Reset UniFi bandwidth sensor when client misses heartbeat (#104522)

* Reset UniFi bandwidth sensor when client misses heartbeat

* Fix initialization sequence

* Code simplification: remove heartbeat_timedelta, unique_id and tracker logic

* Add unit tests

* Remove unused _is_connected attribute

* Remove redundant async_initiate_state

* Make is_connected_fn optional, heartbeat detection will only happen if not None

* Add checks on is_connected_fn

homeassistant/components/unifi/sensor.py

@@ -32,7 +32,8 @@ from homeassistant.components.sensor import (
 )
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import EntityCategory, UnitOfDataRate, UnitOfPower
-from homeassistant.core import HomeAssistant, callback
+from homeassistant.core import Event as core_Event, HomeAssistant, callback
+from homeassistant.helpers.dispatcher import async_dispatcher_connect
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
 import homeassistant.util.dt as dt_util
 
@@ -132,6 +133,20 @@ def async_device_outlet_supported_fn(controller: UniFiController, obj_id: str) -
     return controller.api.devices[obj_id].outlet_ac_power_budget is not None
 
 
+@callback
+def async_client_is_connected_fn(controller: UniFiController, obj_id: str) -> bool:
+    """Check if client was last seen recently."""
+    client = controller.api.clients[obj_id]
+
+    if (
+        dt_util.utcnow() - dt_util.utc_from_timestamp(client.last_seen or 0)
+        > controller.option_detection_time
+    ):
+        return False
+
+    return True
+
+
 @dataclass(frozen=True)
 class UnifiSensorEntityDescriptionMixin(Generic[HandlerT, ApiItemT]):
     """Validate and load entities from different UniFi handlers."""
@@ -153,6 +168,8 @@ class UnifiSensorEntityDescription(
 ):
     """Class describing UniFi sensor entity."""
 
+    is_connected_fn: Callable[[UniFiController, str], bool] | None = None
+
 
 ENTITY_DESCRIPTIONS: tuple[UnifiSensorEntityDescription, ...] = (
     UnifiSensorEntityDescription[Clients, Client](
@@ -169,6 +186,7 @@ ENTITY_DESCRIPTIONS: tuple[UnifiSensorEntityDescription, ...] = (
         device_info_fn=async_client_device_info_fn,
         event_is_on=None,
         event_to_subscribe=None,
+        is_connected_fn=async_client_is_connected_fn,
         name_fn=lambda _: "RX",
         object_fn=lambda api, obj_id: api.clients[obj_id],
         should_poll=False,
@@ -190,6 +208,7 @@ ENTITY_DESCRIPTIONS: tuple[UnifiSensorEntityDescription, ...] = (
         device_info_fn=async_client_device_info_fn,
         event_is_on=None,
         event_to_subscribe=None,
+        is_connected_fn=async_client_is_connected_fn,
         name_fn=lambda _: "TX",
         object_fn=lambda api, obj_id: api.clients[obj_id],
         should_poll=False,
@@ -388,6 +407,16 @@ class UnifiSensorEntity(UnifiEntity[HandlerT, ApiItemT], SensorEntity):
 
     entity_description: UnifiSensorEntityDescription[HandlerT, ApiItemT]
 
+    @callback
+    def _make_disconnected(self, *_: core_Event) -> None:
+        """No heart beat by device.
+
+        Reset sensor value to 0 when client device is disconnected
+        """
+        if self._attr_native_value != 0:
+            self._attr_native_value = 0
+            self.async_write_ha_state()
+
     @callback
     def async_update_state(self, event: ItemEvent, obj_id: str) -> None:
         """Update entity state.
@@ -398,3 +427,33 @@ class UnifiSensorEntity(UnifiEntity[HandlerT, ApiItemT], SensorEntity):
         obj = description.object_fn(self.controller.api, self._obj_id)
         if (value := description.value_fn(self.controller, obj)) != self.native_value:
             self._attr_native_value = value
+
+        if description.is_connected_fn is not None:
+            # Send heartbeat if client is connected
+            if description.is_connected_fn(self.controller, self._obj_id):
+                self.controller.async_heartbeat(
+                    self._attr_unique_id,
+                    dt_util.utcnow() + self.controller.option_detection_time,
+                )
+
+    async def async_added_to_hass(self) -> None:
+        """Register callbacks."""
+        await super().async_added_to_hass()
+
+        if self.entity_description.is_connected_fn is not None:
+            # Register callback for missed heartbeat
+            self.async_on_remove(
+                async_dispatcher_connect(
+                    self.hass,
+                    f"{self.controller.signal_heartbeat_missed}_{self.unique_id}",
+                    self._make_disconnected,
+                )
+            )
+
+    async def async_will_remove_from_hass(self) -> None:
+        """Disconnect object when removed."""
+        await super().async_will_remove_from_hass()
+
+        if self.entity_description.is_connected_fn is not None:
+            # Remove heartbeat registration
+            self.controller.async_heartbeat(self._attr_unique_id)