"""
Support for MQTT cover devices.

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

import voluptuous as vol

from homeassistant.core import callback
import homeassistant.components.mqtt as mqtt
from homeassistant.components.cover import (
    CoverDevice, ATTR_TILT_POSITION, SUPPORT_OPEN_TILT,
    SUPPORT_CLOSE_TILT, SUPPORT_STOP_TILT, SUPPORT_SET_TILT_POSITION,
    SUPPORT_OPEN, SUPPORT_CLOSE, SUPPORT_STOP, SUPPORT_SET_POSITION,
    ATTR_POSITION)
from homeassistant.exceptions import TemplateError
from homeassistant.const import (
    CONF_NAME, CONF_VALUE_TEMPLATE, CONF_OPTIMISTIC, STATE_OPEN,
    STATE_CLOSED, STATE_UNKNOWN)
from homeassistant.components.mqtt import (
    CONF_STATE_TOPIC, CONF_COMMAND_TOPIC, CONF_AVAILABILITY_TOPIC,
    CONF_QOS, CONF_RETAIN, valid_publish_topic, valid_subscribe_topic)
import homeassistant.helpers.config_validation as cv

_LOGGER = logging.getLogger(__name__)

DEPENDENCIES = ['mqtt']

CONF_TILT_COMMAND_TOPIC = 'tilt_command_topic'
CONF_TILT_STATUS_TOPIC = 'tilt_status_topic'
CONF_POSITION_TOPIC = 'set_position_topic'
CONF_SET_POSITION_TEMPLATE = 'set_position_template'

CONF_PAYLOAD_OPEN = 'payload_open'
CONF_PAYLOAD_CLOSE = 'payload_close'
CONF_PAYLOAD_STOP = 'payload_stop'
CONF_PAYLOAD_AVAILABLE = 'payload_available'
CONF_PAYLOAD_NOT_AVAILABLE = 'payload_not_available'
CONF_STATE_OPEN = 'state_open'
CONF_STATE_CLOSED = 'state_closed'
CONF_TILT_CLOSED_POSITION = 'tilt_closed_value'
CONF_TILT_OPEN_POSITION = 'tilt_opened_value'
CONF_TILT_MIN = 'tilt_min'
CONF_TILT_MAX = 'tilt_max'
CONF_TILT_STATE_OPTIMISTIC = 'tilt_optimistic'
CONF_TILT_INVERT_STATE = 'tilt_invert_state'

DEFAULT_NAME = 'MQTT Cover'
DEFAULT_PAYLOAD_OPEN = 'OPEN'
DEFAULT_PAYLOAD_CLOSE = 'CLOSE'
DEFAULT_PAYLOAD_STOP = 'STOP'
DEFAULT_PAYLOAD_AVAILABLE = 'online'
DEFAULT_PAYLOAD_NOT_AVAILABLE = 'offline'
DEFAULT_OPTIMISTIC = False
DEFAULT_RETAIN = False
DEFAULT_TILT_CLOSED_POSITION = 0
DEFAULT_TILT_OPEN_POSITION = 100
DEFAULT_TILT_MIN = 0
DEFAULT_TILT_MAX = 100
DEFAULT_TILT_OPTIMISTIC = False
DEFAULT_TILT_INVERT_STATE = False

OPEN_CLOSE_FEATURES = (SUPPORT_OPEN | SUPPORT_CLOSE | SUPPORT_STOP)
TILT_FEATURES = (SUPPORT_OPEN_TILT | SUPPORT_CLOSE_TILT | SUPPORT_STOP_TILT |
                 SUPPORT_SET_TILT_POSITION)

