"""Support for X10 lights."""
import logging
from subprocess import check_output, CalledProcessError, STDOUT

import voluptuous as vol

from homeassistant.const import CONF_NAME, CONF_ID, CONF_DEVICES
from homeassistant.components.light import (
    ATTR_BRIGHTNESS,
    SUPPORT_BRIGHTNESS,
    Light,
    PLATFORM_SCHEMA,
)
import homeassistant.helpers.config_validation as cv

_LOGGER = logging.getLogger(__name__)

SUPPORT_X10 = SUPPORT_BRIGHTNESS

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Required(CONF_DEVICES): vol.All(
            cv.ensure_list,
            [{vol.Required(CONF_ID): cv.string, vol.Required(CONF_NAME): cv.string}],
        )
    }
)


def x10_command(command):
    """Execute X10 command and check output."""
    return check_output(["heyu"] + command.split(" "), stderr=STDOUT)


def get_unit_status(code):
    """Get on/off status for given unit."""
    output = check_output("heyu onstate " + code, shell=True)
    return int(output.decode("utf-8")[0])


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the x10 Light platform."""
    is_cm11a = True
    try:
        x10_command("info")
    except CalledProcessError as err:
        _LOGGER.info("Assuming that the device is CM17A: %s", err.output)
        is_cm11a = False

    add_entities(X10Light(light, is_cm11a) for light in config[CONF_DEVICES])


class X10Light(Light):
    """Representation of an X10 Light."""

    def __init__(self, light, is_cm11a):
        """Initialize an X10 Light."""
        self._name = light["name"]
        self._id = light["id"]
        self._brightness = 0
        self._state = False
        self._is_cm11a = is_cm11a

    @property
    def name(self):
        """Return the display name of this light."""
        return self._name

    @property
    def brightness(self):
        """Return the brightness of the light."""
        return self._brightness

    @property
    def is_on(self):
        """Return true if light is on."""
        return self._state

    @property
    def supported_features(self):
        """Flag supported features."""
        return SUPPORT_X10

    def turn_on(self, **kwargs):
        """Instruct the light to turn on."""
        if self._is_cm11a:
            x10_command("on " + self._id)
        else:
            x10_command("fon " + self._id)
        self._brightness = kwargs.get(ATTR_BRIGHTNESS, 255)
        self._state = True

    def turn_off(self, **kwargs):
        """Instruct the light to turn off."""
        if self._is_cm11a:
            x10_command("off " + self._id)
        else:
            x10_command("foff " + self._id)
        self._state = False

    def update(self):
        """Fetch update state."""
        if self._is_cm11a:
            self._state = bool(get_unit_status(self._id))
        else:
            # Not supported on CM17A
            pass