Restore states for RFLink devices (#18816)

* Merge branch 'master' of https://github.com/home-assistant/home-assistant into dev

# Conflicts:
#	homeassistant/components/binary_sensor/point.py
#	homeassistant/components/cloud/__init__.py
#	homeassistant/components/cloud/prefs.py
#	homeassistant/components/frontend/__init__.py
#	homeassistant/components/light/fibaro.py
#	homeassistant/components/logbook.py
#	homeassistant/components/point/__init__.py
#	homeassistant/config_entries.py
#	homeassistant/const.py
#	homeassistant/helpers/service.py
#	requirements_all.txt
#	requirements_test_all.txt

* one 'async_get_last_state' refactor left behind

* Remove RestoreEntity inheritance (already in parent class)

* # pylint: disable=too-many-ancestors

* code predictor can be a bitch

* lint corrections

* # pylint: disable=too-many-ancestors

* recover from dict[key]

* Remove all 'coroutine' decorator, replace for 'async def'
Replace all 'yield from' for 'await'
Replace 'hass.async_add_job' for 'hass.async_create_task'

homeassistant/components/rflink.py

@@ -13,7 +13,7 @@ import voluptuous as vol
 
 from homeassistant.const import (
     ATTR_ENTITY_ID, CONF_COMMAND, CONF_HOST, CONF_PORT,
-    EVENT_HOMEASSISTANT_STOP)
+    STATE_ON, EVENT_HOMEASSISTANT_STOP)
 from homeassistant.core import CoreState, callback
 from homeassistant.exceptions import HomeAssistantError
 import homeassistant.helpers.config_validation as cv
@@ -21,7 +21,7 @@ from homeassistant.helpers.deprecation import get_deprecated
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.dispatcher import (
     async_dispatcher_send, async_dispatcher_connect)
-
+from homeassistant.helpers.restore_state import RestoreEntity
 
 REQUIREMENTS = ['rflink==0.0.37']
 
@@ -499,9 +499,17 @@ class RflinkCommand(RflinkDevice):
                 self._async_send_command(cmd, repetitions - 1))
 
 
-class SwitchableRflinkDevice(RflinkCommand):
+class SwitchableRflinkDevice(RflinkCommand, RestoreEntity):
     """Rflink entity which can switch on/off (eg: light, switch)."""
 
+    async def async_added_to_hass(self):
+        """Restore RFLink device state (ON/OFF)."""
+        await super().async_added_to_hass()
+
+        old_state = await self.async_get_last_state()
+        if old_state is not None:
+            self._state = old_state.state == STATE_ON
+
     def _handle_event(self, event):
         """Adjust state if Rflink picks up a remote command for this device."""
         self.cancel_queued_send_commands()