Add Hey Siri detection toggle and vendor event receiver

android/app/src/main/java/me/kavishdevar/librepods/presentation/screens/MicrophoneSettingsScreen.kt

@@ -25,6 +25,7 @@ import me.kavishdevar.librepods.R
 import me.kavishdevar.librepods.bluetooth.AACPManager
 import me.kavishdevar.librepods.presentation.components.StyledList
 import me.kavishdevar.librepods.presentation.components.StyledListItem
+import me.kavishdevar.librepods.presentation.components.StyledToggle
 import me.kavishdevar.librepods.presentation.theme.DesignSystem
 import me.kavishdevar.librepods.presentation.theme.LocalDesignSystem
 import me.kavishdevar.librepods.presentation.viewmodel.AirPodsViewModel
@@ -46,12 +47,18 @@ fun MicrophoneSettingsRoute(
             .fillMaxSize()
             .background(MaterialTheme.colorScheme.surfaceContainer)
     ) {
+        val voiceTriggerId = AACPManager.Companion.ControlCommandIdentifiers.VOICE_TRIGGER
+
         MicrophoneSettingsScreen(
             selectedMode = state.controlStates[id]?.getOrNull(0)?.toInt() ?: 0,
+            heySiriDetectionEnabled = state.controlStates[voiceTriggerId]?.getOrNull(0) != 0x02.toByte(),
             topPadding = topPadding,
             bottomPadding = bottomPadding,
             onMicrophoneSettingsChanged = {
                 viewModel.setControlCommandInt(id, it)
+            },
+            onHeySiriDetectionChanged = {
+                viewModel.setControlCommandBoolean(voiceTriggerId, it)
             }
         )
     }
@@ -60,9 +67,11 @@ fun MicrophoneSettingsRoute(
 @Composable
 fun MicrophoneSettingsScreen(
     selectedMode: Int,
+    heySiriDetectionEnabled: Boolean = true,
     topPadding: Dp = 16.dp,
     bottomPadding: Dp = 16.dp,
-    onMicrophoneSettingsChanged: (Int) -> Unit
+    onMicrophoneSettingsChanged: (Int) -> Unit,
+    onHeySiriDetectionChanged: (Boolean) -> Unit = {}
 ) {
     val scrollState = rememberScrollState()
 
@@ -96,6 +105,17 @@ fun MicrophoneSettingsScreen(
             )
         }
 
+        Spacer(modifier = Modifier.height(16.dp))
+
+        StyledList {
+            StyledToggle(
+                label = stringResource(R.string.hey_siri_detection),
+                description = stringResource(R.string.hey_siri_detection_description),
+                checked = heySiriDetectionEnabled,
+                onCheckedChange = onHeySiriDetectionChanged
+            )
+        }
+
         Spacer(modifier = Modifier.height(bottomPadding))
     }
 }

android/app/src/main/java/me/kavishdevar/librepods/presentation/viewmodel/AirPodsViewModel.kt

@@ -424,6 +424,7 @@ class AirPodsViewModel(
     fun observeAACP() {
         val identifiersList = listOf(
             ControlCommandIdentifiers.MIC_MODE,
+            ControlCommandIdentifiers.VOICE_TRIGGER,
             ControlCommandIdentifiers.DOUBLE_CLICK_INTERVAL,
             ControlCommandIdentifiers.CLICK_HOLD_INTERVAL,
             ControlCommandIdentifiers.LISTENING_MODE_CONFIGS,

android/app/src/main/java/me/kavishdevar/librepods/services/AirPodsService.kt

@@ -751,6 +751,11 @@ class AirPodsService : Service(), SharedPreferences.OnSharedPreferenceChangeList
             registerReceiver(bluetoothReceiver, serviceIntentFilter)
         }
 
