feat: add Bluetooth headset audio routing for calls

Audio route cycling: the speaker button now cycles through
Earpiece → Bluetooth → Speaker (or Earpiece → Speaker if no
Bluetooth device is connected).

CallAudioManager:
- Detects Bluetooth SCO/A2DP/BLE headset devices via AudioManager
- Manages Bluetooth SCO connection (startBluetoothSco/stopBluetoothSco)
- BroadcastReceiver monitors SCO state changes — auto-falls back
  to earpiece if Bluetooth disconnects during call
- Exposes audioRoute and isBluetoothAvailable as StateFlows

CallController:
- Replaced toggleSpeaker() with cycleAudioRoute() which delegates
  to CallAudioManager.cycleAudioRoute()
- Exposes audioRoute and isBluetoothAvailable flows to UI

CallScreen:
- Audio route button shows context-aware icon:
  VolumeOff (earpiece), VolumeUp (speaker), BluetoothAudio
- Blue tint for Bluetooth, cyan for speaker, white for earpiece

Manifest: BLUETOOTH_CONNECT permission added.
Strings: call_bluetooth string resource added.

https://claude.ai/code/session_017hZm7yu7CzmcQgZGSaqSXS

amethyst/src/main/AndroidManifest.xml

@@ -44,6 +44,7 @@
 
     <!-- Phone calls -->
     <uses-permission android:name="android.permission.VIBRATE"/>
+    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
 
     <!-- Keeps screen on while playing videos -->
     <uses-permission android:name="android.permission.WAKE_LOCK" />

amethyst/src/main/java/com/vitorpamplona/amethyst/service/call/CallAudioManager.kt

@@ -20,8 +20,12 @@
  */
 package com.vitorpamplona.amethyst.service.call
 
+import android.content.BroadcastReceiver
 import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
 import android.media.AudioAttributes
+import android.media.AudioDeviceInfo
 import android.media.AudioManager
 import android.media.Ringtone
 import android.media.RingtoneManager
@@ -31,6 +35,15 @@ import android.os.PowerManager
 import android.os.VibrationEffect
 import android.os.Vibrator
 import android.os.VibratorManager
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+enum class AudioRoute {
+    EARPIECE,
+    SPEAKER,
+    BLUETOOTH,
+}
 
 class CallAudioManager(
     private val context: Context,
@@ -41,6 +54,13 @@ class CallAudioManager(
     private var ringbackTone: ToneGenerator? = null
     private val audioManager = context.getSystemService(Context.AUDIO_SERVICE) as AudioManager
     private var previousAudioMode: Int = AudioManager.MODE_NORMAL
+    private var scoReceiver: BroadcastReceiver? = null
+
+    private val _audioRoute = MutableStateFlow(AudioRoute.EARPIECE)
+    val audioRoute: StateFlow<AudioRoute> = _audioRoute.asStateFlow()
+
+    private val _isBluetoothAvailable = MutableStateFlow(false)
+    val isBluetoothAvailable: StateFlow<Boolean> = _isBluetoothAvailable.asStateFlow()
 
     fun startRinging() {
         startRingtone()
@@ -59,7 +79,6 @@ class CallAudioManager(
                     it.startTone(ToneGenerator.TONE_SUP_RINGTONE)
                 }
         } catch (_: Exception) {
-            // ToneGenerator may not be available
         }
     }
 
@@ -72,14 +91,43 @@ class CallAudioManager(
     fun switchToCallAudioMode() {
         previousAudioMode = audioManager.mode
         audioManager.mode = AudioManager.MODE_IN_COMMUNICATION
-        audioManager.isSpeakerphoneOn = false
+
+        _isBluetoothAvailable.value = hasBluetoothDevice()
+        if (_isBluetoothAvailable.value) {
+            startBluetoothSco()
+        } else {
+            routeToEarpiece()
+        }
+        registerBluetoothScoReceiver()
     }
 
     fun restoreAudioMode() {
+        stopBluetoothSco()
+        unregisterBluetoothScoReceiver()
         audioManager.mode = previousAudioMode
         audioManager.isSpeakerphoneOn = false
     }
 
