"""Support for MQTT fans."""
import logging

import voluptuous as vol

from homeassistant.components import fan, mqtt
from homeassistant.components.fan import (
    ATTR_SPEED, SPEED_HIGH, SPEED_LOW, SPEED_MEDIUM, SPEED_OFF,
    SUPPORT_OSCILLATE, SUPPORT_SET_SPEED, FanEntity)
from homeassistant.const import (
    CONF_DEVICE, CONF_NAME, CONF_OPTIMISTIC, CONF_PAYLOAD_OFF, CONF_PAYLOAD_ON,
    CONF_STATE)
from homeassistant.core import callback
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.dispatcher import async_dispatcher_connect
from homeassistant.helpers.typing import ConfigType, HomeAssistantType

from . import (
    ATTR_DISCOVERY_HASH, CONF_COMMAND_TOPIC, CONF_QOS, CONF_RETAIN,
    CONF_STATE_TOPIC, CONF_UNIQUE_ID, MqttAttributes, MqttAvailability,
    MqttDiscoveryUpdate, MqttEntityDeviceInfo, subscription)
from .discovery import MQTT_DISCOVERY_NEW, clear_discovery_hash

_LOGGER = logging.getLogger(__name__)

CONF_STATE_VALUE_TEMPLATE = 'state_value_template'
CONF_SPEED_STATE_TOPIC = 'speed_state_topic'
CONF_SPEED_COMMAND_TOPIC = 'speed_command_topic'
CONF_SPEED_VALUE_TEMPLATE = 'speed_value_template'
CONF_OSCILLATION_STATE_TOPIC = 'oscillation_state_topic'
CONF_OSCILLATION_COMMAND_TOPIC = 'oscillation_command_topic'
CONF_OSCILLATION_VALUE_TEMPLATE = 'oscillation_value_template'
CONF_PAYLOAD_OSCILLATION_ON = 'payload_oscillation_on'
CONF_PAYLOAD_OSCILLATION_OFF = 'payload_oscillation_off'
CONF_PAYLOAD_OFF_SPEED = 'payload_off_speed'
CONF_PAYLOAD_LOW_SPEED = 'payload_low_speed'
CONF_PAYLOAD_MEDIUM_SPEED = 'payload_medium_speed'
CONF_PAYLOAD_HIGH_SPEED = 'payload_high_speed'
CONF_SPEED_LIST = 'speeds'

DEFAULT_NAME = 'MQTT Fan'
DEFAULT_PAYLOAD_ON = 'ON'
DEFAULT_PAYLOAD_OFF = 'OFF'
DEFAULT_OPTIMISTIC = False

OSCILLATE_ON_PAYLOAD = 'oscillate_on'
OSCILLATE_OFF_PAYLOAD = 'oscillate_off'

OSCILLATION = 'oscillation'

PLATFORM_SCHEMA = mqtt.MQTT_RW_PLATFORM_SCHEMA.extend({
    vol.Optional(CONF_DEVICE): mqtt.MQTT_ENTITY_DEVICE_INFO_SCHEMA,
    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
    vol.Optional(CONF_OPTIMISTIC, default=DEFAULT_OPTIMISTIC): cv.boolean,
    vol.Optional(CONF_OSCILLATION_COMMAND_TOPIC): mqtt.valid_publish_topic,
    vol.Optional(CONF_OSCILLATION_STATE_TOPIC): mqtt.valid_subscribe_topic,
    vol.Optional(CONF_OSCILLATION_VALUE_TEMPLATE): cv.template,
    vol.Optional(CONF_PAYLOAD_HIGH_SPEED, default=SPEED_HIGH): cv.string,
    vol.Optional(CONF_PAYLOAD_LOW_SPEED, default=SPEED_LOW): cv.string,
    vol.Optional(CONF_PAYLOAD_MEDIUM_SPEED, default=SPEED_MEDIUM): cv.string,
    vol.Optional(CONF_PAYLOAD_OFF_SPEED, default=SPEED_OFF): cv.string,
    vol.Optional(CONF_PAYLOAD_OFF, default=DEFAULT_PAYLOAD_OFF): cv.string,
    vol.Optional(CONF_PAYLOAD_ON, default=DEFAULT_PAYLOAD_ON): cv.string,
    vol.Optional(CONF_PAYLOAD_OSCILLATION_OFF,
                 default=OSCILLATE_OFF_PAYLOAD): cv.string,
    vol.Optional(CONF_PAYLOAD_OSCILLATION_ON,
                 default=OSCILLATE_ON_PAYLOAD): cv.string,
    vol.Optional(CONF_SPEED_COMMAND_TOPIC): mqtt.valid_publish_topic,
    vol.Optional(CONF_SPEED_LIST,
                 default=[SPEED_OFF, SPEED_LOW,
                          SPEED_MEDIUM, SPEED_HIGH]): cv.ensure_list,
    vol.Optional(CONF_SPEED_STATE_TOPIC): mqtt.valid_subscribe_topic,
    vol.Optional(CONF_SPEED_VALUE_TEMPLATE): cv.template,
    vol.Optional(CONF_STATE_VALUE_TEMPLATE): cv.template,
    vol.Optional(CONF_UNIQUE_ID): cv.string,
}).extend(mqtt.MQTT_AVAILABILITY_SCHEMA.schema).extend(
    mqtt.MQTT_JSON_ATTRS_SCHEMA.schema)