PLATFORM_SCHEMA = mqtt.MQTT_BASE_PLATFORM_SCHEMA.extend({
    vol.Optional(CONF_COMMAND_TOPIC, default=None): valid_publish_topic,
    vol.Optional(CONF_POSITION_TOPIC, default=None): valid_publish_topic,
    vol.Optional(CONF_SET_POSITION_TEMPLATE, default=None): cv.template,
    vol.Optional(CONF_RETAIN, default=DEFAULT_RETAIN): cv.boolean,
    vol.Optional(CONF_STATE_TOPIC): valid_subscribe_topic,
    vol.Optional(CONF_AVAILABILITY_TOPIC, default=None): valid_subscribe_topic,
    vol.Optional(CONF_VALUE_TEMPLATE): cv.template,
    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
    vol.Optional(CONF_PAYLOAD_OPEN, default=DEFAULT_PAYLOAD_OPEN): cv.string,
    vol.Optional(CONF_PAYLOAD_CLOSE, default=DEFAULT_PAYLOAD_CLOSE): cv.string,
    vol.Optional(CONF_PAYLOAD_STOP, default=DEFAULT_PAYLOAD_STOP): cv.string,
    vol.Optional(CONF_PAYLOAD_AVAILABLE,
                 default=DEFAULT_PAYLOAD_AVAILABLE): cv.string,
    vol.Optional(CONF_PAYLOAD_NOT_AVAILABLE,
                 default=DEFAULT_PAYLOAD_NOT_AVAILABLE): cv.string,
    vol.Optional(CONF_STATE_OPEN, default=STATE_OPEN): cv.string,
    vol.Optional(CONF_STATE_CLOSED, default=STATE_CLOSED): cv.string,
    vol.Optional(CONF_OPTIMISTIC, default=DEFAULT_OPTIMISTIC): cv.boolean,
    vol.Optional(CONF_TILT_COMMAND_TOPIC, default=None): valid_publish_topic,
    vol.Optional(CONF_TILT_STATUS_TOPIC, default=None): valid_subscribe_topic,
    vol.Optional(CONF_TILT_CLOSED_POSITION,
                 default=DEFAULT_TILT_CLOSED_POSITION): int,
    vol.Optional(CONF_TILT_OPEN_POSITION,
                 default=DEFAULT_TILT_OPEN_POSITION): int,
    vol.Optional(CONF_TILT_MIN, default=DEFAULT_TILT_MIN): int,
    vol.Optional(CONF_TILT_MAX, default=DEFAULT_TILT_MAX): int,
    vol.Optional(CONF_TILT_STATE_OPTIMISTIC,
                 default=DEFAULT_TILT_OPTIMISTIC): cv.boolean,
    vol.Optional(CONF_TILT_INVERT_STATE,
                 default=DEFAULT_TILT_INVERT_STATE): cv.boolean,
})


@asyncio.coroutine
def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
    """Set up the MQTT Cover."""
    value_template = config.get(CONF_VALUE_TEMPLATE)
    if value_template is not None:
        value_template.hass = hass
    set_position_template = config.get(CONF_SET_POSITION_TEMPLATE)
    if set_position_template is not None:
        set_position_template.hass = hass

    async_add_devices([MqttCover(
        config.get(CONF_NAME),
        config.get(CONF_STATE_TOPIC),
        config.get(CONF_COMMAND_TOPIC),
        config.get(CONF_AVAILABILITY_TOPIC),
        config.get(CONF_TILT_COMMAND_TOPIC),
        config.get(CONF_TILT_STATUS_TOPIC),
        config.get(CONF_QOS),
        config.get(CONF_RETAIN),
        config.get(CONF_STATE_OPEN),
        config.get(CONF_STATE_CLOSED),
        config.get(CONF_PAYLOAD_OPEN),
        config.get(CONF_PAYLOAD_CLOSE),
        config.get(CONF_PAYLOAD_STOP),
        config.get(CONF_PAYLOAD_AVAILABLE),
        config.get(CONF_PAYLOAD_NOT_AVAILABLE),
        config.get(CONF_OPTIMISTIC),
        value_template,
        config.get(CONF_TILT_OPEN_POSITION),
        config.get(CONF_TILT_CLOSED_POSITION),
        config.get(CONF_TILT_MIN),
        config.get(CONF_TILT_MAX),
        config.get(CONF_TILT_STATE_OPTIMISTIC),
        config.get(CONF_TILT_INVERT_STATE),
        config.get(CONF_POSITION_TOPIC),
        set_position_template,
    )])


class MqttCover(CoverDevice):
    """Representation of a cover that can be controlled using MQTT."""

