core/homeassistant/components/automation/zone.py

"""
homeassistant.components.automation.zone
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Offers zone automation rules.
"""
import logging

from homeassistant.components import zone
from homeassistant.helpers.event import track_state_change
from homeassistant.const import (
    ATTR_GPS_ACCURACY, ATTR_LATITUDE, ATTR_LONGITUDE, MATCH_ALL)


CONF_ENTITY_ID = "entity_id"
CONF_ZONE = "zone"
CONF_EVENT = "event"
EVENT_ENTER = "enter"
EVENT_LEAVE = "leave"
DEFAULT_EVENT = EVENT_ENTER


def trigger(hass, config, action):
    """ Listen for state changes based on `config`. """
    entity_id = config.get(CONF_ENTITY_ID)
    zone_entity_id = config.get(CONF_ZONE)

    if entity_id is None or zone_entity_id is None:
        logging.getLogger(__name__).error(
            "Missing trigger configuration key %s or %s", CONF_ENTITY_ID,
            CONF_ZONE)
        return False

    event = config.get(CONF_EVENT, DEFAULT_EVENT)

    def zone_automation_listener(entity, from_s, to_s):
        """ Listens for state changes and calls action. """
        if from_s and None in (from_s.attributes.get(ATTR_LATITUDE),
                               from_s.attributes.get(ATTR_LONGITUDE)):
            return

        if None in (to_s.attributes.get(ATTR_LATITUDE),
                    to_s.attributes.get(ATTR_LONGITUDE)):
            return

        from_zone = _in_zone(hass, from_s) if from_s else None
        to_zone = _in_zone(hass, to_s)
        from_match = from_zone and from_zone.entity_id == zone_entity_id
        to_match = to_zone and to_zone.entity_id == zone_entity_id

        if event == EVENT_ENTER and not from_match and to_match or \
           event == EVENT_LEAVE and from_match and not to_match:
            action()

    track_state_change(
        hass, entity_id, zone_automation_listener, MATCH_ALL, MATCH_ALL)

    return True


def if_action(hass, config):
    """ Wraps action method with zone based condition. """
    entity_id = config.get(CONF_ENTITY_ID)
    zone_entity_id = config.get(CONF_ZONE)

    if entity_id is None or zone_entity_id is None:
        logging.getLogger(__name__).error(
            "Missing condition configuration key %s or %s", CONF_ENTITY_ID,
            CONF_ZONE)
        return False

    def if_in_zone():
        """ Test if condition. """
        state = hass.states.get(entity_id)

        if not state or None in (state.attributes.get(ATTR_LATITUDE),
                                 state.attributes.get(ATTR_LONGITUDE)):
            return

        cur_zone = _in_zone(hass, state)

        return cur_zone and cur_zone.entity_id == zone_entity_id

    return if_in_zone


def _in_zone(hass, state):
    """ Check if state is in zone. """
    return zone.in_zone(
        hass, state.attributes.get(ATTR_LATITUDE),
        state.attributes.get(ATTR_LONGITUDE),
        state.attributes.get(ATTR_GPS_ACCURACY, 0))