"""
Combination of multiple media players into one for a universal controller.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/media_player.universal/
"""
import asyncio
import logging
# pylint: disable=import-error
from copy import copy

from homeassistant.core import callback
from homeassistant.components.media_player import (
    ATTR_APP_ID, ATTR_APP_NAME, ATTR_MEDIA_ALBUM_ARTIST, ATTR_MEDIA_ALBUM_NAME,
    ATTR_MEDIA_ARTIST, ATTR_MEDIA_CHANNEL, ATTR_MEDIA_CONTENT_ID,
    ATTR_MEDIA_CONTENT_TYPE, ATTR_MEDIA_DURATION, ATTR_MEDIA_EPISODE,
    ATTR_MEDIA_PLAYLIST, ATTR_MEDIA_SEASON, ATTR_MEDIA_SEEK_POSITION,
    ATTR_MEDIA_SERIES_TITLE, ATTR_MEDIA_TITLE, ATTR_MEDIA_TRACK,
    ATTR_MEDIA_VOLUME_LEVEL, ATTR_MEDIA_VOLUME_MUTED, ATTR_INPUT_SOURCE_LIST,
    ATTR_MEDIA_POSITION,
    ATTR_MEDIA_POSITION_UPDATED_AT, DOMAIN, SERVICE_PLAY_MEDIA,
    SUPPORT_TURN_OFF, SUPPORT_TURN_ON, SUPPORT_VOLUME_MUTE, SUPPORT_VOLUME_SET,
    SUPPORT_VOLUME_STEP, SUPPORT_SELECT_SOURCE, SUPPORT_CLEAR_PLAYLIST,
    ATTR_INPUT_SOURCE, SERVICE_SELECT_SOURCE, SERVICE_CLEAR_PLAYLIST,
    MediaPlayerDevice)
from homeassistant.const import (
    ATTR_ENTITY_ID, ATTR_ENTITY_PICTURE, CONF_NAME, SERVICE_MEDIA_NEXT_TRACK,
    SERVICE_MEDIA_PAUSE, SERVICE_MEDIA_PLAY, SERVICE_MEDIA_PLAY_PAUSE,
    SERVICE_MEDIA_PREVIOUS_TRACK, SERVICE_MEDIA_SEEK, SERVICE_TURN_OFF,
    SERVICE_TURN_ON, SERVICE_VOLUME_DOWN, SERVICE_VOLUME_MUTE,
    SERVICE_VOLUME_SET, SERVICE_VOLUME_UP, STATE_IDLE, STATE_OFF, STATE_ON,
    SERVICE_MEDIA_STOP, ATTR_SUPPORTED_FEATURES)
from homeassistant.helpers.event import async_track_state_change
from homeassistant.helpers.service import async_call_from_config

ATTR_ACTIVE_CHILD = 'active_child'

CONF_ATTRS = 'attributes'
CONF_CHILDREN = 'children'
CONF_COMMANDS = 'commands'
CONF_PLATFORM = 'platform'
CONF_SERVICE = 'service'
CONF_SERVICE_DATA = 'service_data'
ATTR_DATA = 'data'
CONF_STATE = 'state'

OFF_STATES = [STATE_IDLE, STATE_OFF]
REQUIREMENTS = []
_LOGGER = logging.getLogger(__name__)


@asyncio.coroutine
def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
    """Setup the universal media players."""
    if not validate_config(config):
        return

    player = UniversalMediaPlayer(
        hass,
        config[CONF_NAME],
        config[CONF_CHILDREN],
        config[CONF_COMMANDS],
        config[CONF_ATTRS]
    )

    yield from async_add_devices([player])


def validate_config(config):
    """Validate universal media player configuration."""
    del config[CONF_PLATFORM]