async def async_setup_platform(hass: HomeAssistantType, config: ConfigType,
                               async_add_entities, discovery_info=None):
    """Set up MQTT fan through configuration.yaml."""
    await _async_setup_entity(config, async_add_entities)


async def async_setup_entry(hass, config_entry, async_add_entities):
    """Set up MQTT fan dynamically through MQTT discovery."""
    async def async_discover(discovery_payload):
        """Discover and add a MQTT fan."""
        try:
            discovery_hash = discovery_payload.pop(ATTR_DISCOVERY_HASH)
            config = PLATFORM_SCHEMA(discovery_payload)
            await _async_setup_entity(config, async_add_entities, config_entry,
                                      discovery_hash)
        except Exception:
            if discovery_hash:
                clear_discovery_hash(hass, discovery_hash)
            raise

    async_dispatcher_connect(
        hass, MQTT_DISCOVERY_NEW.format(fan.DOMAIN, 'mqtt'),
        async_discover)


async def _async_setup_entity(config, async_add_entities, config_entry=None,
                              discovery_hash=None):
    """Set up the MQTT fan."""
    async_add_entities([MqttFan(config, config_entry, discovery_hash)])


# pylint: disable=too-many-ancestors
class MqttFan(MqttAttributes, MqttAvailability, MqttDiscoveryUpdate,
              MqttEntityDeviceInfo, FanEntity):
    """A MQTT fan component."""

    def __init__(self, config, config_entry, discovery_hash):
        """Initialize the MQTT fan."""
        self._unique_id = config.get(CONF_UNIQUE_ID)
        self._state = False
        self._speed = None
        self._oscillation = None
        self._supported_features = 0
        self._sub_state = None

        self._topic = None
        self._payload = None
        self._templates = None
        self._optimistic = None
        self._optimistic_oscillation = None
        self._optimistic_speed = None

        # Load config
        self._setup_from_config(config)

        device_config = config.get(CONF_DEVICE)

        MqttAttributes.__init__(self, config)
        MqttAvailability.__init__(self, config)
        MqttDiscoveryUpdate.__init__(self, discovery_hash,
                                     self.discovery_update)
        MqttEntityDeviceInfo.__init__(self, device_config, config_entry)

    async def async_added_to_hass(self):
        """Subscribe to MQTT events."""
        await super().async_added_to_hass()
        await self._subscribe_topics()

    async def discovery_update(self, discovery_payload):
        """Handle updated discovery message."""
        config = PLATFORM_SCHEMA(discovery_payload)
        self._setup_from_config(config)
        await self.attributes_discovery_update(config)
        await self.availability_discovery_update(config)
        await self.device_info_discovery_update(config)
        await self._subscribe_topics()
        self.async_write_ha_state()

