"""Support for the Philips Hue lights."""
import asyncio
from datetime import timedelta
import logging
from time import monotonic
import random

import async_timeout

from homeassistant.components import hue
from homeassistant.components.light import (
    ATTR_BRIGHTNESS, ATTR_COLOR_TEMP, ATTR_EFFECT, ATTR_FLASH,
    ATTR_TRANSITION, ATTR_HS_COLOR, EFFECT_COLORLOOP, EFFECT_RANDOM,
    FLASH_LONG, FLASH_SHORT, SUPPORT_BRIGHTNESS, SUPPORT_COLOR_TEMP,
    SUPPORT_EFFECT, SUPPORT_FLASH, SUPPORT_COLOR, SUPPORT_TRANSITION,
    Light)
from homeassistant.util import color

SCAN_INTERVAL = timedelta(seconds=5)

_LOGGER = logging.getLogger(__name__)

SUPPORT_HUE_ON_OFF = (SUPPORT_FLASH | SUPPORT_TRANSITION)
SUPPORT_HUE_DIMMABLE = (SUPPORT_HUE_ON_OFF | SUPPORT_BRIGHTNESS)
SUPPORT_HUE_COLOR_TEMP = (SUPPORT_HUE_DIMMABLE | SUPPORT_COLOR_TEMP)
SUPPORT_HUE_COLOR = (SUPPORT_HUE_DIMMABLE | SUPPORT_EFFECT | SUPPORT_COLOR)
SUPPORT_HUE_EXTENDED = (SUPPORT_HUE_COLOR_TEMP | SUPPORT_HUE_COLOR)

SUPPORT_HUE = {
    'Extended color light': SUPPORT_HUE_EXTENDED,
    'Color light': SUPPORT_HUE_COLOR,
    'Dimmable light': SUPPORT_HUE_DIMMABLE,
    'On/Off plug-in unit': SUPPORT_HUE_ON_OFF,
    'Color temperature light': SUPPORT_HUE_COLOR_TEMP,
}

ATTR_IS_HUE_GROUP = 'is_hue_group'
GAMUT_TYPE_UNAVAILABLE = 'None'
# Minimum Hue Bridge API version to support groups
# 1.4.0 introduced extended group info
# 1.12 introduced the state object for groups
# 1.13 introduced "any_on" to group state objects
GROUP_MIN_API_VERSION = (1, 13, 0)


async def async_setup_platform(
        hass, config, async_add_entities, discovery_info=None):
    """Old way of setting up Hue lights.

    Can only be called when a user accidentally mentions hue platform in their
    config. But even in that case it would have been ignored.
    """
    pass


async def async_setup_entry(hass, config_entry, async_add_entities):
    """Set up the Hue lights from a config entry."""
    bridge = hass.data[hue.DOMAIN][config_entry.data['host']]
    cur_lights = {}
    cur_groups = {}

    api_version = tuple(
        int(v) for v in bridge.api.config.apiversion.split('.'))

    allow_groups = bridge.allow_groups
    if allow_groups and api_version < GROUP_MIN_API_VERSION:
        _LOGGER.warning('Please update your Hue bridge to support groups')
        allow_groups = False

    # Hue updates all lights via a single API call.
    #
    # If we call a service to update 2 lights, we only want the API to be
    # called once.
    #
    # The throttle decorator will return right away if a call is currently
    # in progress. This means that if we are updating 2 lights, the first one
    # is in the update method, the second one will skip it and assume the
    # update went through and updates it's data, not good!
    #
    # The current mechanism will make sure that all lights will wait till
    # the update call is done before writing their data to the state machine.
    #
    # An alternative approach would be to disable automatic polling by Home
    # Assistant and take control ourselves. This works great for polling as now
    # we trigger from 1 time update an update to all entities. However it gets
    # tricky from inside async_turn_on and async_turn_off.
    #
    # If automatic polling is enabled, Home Assistant will call the entity
    # update method after it is done calling all the services. This means that
    # when we update, we know all commands have been processed. If we trigger
    # the update from inside async_turn_on, the update will not capture the
    # changes to the second entity until the next polling update because the
    # throttle decorator will prevent the call.

    progress = None
    light_progress = set()
    group_progress = set()

    async def request_update(is_group, object_id):
        """Request an update.

        We will only make 1 request to the server for updating at a time. If a
        request is in progress, we will join the request that is in progress.

        This approach is possible because should_poll=True. That means that
        Home Assistant will ask lights for updates during a polling cycle or
        after it has called a service.