    # Validate name
    if CONF_NAME not in config:
        _LOGGER.error('Universal Media Player configuration requires name')
        return False

    validate_children(config)
    validate_commands(config)
    validate_attributes(config)

    del_keys = []
    for key in config:
        if key not in [CONF_NAME, CONF_CHILDREN, CONF_COMMANDS, CONF_ATTRS]:
            _LOGGER.warning(
                'Universal Media Player (%s) unrecognized parameter %s',
                config[CONF_NAME], key)
            del_keys.append(key)
    for key in del_keys:
        del config[key]

    return True


def validate_children(config):
    """Validate children."""
    if CONF_CHILDREN not in config:
        _LOGGER.info(
            'No children under Universal Media Player (%s)', config[CONF_NAME])
        config[CONF_CHILDREN] = []
    elif not isinstance(config[CONF_CHILDREN], list):
        _LOGGER.warning(
            'Universal Media Player (%s) children not list in config. '
            'They will be ignored.',
            config[CONF_NAME])
        config[CONF_CHILDREN] = []


def validate_commands(config):
    """Validate commands."""
    if CONF_COMMANDS not in config:
        config[CONF_COMMANDS] = {}
    elif not isinstance(config[CONF_COMMANDS], dict):
        _LOGGER.warning(
            'Universal Media Player (%s) specified commands not dict in '
            'config. They will be ignored.',
            config[CONF_NAME])
        config[CONF_COMMANDS] = {}


def validate_attributes(config):
    """Validate attributes."""
    if CONF_ATTRS not in config:
        config[CONF_ATTRS] = {}
    elif not isinstance(config[CONF_ATTRS], dict):
        _LOGGER.warning(
            'Universal Media Player (%s) specified attributes '
            'not dict in config. They will be ignored.',
            config[CONF_NAME])
        config[CONF_ATTRS] = {}

    for key, val in config[CONF_ATTRS].items():
        attr = val.split('|', 1)
        if len(attr) == 1:
            attr.append(None)
        config[CONF_ATTRS][key] = attr


class UniversalMediaPlayer(MediaPlayerDevice):
    """Representation of an universal media player."""

    def __init__(self, hass, name, children, commands, attributes):
        """Initialize the Universal media device."""
        self.hass = hass
        self._name = name
        self._children = children
        self._cmds = commands
        self._attrs = attributes
        self._child_state = None

        @callback
        def async_on_dependency_update(*_):
            """Update ha state when dependencies update."""
            self.hass.async_add_job(self.async_update_ha_state(True))

        depend = copy(children)
        for entity in attributes.values():
            depend.append(entity[0])

        async_track_state_change(hass, depend, async_on_dependency_update)

    def _entity_lkp(self, entity_id, state_attr=None):
        """Look up an entity state."""
        state_obj = self.hass.states.get(entity_id)

        if state_obj is None:
            return

        if state_attr:
            return state_obj.attributes.get(state_attr)
        return state_obj.state

    def _override_or_child_attr(self, attr_name):
        """Return either the override or the active child for attr_name."""
        if attr_name in self._attrs:
            return self._entity_lkp(self._attrs[attr_name][0],
                                    self._attrs[attr_name][1])

        return self._child_attr(attr_name)

    def _child_attr(self, attr_name):
        """Return the active child's attributes."""
        active_child = self._child_state
        return active_child.attributes.get(attr_name) if active_child else None

    @asyncio.coroutine
    def _async_call_service(self, service_name, service_data=None,
                            allow_override=False):
        """Call either a specified or active child's service."""
        if service_data is None:
            service_data = {}

        if allow_override and service_name in self._cmds:
            yield from async_call_from_config(
                self.hass, self._cmds[service_name],
                variables=service_data, blocking=True)
            return

        active_child = self._child_state
        if active_child is None:
            # No child to call service on
            return

        service_data[ATTR_ENTITY_ID] = active_child.entity_id

        yield from self.hass.services.async_call(
            DOMAIN, service_name, service_data, blocking=True)

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

    @property
    def master_state(self):
        """Return the master state for entity or None."""
        if CONF_STATE in self._attrs:
            master_state = self._entity_lkp(self._attrs[CONF_STATE][0],
                                            self._attrs[CONF_STATE][1])
            return master_state if master_state else STATE_OFF
        else:
            return None

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

    @property
    def state(self):
        """Current state of media player.