    def _setup_from_config(self, config):
        """(Re)Setup the entity."""
        self._config = config
        self._topic = {
            key: config.get(key) for key in (
                CONF_STATE_TOPIC,
                CONF_COMMAND_TOPIC,
                CONF_SPEED_STATE_TOPIC,
                CONF_SPEED_COMMAND_TOPIC,
                CONF_OSCILLATION_STATE_TOPIC,
                CONF_OSCILLATION_COMMAND_TOPIC,
            )
        }
        self._templates = {
            CONF_STATE: config.get(CONF_STATE_VALUE_TEMPLATE),
            ATTR_SPEED: config.get(CONF_SPEED_VALUE_TEMPLATE),
            OSCILLATION: config.get(CONF_OSCILLATION_VALUE_TEMPLATE)
        }
        self._payload = {
            'STATE_ON': config[CONF_PAYLOAD_ON],
            'STATE_OFF': config[CONF_PAYLOAD_OFF],
            'OSCILLATE_ON_PAYLOAD': config[CONF_PAYLOAD_OSCILLATION_ON],
            'OSCILLATE_OFF_PAYLOAD': config[CONF_PAYLOAD_OSCILLATION_OFF],
            'SPEED_LOW': config[CONF_PAYLOAD_LOW_SPEED],
            'SPEED_MEDIUM': config[CONF_PAYLOAD_MEDIUM_SPEED],
            'SPEED_HIGH': config[CONF_PAYLOAD_HIGH_SPEED],
            'SPEED_OFF': config[CONF_PAYLOAD_OFF_SPEED],
        }
        optimistic = config[CONF_OPTIMISTIC]
        self._optimistic = optimistic or self._topic[CONF_STATE_TOPIC] is None
        self._optimistic_oscillation = (
            optimistic or self._topic[CONF_OSCILLATION_STATE_TOPIC] is None)
        self._optimistic_speed = (
            optimistic or self._topic[CONF_SPEED_STATE_TOPIC] is None)

        self._supported_features = 0
        self._supported_features |= (self._topic[CONF_OSCILLATION_STATE_TOPIC]
                                     is not None and SUPPORT_OSCILLATE)
        self._supported_features |= (self._topic[CONF_SPEED_STATE_TOPIC]
                                     is not None and SUPPORT_SET_SPEED)

    async def _subscribe_topics(self):
        """(Re)Subscribe to topics."""
        topics = {}
        templates = {}
        for key, tpl in list(self._templates.items()):
            if tpl is None:
                templates[key] = lambda value: value
            else:
                tpl.hass = self.hass
                templates[key] = tpl.async_render_with_possible_json_value

        @callback
        def state_received(msg):
            """Handle new received MQTT message."""
            payload = templates[CONF_STATE](msg.payload)
            if payload == self._payload['STATE_ON']:
                self._state = True
            elif payload == self._payload['STATE_OFF']:
                self._state = False
            self.async_write_ha_state()

        if self._topic[CONF_STATE_TOPIC] is not None:
            topics[CONF_STATE_TOPIC] = {
                'topic': self._topic[CONF_STATE_TOPIC],
                'msg_callback': state_received,
                'qos': self._config[CONF_QOS]}

        @callback
        def speed_received(msg):
            """Handle new received MQTT message for the speed."""
            payload = templates[ATTR_SPEED](msg.payload)
            if payload == self._payload['SPEED_LOW']:
                self._speed = SPEED_LOW
            elif payload == self._payload['SPEED_MEDIUM']:
                self._speed = SPEED_MEDIUM
            elif payload == self._payload['SPEED_HIGH']:
                self._speed = SPEED_HIGH
            elif payload == self._payload['SPEED_OFF']:
                self._speed = SPEED_OFF
            self.async_write_ha_state()

        if self._topic[CONF_SPEED_STATE_TOPIC] is not None:
            topics[CONF_SPEED_STATE_TOPIC] = {
                'topic': self._topic[CONF_SPEED_STATE_TOPIC],
                'msg_callback': speed_received,
                'qos': self._config[CONF_QOS]}
            self._speed = SPEED_OFF

