Add support for controlling homekit lights and switches (#13346)

* Add support for controlling homekit lights and switches

This adds support for controlling lights and switches that expose a HomeKit
control interface, avoiding the requirement to implement protocol-specific
components.

* Comment out the homekit requirement

This needs to build native code, so leave it commented for now

* Review updates

* Make HomeKit auto-discovery optional

Add an "enable" argument to the discovery component and add a list of
optional devices types (currently just HomeKit) to discover

* Further review comments

* Update requirements_all.txt

* Fix houndci complaints

* Further review updates

* Final review fixup

* Lint fixups

* Fix discovery tests

* Further review updates

homeassistant/components/light/homekit_controller.py

@@ -0,0 +1,134 @@
+"""
+Support for Homekit lights.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/light.homekit_controller/
+"""
+import json
+import logging
+
+from homeassistant.components.homekit_controller import (
+    HomeKitEntity, KNOWN_ACCESSORIES)
+from homeassistant.components.light import (
+    ATTR_BRIGHTNESS, ATTR_HS_COLOR, ATTR_COLOR_TEMP, SUPPORT_BRIGHTNESS,
+    SUPPORT_COLOR, SUPPORT_COLOR_TEMP, Light)
+
+DEPENDENCIES = ['homekit_controller']
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """Set up Homekit lighting."""
+    if discovery_info is not None:
+        accessory = hass.data[KNOWN_ACCESSORIES][discovery_info['serial']]
+        add_devices([HomeKitLight(accessory, discovery_info)], True)
+
+
+class HomeKitLight(HomeKitEntity, Light):
+    """Representation of a Homekit light."""
+
+    def __init__(self, *args):
+        """Initialise the light."""
+        super().__init__(*args)
+        self._on = None
+        self._brightness = None
+        self._color_temperature = None
+        self._hue = None
+        self._saturation = None
+
+    def update_characteristics(self, characteristics):
+        """Synchronise light state with Home Assistant."""
+        # pylint: disable=import-error
+        import homekit
+
+        for characteristic in characteristics:
+            ctype = characteristic['type']
+            ctype = homekit.CharacteristicsTypes.get_short(ctype)
+            if ctype == "on":
+                self._chars['on'] = characteristic['iid']
+                self._on = characteristic['value']
+            elif ctype == 'brightness':
+                self._chars['brightness'] = characteristic['iid']
+                self._features |= SUPPORT_BRIGHTNESS
+                self._brightness = characteristic['value']
+            elif ctype == 'color-temperature':
+                self._chars['color_temperature'] = characteristic['iid']
+                self._features |= SUPPORT_COLOR_TEMP
+                self._color_temperature = characteristic['value']
+            elif ctype == "hue":
+                self._chars['hue'] = characteristic['iid']
+                self._features |= SUPPORT_COLOR
+                self._hue = characteristic['value']
+            elif ctype == "saturation":
+                self._chars['saturation'] = characteristic['iid']
+                self._features |= SUPPORT_COLOR
+                self._saturation = characteristic['value']
+
+    @property
+    def is_on(self):
+        """Return true if device is on."""
+        return self._on
+
+    @property
+    def brightness(self):
+        """Return the brightness of this light between 0..255."""
+        if self._features & SUPPORT_BRIGHTNESS:
+            return self._brightness * 255 / 100
+        return None
+
+    @property
+    def hs_color(self):
+        """Return the color property."""
+        if self._features & SUPPORT_COLOR:
+            return (self._hue, self._saturation)
+        return None
+
+    @property
+    def color_temp(self):
+        """Return the color temperature."""
+        if self._features & SUPPORT_COLOR_TEMP:
+            return self._color_temperature
+        return None
+
+    @property
+    def supported_features(self):
+        """Flag supported features."""
+        return self._features
+
+    def turn_on(self, **kwargs):
+        """Turn the specified light on."""
+        hs_color = kwargs.get(ATTR_HS_COLOR)
+        temperature = kwargs.get(ATTR_COLOR_TEMP)
+        brightness = kwargs.get(ATTR_BRIGHTNESS)
+
+        characteristics = []
+        if hs_color is not None:
+            characteristics.append({'aid': self._aid,
+                                    'iid': self._chars['hue'],
+                                    'value': hs_color[0]})
+            characteristics.append({'aid': self._aid,
+                                    'iid': self._chars['saturation'],
+                                    'value': hs_color[1]})
+        if brightness is not None:
+            characteristics.append({'aid': self._aid,
+                                    'iid': self._chars['brightness'],
+                                    'value': int(brightness * 100 / 255)})
+
+        if temperature is not None:
+            characteristics.append({'aid': self._aid,
+                                    'iid': self._chars['color-temperature'],
+                                    'value': int(temperature)})
+        characteristics.append({'aid': self._aid,
+                                'iid': self._chars['on'],
+                                'value': True})
+        body = json.dumps({'characteristics': characteristics})
+        self._securecon.put('/characteristics', body)
+
+    def turn_off(self, **kwargs):
+        """Turn the specified light off."""
+        characteristics = [{'aid': self._aid,
+                            'iid': self._chars['on'],
+                            'value': False}]
+        body = json.dumps({'characteristics': characteristics})
+        self._securecon.put('/characteristics', body)