        We keep track of the lights that are waiting for the request to finish.
        When new data comes in, we'll trigger an update for all non-waiting
        lights. This covers the case where a service is called to enable 2
        lights but in the meanwhile some other light has changed too.
        """
        nonlocal progress

        progress_set = group_progress if is_group else light_progress
        progress_set.add(object_id)

        if progress is not None:
            return await progress

        progress = asyncio.ensure_future(update_bridge())
        result = await progress
        progress = None
        light_progress.clear()
        group_progress.clear()
        return result

    async def update_bridge():
        """Update the values of the bridge.

        Will update lights and, if enabled, groups from the bridge.
        """
        tasks = []
        tasks.append(async_update_items(
            hass, bridge, async_add_entities, request_update,
            False, cur_lights, light_progress
        ))

        if allow_groups:
            tasks.append(async_update_items(
                hass, bridge, async_add_entities, request_update,
                True, cur_groups, group_progress
            ))

        await asyncio.wait(tasks)

    await update_bridge()


async def async_update_items(hass, bridge, async_add_entities,
                             request_bridge_update, is_group, current,
                             progress_waiting):
    """Update either groups or lights from the bridge."""
    import aiohue

    if is_group:
        api_type = 'group'
        api = bridge.api.groups
    else:
        api_type = 'light'
        api = bridge.api.lights

    try:
        start = monotonic()
        with async_timeout.timeout(4):
            await api.update()
    except (asyncio.TimeoutError, aiohue.AiohueException) as err:
        _LOGGER.debug('Failed to fetch %s: %s', api_type, err)

        if not bridge.available:
            return

        _LOGGER.error('Unable to reach bridge %s (%s)', bridge.host, err)
        bridge.available = False

        for light_id, light in current.items():
            if light_id not in progress_waiting:
                light.async_schedule_update_ha_state()

        return

    finally:
        _LOGGER.debug('Finished %s request in %.3f seconds',
                      api_type, monotonic() - start)

    if not bridge.available:
        _LOGGER.info('Reconnected to bridge %s', bridge.host)
        bridge.available = True

    new_lights = []

    for item_id in api:
        if item_id not in current:
            current[item_id] = HueLight(
                api[item_id], request_bridge_update, bridge, is_group)

            new_lights.append(current[item_id])
        elif item_id not in progress_waiting:
            current[item_id].async_schedule_update_ha_state()

    if new_lights:
        async_add_entities(new_lights)


class HueLight(Light):
    """Representation of a Hue light."""

    def __init__(self, light, request_bridge_update, bridge, is_group=False):
        """Initialize the light."""
        self.light = light
        self.async_request_bridge_update = request_bridge_update
        self.bridge = bridge
        self.is_group = is_group

        if is_group:
            self.is_osram = False
            self.is_philips = False
            self.gamut_typ = GAMUT_TYPE_UNAVAILABLE
            self.gamut = None
        else:
            self.is_osram = light.manufacturername == 'OSRAM'
            self.is_philips = light.manufacturername == 'Philips'
            self.gamut_typ = self.light.colorgamuttype
            self.gamut = self.light.colorgamut
            _LOGGER.debug("Color gamut of %s: %s", self.name, str(self.gamut))
            if self.light.swupdatestate == "readytoinstall":
                err = (
                    "Please check for software updates of the %s "
                    "bulb in the Philips Hue App."
                )
                _LOGGER.warning(err, self.name)
            if self.gamut:
                if not color.check_valid_gamut(self.gamut):
                    err = (
                        "Color gamut of %s: %s, not valid, "
                        "setting gamut to None."
                    )
                    _LOGGER.warning(err, self.name, str(self.gamut))
                    self.gamut_typ = GAMUT_TYPE_UNAVAILABLE
                    self.gamut = None

    @property
    def unique_id(self):
        """Return the ID of this Hue light."""
        return self.light.uniqueid

    @property
    def name(self):
        """Return the name of the Hue light."""
        return self.light.name

    @property
    def brightness(self):
        """Return the brightness of this light between 0..255."""
        if self.is_group:
            return self.light.action.get('bri')
        return self.light.state.get('bri')

    @property
    def _color_mode(self):
        """Return the hue color mode."""
        if self.is_group:
            return self.light.action.get('colormode')
        return self.light.state.get('colormode')

    @property
    def hs_color(self):
        """Return the hs color value."""
        mode = self._color_mode
        source = self.light.action if self.is_group else self.light.state

        if mode in ('xy', 'hs') and 'xy' in source:
            return color.color_xy_to_hs(*source['xy'], self.gamut)

        return None

    @property
    def color_temp(self):
        """Return the CT color value."""
        # Don't return color temperature unless in color temperature mode
        if self._color_mode != "ct":
            return None

        if self.is_group:
            return self.light.action.get('ct')
        return self.light.state.get('ct')

