hass-core/homeassistant/components/light/hue.py

""" Support for Hue lights. """
import logging
import socket
from datetime import timedelta

import homeassistant.util as util
from homeassistant.helpers import ToggleDevice
from homeassistant.const import ATTR_FRIENDLY_NAME, CONF_HOST
from homeassistant.components.light import (
    ATTR_BRIGHTNESS, ATTR_XY_COLOR, ATTR_TRANSITION,
    ATTR_FLASH, FLASH_LONG, FLASH_SHORT)

MIN_TIME_BETWEEN_SCANS = timedelta(seconds=10)
MIN_TIME_BETWEEN_FORCED_SCANS = timedelta(seconds=1)

PHUE_CONFIG_FILE = "phue.conf"


def get_devices(hass, config):
    """ Gets the Hue lights. """
    logger = logging.getLogger(__name__)
    try:
        import phue
    except ImportError:
        logger.exception("Error while importing dependency phue.")

        return []

    host = config.get(CONF_HOST, None)

    try:
        bridge = phue.Bridge(
            host, config_file_path=hass.get_config_path(PHUE_CONFIG_FILE))
    except socket.error:  # Error connecting using Phue
        logger.exception((
            "Error while connecting to the bridge. "
            "Did you follow the instructions to set it up?"))

        return []

    lights = {}

    @util.Throttle(MIN_TIME_BETWEEN_SCANS, MIN_TIME_BETWEEN_FORCED_SCANS)
    def update_lights():
        """ Updates the Hue light objects with latest info from the bridge. """
        try:
            api = bridge.get_api()
        except socket.error:
            # socket.error when we cannot reach Hue
            logger.exception("Cannot reach the bridge")
            return

        api_states = api.get('lights')

        if not isinstance(api_states, dict):
            logger.error("Got unexpected result from Hue API")
            return

        for light_id, info in api_states.items():
            if light_id not in lights:
                lights[light_id] = HueLight(int(light_id), info,
                                            bridge, update_lights)
            else:
                lights[light_id].info = info

    update_lights()

    return list(lights.values())


class HueLight(ToggleDevice):
    """ Represents a Hue light """

    def __init__(self, light_id, info, bridge, update_lights):
        self.light_id = light_id
        self.info = info
        self.bridge = bridge
        self.update_lights = update_lights

    def get_name(self):
        """ Get the mame of the Hue light. """
        return self.info['name']

    def turn_on(self, **kwargs):
        """ Turn the specified or all lights on. """
        command = {'on': True}

        if ATTR_TRANSITION in kwargs:
            # Transition time is in 1/10th seconds and cannot exceed
            # 900 seconds.
            command['transitiontime'] = min(9000, kwargs[ATTR_TRANSITION] * 10)

        if ATTR_BRIGHTNESS in kwargs:
            command['bri'] = kwargs[ATTR_BRIGHTNESS]

        if ATTR_XY_COLOR in kwargs:
            command['xy'] = kwargs[ATTR_XY_COLOR]

        flash = kwargs.get(ATTR_FLASH)

        if flash == FLASH_LONG:
            command['alert'] = 'lselect'
        elif flash == FLASH_SHORT:
            command['alert'] = 'select'
        else:
            command['alert'] = 'none'

        self.bridge.set_light(self.light_id, command)

    def turn_off(self, **kwargs):
        """ Turn the specified or all lights off. """
        command = {'on': False}

        if ATTR_TRANSITION in kwargs:
            # Transition time is in 1/10th seconds and cannot exceed
            # 900 seconds.
            command['transitiontime'] = min(9000, kwargs[ATTR_TRANSITION] * 10)

        self.bridge.set_light(self.light_id, command)

    def is_on(self):
        """ True if device is on. """
        self.update_lights()

        return self.info['state']['reachable'] and self.info['state']['on']

    def get_state_attributes(self):
        """ Returns optional state attributes. """
        attr = {
            ATTR_FRIENDLY_NAME: self.get_name()
        }

        if self.is_on():
            attr[ATTR_BRIGHTNESS] = self.info['state']['bri']
            attr[ATTR_XY_COLOR] = self.info['state']['xy']

        return attr

    def update(self):
        """ Synchronize state with bridge. """
        self.update_lights(no_throttle=True)