Avoid crashing when Bluetooth adapter is not available

app/src/main/kotlin/io/homeassistant/companion/android/frontend/improv/FrontendImprovModule.kt

@@ -1,5 +1,6 @@
 package io.homeassistant.companion.android.frontend.improv
 
+import android.bluetooth.BluetoothManager
 import android.content.Context
 import android.content.pm.PackageManager
 import com.wifi.improv.ImprovManager
@@ -32,6 +33,10 @@ abstract class FrontendImprovModule {
         @Provides
         @Singleton
         fun provideImprovManagerFactory(@ApplicationContext context: Context): ImprovManagerFactory =
-            ImprovManagerFactory { callback -> ImprovManager(context.applicationContext, callback) }
+            ImprovManagerFactory { callback ->
+                context.getSystemService(BluetoothManager::class.java)?.adapter?.let {
+                    ImprovManager(context.applicationContext, callback)
+                }
+            }
     }
 }

app/src/main/kotlin/io/homeassistant/companion/android/frontend/improv/ImprovManagerFactory.kt

@@ -9,7 +9,10 @@ import com.wifi.improv.ImprovManagerCallback
  * Exists so the repository does not have to hold an Android `Context` — the factory closes over
  * the application context at the Hilt provision site, leaving the repository fully unit-testable
  * with a mock factory.
+ *
+ * Returns `null` on devices without a Bluetooth adapter: [ImprovManager] dereferences the adapter
+ * at construction and would crash.
  */
 fun interface ImprovManagerFactory {
-    fun create(callback: ImprovManagerCallback): ImprovManager
+    fun create(callback: ImprovManagerCallback): ImprovManager?
 }

app/src/main/kotlin/io/homeassistant/companion/android/frontend/improv/ImprovRepositoryImpl.kt

@@ -60,7 +60,8 @@ class ImprovRepositoryImpl @VisibleForTesting constructor(
         backgroundDispatcher = Dispatchers.IO,
     )
 
-    private val manager: ImprovManager = improvManagerFactory.create(this)
+    // Null on devices without a Bluetooth adapter; scanning and provisioning are then inert.
+    private val manager: ImprovManager? = improvManagerFactory.create(this)
 
     private val devices = MutableStateFlow(emptyList<ImprovDevice>())
     private val stateEvents = MutableSharedFlow<DeviceState>(extraBufferCapacity = 16)
@@ -98,6 +99,11 @@ class ImprovRepositoryImpl @VisibleForTesting constructor(
 
     override fun provisionDevice(device: ImprovDevice, ssid: String, password: String): Flow<ProvisioningEvent> =
         channelFlow {
+            val manager = manager ?: run {
+                Timber.w("Ignoring Improv provisioning: device has no Bluetooth adapter")
+                close()
+                return@channelFlow
+            }
             var credentialsSent = false
 
             // Forward error events for the duration of the session.
@@ -190,6 +196,7 @@ class ImprovRepositoryImpl @VisibleForTesting constructor(
     // endregion
 
     private suspend fun startScanInternal() = withContext(backgroundDispatcher) {
+        val manager = manager ?: return@withContext
         if (!hasPermissions()) return@withContext
         try {
             manager.findDevices()
@@ -206,7 +213,7 @@ class ImprovRepositoryImpl @VisibleForTesting constructor(
     // `ensureActive` and the BLE scan would never be torn down.
     private suspend fun stopScanInternal() = withContext(NonCancellable + backgroundDispatcher) {
         try {
-            manager.stopScan()
+            manager?.stopScan()
         } catch (e: Exception) {
             Timber.w(e, "Cannot stop scanning")
         }

app/src/test/kotlin/io/homeassistant/companion/android/frontend/improv/ImprovRepositoryImplTest.kt

@@ -36,11 +36,12 @@ class ImprovRepositoryImplTest {
         sdkInt: Int = Build.VERSION_CODES.S,
         scope: CoroutineScope = backgroundScope,
         ioDispatcher: CoroutineDispatcher = StandardTestDispatcher(testScheduler),
+        factory: ImprovManagerFactory = improvManagerFactory,
     ): ImprovRepositoryImpl {
         SdkVersion.sdkInt = sdkInt
         return ImprovRepositoryImpl(
             permissionChecker = permissionChecker,
-            improvManagerFactory = improvManagerFactory,
+            improvManagerFactory = factory,
             shareInScope = scope,
             backgroundDispatcher = ioDispatcher,
         )
@@ -348,4 +349,30 @@ class ImprovRepositoryImplTest {
             }
         }
     }
+
+    @Nested
+    inner class WithoutBluetoothAdapter {
+
+        @Test
+        fun `Given no Bluetooth adapter when scanDevices subscribed then scan stays inert`() = runTest {
+            every { permissionChecker.hasPermission(any()) } returns true
+            val repository = createRepository(factory = { null })
+
+            repository.scanDevices().test {
+                assertEquals(emptyList<ImprovDevice>(), awaitItem())
+                cancelAndIgnoreRemainingEvents()
+            }
+            // Also covers the teardown path: stopScan on a missing manager must not throw.
+            advanceTimeBy(SCAN_IDLE_WINDOW_MS + 1)
+        }
+
+        @Test
+        fun `Given no Bluetooth adapter when provisionDevice then flow completes without events`() = runTest {
+            val repository = createRepository(factory = { null })
+
+            repository.provisionDevice(ImprovDevice("d", "AA"), "wifi", "pwd").test {
+                awaitComplete()
+            }
+        }
+    }
 }