    @property
    def is_on(self):
        """Return true if device is on."""
        if self.is_group:
            return self.light.state['any_on']
        return self.light.state['on']

    @property
    def available(self):
        """Return if light is available."""
        return self.bridge.available and (self.is_group or
                                          self.bridge.allow_unreachable or
                                          self.light.state['reachable'])

    @property
    def supported_features(self):
        """Flag supported features."""
        return SUPPORT_HUE.get(self.light.type, SUPPORT_HUE_EXTENDED)

    @property
    def effect(self):
        """Return the current effect."""
        return self.light.state.get('effect', None)

    @property
    def effect_list(self):
        """Return the list of supported effects."""
        return [EFFECT_COLORLOOP, EFFECT_RANDOM]

    @property
    def device_info(self):
        """Return the device info."""
        if self.light.type in ('LightGroup', 'Room',
                               'Luminaire', 'LightSource'):
            return None

        return {
            'identifiers': {
                (hue.DOMAIN, self.unique_id)
            },
            'name': self.name,
            'manufacturer': self.light.manufacturername,
            # productname added in Hue Bridge API 1.24
            # (published 03/05/2018)
            'model': self.light.productname or self.light.modelid,
            # Not yet exposed as properties in aiohue
            'sw_version': self.light.raw['swversion'],
            'via_hub': (hue.DOMAIN, self.bridge.api.config.bridgeid),
        }

    async def async_turn_on(self, **kwargs):
        """Turn the specified or all lights on."""
        command = {'on': True}

        if ATTR_TRANSITION in kwargs:
            command['transitiontime'] = int(kwargs[ATTR_TRANSITION] * 10)

        if ATTR_HS_COLOR in kwargs:
            if self.is_osram:
                command['hue'] = int(kwargs[ATTR_HS_COLOR][0] / 360 * 65535)
                command['sat'] = int(kwargs[ATTR_HS_COLOR][1] / 100 * 255)
            else:
                # Philips hue bulb models respond differently to hue/sat
                # requests, so we convert to XY first to ensure a consistent
                # color.
                xy_color = color.color_hs_to_xy(*kwargs[ATTR_HS_COLOR],
                                                self.gamut)
                command['xy'] = xy_color
        elif ATTR_COLOR_TEMP in kwargs:
            temp = kwargs[ATTR_COLOR_TEMP]
            command['ct'] = max(self.min_mireds, min(temp, self.max_mireds))

        if ATTR_BRIGHTNESS in kwargs:
            command['bri'] = kwargs[ATTR_BRIGHTNESS]

        flash = kwargs.get(ATTR_FLASH)

        if flash == FLASH_LONG:
            command['alert'] = 'lselect'
            del command['on']
        elif flash == FLASH_SHORT:
            command['alert'] = 'select'
            del command['on']
        else:
            command['alert'] = 'none'

        effect = kwargs.get(ATTR_EFFECT)

        if effect == EFFECT_COLORLOOP:
            command['effect'] = 'colorloop'
        elif effect == EFFECT_RANDOM:
            command['hue'] = random.randrange(0, 65535)
            command['sat'] = random.randrange(150, 254)
        elif self.is_philips:
            command['effect'] = 'none'

        if self.is_group:
            await self.light.set_action(**command)
        else:
            await self.light.set_state(**command)

    async def async_turn_off(self, **kwargs):
        """Turn the specified or all lights off."""
        command = {'on': False}

        if ATTR_TRANSITION in kwargs:
            command['transitiontime'] = int(kwargs[ATTR_TRANSITION] * 10)

        flash = kwargs.get(ATTR_FLASH)

        if flash == FLASH_LONG:
            command['alert'] = 'lselect'
            del command['on']
        elif flash == FLASH_SHORT:
            command['alert'] = 'select'
            del command['on']
        else:
            command['alert'] = 'none'

        if self.is_group:
            await self.light.set_action(**command)
        else:
            await self.light.set_state(**command)

    async def async_update(self):
        """Synchronize state with bridge."""
        await self.async_request_bridge_update(self.is_group, self.light.id)

    @property
    def device_state_attributes(self):
        """Return the device state attributes."""
        attributes = {}
        if self.is_group:
            attributes[ATTR_IS_HUE_GROUP] = self.is_group
        return attributes
