core/homeassistant/helpers/event.py

343 lines
11 KiB
Python

"""Helpers for listening to events."""
import functools as ft
from homeassistant.helpers.sun import get_astral_event_next
from ..core import HomeAssistant, callback
from ..const import (
ATTR_NOW, EVENT_STATE_CHANGED, EVENT_TIME_CHANGED, MATCH_ALL)
from ..util import dt as dt_util
from ..util.async import run_callback_threadsafe
# PyLint does not like the use of threaded_listener_factory
# pylint: disable=invalid-name
def threaded_listener_factory(async_factory):
"""Convert an async event helper to a threaded one."""
@ft.wraps(async_factory)
def factory(*args, **kwargs):
"""Call async event helper safely."""
hass = args[0]
if not isinstance(hass, HomeAssistant):
raise TypeError('First parameter needs to be a hass instance')
async_remove = run_callback_threadsafe(
hass.loop, ft.partial(async_factory, *args, **kwargs)).result()
def remove():
"""Threadsafe removal."""
run_callback_threadsafe(hass.loop, async_remove).result()
return remove
return factory
@callback
def async_track_state_change(hass, entity_ids, action, from_state=None,
to_state=None):
"""Track specific state changes.
entity_ids, from_state and to_state can be string or list.
Use list to match multiple.
Returns a function that can be called to remove the listener.
Must be run within the event loop.
"""
from_state = _process_state_match(from_state)
to_state = _process_state_match(to_state)
# Ensure it is a lowercase list with entity ids we want to match on
if entity_ids == MATCH_ALL:
pass
elif isinstance(entity_ids, str):
entity_ids = (entity_ids.lower(),)
else:
entity_ids = tuple(entity_id.lower() for entity_id in entity_ids)
@callback
def state_change_listener(event):
"""Handle specific state changes."""
if entity_ids != MATCH_ALL and \
event.data.get('entity_id') not in entity_ids:
return
if event.data.get('old_state') is not None:
old_state = event.data['old_state'].state
else:
old_state = None
if event.data.get('new_state') is not None:
new_state = event.data['new_state'].state
else:
new_state = None
if _matcher(old_state, from_state) and _matcher(new_state, to_state):
hass.async_run_job(action, event.data.get('entity_id'),
event.data.get('old_state'),
event.data.get('new_state'))
return hass.bus.async_listen(EVENT_STATE_CHANGED, state_change_listener)
track_state_change = threaded_listener_factory(async_track_state_change)
@callback
def async_track_template(hass, template, action, variables=None):
"""Add a listener that track state changes with template condition."""
from . import condition
# Local variable to keep track of if the action has already been triggered
already_triggered = False
@callback
def template_condition_listener(entity_id, from_s, to_s):
"""Check if condition is correct and run action."""
nonlocal already_triggered
template_result = condition.async_template(hass, template, variables)
# Check to see if template returns true
if template_result and not already_triggered:
already_triggered = True
hass.async_run_job(action, entity_id, from_s, to_s)
elif not template_result:
already_triggered = False
return async_track_state_change(
hass, template.extract_entities(), template_condition_listener)
track_template = threaded_listener_factory(async_track_template)
@callback
def async_track_point_in_time(hass, action, point_in_time):
"""Add a listener that fires once after a specific point in time."""
utc_point_in_time = dt_util.as_utc(point_in_time)
@callback
def utc_converter(utc_now):
"""Convert passed in UTC now to local now."""
hass.async_run_job(action, dt_util.as_local(utc_now))
return async_track_point_in_utc_time(hass, utc_converter,
utc_point_in_time)
track_point_in_time = threaded_listener_factory(async_track_point_in_time)
@callback
def async_track_point_in_utc_time(hass, action, point_in_time):
"""Add a listener that fires once after a specific point in UTC time."""
# Ensure point_in_time is UTC
point_in_time = dt_util.as_utc(point_in_time)
@callback
def point_in_time_listener(event):
"""Listen for matching time_changed events."""
now = event.data[ATTR_NOW]
if now < point_in_time or hasattr(point_in_time_listener, 'run'):
return
# Set variable so that we will never run twice.
# Because the event bus might have to wait till a thread comes
# available to execute this listener it might occur that the
# listener gets lined up twice to be executed. This will make
# sure the second time it does nothing.
point_in_time_listener.run = True
async_unsub()
hass.async_run_job(action, now)
async_unsub = hass.bus.async_listen(EVENT_TIME_CHANGED,
point_in_time_listener)
return async_unsub
track_point_in_utc_time = threaded_listener_factory(
async_track_point_in_utc_time)
@callback
def async_track_time_interval(hass, action, interval):
"""Add a listener that fires repetitively at every timedelta interval."""