    def __init__(self, name, state_topic, command_topic, availability_topic,
                 tilt_command_topic, tilt_status_topic, qos, retain,
                 state_open, state_closed, payload_open, payload_close,
                 payload_stop, payload_available, payload_not_available,
                 optimistic, value_template, tilt_open_position,
                 tilt_closed_position, tilt_min, tilt_max, tilt_optimistic,
                 tilt_invert, position_topic, set_position_template):
        """Initialize the cover."""
        self._position = None
        self._state = None
        self._name = name
        self._state_topic = state_topic
        self._command_topic = command_topic
        self._availability_topic = availability_topic
        self._available = True if availability_topic is None else False
        self._tilt_command_topic = tilt_command_topic
        self._tilt_status_topic = tilt_status_topic
        self._qos = qos
        self._payload_open = payload_open
        self._payload_close = payload_close
        self._payload_stop = payload_stop
        self._payload_available = payload_available
        self._payload_not_available = payload_not_available
        self._state_open = state_open
        self._state_closed = state_closed
        self._retain = retain
        self._tilt_open_position = tilt_open_position
        self._tilt_closed_position = tilt_closed_position
        self._optimistic = optimistic or state_topic is None
        self._template = value_template
        self._tilt_value = None
        self._tilt_min = tilt_min
        self._tilt_max = tilt_max
        self._tilt_optimistic = tilt_optimistic
        self._tilt_invert = tilt_invert
        self._position_topic = position_topic
        self._set_position_template = set_position_template

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

        This method is a coroutine.
        """
        @callback
        def tilt_updated(topic, payload, qos):
            """Handle tilt updates."""
            if (payload.isnumeric() and
                    self._tilt_min <= int(payload) <= self._tilt_max):

                level = self.find_percentage_in_range(float(payload))
                self._tilt_value = level
                self.async_schedule_update_ha_state()

        @callback
        def state_message_received(topic, payload, qos):
            """Handle new MQTT state messages."""
            if self._template is not None:
                payload = self._template.async_render_with_possible_json_value(
                    payload)

            if payload == self._state_open:
                self._state = False
            elif payload == self._state_closed:
                self._state = True
            elif payload.isnumeric() and 0 <= int(payload) <= 100:
                if int(payload) > 0:
                    self._state = False
                else:
                    self._state = True
                self._position = int(payload)
            else:
                _LOGGER.warning(
                    "Payload is not True, False, or integer (0-100): %s",
                    payload)
                return

            self.async_schedule_update_ha_state()

        @callback
        def availability_message_received(topic, payload, qos):
            """Handle new MQTT availability messages."""
            if payload == self._payload_available:
                self._available = True
            elif payload == self._payload_not_available:
                self._available = False

            self.async_schedule_update_ha_state()

        if self._state_topic is None:
            # Force into optimistic mode.
            self._optimistic = True
        else:
            yield from mqtt.async_subscribe(
                self.hass, self._state_topic,
                state_message_received, self._qos)

        if self._availability_topic is not None:
            yield from mqtt.async_subscribe(
                self.hass, self._availability_topic,
                availability_message_received, self._qos)

        if self._tilt_status_topic is None:
            self._tilt_optimistic = True
        else:
            self._tilt_optimistic = False
            self._tilt_value = STATE_UNKNOWN
            yield from mqtt.async_subscribe(
                self.hass, self._tilt_status_topic, tilt_updated, self._qos)

    @property
    def should_poll(self):
        """No polling needed."""
        return False

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

    @property
    def available(self) -> bool:
        """Return if cover is available."""
        return self._available

    @property
    def is_closed(self):
        """Return if the cover is closed."""
        return self._state

    @property
    def current_cover_position(self):
        """Return current position of cover.