        Off if master state is off
        else Status of first active child
        else master state or off
        """
        master_state = self.master_state  # avoid multiple lookups
        if master_state == STATE_OFF:
            return STATE_OFF

        active_child = self._child_state
        if active_child:
            return active_child.state

        return master_state if master_state else STATE_OFF

    @property
    def volume_level(self):
        """Volume level of entity specified in attributes or active child."""
        return self._override_or_child_attr(ATTR_MEDIA_VOLUME_LEVEL)

    @property
    def is_volume_muted(self):
        """Boolean if volume is muted."""
        return self._override_or_child_attr(ATTR_MEDIA_VOLUME_MUTED) \
            in [True, STATE_ON]

    @property
    def media_content_id(self):
        """Content ID of current playing media."""
        return self._child_attr(ATTR_MEDIA_CONTENT_ID)

    @property
    def media_content_type(self):
        """Content type of current playing media."""
        return self._child_attr(ATTR_MEDIA_CONTENT_TYPE)

    @property
    def media_duration(self):
        """Duration of current playing media in seconds."""
        return self._child_attr(ATTR_MEDIA_DURATION)

    @property
    def media_image_url(self):
        """Image url of current playing media."""
        return self._child_attr(ATTR_ENTITY_PICTURE)

    @property
    def entity_picture(self):
        """
        Return image of the media playing.

        The universal media player doesn't use the parent class logic, since
        the url is coming from child entity pictures which have already been
        sent through the API proxy.
        """
        return self.media_image_url

    @property
    def media_title(self):
        """Title of current playing media."""
        return self._child_attr(ATTR_MEDIA_TITLE)

    @property
    def media_artist(self):
        """Artist of current playing media (Music track only)."""
        return self._child_attr(ATTR_MEDIA_ARTIST)

    @property
    def media_album_name(self):
        """Album name of current playing media (Music track only)."""
        return self._child_attr(ATTR_MEDIA_ALBUM_NAME)

    @property
    def media_album_artist(self):
        """Album artist of current playing media (Music track only)."""
        return self._child_attr(ATTR_MEDIA_ALBUM_ARTIST)

    @property
    def media_track(self):
        """Track number of current playing media (Music track only)."""
        return self._child_attr(ATTR_MEDIA_TRACK)

    @property
    def media_series_title(self):
        """The title of the series of current playing media (TV Show only)."""
        return self._child_attr(ATTR_MEDIA_SERIES_TITLE)

    @property
    def media_season(self):
        """Season of current playing media (TV Show only)."""
        return self._child_attr(ATTR_MEDIA_SEASON)

    @property
    def media_episode(self):
        """Episode of current playing media (TV Show only)."""
        return self._child_attr(ATTR_MEDIA_EPISODE)

    @property
    def media_channel(self):
        """Channel currently playing."""
        return self._child_attr(ATTR_MEDIA_CHANNEL)

    @property
    def media_playlist(self):
        """Title of Playlist currently playing."""
        return self._child_attr(ATTR_MEDIA_PLAYLIST)

    @property
    def app_id(self):
        """ID of the current running app."""
        return self._child_attr(ATTR_APP_ID)

    @property
    def app_name(self):
        """Name of the current running app."""
        return self._child_attr(ATTR_APP_NAME)

    @property
    def source(self):
        """"Return the current input source of the device."""
        return self._override_or_child_attr(ATTR_INPUT_SOURCE)

    @property
    def source_list(self):
        """List of available input sources."""
        return self._override_or_child_attr(ATTR_INPUT_SOURCE_LIST)

    @property
    def supported_features(self):
        """Flag media player features that are supported."""
        flags = self._child_attr(ATTR_SUPPORTED_FEATURES) or 0

        if SERVICE_TURN_ON in self._cmds:
            flags |= SUPPORT_TURN_ON
        if SERVICE_TURN_OFF in self._cmds:
            flags |= SUPPORT_TURN_OFF

        if any([cmd in self._cmds for cmd in [SERVICE_VOLUME_UP,
                                              SERVICE_VOLUME_DOWN]]):
            flags |= SUPPORT_VOLUME_STEP
            flags &= ~SUPPORT_VOLUME_SET
        elif SERVICE_VOLUME_SET in self._cmds:
            flags |= SUPPORT_VOLUME_SET

