"""
Support for MQTT Template lights.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/light.mqtt_template/
"""
import asyncio
import logging
import voluptuous as vol

from homeassistant.core import callback
import homeassistant.components.mqtt as mqtt
from homeassistant.components.light import (
    ATTR_BRIGHTNESS, ATTR_EFFECT, ATTR_FLASH, ATTR_RGB_COLOR, ATTR_TRANSITION,
    PLATFORM_SCHEMA, SUPPORT_BRIGHTNESS, SUPPORT_EFFECT, SUPPORT_FLASH,
    SUPPORT_RGB_COLOR, SUPPORT_TRANSITION, Light)
from homeassistant.const import CONF_NAME, CONF_OPTIMISTIC, STATE_ON, STATE_OFF
from homeassistant.components.mqtt import (
    CONF_STATE_TOPIC, CONF_COMMAND_TOPIC, CONF_QOS, CONF_RETAIN)
import homeassistant.helpers.config_validation as cv

_LOGGER = logging.getLogger(__name__)

DOMAIN = 'mqtt_template'

DEPENDENCIES = ['mqtt']

DEFAULT_NAME = 'MQTT Template Light'
DEFAULT_OPTIMISTIC = False

CONF_EFFECT_LIST = "effect_list"
CONF_COMMAND_ON_TEMPLATE = 'command_on_template'
CONF_COMMAND_OFF_TEMPLATE = 'command_off_template'
CONF_STATE_TEMPLATE = 'state_template'
CONF_BRIGHTNESS_TEMPLATE = 'brightness_template'
CONF_RED_TEMPLATE = 'red_template'
CONF_GREEN_TEMPLATE = 'green_template'
CONF_BLUE_TEMPLATE = 'blue_template'
CONF_EFFECT_TEMPLATE = 'effect_template'

SUPPORT_MQTT_TEMPLATE = (SUPPORT_BRIGHTNESS | SUPPORT_EFFECT | SUPPORT_FLASH |
                         SUPPORT_RGB_COLOR | SUPPORT_TRANSITION)

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
    vol.Optional(CONF_EFFECT_LIST): vol.All(cv.ensure_list, [cv.string]),
    vol.Required(CONF_COMMAND_TOPIC): mqtt.valid_publish_topic,
    vol.Optional(CONF_STATE_TOPIC): mqtt.valid_subscribe_topic,
    vol.Required(CONF_COMMAND_ON_TEMPLATE): cv.template,
    vol.Required(CONF_COMMAND_OFF_TEMPLATE): cv.template,
    vol.Optional(CONF_STATE_TEMPLATE): cv.template,
    vol.Optional(CONF_BRIGHTNESS_TEMPLATE): cv.template,
    vol.Optional(CONF_RED_TEMPLATE): cv.template,
    vol.Optional(CONF_GREEN_TEMPLATE): cv.template,
    vol.Optional(CONF_BLUE_TEMPLATE): cv.template,
    vol.Optional(CONF_EFFECT_TEMPLATE): cv.template,
    vol.Optional(CONF_OPTIMISTIC, default=DEFAULT_OPTIMISTIC): cv.boolean,
    vol.Optional(CONF_QOS, default=mqtt.DEFAULT_QOS):
        vol.All(vol.Coerce(int), vol.In([0, 1, 2])),
    vol.Optional(CONF_RETAIN, default=mqtt.DEFAULT_RETAIN): cv.boolean
})


@asyncio.coroutine
def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
    """Setup a MQTT Template light."""
    yield from async_add_devices([MqttTemplate(
        hass,
        config.get(CONF_NAME),
        config.get(CONF_EFFECT_LIST),
        {
            key: config.get(key) for key in (
                CONF_STATE_TOPIC,
                CONF_COMMAND_TOPIC
            )
        },
        {
            key: config.get(key) for key in (
                CONF_COMMAND_ON_TEMPLATE,
                CONF_COMMAND_OFF_TEMPLATE,
                CONF_STATE_TEMPLATE,
                CONF_BRIGHTNESS_TEMPLATE,
                CONF_RED_TEMPLATE,
                CONF_GREEN_TEMPLATE,
                CONF_BLUE_TEMPLATE,
                CONF_EFFECT_TEMPLATE
            )
        },
        config.get(CONF_OPTIMISTIC),
        config.get(CONF_QOS),
        config.get(CONF_RETAIN)
    )])


class MqttTemplate(Light):
    """Representation of a MQTT Template light."""

    def __init__(self, hass, name, effect_list, topics, templates, optimistic,
                 qos, retain):
        """Initialize MQTT Template light."""
        self._name = name
        self._effect_list = effect_list
        self._topics = topics
        self._templates = templates
        self._optimistic = optimistic or topics[CONF_STATE_TOPIC] is None \
            or templates[CONF_STATE_TEMPLATE] is None
        self._qos = qos
        self._retain = retain

        # features
        self._state = False
        if self._templates[CONF_BRIGHTNESS_TEMPLATE] is not None:
            self._brightness = 255
        else:
            self._brightness = None

        if (self._templates[CONF_RED_TEMPLATE] is not None and
                self._templates[CONF_GREEN_TEMPLATE] is not None and
                self._templates[CONF_BLUE_TEMPLATE] is not None):
            self._rgb = [0, 0, 0]
        else:
            self._rgb = None
        self._effect = None

        # init hass to template
        for tpl in self._templates.values():
            if tpl is not None:
                tpl.hass = hass

    @asyncio.coroutine
    def async_added_to_hass(self):
        """Subscribe mqtt events.