        None is unknown, 0 is closed, 100 is fully open.
        """
        return self._position

    @property
    def current_cover_tilt_position(self):
        """Return current position of cover tilt."""
        return self._tilt_value

    @property
    def supported_features(self):
        """Flag supported features."""
        supported_features = 0
        if self._command_topic is not None:
            supported_features = OPEN_CLOSE_FEATURES

        if self._position_topic is not None:
            supported_features |= SUPPORT_SET_POSITION

        if self._tilt_command_topic is not None:
            supported_features |= TILT_FEATURES

        return supported_features

    @asyncio.coroutine
    def async_open_cover(self, **kwargs):
        """Move the cover up.

        This method is a coroutine.
        """
        mqtt.async_publish(
            self.hass, self._command_topic, self._payload_open, self._qos,
            self._retain)
        if self._optimistic:
            # Optimistically assume that cover has changed state.
            self._state = False
            self.async_schedule_update_ha_state()

    @asyncio.coroutine
    def async_close_cover(self, **kwargs):
        """Move the cover down.

        This method is a coroutine.
        """
        mqtt.async_publish(
            self.hass, self._command_topic, self._payload_close, self._qos,
            self._retain)
        if self._optimistic:
            # Optimistically assume that cover has changed state.
            self._state = True
            self.async_schedule_update_ha_state()

    @asyncio.coroutine
    def async_stop_cover(self, **kwargs):
        """Stop the device.

        This method is a coroutine.
        """
        mqtt.async_publish(
            self.hass, self._command_topic, self._payload_stop, self._qos,
            self._retain)

    @asyncio.coroutine
    def async_open_cover_tilt(self, **kwargs):
        """Tilt the cover open."""
        mqtt.async_publish(self.hass, self._tilt_command_topic,
                           self._tilt_open_position, self._qos,
                           self._retain)
        if self._tilt_optimistic:
            self._tilt_value = self._tilt_open_position
            self.async_schedule_update_ha_state()

    @asyncio.coroutine
    def async_close_cover_tilt(self, **kwargs):
        """Tilt the cover closed."""
        mqtt.async_publish(self.hass, self._tilt_command_topic,
                           self._tilt_closed_position, self._qos,
                           self._retain)
        if self._tilt_optimistic:
            self._tilt_value = self._tilt_closed_position
            self.async_schedule_update_ha_state()

    @asyncio.coroutine
    def async_set_cover_tilt_position(self, **kwargs):
        """Move the cover tilt to a specific position."""
        if ATTR_TILT_POSITION not in kwargs:
            return

        position = float(kwargs[ATTR_TILT_POSITION])

        # The position needs to be between min and max
        level = self.find_in_range_from_percent(position)

        mqtt.async_publish(self.hass, self._tilt_command_topic,
                           level, self._qos, self._retain)

    @asyncio.coroutine
    def async_set_cover_position(self, **kwargs):
        """Move the cover to a specific position."""
        if ATTR_POSITION in kwargs:
            position = kwargs[ATTR_POSITION]
            if self._set_position_template is not None:
                try:
                    position = self._set_position_template.async_render(
                        **kwargs)
                except TemplateError as ex:
                    _LOGGER.error(ex)
                    self._state = None

            mqtt.async_publish(self.hass, self._position_topic,
                               position, self._qos, self._retain)

    def find_percentage_in_range(self, position):
        """Find the 0-100% value within the specified range."""
        # the range of motion as defined by the min max values
        tilt_range = self._tilt_max - self._tilt_min
        # offset to be zero based
        offset_position = position - self._tilt_min
        # the percentage value within the range
        position_percentage = float(offset_position) / tilt_range * 100.0
        if self._tilt_invert:
            return 100 - position_percentage
        return position_percentage

    def find_in_range_from_percent(self, percentage):
        """
        Find the adjusted value for 0-100% within the specified range.

        if the range is 80-180 and the percentage is 90
        this method would determine the value to send on the topic
        by offsetting the max and min, getting the percentage value and
        returning the offset
        """
        offset = self._tilt_min
        tilt_range = self._tilt_max - self._tilt_min

        position = round(tilt_range * (percentage / 100.0))
        position += offset

        if self._tilt_invert:
            position = self._tilt_max - position + offset
        return position