+    fun cycleAudioRoute() {
+        val hasBt = _isBluetoothAvailable.value
+        val next =
+            when (_audioRoute.value) {
+                AudioRoute.EARPIECE -> if (hasBt) AudioRoute.BLUETOOTH else AudioRoute.SPEAKER
+                AudioRoute.BLUETOOTH -> AudioRoute.SPEAKER
+                AudioRoute.SPEAKER -> AudioRoute.EARPIECE
+            }
+        setAudioRoute(next)
+    }
+
+    fun setAudioRoute(route: AudioRoute) {
+        _audioRoute.value = route
+        when (route) {
+            AudioRoute.EARPIECE -> routeToEarpiece()
+            AudioRoute.SPEAKER -> routeToSpeaker()
+            AudioRoute.BLUETOOTH -> routeToBluetooth()
+        }
+    }
+
     fun acquireProximityWakeLock() {
         if (proximityWakeLock != null) return
         val powerManager = context.getSystemService(Context.POWER_SERVICE) as PowerManager
@@ -88,13 +136,11 @@ class CallAudioManager(
                 PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK,
                 "amethyst:call_proximity",
             )
-        proximityWakeLock?.acquire(60 * 60 * 1000L) // 1 hour max
+        proximityWakeLock?.acquire(60 * 60 * 1000L)
     }
 
     fun releaseProximityWakeLock() {
-        proximityWakeLock?.let {
+        proximityWakeLock?.let { if (it.isHeld) it.release() }
-            if (it.isHeld) it.release()
-        }
         proximityWakeLock = null
     }
 
@@ -105,6 +151,100 @@ class CallAudioManager(
         releaseProximityWakeLock()
     }
 
+    private fun routeToEarpiece() {
+        stopBluetoothSco()
+        audioManager.isSpeakerphoneOn = false
+    }
+
+    private fun routeToSpeaker() {
+        stopBluetoothSco()
+        audioManager.isSpeakerphoneOn = true
+    }
+
+    private fun routeToBluetooth() {
+        audioManager.isSpeakerphoneOn = false
+        startBluetoothSco()
+    }
+
+    private fun hasBluetoothDevice(): Boolean =
+        try {
+            audioManager
+                .getDevices(AudioManager.GET_DEVICES_OUTPUTS)
+                .any {
+                    it.type == AudioDeviceInfo.TYPE_BLUETOOTH_SCO ||
+                        it.type == AudioDeviceInfo.TYPE_BLUETOOTH_A2DP ||
+                        it.type == AudioDeviceInfo.TYPE_BLE_HEADSET
+                }
+        } catch (_: Exception) {
+            false
+        }
+
+    @Suppress("DEPRECATION")
+    private fun startBluetoothSco() {
+        try {
+            if (!audioManager.isBluetoothScoOn) {
+                audioManager.startBluetoothSco()
+                audioManager.isBluetoothScoOn = true
+            }
+        } catch (_: Exception) {
+        }
+    }
+
+    @Suppress("DEPRECATION")
+    private fun stopBluetoothSco() {
+        try {
+            if (audioManager.isBluetoothScoOn) {
+                audioManager.isBluetoothScoOn = false
+                audioManager.stopBluetoothSco()
+            }
+        } catch (_: Exception) {
+        }
+    }
+
+    private fun registerBluetoothScoReceiver() {
+        if (scoReceiver != null) return
+        scoReceiver =
+            object : BroadcastReceiver() {
+                override fun onReceive(
+                    ctx: Context?,
+                    intent: Intent?,
+                ) {
+                    val state = intent?.getIntExtra(AudioManager.EXTRA_SCO_AUDIO_STATE, -1)
+                    when (state) {
+                        AudioManager.SCO_AUDIO_STATE_CONNECTED -> {
+                            _isBluetoothAvailable.value = true
+                            if (_audioRoute.value == AudioRoute.BLUETOOTH) {
+                                audioManager.isBluetoothScoOn = true
+                            }
+                        }
+
+                        AudioManager.SCO_AUDIO_STATE_DISCONNECTED -> {
+                            _isBluetoothAvailable.value = hasBluetoothDevice()
+                            if (_audioRoute.value == AudioRoute.BLUETOOTH) {
+                                _audioRoute.value = AudioRoute.EARPIECE
+                                routeToEarpiece()
+                            }
+                        }
+                    }
+                }
+            }
+        @Suppress("DEPRECATION")
+        context.registerReceiver(
+            scoReceiver,
+            IntentFilter(AudioManager.ACTION_SCO_AUDIO_STATE_UPDATED),
+        )
+    }
+
+    private fun unregisterBluetoothScoReceiver() {
+        scoReceiver?.let {
+            try {
+                context.unregisterReceiver(it)
+            } catch (_: Exception) {
+            }
+        }
+        scoReceiver = null
+    }
+
     private fun startRingtone() {
         try {
             val ringtoneUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE)
@@ -120,7 +260,6 @@ class CallAudioManager(
                     play()
                 }
         } catch (_: Exception) {
-            // Ringtone may not be available
         }
     }
 
