Add support for x10 lights (#2637)

* Add support for x10 lights

* X10 linting and add to .coveragerc

homeassistant/components/light/x10.py

@@ -0,0 +1,103 @@
+"""
+Support for X10 lights.
+
+Requires heyu x10 interface
+http://www.heyu.org
+
+To enable x10 lights, add something like this to your `configuration.yaml`:
+
+    light:
+    - platform: x10
+        lights:
+        - name: Living Room Lamp
+            id: a2
+        - name: Bedroom Lamp
+            id: a3
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/light.x10/
+"""
+
+import logging
+from subprocess import check_output, CalledProcessError, STDOUT
+from homeassistant.components.light import ATTR_BRIGHTNESS, Light
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def x10_command(command):
+    """Execute X10 command and check output."""
+    return check_output(["heyu"] + command.split(' '), stderr=STDOUT)
+
+
+def get_status():
+    """Get on/off status for all x10 units in default housecode."""
+    output = check_output("heyu info | grep monitored", shell=True)
+    return output.decode('utf-8').split(' ')[-1].strip('\n()')
+
+
+def get_unit_status(code):
+    """Get on/off status for given unit."""
+    unit = int(code[1])
+    return get_status()[16 - int(unit)] == '1'
+
+
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """Initialize Awesome Light platform."""
+    # Verify that heyu is active
+    try:
+        x10_command("info")
+    except CalledProcessError as err:
+        _LOGGER.error(err.output)
+        return False
+
+    # Add devices
+    add_devices(X10Light(light) for light in config['lights'])
+
+
+class X10Light(Light):
+    """Represents an X10 Light in Home Assistant."""
+
+    def __init__(self, light):
+        """Initialize an X10 Light."""
+        self._name = light['name']
+        self._id = light['id']
+        self._is_on = False
+        self._brightness = 0
+
+    @property
+    def name(self):
+        """Return the display name of this light."""
+        return self._name
+
+    @property
+    def brightness(self):
+        """Brightness of the light (an integer in the range 1-255).
+
+        This method is optional. Removing it indicates to Home Assistant
+        that brightness is not supported for this light.
+        """
+        return self._brightness
+
+    @property
+    def is_on(self):
+        """If light is on."""
+        return self._is_on
+
+    def turn_on(self, **kwargs):
+        """Instruct the light to turn on."""
+        x10_command("on " + self._id)
+        self._brightness = kwargs.get(ATTR_BRIGHTNESS, 255)
+        self._is_on = True
+
+    def turn_off(self, **kwargs):
+        """Instruct the light to turn off."""
+        x10_command("off " + self._id)
+        self._is_on = False
+
+    def update(self):
+        """Fetch new state data for this light.
+
+        This is the only method that should fetch new data for Home Assitant.
+        """
+        self._is_on = get_unit_status(self._id)