Add do not disturb sensor (#813)

* Initial commit of DND sensor

* Update sensor name

* Adapt to new sensor model

* Review comments

app/src/main/java/io/homeassistant/companion/android/HomeAssistantApplication.kt

@@ -1,6 +1,7 @@
 package io.homeassistant.companion.android
 
 import android.app.Application
+import android.app.NotificationManager
 import android.bluetooth.BluetoothAdapter
 import android.content.Intent
 import android.content.IntentFilter
@@ -77,6 +78,14 @@ open class HomeAssistantApplication : Application(), GraphComponentAccessor {
                 }
             )
         }
+
+        // Add receiver for DND changes on devices that support it
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            registerReceiver(
+                sensorReceiver,
+                IntentFilter(NotificationManager.ACTION_INTERRUPTION_FILTER_CHANGED)
+            )
+        }
     }
 
     override val appComponent: AppComponent

app/src/main/java/io/homeassistant/companion/android/sensors/DNDSensorManager.kt

@@ -0,0 +1,58 @@
+package io.homeassistant.companion.android.sensors
+
+import android.content.Context
+import android.provider.Settings.Global
+import android.util.Log
+
+class DNDSensorManager : SensorManager {
+    companion object {
+        private const val TAG = "DNDSensor"
+
+        private val dndSensor = SensorManager.BasicSensor(
+            "dnd_sensor",
+            "sensor",
+            "Do Not Disturb Sensor"
+        )
+    }
+
+    override val name: String
+        get() = "Do Not Disturb Sensor"
+
+    override val availableSensors: List<SensorManager.BasicSensor>
+        get() = listOf(dndSensor)
+
+    override fun requiredPermissions(): Array<String> {
+        return emptyArray()
+    }
+
+    override fun requestSensorUpdate(context: Context) {
+        updateDNDState(context)
+    }
+
+    private fun updateDNDState(context: Context) {
+
+        if (!isEnabled(context, dndSensor.id))
+            return
+
+        var dndState = "unavailable"
+        try {
+            dndState = when (Global.getInt(context.contentResolver, "zen_mode")) {
+                0 -> "off"
+                1 -> "priority_only"
+                2 -> "total_silence"
+                3 -> "alarms_only"
+                else -> "unknown"
+            }
+            val icon = "mdi:do-not-disturb"
+
+            onSensorUpdated(context,
+                dndSensor,
+                dndState,
+                icon,
+                mapOf()
+            )
+        } catch (e: Exception) {
+            Log.e(TAG, "Error getting the devices DND mode", e)
+        }
+    }
+}

app/src/main/java/io/homeassistant/companion/android/sensors/SensorReceiver.kt

@@ -24,6 +24,7 @@ class SensorReceiver : BroadcastReceiver() {
             AudioSensorManager(),
             BatterySensorManager(),
             BluetoothSensorManager(),
+            DNDSensorManager(),
             GeocodeSensorManager(),
             LastRebootSensorManager(),
             LightSensorManager(),