Grouped light platform for Home Assistant

grouped_light.py

import logging

# Import the device class from the component that you want to support
from homeassistant.components import light
from homeassistant.const import (STATE_OFF, STATE_ON, SERVICE_TURN_ON, SERVICE_TURN_OFF, ATTR_ENTITY_ID)

CONF_NAME = 'name'
CONF_ENTITIES = 'entities'

_LOGGER = logging.getLogger(__name__)


def setup_platform(hass, config, add_devices, discovery_info=None):
    """Initialize grouped light platform."""
    name = config.get(CONF_NAME)
    entity_ids = config.get(CONF_ENTITIES)
    
    if name is None or entity_ids is None or len(entity_ids) == 0:
        _LOGGER.error('Invalid config. Excepted %s and %s', CONF_NAME, CONF_ENTITIES)
        return False

    add_devices([GroupedLight(hass, name, entity_ids)])


class GroupedLight(light.Light):
    """Represents an Grouped Light in Home Assistant."""

    def __init__(self, hass, name, entity_ids):
        """Initialize a Grouped Light."""
        self.hass = hass
        self._name = name
        self._entity_ids = entity_ids
    
    
    @property    
    def name(self):
        return self._name
        
        
    def _light_states(self):
        """The states that the group is tracking."""
        states = []
        
        for entity_id in self._entity_ids:
            state = self.hass.states.get(entity_id)
            _LOGGER.error("Got state for entity " + str(state))
            if state is not None:
                states.append(state)

        return states
        
    @property
    def brightness(self):
        """Brightness of the light group"""   
        brightness = 0
        for state in self._light_states():
            if not 'brightness' in state.attributes:
                return None
            brightness += state.attributes.get('brightness')
        brightness = brightness / float(len(self._entity_ids))
        return brightness

    
    @property
    def color_temp(self):
        """Return the CT color value."""
        for state in self._light_states():
            if not 'color_temp' in state.attributes:
                return None
            return state.attributes.get('color_temp')
        
        
    @property
    def xy_color(self):
        """Return the XY color value."""
        for state in self._light_states():
            if not 'xy_color' in state.attributes:
                return None
            #return the first value we get since merging color values does not make sense
            return state.attributes.get('xy_color')
            
            
    @property
    def is_on(self):
        """If light is on."""     
        for state in self._light_states():
            _LOGGER.error("Checking is on " + str(state))
            if state.state == STATE_ON:
                return True
        return False

        
    def turn_on(self, **kwargs):
        """Forward the turn_on command to all lights in the group"""
        for entity_id in self._entity_ids:
            kwargs[ATTR_ENTITY_ID] = entity_id
            self.hass.services.call('light', SERVICE_TURN_ON, kwargs, blocking=True)
            
            
    def turn_off(self, **kwargs):
        """Forward the turn_off command to all lights in the group"""
        for entity_id in self._entity_ids:
            kwargs[ATTR_ENTITY_ID] = entity_id
            self.hass.services.call('light', SERVICE_TURN_OFF, kwargs, blocking=True)