"""Support for Lutron Caseta lights."""
from datetime import timedelta
import logging

from homeassistant.components.light import (
    ATTR_BRIGHTNESS,
    ATTR_TRANSITION,
    DOMAIN,
    SUPPORT_BRIGHTNESS,
    SUPPORT_TRANSITION,
    LightEntity,
)

from . import LutronCasetaDevice
from .const import BRIDGE_DEVICE, BRIDGE_LEAP, DOMAIN as CASETA_DOMAIN

_LOGGER = logging.getLogger(__name__)


def to_lutron_level(level):
    """Convert the given Home Assistant light level (0-255) to Lutron (0-100)."""
    return int(round((level * 100) / 255))


def to_hass_level(level):
    """Convert the given Lutron (0-100) light level to Home Assistant (0-255)."""
    return int((level * 255) // 100)


async def async_setup_entry(hass, config_entry, async_add_entities):
    """Set up the Lutron Caseta light platform.

    Adds dimmers from the Caseta bridge associated with the config_entry as
    light entities.
    """
    entities = []
    data = hass.data[CASETA_DOMAIN][config_entry.entry_id]
    bridge = data[BRIDGE_LEAP]
    bridge_device = data[BRIDGE_DEVICE]
    light_devices = bridge.get_devices_by_domain(DOMAIN)

    for light_device in light_devices:
        entity = LutronCasetaLight(light_device, bridge, bridge_device)
        entities.append(entity)

    async_add_entities(entities, True)


class LutronCasetaLight(LutronCasetaDevice, LightEntity):
    """Representation of a Lutron Light, including dimmable."""

    @property
    def supported_features(self):
        """Flag supported features."""
        return SUPPORT_BRIGHTNESS | SUPPORT_TRANSITION

    @property
    def brightness(self):
        """Return the brightness of the light."""
        return to_hass_level(self._device["current_state"])

    async def _set_brightness(self, brightness, **kwargs):
        args = {}
        if ATTR_TRANSITION in kwargs:
            args["fade_time"] = timedelta(seconds=kwargs[ATTR_TRANSITION])

        await self._smartbridge.set_value(
            self.device_id, to_lutron_level(brightness), **args
        )

    async def async_turn_on(self, **kwargs):
        """Turn the light on."""
        brightness = kwargs.pop(ATTR_BRIGHTNESS, 255)

        await self._set_brightness(brightness, **kwargs)

    async def async_turn_off(self, **kwargs):
        """Turn the light off."""
        await self._set_brightness(0, **kwargs)

    @property
    def is_on(self):
        """Return true if device is on."""
        return self._device["current_state"] > 0

    async def async_update(self):
        """Call when forcing a refresh of the device."""
        self._device = self._smartbridge.get_device_by_id(self.device_id)
        _LOGGER.debug(self._device)
