feat: Add Nearest scanner entity_id sensor

custom_components/bermuda/sensor.py

@@ -13,6 +13,8 @@
     UnitOfLength,
 )
 from homeassistant.core import HomeAssistant, callback
+from homeassistant.helpers import device_registry as dr
+from homeassistant.helpers import entity_registry as er
 from homeassistant.helpers.dispatcher import async_dispatcher_connect
 
 from .const import (
@@ -173,6 +175,34 @@ def name(self):
     def native_value(self):
         return self._device.area_scanner
 
+    @property
+    def extra_state_attributes(self) -> Mapping[str, Any] | None:
+        attributes = super().extra_state_attributes or {}
+
+        scanner_mac = next(
+            (mac for mac in self._device.scanners if mac.upper() in self._device.area_scanner.upper()),
+            None,
+        )
+
+        if scanner_mac:
+            device = self.devreg.async_get_device({}, {(dr.CONNECTION_NETWORK_MAC, scanner_mac.lower())})
+            if device:
+                ent_reg = er.async_get(self.hass)
+                entities = [
+                    entry.entity_id
+                    for entry in ent_reg.entities.values()
+                    if entry.domain
+                    in [
+                        "light",
+                        "switch",
+                    ]  # Filter out devices unlikely to be bluetooth proxies
+                    and entry.device_id == device.id
+                ]
+                if entities:
+                    attributes["nearest_scanner_entity_id"] = entities[0]
+
+        return attributes
+
 
 class BermudaSensorRssi(BermudaSensor):
     """Sensor for RSSI of closest scanner."""