+        val hotwordIntentFilter = IntentFilter(BluetoothHeadset.ACTION_VENDOR_SPECIFIC_HEADSET_EVENT).apply {
+            addCategory("${BluetoothHeadset.VENDOR_SPECIFIC_HEADSET_EVENT_COMPANY_ID_CATEGORY}.$APPLE")
+        }
+        registerReceiver(hotwordReceiver, hotwordIntentFilter, RECEIVER_EXPORTED)
+
         val bluetoothAdapter = getSystemService(BluetoothManager::class.java).adapter
 
         bluetoothAdapter.bondedDevices.forEach { device ->
@@ -1185,6 +1190,45 @@ class AirPodsService : Service(), SharedPreferences.OnSharedPreferenceChangeList
         })
     }
 
+    /**
+     * Receives vendor-specific headset AT events from the Bluetooth stack. When AirPods report
+     * a "Hey Siri" trigger (+APLSIRI), start the digital assistant, unless the user has turned
+     * background Hey Siri detection off in Microphone Mode settings.
+     *
+     * The event format is not yet confirmed on a real device: every vendor event is logged so
+     * the actual traffic can be checked against VENDOR_SPECIFIC_HEADSET_EVENT_APLSIRI.
+     */
+    private val hotwordReceiver = object : BroadcastReceiver() {
+        override fun onReceive(context: Context?, intent: Intent?) {
+            if (intent == null) return
+            val cmd = intent.getStringExtra(BluetoothHeadset.EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD)
+            val cmdType = intent.getIntExtra(BluetoothHeadset.EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE, -1)
+            val args = intent.getSerializableExtra(BluetoothHeadset.EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_ARGS)
+            Log.d(TAG, "Vendor headset event: cmd=$cmd type=$cmdType args=$args")
+
+            if (cmd != VENDOR_SPECIFIC_HEADSET_EVENT_APLSIRI) return
+
+            if (!isHeySiriDetectionEnabled()) {
+                Log.d(TAG, "Hey Siri trigger received but background detection is off; ignoring")
+                return
+            }
+
+            Log.d(TAG, "Hey Siri trigger received; starting digital assistant")
+            executeStemAction(StemAction.DIGITAL_ASSISTANT)
+        }
+    }
+
+    /**
+     * Reads the last VOICE_TRIGGER value reported by (or sent to) the buds.
+     * Treats an unknown value as enabled, matching the default on the buds.
+     */
+    private fun isHeySiriDetectionEnabled(): Boolean {
+        val status = aacpManager.getControlCommandStatus(
+            AACPManager.Companion.ControlCommandIdentifiers.VOICE_TRIGGER
+        )
+        return status?.value?.getOrNull(0) != 0x02.toByte()
+    }
+
     private fun getActionFor(
         bud: AACPManager.Companion.StemPressBudType, type: StemPressType
     ): StemAction? {
@@ -2227,6 +2271,9 @@ class AirPodsService : Service(), SharedPreferences.OnSharedPreferenceChangeList
     @Suppress("PrivatePropertyName")
     private val APPLE = 0x004C
 
+    @Suppress("PrivatePropertyName")
+    private val VENDOR_SPECIFIC_HEADSET_EVENT_APLSIRI = "+APLSIRI"
+
     @Suppress("PrivatePropertyName")
     private val ACTION_BATTERY_LEVEL_CHANGED =
         "android.bluetooth.device.action.BATTERY_LEVEL_CHANGED"
@@ -3112,6 +3159,11 @@ class AirPodsService : Service(), SharedPreferences.OnSharedPreferenceChangeList
         } catch (e: Exception) {
             e.printStackTrace()
         }
+        try {
+            unregisterReceiver(hotwordReceiver)
+        } catch (e: Exception) {
+            e.printStackTrace()
+        }
         try {
             unregisterReceiver(externalBroadcastReceiver)
         } catch (e: Exception) {

android/app/src/main/res/values/strings.xml

@@ -92,6 +92,8 @@
     <string name="microphone">Microphone</string>
     <string name="microphone_mode">Microphone Mode</string>
     <string name="microphone_automatic">Automatic</string>
+    <string name="hey_siri_detection">Hey Siri detection</string>
+    <string name="hey_siri_detection_description">Start your digital assistant when AirPods hear \"Hey Siri\"</string>
     <string name="microphone_always_right">Always Right</string>
     <string name="microphone_always_left">Always Left</string>
     <string name="answer_call">Answer call</string>