text: """
  Support for repeating alerts when conditions are met.
  
  For more details about this component, please refer to the documentation at
  https://home-assistant.io/components/alert/
  """
  import asyncio
  import logging
  from datetime import datetime, timedelta
  
  import voluptuous as vol
  
  import homeassistant.helpers.config_validation as cv
  from homeassistant.components.notify import (
      ATTR_MESSAGE, ATTR_TITLE, ATTR_DATA, DOMAIN as DOMAIN_NOTIFY)
  from homeassistant.const import (
      CONF_ENTITY_ID, STATE_IDLE, CONF_NAME, CONF_STATE, STATE_ON, STATE_OFF,
      SERVICE_TURN_ON, SERVICE_TURN_OFF, SERVICE_TOGGLE, ATTR_ENTITY_ID)
  from homeassistant.helpers import service, event
  from homeassistant.helpers.entity import ToggleEntity
  
  _LOGGER = logging.getLogger(__name__)
  
  DOMAIN = 'alert'
  ENTITY_ID_FORMAT = DOMAIN + '.{}'
  
  CONF_CAN_ACK = 'can_acknowledge'
  CONF_NOTIFIERS = 'notifiers'
  CONF_REPEAT = 'repeat'
  CONF_SKIP_FIRST = 'skip_first'
  CONF_ALERT_MESSAGE = 'message'
  CONF_DONE_MESSAGE = 'done_message'
  CONF_TITLE = 'title'
  CONF_DATA = 'data'
  
  DEFAULT_CAN_ACK = True
  DEFAULT_SKIP_FIRST = False
  
  ALERT_SCHEMA = vol.Schema({
      vol.Required(CONF_NAME): cv.string,
      vol.Required(CONF_ENTITY_ID): cv.entity_id,
      vol.Required(CONF_STATE, default=STATE_ON): cv.string,
      vol.Required(CONF_REPEAT): vol.All(cv.ensure_list, [vol.Coerce(float)]),
      vol.Required(CONF_CAN_ACK, default=DEFAULT_CAN_ACK): cv.boolean,
      vol.Required(CONF_SKIP_FIRST, default=DEFAULT_SKIP_FIRST): cv.boolean,
      vol.Optional(CONF_ALERT_MESSAGE): cv.template,
      vol.Optional(CONF_DONE_MESSAGE): cv.template,
      vol.Optional(CONF_TITLE): cv.template,
      vol.Optional(CONF_DATA): dict,
      vol.Required(CONF_NOTIFIERS): cv.ensure_list})
  
  CONFIG_SCHEMA = vol.Schema({
      DOMAIN: cv.schema_with_slug_keys(ALERT_SCHEMA),
  }, extra=vol.ALLOW_EXTRA)
  
  ALERT_SERVICE_SCHEMA = vol.Schema({
      vol.Required(ATTR_ENTITY_ID): cv.entity_ids,
  })
  
  
  def is_on(hass, entity_id):
      """Return if the alert is firing and not acknowledged."""
      return hass.states.is_state(entity_id, STATE_ON)
  
  
  async def async_setup(hass, config):
      """Set up the Alert component."""
      entities = []
  
      for object_id, cfg in config[DOMAIN].items():
          if not cfg:
              cfg = {}
  
          name = cfg.get(CONF_NAME)
          watched_entity_id = cfg.get(CONF_ENTITY_ID)
          alert_state = cfg.get(CONF_STATE)
          repeat = cfg.get(CONF_REPEAT)
          skip_first = cfg.get(CONF_SKIP_FIRST)
          message_template = cfg.get(CONF_ALERT_MESSAGE)
          done_message_template = cfg.get(CONF_DONE_MESSAGE)
          notifiers = cfg.get(CONF_NOTIFIERS)
          can_ack = cfg.get(CONF_CAN_ACK)
          title_template = cfg.get(CONF_TITLE)
          data = cfg.get(CONF_DATA)
  
          entities.append(Alert(hass, object_id, name,
                                watched_entity_id, alert_state, repeat,
                                skip_first, message_template,
                                done_message_template, notifiers,
                                can_ack, title_template, data))
  
      if not entities:
          return False
  
      async def async_handle_alert_service(service_call):
          """Handle calls to alert services."""
          alert_ids = service.extract_entity_ids(hass, service_call)
  
          for alert_id in alert_ids:
              for alert in entities:
                  if alert.entity_id != alert_id:
                      continue
  
                  alert.async_set_context(service_call.context)
                  if service_call.service == SERVICE_TURN_ON:
                      await alert.async_turn_on()
                  elif service_call.service == SERVICE_TOGGLE:
                      await alert.async_toggle()
                  else:
                      await alert.async_turn_off()
  
