Various enhancements for WeMo component/platforms (#19419)

* WeMo - Various fixes and improvements

Various fixes & improvements to the WeMo components, including:
-- Fixes to rediscovery
-- New reset filter service for the WeMo Humidifier
-- Switched the remainder of the WeMo components to async IO
-- Removed any remaining IO in entity properties and moved them to the polling/subscription update process

* WeMo - Fix pywemo version and remove test code from WeMo fan component

* WeMo Humidifier - Add services.yaml entry for reset filter life service

* WeMo - Update binary_sensor component to use asyncio

* WeMo - Add available property to binary_sensor component

* WeMo - Fixed line length issue

* WeMo - Fix issue with discovering the same device multiple times

* WeMo - Fix for the fix for discovering devices multiple times

* WeMo - Fix long lines

* WeMo - Fixes from code review

* WeMo - Breaking Change - entity_ids is now required on wemo_set_humidity

* WeMo - Code review fixes

* WeMo - Code review fixes

* WeMo - Code review fixes

homeassistant/components/binary_sensor/wemo.py

@@ -4,7 +4,10 @@ Support for WeMo sensors.
 For more details about this component, please refer to the documentation at
 https://home-assistant.io/components/binary_sensor.wemo/
 """
+import asyncio
 import logging
+
+import async_timeout
 import requests
 
 from homeassistant.components.binary_sensor import BinarySensorDevice
@@ -41,48 +44,90 @@ class WemoBinarySensor(BinarySensorDevice):
         """Initialize the WeMo sensor."""
         self.wemo = device
         self._state = None
+        self._available = True
+        self._update_lock = None
+        self._model_name = self.wemo.model_name
+        self._name = self.wemo.name
+        self._serialnumber = self.wemo.serialnumber
 
-        wemo = hass.components.wemo
-        wemo.SUBSCRIPTION_REGISTRY.register(self.wemo)
-        wemo.SUBSCRIPTION_REGISTRY.on(self.wemo, None, self._update_callback)
-
-    def _update_callback(self, _device, _type, _params):
-        """Handle state changes."""
-        _LOGGER.info("Subscription update for %s", _device)
+    def _subscription_callback(self, _device, _type, _params):
+        """Update the state by the Wemo sensor."""
+        _LOGGER.debug("Subscription update for %s", self.name)
         updated = self.wemo.subscription_update(_type, _params)
-        self._update(force_update=(not updated))
+        self.hass.add_job(
+            self._async_locked_subscription_callback(not updated))
 
-        if not hasattr(self, 'hass'):
+    async def _async_locked_subscription_callback(self, force_update):
+        """Handle an update from a subscription."""
+        # If an update is in progress, we don't do anything
+        if self._update_lock.locked():
             return
-        self.schedule_update_ha_state()
 
-    @property
-    def should_poll(self):
-        """No polling needed with subscriptions."""
-        return False
+        await self._async_locked_update(force_update)
+        self.async_schedule_update_ha_state()
+
+    async def async_added_to_hass(self):
+        """Wemo sensor added to HASS."""
+        # Define inside async context so we know our event loop
+        self._update_lock = asyncio.Lock()
+
+        registry = self.hass.components.wemo.SUBSCRIPTION_REGISTRY
+        await self.hass.async_add_executor_job(registry.register, self.wemo)
+        registry.on(self.wemo, None, self._subscription_callback)
+
+    async def async_update(self):
+        """Update WeMo state.
+
+        Wemo has an aggressive retry logic that sometimes can take over a
+        minute to return. If we don't get a state after 5 seconds, assume the
+        Wemo sensor is unreachable. If update goes through, it will be made
+        available again.
+        """
+        # If an update is in progress, we don't do anything
+        if self._update_lock.locked():
+            return
+
+        try:
+            with async_timeout.timeout(5):
+                await asyncio.shield(self._async_locked_update(True))
+        except asyncio.TimeoutError:
+            _LOGGER.warning('Lost connection to %s', self.name)
+            self._available = False
+
+    async def _async_locked_update(self, force_update):
+        """Try updating within an async lock."""
+        async with self._update_lock:
+            await self.hass.async_add_executor_job(self._update, force_update)
+
+    def _update(self, force_update=True):
+        """Update the sensor state."""
+        try:
+            self._state = self.wemo.get_state(force_update)
+
+            if not self._available:
+                _LOGGER.info('Reconnected to %s', self.name)
+                self._available = True
+        except AttributeError as err:
+            _LOGGER.warning("Could not update status for %s (%s)",
+                            self.name, err)
+            self._available = False
 
     @property
     def unique_id(self):
-        """Return the id of this WeMo device."""
-        return self.wemo.serialnumber
+        """Return the id of this WeMo sensor."""
+        return self._serialnumber
 
     @property
     def name(self):
         """Return the name of the service if any."""
-        return self.wemo.name
+        return self._name
 
     @property
     def is_on(self):
         """Return true if sensor is on."""
         return self._state
 
-    def update(self):
-        """Update WeMo state."""
-        self._update(force_update=True)
-
-    def _update(self, force_update=True):
-        try:
-            self._state = self.wemo.get_state(force_update)
-        except AttributeError as err:
-            _LOGGER.warning(
-                "Could not update status for %s (%s)", self.name, err)
+    @property
+    def available(self):
+        """Return true if sensor is available."""
+        return self._available