

    @property
    def unit_of_measurement(self):
        """Unit the value is expressed in."""
        return TEMP_CELSIUS

    def update(self, *args):
        """Get the latest data."""
        try:
            self._temp = zigbee.DEVICE.get_temperature(self._config.address)
        except zigbee.ZIGBEE_TX_FAILURE:
            _LOGGER.warning(
                "Transmission failure when attempting to get sample from "
                "ZigBee device at address: %s", hexlify(self._config.address))
        except zigbee.ZIGBEE_EXCEPTION as exc:
            _LOGGER.exception(
                "Unable to get sample from ZigBee device: %s", exc)


# This must be below the classes to which it refers.
TYPE_CLASSES = {
    "temperature": (ZigBeeTemperatureSensor, zigbee.ZigBeeConfig),
    "analog": (zigbee.ZigBeeAnalogIn, zigbee.ZigBeeAnalogInConfig)
}