"""Support for Template fans."""
import logging

import voluptuous as vol

from homeassistant.components.fan import (
    ATTR_DIRECTION,
    ATTR_OSCILLATING,
    ATTR_SPEED,
    DIRECTION_FORWARD,
    DIRECTION_REVERSE,
    ENTITY_ID_FORMAT,
    SPEED_HIGH,
    SPEED_LOW,
    SPEED_MEDIUM,
    SUPPORT_DIRECTION,
    SUPPORT_OSCILLATE,
    SUPPORT_SET_SPEED,
    FanEntity,
)
from homeassistant.const import (
    CONF_ENTITY_ID,
    CONF_FRIENDLY_NAME,
    CONF_VALUE_TEMPLATE,
    EVENT_HOMEASSISTANT_START,
    MATCH_ALL,
    STATE_OFF,
    STATE_ON,
    STATE_UNKNOWN,
)
from homeassistant.core import callback
from homeassistant.exceptions import TemplateError
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import async_generate_entity_id
from homeassistant.helpers.script import Script

from . import extract_entities, initialise_templates
from .const import CONF_AVAILABILITY_TEMPLATE

_LOGGER = logging.getLogger(__name__)

CONF_FANS = "fans"
CONF_SPEED_LIST = "speeds"
CONF_SPEED_TEMPLATE = "speed_template"
CONF_OSCILLATING_TEMPLATE = "oscillating_template"
CONF_DIRECTION_TEMPLATE = "direction_template"
CONF_ON_ACTION = "turn_on"
CONF_OFF_ACTION = "turn_off"
CONF_SET_SPEED_ACTION = "set_speed"
CONF_SET_OSCILLATING_ACTION = "set_oscillating"
CONF_SET_DIRECTION_ACTION = "set_direction"

_VALID_STATES = [STATE_ON, STATE_OFF]
_VALID_OSC = [True, False]
_VALID_DIRECTIONS = [DIRECTION_FORWARD, DIRECTION_REVERSE]

FAN_SCHEMA = vol.Schema(
    {
        vol.Optional(CONF_FRIENDLY_NAME): cv.string,
        vol.Required(CONF_VALUE_TEMPLATE): cv.template,
        vol.Optional(CONF_SPEED_TEMPLATE): cv.template,
        vol.Optional(CONF_OSCILLATING_TEMPLATE): cv.template,
        vol.Optional(CONF_DIRECTION_TEMPLATE): cv.template,
        vol.Optional(CONF_AVAILABILITY_TEMPLATE): cv.template,
        vol.Required(CONF_ON_ACTION): cv.SCRIPT_SCHEMA,
        vol.Required(CONF_OFF_ACTION): cv.SCRIPT_SCHEMA,
        vol.Optional(CONF_SET_SPEED_ACTION): cv.SCRIPT_SCHEMA,
        vol.Optional(CONF_SET_OSCILLATING_ACTION): cv.SCRIPT_SCHEMA,
        vol.Optional(CONF_SET_DIRECTION_ACTION): cv.SCRIPT_SCHEMA,
        vol.Optional(
            CONF_SPEED_LIST, default=[SPEED_LOW, SPEED_MEDIUM, SPEED_HIGH]
        ): cv.ensure_list,
        vol.Optional(CONF_ENTITY_ID): cv.entity_ids,
    }
)

PLATFORM_SCHEMA = cv.PLATFORM_SCHEMA.extend(
    {vol.Required(CONF_FANS): cv.schema_with_slug_keys(FAN_SCHEMA)}
)


async def async_setup_platform(hass, config, async_add_entities, discovery_info=None):
    """Set up the Template Fans."""
    fans = []

    for device, device_config in config[CONF_FANS].items():
        friendly_name = device_config.get(CONF_FRIENDLY_NAME, device)

        state_template = device_config[CONF_VALUE_TEMPLATE]
        speed_template = device_config.get(CONF_SPEED_TEMPLATE)
        oscillating_template = device_config.get(CONF_OSCILLATING_TEMPLATE)
        direction_template = device_config.get(CONF_DIRECTION_TEMPLATE)
        availability_template = device_config.get(CONF_AVAILABILITY_TEMPLATE)