remove = None
def next_interval():
"""Return the next interval."""
return dt_util.utcnow() + interval
@callback
def interval_listener(now):
"""Handle elaspsed intervals."""
nonlocal remove
remove = async_track_point_in_utc_time(
hass, interval_listener, next_interval())
hass.async_run_job(action, now)
remove = async_track_point_in_utc_time(
hass, interval_listener, next_interval())
def remove_listener():
"""Remove interval listener."""
remove()
return remove_listener
track_time_interval = threaded_listener_factory(async_track_time_interval)
@callback
def async_track_sunrise(hass, action, offset=None):
"""Add a listener that will fire a specified offset from sunrise daily."""
remove = None
@callback
def sunrise_automation_listener(now):
"""Handle points in time to execute actions."""
nonlocal remove
remove = async_track_point_in_utc_time(
hass, sunrise_automation_listener, get_astral_event_next(
hass, 'sunrise', offset=offset))
hass.async_run_job(action)
remove = async_track_point_in_utc_time(
hass, sunrise_automation_listener, get_astral_event_next(
hass, 'sunrise', offset=offset))
def remove_listener():
"""Remove sunset listener."""
remove()
return remove_listener
track_sunrise = threaded_listener_factory(async_track_sunrise)
@callback
def async_track_sunset(hass, action, offset=None):
"""Add a listener that will fire a specified offset from sunset daily."""
remove = None
@callback
def sunset_automation_listener(now):
"""Handle points in time to execute actions."""
nonlocal remove
remove = async_track_point_in_utc_time(
hass, sunset_automation_listener, get_astral_event_next(
hass, 'sunset', offset=offset))
hass.async_run_job(action)
remove = async_track_point_in_utc_time(
hass, sunset_automation_listener, get_astral_event_next(
hass, 'sunset', offset=offset))
def remove_listener():
"""Remove sunset listener."""
remove()
return remove_listener
track_sunset = threaded_listener_factory(async_track_sunset)
@callback
def async_track_utc_time_change(hass, action, year=None, month=None, day=None,
hour=None, minute=None, second=None,
local=False):
"""Add a listener that will fire if time matches a pattern."""
# We do not have to wrap the function with time pattern matching logic
# if no pattern given
if all(val is None for val in (year, month, day, hour, minute, second)):
@callback
def time_change_listener(event):
"""Fire every time event that comes in."""
hass.async_run_job(action, event.data[ATTR_NOW])
return hass.bus.async_listen(EVENT_TIME_CHANGED, time_change_listener)
pmp = _process_time_match
year, month, day = pmp(year), pmp(month), pmp(day)
hour, minute, second = pmp(hour), pmp(minute), pmp(second)
@callback
def pattern_time_change_listener(event):
"""Listen for matching time_changed events."""
now = event.data[ATTR_NOW]
if local:
now = dt_util.as_local(now)
mat = _matcher
# pylint: disable=too-many-boolean-expressions
if mat(now.year, year) and \
mat(now.month, month) and \
mat(now.day, day) and \
mat(now.hour, hour) and \
mat(now.minute, minute) and \
mat(now.second, second):
hass.async_run_job(action, now)
return hass.bus.async_listen(EVENT_TIME_CHANGED,
pattern_time_change_listener)
track_utc_time_change = threaded_listener_factory(async_track_utc_time_change)
@callback
def async_track_time_change(hass, action, year=None, month=None, day=None,
hour=None, minute=None, second=None):
"""Add a listener that will fire if UTC time matches a pattern."""
return async_track_utc_time_change(hass, action, year, month, day, hour,
minute, second, local=True)
track_time_change = threaded_listener_factory(async_track_time_change)
def _process_state_match(parameter):
"""Wrap parameter in a tuple if it is not one and returns it."""
if parameter is None or parameter == MATCH_ALL:
return MATCH_ALL
elif isinstance(parameter, str) or not hasattr(parameter, '__iter__'):
return (parameter,)
else:
return tuple(parameter)
def _process_time_match(parameter):
"""Wrap parameter in a tuple if it is not one and returns it."""
if parameter is None or parameter == MATCH_ALL:
return MATCH_ALL
elif isinstance(parameter, str) and parameter.startswith('/'):
return parameter
elif isinstance(parameter, str) or not hasattr(parameter, '__iter__'):
return (parameter,)
else:
return tuple(parameter)
def _matcher(subject, pattern):
"""Return True if subject matches the pattern.
Pattern is either a tuple of allowed subjects or a `MATCH_ALL`.
"""
if isinstance(pattern, str) and pattern.startswith('/'):
try:
return subject % float(pattern.lstrip('/')) == 0
except ValueError:
return False
return MATCH_ALL == pattern or subject in pattern