core/homeassistant/components/group.py

"""
Provides functionality to group entities.

For more details about this component, please refer to the documentation at
https://home-assistant.io/components/group/
"""
import logging
import os
import threading

import voluptuous as vol

from homeassistant import config as conf_util, core as ha
from homeassistant.const import (
    ATTR_ENTITY_ID, CONF_ICON, CONF_NAME, STATE_CLOSED, STATE_HOME,
    STATE_NOT_HOME, STATE_OFF, STATE_ON, STATE_OPEN, STATE_LOCKED,
    STATE_UNLOCKED, STATE_UNKNOWN, ATTR_ASSUMED_STATE)
from homeassistant.helpers.entity import Entity, generate_entity_id
from homeassistant.helpers.entity_component import EntityComponent
from homeassistant.helpers.event import track_state_change
import homeassistant.helpers.config_validation as cv

DOMAIN = 'group'

ENTITY_ID_FORMAT = DOMAIN + '.{}'

CONF_ENTITIES = 'entities'
CONF_VIEW = 'view'

ATTR_AUTO = 'auto'
ATTR_ORDER = 'order'
ATTR_VIEW = 'view'

SERVICE_RELOAD = 'reload'
RELOAD_SERVICE_SCHEMA = vol.Schema({})

_LOGGER = logging.getLogger(__name__)


def _conf_preprocess(value):
    """Preprocess alternative configuration formats."""
    if not isinstance(value, dict):
        value = {CONF_ENTITIES: value}

    return value


CONFIG_SCHEMA = vol.Schema({
    DOMAIN: cv.ordered_dict(vol.All(_conf_preprocess, {
        vol.Optional(CONF_ENTITIES): vol.Any(cv.entity_ids, None),
        CONF_VIEW: cv.boolean,
        CONF_NAME: cv.string,
        CONF_ICON: cv.icon,
    }, cv.match_all))
}, extra=vol.ALLOW_EXTRA)

# List of ON/OFF state tuples for groupable states
_GROUP_TYPES = [(STATE_ON, STATE_OFF), (STATE_HOME, STATE_NOT_HOME),
                (STATE_OPEN, STATE_CLOSED), (STATE_LOCKED, STATE_UNLOCKED)]


def _get_group_on_off(state):
    """Determine the group on/off states based on a state."""
    for states in _GROUP_TYPES:
        if state in states:
            return states

    return None, None


def is_on(hass, entity_id):
    """Test if the group state is in its ON-state."""
    state = hass.states.get(entity_id)

    if state:
        group_on, _ = _get_group_on_off(state.state)

        # If we found a group_type, compare to ON-state
        return group_on is not None and state.state == group_on

    return False


def reload(hass):
    """Reload the automation from config."""
    hass.services.call(DOMAIN, SERVICE_RELOAD)


def expand_entity_ids(hass, entity_ids):
    """Return entity_ids with group entity ids replaced by their members."""
    found_ids = []

    for entity_id in entity_ids:
        if not isinstance(entity_id, str):
            continue

        entity_id = entity_id.lower()

        try:
            # If entity_id points at a group, expand it
            domain, _ = ha.split_entity_id(entity_id)

            if domain == DOMAIN:
                found_ids.extend(
                    ent_id for ent_id
                    in expand_entity_ids(hass, get_entity_ids(hass, entity_id))
                    if ent_id not in found_ids)

            else:
                if entity_id not in found_ids:
                    found_ids.append(entity_id)

        except AttributeError:
            # Raised by split_entity_id if entity_id is not a string
            pass

    return found_ids


def get_entity_ids(hass, entity_id, domain_filter=None):
    """Get members of this group."""
    group = hass.states.get(entity_id)

    if not group or ATTR_ENTITY_ID not in group.attributes:
        return []

    entity_ids = group.attributes[ATTR_ENTITY_ID]

    if not domain_filter:
        return entity_ids

    domain_filter = domain_filter.lower() + '.'

    return [ent_id for ent_id in entity_ids
            if ent_id.startswith(domain_filter)]


def setup(hass, config):
    """Setup all groups found definded in the configuration."""
    component = EntityComponent(_LOGGER, DOMAIN, hass)

    success = _process_config(hass, config, component)

    if not success:
        return False

    descriptions = conf_util.load_yaml_config_file(
        os.path.join(os.path.dirname(__file__), 'services.yaml'))

    def reload_service_handler(service_call):
        """Remove all groups and load new ones from config."""
        conf = component.prepare_reload()
        if conf is None:
            return
        _process_config(hass, conf, component)

    hass.services.register(DOMAIN, SERVICE_RELOAD, reload_service_handler,
                           descriptions[DOMAIN][SERVICE_RELOAD],
                           schema=RELOAD_SERVICE_SCHEMA)

    return True


def _process_config(hass, config, component):
    """Process group configuration."""
    for object_id, conf in config.get(DOMAIN, {}).items():
        name = conf.get(CONF_NAME, object_id)
        entity_ids = conf.get(CONF_ENTITIES) or []
        icon = conf.get(CONF_ICON)
        view = conf.get(CONF_VIEW)

        group = Group(hass, name, entity_ids, icon=icon, view=view,
                      object_id=object_id)
        component.add_entities((group,))

    return True


class Group(Entity):
    """Track a group of entity ids."""

