"""
homeassistant.components.rollershutter.mqtt
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Allows to configure a MQTT rollershutter.
For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/rollershutter.mqtt/
"""
import logging
import homeassistant.components.mqtt as mqtt
from homeassistant.components.rollershutter import RollershutterDevice
from homeassistant.const import (STATE_OPEN, STATE_CLOSED, STATE_UNKNOWN)
_LOGGER = logging.getLogger(__name__)

DEPENDENCIES = ['mqtt']

DEFAULT_NAME = "MQTT Shutter"
DEFAULT_QOS = 0
DEFAULT_PAYLOAD_UP = "UP"
DEFAULT_PAYLOAD_DOWN = "DOWN"
DEFAULT_PAYLOAD_STOP = "STOP"

ATTR_CURRENT_POSITION = 'current_position'


# pylint: disable=unused-argument
def setup_platform(hass, config, add_devices_callback, discovery_info=None):
    """ Add MQTT Roller Shutter """

    if config.get('command_topic') is None:
        _LOGGER.error("Missing required variable: command_topic")
        return False

    add_devices_callback([MqttRollershutter(
        hass,
        config.get('name', DEFAULT_NAME),
        config.get('state_topic'),
        config.get('command_topic'),
        config.get('qos', DEFAULT_QOS),
        config.get('payload_up', DEFAULT_PAYLOAD_UP),
        config.get('payload_down', DEFAULT_PAYLOAD_DOWN),
        config.get('payload_stop', DEFAULT_PAYLOAD_STOP),
        config.get('state_format'))])


# pylint: disable=too-many-arguments, too-many-instance-attributes
class MqttRollershutter(RollershutterDevice):
    """ Represents a rollershutter that can be togggled using MQTT """
    def __init__(self, hass, name, state_topic, command_topic, qos,
                 payload_up, payload_down, payload_stop, state_format):
        self._state = -1
        self._hass = hass
        self._name = name
        self._state_topic = state_topic
        self._command_topic = command_topic
        self._qos = qos
        self._payload_up = payload_up
        self._payload_down = payload_down
        self._payload_stop = payload_stop
        self._parse = mqtt.FmtParser(state_format)

        if self._state_topic:
            def message_received(topic, payload, qos):
                """ A new MQTT message has been received. """
                value = self._parse(payload)
                if value.isnumeric():
                    if 0 <= int(value) <= 100:
                        self._state = int(value)
                        self.update_ha_state()

            mqtt.subscribe(hass, self._state_topic, message_received,
                           self._qos)

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

    @property
    def name(self):
        """ The name of the rollershutter """
        return self._name

    @property
    def state(self):
        """ Returns the state of the device. """
        if self._state == -1:
            return STATE_UNKNOWN
        elif self._state == 0:
            return STATE_CLOSED
        else:
            return STATE_OPEN

    @property
    def is_open(self):
        """ True if device is open. """
        return self.state == STATE_OPEN

    def move_up(self, **kwargs):
        """ Moves the device UP. """
        mqtt.publish(self.hass, self._command_topic, self._payload_up,
                     self._qos)

    def move_down(self, **kwargs):
        """ Moves the device DOWN. """
        mqtt.publish(self.hass, self._command_topic, self._payload_down,
                     self._qos)

    def move_stop(self, **kwargs):
        """ Moves the device to STOP. """
        mqtt.publish(self.hass, self._command_topic, self._payload_stop,
                     self._qos)

    @property
    def state_attributes(self):
        """ Return the state attributes. """
        state_attr = {
            ATTR_CURRENT_POSITION: self._state,
        }
        return state_attr