        @callback
        def oscillation_received(msg):
            """Handle new received MQTT message for the oscillation."""
            payload = templates[OSCILLATION](msg.payload)
            if payload == self._payload['OSCILLATE_ON_PAYLOAD']:
                self._oscillation = True
            elif payload == self._payload['OSCILLATE_OFF_PAYLOAD']:
                self._oscillation = False
            self.async_write_ha_state()

        if self._topic[CONF_OSCILLATION_STATE_TOPIC] is not None:
            topics[CONF_OSCILLATION_STATE_TOPIC] = {
                'topic': self._topic[CONF_OSCILLATION_STATE_TOPIC],
                'msg_callback': oscillation_received,
                'qos': self._config[CONF_QOS]}
            self._oscillation = False

        self._sub_state = await subscription.async_subscribe_topics(
            self.hass, self._sub_state,
            topics)

    async def async_will_remove_from_hass(self):
        """Unsubscribe when removed."""
        self._sub_state = await subscription.async_unsubscribe_topics(
            self.hass, self._sub_state)
        await MqttAttributes.async_will_remove_from_hass(self)
        await MqttAvailability.async_will_remove_from_hass(self)

    @property
    def should_poll(self):
        """No polling needed for a MQTT fan."""
        return False

    @property
    def assumed_state(self):
        """Return true if we do optimistic updates."""
        return self._optimistic

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

    @property
    def name(self) -> str:
        """Get entity name."""
        return self._config[CONF_NAME]

    @property
    def speed_list(self) -> list:
        """Get the list of available speeds."""
        return self._config[CONF_SPEED_LIST]

    @property
    def supported_features(self) -> int:
        """Flag supported features."""
        return self._supported_features

    @property
    def speed(self):
        """Return the current speed."""
        return self._speed

    @property
    def oscillating(self):
        """Return the oscillation state."""
        return self._oscillation

    async def async_turn_on(self, speed: str = None, **kwargs) -> None:
        """Turn on the entity.

        This method is a coroutine.
        """
        mqtt.async_publish(
            self.hass, self._topic[CONF_COMMAND_TOPIC],
            self._payload['STATE_ON'], self._config[CONF_QOS],
            self._config[CONF_RETAIN])
        if speed:
            await self.async_set_speed(speed)
        if self._optimistic:
            self._state = True
            self.async_write_ha_state()

    async def async_turn_off(self, **kwargs) -> None:
        """Turn off the entity.

        This method is a coroutine.
        """
        mqtt.async_publish(
            self.hass, self._topic[CONF_COMMAND_TOPIC],
            self._payload['STATE_OFF'], self._config[CONF_QOS],
            self._config[CONF_RETAIN])
        if self._optimistic:
            self._state = False
            self.async_write_ha_state()

    async def async_set_speed(self, speed: str) -> None:
        """Set the speed of the fan.

        This method is a coroutine.
        """
        if self._topic[CONF_SPEED_COMMAND_TOPIC] is None:
            return

        if speed == SPEED_LOW:
            mqtt_payload = self._payload['SPEED_LOW']
        elif speed == SPEED_MEDIUM:
            mqtt_payload = self._payload['SPEED_MEDIUM']
        elif speed == SPEED_HIGH:
            mqtt_payload = self._payload['SPEED_HIGH']
        elif speed == SPEED_OFF:
            mqtt_payload = self._payload['SPEED_OFF']
        else:
            mqtt_payload = speed

        mqtt.async_publish(
            self.hass, self._topic[CONF_SPEED_COMMAND_TOPIC],
            mqtt_payload, self._config[CONF_QOS],
            self._config[CONF_RETAIN])

        if self._optimistic_speed:
            self._speed = speed
            self.async_write_ha_state()

    async def async_oscillate(self, oscillating: bool) -> None:
        """Set oscillation.

        This method is a coroutine.
        """
        if self._topic[CONF_OSCILLATION_COMMAND_TOPIC] is None:
            return

        if oscillating is False:
            payload = self._payload['OSCILLATE_OFF_PAYLOAD']
        else:
            payload = self._payload['OSCILLATE_ON_PAYLOAD']

        mqtt.async_publish(
            self.hass, self._topic[CONF_OSCILLATION_COMMAND_TOPIC],
            payload, self._config[CONF_QOS], self._config[CONF_RETAIN])

        if self._optimistic_oscillation:
            self._oscillation = oscillating
            self.async_write_ha_state()

    @property
    def unique_id(self):
        """Return a unique ID."""
        return self._unique_id