        on_action = device_config[CONF_ON_ACTION]
        off_action = device_config[CONF_OFF_ACTION]
        set_speed_action = device_config.get(CONF_SET_SPEED_ACTION)
        set_oscillating_action = device_config.get(CONF_SET_OSCILLATING_ACTION)
        set_direction_action = device_config.get(CONF_SET_DIRECTION_ACTION)

        speed_list = device_config[CONF_SPEED_LIST]

        templates = {
            CONF_VALUE_TEMPLATE: state_template,
            CONF_SPEED_TEMPLATE: speed_template,
            CONF_OSCILLATING_TEMPLATE: oscillating_template,
            CONF_DIRECTION_TEMPLATE: direction_template,
            CONF_AVAILABILITY_TEMPLATE: availability_template,
        }

        initialise_templates(hass, templates)
        entity_ids = extract_entities(device, "fan", None, templates)

        fans.append(
            TemplateFan(
                hass,
                device,
                friendly_name,
                state_template,
                speed_template,
                oscillating_template,
                direction_template,
                availability_template,
                on_action,
                off_action,
                set_speed_action,
                set_oscillating_action,
                set_direction_action,
                speed_list,
                entity_ids,
            )
        )

    async_add_entities(fans)


class TemplateFan(FanEntity):
    """A template fan component."""

    def __init__(
        self,
        hass,
        device_id,
        friendly_name,
        state_template,
        speed_template,
        oscillating_template,
        direction_template,
        availability_template,
        on_action,
        off_action,
        set_speed_action,
        set_oscillating_action,
        set_direction_action,
        speed_list,
        entity_ids,
    ):
        """Initialize the fan."""
        self.hass = hass
        self.entity_id = async_generate_entity_id(
            ENTITY_ID_FORMAT, device_id, hass=hass
        )
        self._name = friendly_name

        self._template = state_template
        self._speed_template = speed_template
        self._oscillating_template = oscillating_template
        self._direction_template = direction_template
        self._availability_template = availability_template
        self._available = True
        self._supported_features = 0

        self._on_script = Script(hass, on_action)
        self._off_script = Script(hass, off_action)

        self._set_speed_script = None
        if set_speed_action:
            self._set_speed_script = Script(hass, set_speed_action)

        self._set_oscillating_script = None
        if set_oscillating_action:
            self._set_oscillating_script = Script(hass, set_oscillating_action)

        self._set_direction_script = None
        if set_direction_action:
            self._set_direction_script = Script(hass, set_direction_action)

        self._state = STATE_OFF
        self._speed = None
        self._oscillating = None
        self._direction = None

        if self._speed_template:
            self._supported_features |= SUPPORT_SET_SPEED
        if self._oscillating_template:
            self._supported_features |= SUPPORT_OSCILLATE
        if self._direction_template:
            self._supported_features |= SUPPORT_DIRECTION

        self._entities = entity_ids
        # List of valid speeds
        self._speed_list = speed_list

    @property
    def name(self):
        """Return the display name of this fan."""
        return self._name

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

    @property
    def speed_list(self) -> list:
        """Get the list of available speeds."""
        return self._speed_list

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

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

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

    @property
    def current_direction(self):
        """Return the oscillation state."""
        return self._direction

    @property
    def should_poll(self):
        """Return the polling state."""
        return False

    @property
    def available(self):
        """Return availability of Device."""
        return self._available

    # pylint: disable=arguments-differ
    async def async_turn_on(self, speed: str = None) -> None:
        """Turn on the fan."""
        await self._on_script.async_run({ATTR_SPEED: speed}, context=self._context)
        self._state = STATE_ON

        if speed is not None:
            await self.async_set_speed(speed)

    # pylint: disable=arguments-differ
    async def async_turn_off(self) -> None:
        """Turn off the fan."""
        await self._off_script.async_run(context=self._context)
        self._state = STATE_OFF