      # Setup service calls
      hass.services.async_register(
          DOMAIN, SERVICE_TURN_OFF, async_handle_alert_service,
          schema=ALERT_SERVICE_SCHEMA)
      hass.services.async_register(
          DOMAIN, SERVICE_TURN_ON, async_handle_alert_service,
          schema=ALERT_SERVICE_SCHEMA)
      hass.services.async_register(
          DOMAIN, SERVICE_TOGGLE, async_handle_alert_service,
          schema=ALERT_SERVICE_SCHEMA)
  
      tasks = [alert.async_update_ha_state() for alert in entities]
      if tasks:
          await asyncio.wait(tasks, loop=hass.loop)
  
      return True
  
  
  class Alert(ToggleEntity):
      """Representation of an alert."""
  
      def __init__(self, hass, entity_id, name, watched_entity_id,
                   state, repeat, skip_first, message_template,
                   done_message_template, notifiers, can_ack, title_template,
                   data):
          """Initialize the alert."""
          self.hass = hass
          self._name = name
          self._alert_state = state
          self._skip_first = skip_first
          self._data = data
  
          self._message_template = message_template
          if self._message_template is not None:
              self._message_template.hass = hass
  
          self._done_message_template = done_message_template
          if self._done_message_template is not None:
              self._done_message_template.hass = hass
  
          self._title_template = title_template
          if self._title_template is not None:
              self._title_template.hass = hass
  
          self._notifiers = notifiers
          self._can_ack = can_ack
  
          self._delay = [timedelta(minutes=val) for val in repeat]
          self._next_delay = 0
  
          self._firing = False
          self._ack = False
          self._cancel = None
          self._send_done_message = False
          self.entity_id = ENTITY_ID_FORMAT.format(entity_id)
  
          event.async_track_state_change(
              hass, watched_entity_id, self.watched_entity_change)
  
      @property
      def name(self):
          """Return the name of the alert."""
          return self._name
  
      @property
      def should_poll(self):
          """HASS need not poll these entities."""
          return False
  
      @property
      def state(self):
          """Return the alert status."""
          if self._firing:
              if self._ack:
                  return STATE_OFF
              return STATE_ON
          return STATE_IDLE
  
      @property
      def hidden(self):
          """Hide the alert when it is not firing."""
          return not self._can_ack or not self._firing
  
      async def watched_entity_change(self, entity, from_state, to_state):
          """Determine if the alert should start or stop."""
          _LOGGER.debug("Watched entity (%s) has changed", entity)
          if to_state.state == self._alert_state and not self._firing:
              await self.begin_alerting()
          if to_state.state != self._alert_state and self._firing:
              await self.end_alerting()
  
      async def begin_alerting(self):
          """Begin the alert procedures."""
          _LOGGER.debug("Beginning Alert: %s", self._name)
          self._ack = False
          self._firing = True
          self._next_delay = 0
  
          if not self._skip_first:
              await self._notify()
          else:
              await self._schedule_notify()
  
          self.async_schedule_update_ha_state()
  
      async def end_alerting(self):
          """End the alert procedures."""
          _LOGGER.debug("Ending Alert: %s", self._name)
          self._cancel()
          self._ack = False
          self._firing = False
          if self._send_done_message:
              await self._notify_done_message()
          self.async_schedule_update_ha_state()
  
      async def _schedule_notify(self):
          """Schedule a notification."""
          delay = self._delay[self._next_delay]
          next_msg = datetime.now() + delay
          self._cancel = \
              event.async_track_point_in_time(self.hass, self._notify, next_msg)
          self._next_delay = min(self._next_delay + 1, len(self._delay) - 1)
  
      async def _notify(self, *args):
          """Send the alert notification."""
          if not self._firing:
              return
  
          if not self._ack:
              _LOGGER.info("Alerting: %s", self._name)
              self._send_done_message = True
  
              if self._message_template is not None:
                  message = self._message_template.async_render()
              else:
                  message = self._name
  
              await self._send_notification_message(message)
          await self._schedule_notify()
  
      async def _notify_done_message(self, *args):
          """Send notification of complete alert."""
          _LOGGER.info("Alerting: %s", self._done_message_template)
          self._send_done_message = False
  
          if self._done_message_template is None:
              return
  
          message = self._done_message_template.async_render()
  
          await self._send_notification_message(message)
  
      async def _send_notification_message(self, message):
  
          msg_payload = {ATTR_MESSAGE: message}
  
          if self._title_template is not None:
              title = self._title_template.async_render()
              msg_payload.update({ATTR_TITLE: title})
          if self._data:
              msg_payload.update({ATTR_DATA: self._data})
  
          _LOGGER.debug(msg_payload)
  
          for target in self._notifiers:
              await self.hass.services.async_call(
                  DOMAIN_NOTIFY, target, msg_payload)
  
      async def async_turn_on(self, **kwargs):
          """Async Unacknowledge alert."""
          _LOGGER.debug("Reset Alert: %s", self._name)
          self._ack = False
          await self.async_update_ha_state()
  
      async def async_turn_off(self, **kwargs):
          """Async Acknowledge alert."""
          _LOGGER.debug("Acknowledged Alert: %s", self._name)
          self._ack = True
          await self.async_update_ha_state()
  
      async def async_toggle(self, **kwargs):
          """Async toggle alert."""
          if self._ack:
              return await self.async_turn_on()
          return await self.async_turn_off()
  