        This method is a coroutine.
        """
        @callback
        def state_received(topic, payload, qos):
            """A new MQTT message has been received."""
            # read state
            state = self._templates[CONF_STATE_TEMPLATE].\
                async_render_with_possible_json_value(payload)
            if state == STATE_ON:
                self._state = True
            elif state == STATE_OFF:
                self._state = False
            else:
                _LOGGER.warning('Invalid state value received')

            # read brightness
            if self._brightness is not None:
                try:
                    self._brightness = int(
                        self._templates[CONF_BRIGHTNESS_TEMPLATE].
                        async_render_with_possible_json_value(payload)
                    )
                except ValueError:
                    _LOGGER.warning('Invalid brightness value received')

            # read color
            if self._rgb is not None:
                try:
                    self._rgb[0] = int(
                        self._templates[CONF_RED_TEMPLATE].
                        async_render_with_possible_json_value(payload))
                    self._rgb[1] = int(
                        self._templates[CONF_GREEN_TEMPLATE].
                        async_render_with_possible_json_value(payload))
                    self._rgb[2] = int(
                        self._templates[CONF_BLUE_TEMPLATE].
                        async_render_with_possible_json_value(payload))
                except ValueError:
                    _LOGGER.warning('Invalid color value received')

            # read effect
            if self._templates[CONF_EFFECT_TEMPLATE] is not None:
                effect = self._templates[CONF_EFFECT_TEMPLATE].\
                    async_render_with_possible_json_value(payload)

                # validate effect value
                if effect in self._effect_list:
                    self._effect = effect
                else:
                    _LOGGER.warning('Unsupported effect value received')

            self.hass.async_add_job(self.async_update_ha_state())

        if self._topics[CONF_STATE_TOPIC] is not None:
            yield from mqtt.async_subscribe(
                self.hass, self._topics[CONF_STATE_TOPIC], state_received,
                self._qos)

    @property
    def brightness(self):
        """Return the brightness of this light between 0..255."""
        return self._brightness

    @property
    def rgb_color(self):
        """Return the RGB color value [int, int, int]."""
        return self._rgb

    @property
    def should_poll(self):
        """Return True if entity has to be polled for state.

        False if entity pushes its state to HA.
        """
        return False

    @property
    def name(self):
        """Return the name of the entity."""
        return self._name

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

    @property
    def assumed_state(self):
        """Return True if unable to access real state of the entity."""
        return self._optimistic

    @property
    def effect_list(self):
        """Return the list of supported effects."""
        return self._effect_list

    @property
    def effect(self):
        """Return the current effect."""
        return self._effect

    @asyncio.coroutine
    def async_turn_on(self, **kwargs):
        """Turn the entity on.

        This method is a coroutine.
        """
        # state
        values = {'state': True}
        if self._optimistic:
            self._state = True

        # brightness
        if ATTR_BRIGHTNESS in kwargs:
            values['brightness'] = int(kwargs[ATTR_BRIGHTNESS])

            if self._optimistic:
                self._brightness = kwargs[ATTR_BRIGHTNESS]

        # color
        if ATTR_RGB_COLOR in kwargs:
            values['red'] = kwargs[ATTR_RGB_COLOR][0]
            values['green'] = kwargs[ATTR_RGB_COLOR][1]
            values['blue'] = kwargs[ATTR_RGB_COLOR][2]

            if self._optimistic:
                self._rgb = kwargs[ATTR_RGB_COLOR]

        # effect
        if ATTR_EFFECT in kwargs:
            values['effect'] = kwargs.get(ATTR_EFFECT)

        # flash
        if ATTR_FLASH in kwargs:
            values['flash'] = kwargs.get(ATTR_FLASH)

        # transition
        if ATTR_TRANSITION in kwargs:
            values['transition'] = kwargs[ATTR_TRANSITION]

        mqtt.async_publish(
            self.hass, self._topics[CONF_COMMAND_TOPIC],
            self._templates[CONF_COMMAND_ON_TEMPLATE].async_render(**values),
            self._qos, self._retain
        )

        if self._optimistic:
            self.hass.async_add_job(self.async_update_ha_state())

    @asyncio.coroutine
    def async_turn_off(self, **kwargs):
        """Turn the entity off.

        This method is a coroutine.
        """
        # state
        values = {'state': False}
        if self._optimistic:
            self._state = False

        # transition
        if ATTR_TRANSITION in kwargs:
            values['transition'] = kwargs[ATTR_TRANSITION]

        mqtt.async_publish(
            self.hass, self._topics[CONF_COMMAND_TOPIC],
            self._templates[CONF_COMMAND_OFF_TEMPLATE].async_render(**values),
            self._qos, self._retain
        )

        if self._optimistic:
            self.hass.async_add_job(self.async_update_ha_state())

    @property
    def supported_features(self):
        """Flag supported features."""
        features = 0
        if self._brightness is not None:
            features = features | SUPPORT_BRIGHTNESS
        if self._rgb is not None:
            features = features | SUPPORT_RGB_COLOR
        if self._effect_list is not None:
            features = features | SUPPORT_EFFECT

        return features