        if SERVICE_VOLUME_MUTE in self._cmds and \
                ATTR_MEDIA_VOLUME_MUTED in self._attrs:
            flags |= SUPPORT_VOLUME_MUTE

        if SERVICE_SELECT_SOURCE in self._cmds:
            flags |= SUPPORT_SELECT_SOURCE

        if SERVICE_CLEAR_PLAYLIST in self._cmds:
            flags |= SUPPORT_CLEAR_PLAYLIST

        return flags

    @property
    def device_state_attributes(self):
        """Return device specific state attributes."""
        active_child = self._child_state
        return {ATTR_ACTIVE_CHILD: active_child.entity_id} \
            if active_child else {}

    @property
    def media_position(self):
        """Position of current playing media in seconds."""
        return self._child_attr(ATTR_MEDIA_POSITION)

    @property
    def media_position_updated_at(self):
        """When was the position of the current playing media valid."""
        return self._child_attr(ATTR_MEDIA_POSITION_UPDATED_AT)

    def async_turn_on(self):
        """Turn the media player on.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_TURN_ON, allow_override=True)

    def async_turn_off(self):
        """Turn the media player off.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_TURN_OFF, allow_override=True)

    def async_mute_volume(self, is_volume_muted):
        """Mute the volume.

        This method must be run in the event loop and returns a coroutine.
        """
        data = {ATTR_MEDIA_VOLUME_MUTED: is_volume_muted}
        return self._async_call_service(
            SERVICE_VOLUME_MUTE, data, allow_override=True)

    def async_set_volume_level(self, volume_level):
        """Set volume level, range 0..1.

        This method must be run in the event loop and returns a coroutine.
        """
        data = {ATTR_MEDIA_VOLUME_LEVEL: volume_level}
        return self._async_call_service(
            SERVICE_VOLUME_SET, data, allow_override=True)

    def async_media_play(self):
        """Send play commmand.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_MEDIA_PLAY)

    def async_media_pause(self):
        """Send pause command.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_MEDIA_PAUSE)

    def async_media_stop(self):
        """Send stop command.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_MEDIA_STOP)

    def async_media_previous_track(self):
        """Send previous track command.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_MEDIA_PREVIOUS_TRACK)

    def async_media_next_track(self):
        """Send next track command.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_MEDIA_NEXT_TRACK)

    def async_media_seek(self, position):
        """Send seek command.

        This method must be run in the event loop and returns a coroutine.
        """
        data = {ATTR_MEDIA_SEEK_POSITION: position}
        return self._async_call_service(SERVICE_MEDIA_SEEK, data)

    def async_play_media(self, media_type, media_id, **kwargs):
        """Play a piece of media.

        This method must be run in the event loop and returns a coroutine.
        """
        data = {ATTR_MEDIA_CONTENT_TYPE: media_type,
                ATTR_MEDIA_CONTENT_ID: media_id}
        return self._async_call_service(SERVICE_PLAY_MEDIA, data)

    def async_volume_up(self):
        """Turn volume up for media player.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_VOLUME_UP, allow_override=True)

    def async_volume_down(self):
        """Turn volume down for media player.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(
            SERVICE_VOLUME_DOWN, allow_override=True)

    def async_media_play_pause(self):
        """Play or pause the media player.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_MEDIA_PLAY_PAUSE)

    def async_select_source(self, source):
        """Set the input source.

        This method must be run in the event loop and returns a coroutine.
        """
        data = {ATTR_INPUT_SOURCE: source}
        return self._async_call_service(
            SERVICE_SELECT_SOURCE, data, allow_override=True)

    def async_clear_playlist(self):
        """Clear players playlist.

        This method must be run in the event loop and returns a coroutine.
        """
        return self._async_call_service(SERVICE_CLEAR_PLAYLIST)

    @asyncio.coroutine
    def async_update(self):
        """Update state in HA."""
        for child_name in self._children:
            child_state = self.hass.states.get(child_name)
            if child_state and child_state.state not in OFF_STATES:
                self._child_state = child_state
                return
        self._child_state = None
