"""
Support for Tellstick lights.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/light.tellstick/
"""

from homeassistant.components.light import (
    ATTR_BRIGHTNESS, SUPPORT_BRIGHTNESS, Light)
from homeassistant.components.tellstick import (
    DEFAULT_SIGNAL_REPETITIONS, ATTR_DISCOVER_DEVICES, ATTR_DISCOVER_CONFIG,
    DATA_TELLSTICK, TellstickDevice)


SUPPORT_TELLSTICK = SUPPORT_BRIGHTNESS


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the Tellstick lights."""
    if (discovery_info is None or
            discovery_info[ATTR_DISCOVER_DEVICES] is None):
        return

    signal_repetitions = discovery_info.get(
        ATTR_DISCOVER_CONFIG, DEFAULT_SIGNAL_REPETITIONS)

    add_entities([TellstickLight(hass.data[DATA_TELLSTICK][tellcore_id],
                                 signal_repetitions)
                  for tellcore_id in discovery_info[ATTR_DISCOVER_DEVICES]],
                 True)


class TellstickLight(TellstickDevice, Light):
    """Representation of a Tellstick light."""

    def __init__(self, tellcore_device, signal_repetitions):
        """Initialize the Tellstick light."""
        super().__init__(tellcore_device, signal_repetitions)

        self._brightness = 255

    @property
    def brightness(self):
        """Return the brightness of this light between 0..255."""
        return self._brightness

    @property
    def supported_features(self):
        """Flag supported features."""
        return SUPPORT_TELLSTICK

    def _parse_ha_data(self, kwargs):
        """Turn the value from HA into something useful."""
        return kwargs.get(ATTR_BRIGHTNESS)

    def _parse_tellcore_data(self, tellcore_data):
        """Turn the value received from tellcore into something useful."""
        if tellcore_data:
            return int(tellcore_data)  # brightness
        return None

    def _update_model(self, new_state, data):
        """Update the device entity state to match the arguments."""
        if new_state:
            brightness = data
            if brightness is not None:
                self._brightness = brightness

            # _brightness is not defined when called from super
            try:
                self._state = (self._brightness > 0)
            except AttributeError:
                self._state = True
        else:
            self._state = False

    def _send_device_command(self, requested_state, requested_data):
        """Let tellcore update the actual device to the requested state."""
        if requested_state:
            if requested_data is not None:
                self._brightness = int(requested_data)

            self._tellcore_device.dim(self._brightness)
        else:
            self._tellcore_device.turn_off()