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

        if speed in self._speed_list:
            self._speed = speed
            await self._set_speed_script.async_run(
                {ATTR_SPEED: speed}, context=self._context
            )
        else:
            _LOGGER.error(
                "Received invalid speed: %s. Expected: %s", speed, self._speed_list
            )

    async def async_oscillate(self, oscillating: bool) -> None:
        """Set oscillation of the fan."""
        if self._set_oscillating_script is None:
            return

        if oscillating in _VALID_OSC:
            self._oscillating = oscillating
            await self._set_oscillating_script.async_run(
                {ATTR_OSCILLATING: oscillating}, context=self._context
            )
        else:
            _LOGGER.error(
                "Received invalid oscillating value: %s. Expected: %s",
                oscillating,
                ", ".join(_VALID_OSC),
            )

    async def async_set_direction(self, direction: str) -> None:
        """Set the direction of the fan."""
        if self._set_direction_script is None:
            return

        if direction in _VALID_DIRECTIONS:
            self._direction = direction
            await self._set_direction_script.async_run(
                {ATTR_DIRECTION: direction}, context=self._context
            )
        else:
            _LOGGER.error(
                "Received invalid direction: %s. Expected: %s",
                direction,
                ", ".join(_VALID_DIRECTIONS),
            )

    async def async_added_to_hass(self):
        """Register callbacks."""

        @callback
        def template_fan_state_listener(event):
            """Handle target device state changes."""
            self.async_schedule_update_ha_state(True)

        @callback
        def template_fan_startup(event):
            """Update template on startup."""
            if self._entities != MATCH_ALL:
                # Track state change only for valid templates
                self.hass.helpers.event.async_track_state_change_event(
                    self._entities, template_fan_state_listener
                )

            self.async_schedule_update_ha_state(True)

        self.hass.bus.async_listen_once(EVENT_HOMEASSISTANT_START, template_fan_startup)

    async def async_update(self):
        """Update the state from the template."""
        # Update state
        try:
            state = self._template.async_render()
        except TemplateError as ex:
            _LOGGER.error(ex)
            state = None
            self._state = None

        # Validate state
        if state in _VALID_STATES:
            self._state = state
        elif state == STATE_UNKNOWN:
            self._state = None
        else:
            _LOGGER.error(
                "Received invalid fan is_on state: %s. Expected: %s",
                state,
                ", ".join(_VALID_STATES),
            )
            self._state = None

        # Update speed if 'speed_template' is configured
        if self._speed_template is not None:
            try:
                speed = self._speed_template.async_render()
            except TemplateError as ex:
                _LOGGER.error(ex)
                speed = None
                self._state = None

            # Validate speed
            if speed in self._speed_list:
                self._speed = speed
            elif speed == STATE_UNKNOWN:
                self._speed = None
            else:
                _LOGGER.error(
                    "Received invalid speed: %s. Expected: %s", speed, self._speed_list
                )
                self._speed = None

        # Update oscillating if 'oscillating_template' is configured
        if self._oscillating_template is not None:
            try:
                oscillating = self._oscillating_template.async_render()
            except TemplateError as ex:
                _LOGGER.error(ex)
                oscillating = None
                self._state = None

            # Validate osc
            if oscillating == "True" or oscillating is True:
                self._oscillating = True
            elif oscillating == "False" or oscillating is False:
                self._oscillating = False
            elif oscillating == STATE_UNKNOWN:
                self._oscillating = None
            else:
                _LOGGER.error(
                    "Received invalid oscillating: %s. Expected: True/False",
                    oscillating,
                )
                self._oscillating = None

        # Update direction if 'direction_template' is configured
        if self._direction_template is not None:
            try:
                direction = self._direction_template.async_render()
            except TemplateError as ex:
                _LOGGER.error(ex)
                direction = None
                self._state = None

            # Validate speed
            if direction in _VALID_DIRECTIONS:
                self._direction = direction
            elif direction == STATE_UNKNOWN:
                self._direction = None
            else:
                _LOGGER.error(
                    "Received invalid direction: %s. Expected: %s",
                    direction,
                    ", ".join(_VALID_DIRECTIONS),
                )
                self._direction = None

        # Update Availability if 'availability_template' is defined
        if self._availability_template is not None:
            try:
                self._available = (
                    self._availability_template.async_render().lower() == "true"
                )
            except (TemplateError, ValueError) as ex:
                _LOGGER.error(
                    "Could not render %s template %s: %s",
                    CONF_AVAILABILITY_TEMPLATE,
                    self._name,
                    ex,
                )
