Bluetooth mic routing fix

AudioRecorder.kt

@@ -0,0 +1,20 @@
+// Other existing imports
+import android.media.AudioManager;
+import android.telecom.Call;
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+
+// Function to detect connected Bluetooth devices
+private AudioDevice getAudioSource() {
+    BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
+    if (bluetoothAdapter != null && bluetoothAdapter.isEnabled()) {
+        for (BluetoothDevice device : bluetoothAdapter.getBondedDevices()) {
+            if (device.getType() == BluetoothDevice.DEVICE_TYPE_AUDIO) {
+                // return audio source associated with the Bluetooth device
+                return AudioDevice.BLUETOOTH;
+            }
+        }
+    }
+    // Fallback to default audio source if no Bluetooth devices are connected
+    return AudioDevice.DEFAULT;
+}

common/src/main/kotlin/io/homeassistant/companion/android/common/util/AudioRecorder.kt

@@ -30,7 +30,6 @@ class AudioRecorder(private val audioManager: AudioManager?) {
         // Docs: only format '[g]uaranteed to be supported by devices'
         private const val AUDIO_FORMAT = AudioFormat.ENCODING_PCM_16BIT
 
-        private const val AUDIO_SOURCE = AudioSource.MIC
         private const val CHANNEL_CONFIG = AudioFormat.CHANNEL_IN_MONO
     }
 
@@ -49,6 +48,26 @@ class AudioRecorder(private val audioManager: AudioManager?) {
 
     private var focusRequest: AudioFocusRequestCompat? = null
     private val focusListener = OnAudioFocusChangeListener { /* Not used */ }
+    private var scoStarted = false
+
+    /**
+     * Determine the appropriate audio source based on connected devices.
+     * Returns VOICE_COMMUNICATION when Bluetooth SCO is available off-call,
+     * otherwise returns MIC.
+     */
+    private fun getAudioSource(): Int {
+        if (audioManager == null) {
+            return AudioSource.MIC
+        }
+
+        // Check if Bluetooth SCO is available
+        return if (audioManager.isBluetoothScoAvailableOffCall()) {
+            // Use VOICE_COMMUNICATION which is the standard for Bluetooth audio
+            AudioSource.VOICE_COMMUNICATION
+        } else {
+            AudioSource.MIC
+        }
+    }
 
     /**
      * Start the recorder. After calling this function, data will be available via [audioBytes].
@@ -101,8 +120,9 @@ class AudioRecorder(private val audioManager: AudioManager?) {
     private fun setupRecorder() {
         if (recorder != null) stopRecording()
 
+        val audioSource = getAudioSource()
         val bufferSize = minBufferSize() * 10
-        recorder = AudioRecord(AUDIO_SOURCE, SAMPLE_RATE, CHANNEL_CONFIG, AUDIO_FORMAT, bufferSize)
+        recorder = AudioRecord(audioSource, SAMPLE_RATE, CHANNEL_CONFIG, AUDIO_FORMAT, bufferSize)
     }
 
     private fun releaseRecorder() {
@@ -114,6 +134,13 @@ class AudioRecorder(private val audioManager: AudioManager?) {
 
     private fun requestFocus() {
         if (audioManager == null) return
+
+        // Enable Bluetooth SCO if available
+        if (audioManager.isBluetoothScoAvailableOffCall()) {
+            audioManager.startBluetoothSco()
+            scoStarted = true
+        }
+
         if (focusRequest == null) {
             focusRequest = AudioFocusRequestCompat.Builder(AudioManagerCompat.AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE).run {
                 setAudioAttributes(
@@ -138,7 +165,16 @@ class AudioRecorder(private val audioManager: AudioManager?) {
     }
 
     private fun abandonFocus() {
-        if (audioManager == null || focusRequest == null) return
-        AudioManagerCompat.abandonAudioFocusRequest(audioManager, focusRequest!!)
+        if (audioManager == null) return
+
+        // Disable Bluetooth SCO only if this instance started it
+        if (scoStarted) {
+            audioManager.stopBluetoothSco()
+            scoStarted = false
+        }
+
+        if (focusRequest != null) {
+            AudioManagerCompat.abandonAudioFocusRequest(audioManager, focusRequest!!)
+        }
     }
 }