    # pylint: disable=too-many-instance-attributes, too-many-arguments
    def __init__(self, hass, name, entity_ids=None, user_defined=True,
                 icon=None, view=False, object_id=None):
        """Initialize a group."""
        self.hass = hass
        self._name = name
        self._state = STATE_UNKNOWN
        self._order = len(hass.states.entity_ids(DOMAIN))
        self._user_defined = user_defined
        self._icon = icon
        self._view = view
        self.entity_id = generate_entity_id(
            ENTITY_ID_FORMAT, object_id or name, hass=hass)
        self.tracking = []
        self.group_on = None
        self.group_off = None
        self._assumed_state = False
        self._lock = threading.Lock()
        self._unsub_state_changed = None

        if entity_ids is not None:
            self.update_tracked_entity_ids(entity_ids)
        else:
            self.update_ha_state(True)

    @property
    def should_poll(self):
        """No need to poll because groups will update themselves."""
        return False

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

    @property
    def state(self):
        """Return the state of the group."""
        return self._state

    @property
    def icon(self):
        """Return the icon of the group."""
        return self._icon

    @property
    def hidden(self):
        """If group should be hidden or not."""
        return not self._user_defined or self._view

    @property
    def state_attributes(self):
        """Return the state attributes for the group."""
        data = {
            ATTR_ENTITY_ID: self.tracking,
            ATTR_ORDER: self._order,
        }
        if not self._user_defined:
            data[ATTR_AUTO] = True
        if self._view:
            data[ATTR_VIEW] = True
        return data

    @property
    def assumed_state(self):
        """Test if any member has an assumed state."""
        return self._assumed_state

    def update_tracked_entity_ids(self, entity_ids):
        """Update the member entity IDs."""
        self.stop()
        self.tracking = tuple(ent_id.lower() for ent_id in entity_ids)
        self.group_on, self.group_off = None, None

        self.update_ha_state(True)

        self.start()

    def start(self):
        """Start tracking members."""
        self._unsub_state_changed = track_state_change(
            self.hass, self.tracking, self._state_changed_listener)

    def stop(self):
        """Unregister the group from Home Assistant."""
        self.remove()

    def update(self):
        """Query all members and determine current group state."""
        self._state = STATE_UNKNOWN
        self._update_group_state()

    def remove(self):
        """Remove group from HASS."""
        super().remove()

        if self._unsub_state_changed:
            self._unsub_state_changed()
            self._unsub_state_changed = None

    def _state_changed_listener(self, entity_id, old_state, new_state):
        """Respond to a member state changing."""
        self._update_group_state(new_state)
        self.update_ha_state()

    @property
    def _tracking_states(self):
        """The states that the group is tracking."""
        states = []

        for entity_id in self.tracking:
            state = self.hass.states.get(entity_id)

            if state is not None:
                states.append(state)

        return states

    def _update_group_state(self, tr_state=None):
        """Update group state.

        Optionally you can provide the only state changed since last update
        allowing this method to take shortcuts.
        """
        # pylint: disable=too-many-branches
        # To store current states of group entities. Might not be needed.
        with self._lock:
            states = None
            gr_state = self._state
            gr_on = self.group_on
            gr_off = self.group_off

            # We have not determined type of group yet
            if gr_on is None:
                if tr_state is None:
                    states = self._tracking_states

                    for state in states:
                        gr_on, gr_off = \
                            _get_group_on_off(state.state)
                        if gr_on is not None:
                            break
                else:
                    gr_on, gr_off = _get_group_on_off(tr_state.state)

                if gr_on is not None:
                    self.group_on, self.group_off = gr_on, gr_off

            # We cannot determine state of the group
            if gr_on is None:
                return

            if tr_state is None or ((gr_state == gr_on and
                                     tr_state.state == gr_off) or
                                    tr_state.state not in (gr_on, gr_off)):
                if states is None:
                    states = self._tracking_states

                if any(state.state == gr_on for state in states):
                    self._state = gr_on
                else:
                    self._state = gr_off

            elif tr_state.state in (gr_on, gr_off):
                self._state = tr_state.state

            if tr_state is None or self._assumed_state and \
               not tr_state.attributes.get(ATTR_ASSUMED_STATE):
                if states is None:
                    states = self._tracking_states

                self._assumed_state = any(
                    state.attributes.get(ATTR_ASSUMED_STATE) for state
                    in states)

            elif tr_state.attributes.get(ATTR_ASSUMED_STATE):
                self._assumed_state = True