"""Component for interfacing to Lutron Homeworks Series 4 and 8 systems.

For more details about this component, please refer to the documentation at
https://home-assistant.io/components/homeworks/
"""
import logging

import voluptuous as vol

from homeassistant.core import callback
from homeassistant.const import (
    CONF_HOST, CONF_ID, CONF_NAME, CONF_PORT, EVENT_HOMEASSISTANT_STOP)
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.discovery import load_platform
from homeassistant.helpers.dispatcher import (
    dispatcher_send, async_dispatcher_connect)
from homeassistant.util import slugify

REQUIREMENTS = ['pyhomeworks==0.0.6']

_LOGGER = logging.getLogger(__name__)

DOMAIN = 'homeworks'

HOMEWORKS_CONTROLLER = 'homeworks'
ENTITY_SIGNAL = 'homeworks_entity_{}'
EVENT_BUTTON_PRESS = 'homeworks_button_press'
EVENT_BUTTON_RELEASE = 'homeworks_button_release'

CONF_DIMMERS = 'dimmers'
CONF_KEYPADS = 'keypads'
CONF_ADDR = 'addr'
CONF_RATE = 'rate'

FADE_RATE = 1.

CV_FADE_RATE = vol.All(vol.Coerce(float), vol.Range(min=0, max=20))

DIMMER_SCHEMA = vol.Schema({
    vol.Required(CONF_ADDR): cv.string,
    vol.Required(CONF_NAME): cv.string,
    vol.Optional(CONF_RATE, default=FADE_RATE): CV_FADE_RATE
})

KEYPAD_SCHEMA = vol.Schema({
    vol.Required(CONF_ADDR): cv.string,
    vol.Required(CONF_NAME): cv.string,
})

CONFIG_SCHEMA = vol.Schema({
    DOMAIN: vol.Schema({
        vol.Required(CONF_HOST): cv.string,
        vol.Required(CONF_PORT): cv.port,
        vol.Required(CONF_DIMMERS): vol.All(cv.ensure_list, [DIMMER_SCHEMA]),
        vol.Optional(CONF_KEYPADS, default=[]): vol.All(cv.ensure_list,
                                                        [KEYPAD_SCHEMA]),
    }),
}, extra=vol.ALLOW_EXTRA)


def setup(hass, base_config):
    """Start Homeworks controller."""
    from pyhomeworks.pyhomeworks import Homeworks

    def hw_callback(msg_type, values):
        """Dispatch state changes."""
        _LOGGER.debug('callback: %s, %s', msg_type, values)
        addr = values[0]
        signal = ENTITY_SIGNAL.format(addr)
        dispatcher_send(hass, signal, msg_type, values)

    config = base_config.get(DOMAIN)
    controller = Homeworks(config[CONF_HOST], config[CONF_PORT], hw_callback)
    hass.data[HOMEWORKS_CONTROLLER] = controller

    def cleanup(event):
        controller.close()

    hass.bus.listen_once(EVENT_HOMEASSISTANT_STOP, cleanup)

    dimmers = config[CONF_DIMMERS]
    load_platform(hass, 'light', DOMAIN, {CONF_DIMMERS: dimmers}, base_config)

    for key_config in config[CONF_KEYPADS]:
        addr = key_config[CONF_ADDR]
        name = key_config[CONF_NAME]
        HomeworksKeypadEvent(hass, addr, name)

    return True


class HomeworksDevice():
    """Base class of a Homeworks device."""

    def __init__(self, controller, addr, name):
        """Controller, address, and name of the device."""
        self._addr = addr
        self._name = name
        self._controller = controller

    @property
    def unique_id(self):
        """Return a unique identifier."""
        return 'homeworks.{}'.format(self._addr)

    @property
    def name(self):
        """Device name."""
        return self._name

    @property
    def should_poll(self):
        """No need to poll."""
        return False


class HomeworksKeypadEvent:
    """When you want signals instead of entities.

    Stateless sensors such as keypads are expected to generate an event
    instead of a sensor entity in hass.
    """

    def __init__(self, hass, addr, name):
        """Register callback that will be used for signals."""
        self._hass = hass
        self._addr = addr
        self._name = name
        self._id = slugify(self._name)
        signal = ENTITY_SIGNAL.format(self._addr)
        async_dispatcher_connect(
            self._hass, signal, self._update_callback)

    @callback
    def _update_callback(self, msg_type, values):
        """Fire events if button is pressed or released."""
        from pyhomeworks.pyhomeworks import (
            HW_BUTTON_PRESSED, HW_BUTTON_RELEASED)
        if msg_type == HW_BUTTON_PRESSED:
            event = EVENT_BUTTON_PRESS
        elif msg_type == HW_BUTTON_RELEASED:
            event = EVENT_BUTTON_RELEASE
        else:
            return
        data = {CONF_ID: self._id, CONF_NAME: self._name, 'button': values[1]}
        self._hass.bus.async_fire(event, data)