@@ -139,11 +278,9 @@ class CallAudioManager(
                     @Suppress("DEPRECATION")
                     context.getSystemService(Context.VIBRATOR_SERVICE) as Vibrator
                 }
-
+            val pattern = longArrayOf(0, 1000, 1000)
-            val pattern = longArrayOf(0, 1000, 1000) // vibrate 1s, pause 1s, repeat
             vibrator?.vibrate(VibrationEffect.createWaveform(pattern, 0))
         } catch (_: Exception) {
-            // Vibrator may not be available
         }
     }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/service/call/CallController.kt

@@ -22,7 +22,6 @@ package com.vitorpamplona.amethyst.service.call
 
 import android.content.Context
 import android.content.Intent
-import android.media.AudioManager
 import com.vitorpamplona.amethyst.commons.call.CallManager
 import com.vitorpamplona.amethyst.commons.call.CallState
 import com.vitorpamplona.amethyst.service.notifications.NotificationUtils
@@ -75,8 +74,8 @@ class CallController(
     val isAudioMuted: StateFlow<Boolean> = _isAudioMuted.asStateFlow()
     private val _isVideoEnabled = MutableStateFlow(true)
     val isVideoEnabled: StateFlow<Boolean> = _isVideoEnabled.asStateFlow()
-    private val _isSpeakerOn = MutableStateFlow(false)
+    val audioRoute: StateFlow<AudioRoute> = audioManager.audioRoute
-    val isSpeakerOn: StateFlow<Boolean> = _isSpeakerOn.asStateFlow()
+    val isBluetoothAvailable: StateFlow<Boolean> = audioManager.isBluetoothAvailable
 
     init {
         scope.launch {
@@ -232,11 +231,8 @@ class CallController(
         webRtcSession?.setVideoEnabled(enabled)
     }
 
-    fun toggleSpeaker() {
+    fun cycleAudioRoute() {
-        val on = !_isSpeakerOn.value
+        audioManager.cycleAudioRoute()
-        _isSpeakerOn.value = on
-        val am = context.getSystemService(Context.AUDIO_SERVICE) as AudioManager
-        am.isSpeakerphoneOn = on
     }
 
     fun getEglBase() = webRtcSession?.eglBase
@@ -258,7 +254,6 @@ class CallController(
         _localVideoTrack.value = null
         _isAudioMuted.value = false
         _isVideoEnabled.value = true
-        _isSpeakerOn.value = false
         webRtcSession?.dispose()
         webRtcSession = null
         remoteDescriptionSet = false

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/call/CallScreen.kt

@@ -35,6 +35,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.BluetoothAudio
 import androidx.compose.material.icons.filled.Call
 import androidx.compose.material.icons.filled.CallEnd
 import androidx.compose.material.icons.filled.Mic
@@ -69,6 +70,7 @@ import androidx.compose.ui.viewinterop.AndroidView
 import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.commons.call.CallManager
 import com.vitorpamplona.amethyst.commons.call.CallState
+import com.vitorpamplona.amethyst.service.call.AudioRoute
 import com.vitorpamplona.amethyst.service.call.CallController
 import com.vitorpamplona.amethyst.ui.note.ClickableUserPicture
 import com.vitorpamplona.amethyst.ui.note.UsernameDisplay
@@ -148,7 +150,7 @@ fun CallScreen(
                     onHangup = { scope.launch { callManager.hangup() } },
                     onToggleMute = { callController?.toggleAudioMute() },
                     onToggleVideo = { callController?.toggleVideo() },
-                    onToggleSpeaker = { callController?.toggleSpeaker() },
+                    onCycleAudioRoute = { callController?.cycleAudioRoute() },
                 )
             }
 
@@ -327,7 +329,7 @@ private fun ConnectedCallUI(
     onHangup: () -> Unit,
     onToggleMute: () -> Unit,
     onToggleVideo: () -> Unit,
-    onToggleSpeaker: () -> Unit,
+    onCycleAudioRoute: () -> Unit,
 ) {
     var elapsed by remember { mutableLongStateOf(0L) }
 
@@ -343,9 +345,10 @@ private fun ConnectedCallUI(
     val localVideoTrack by (callController?.localVideoTrack ?: emptyVideoFlow).collectAsState()
     val defaultFalse = remember { kotlinx.coroutines.flow.MutableStateFlow(false) }
     val defaultTrue = remember { kotlinx.coroutines.flow.MutableStateFlow(true) }
+    val defaultRoute = remember { kotlinx.coroutines.flow.MutableStateFlow(AudioRoute.EARPIECE) }
     val isAudioMuted by (callController?.isAudioMuted ?: defaultFalse).collectAsState()
     val isVideoEnabled by (callController?.isVideoEnabled ?: defaultTrue).collectAsState()
-    val isSpeakerOn by (callController?.isSpeakerOn ?: defaultFalse).collectAsState()
+    val currentAudioRoute by (callController?.audioRoute ?: defaultRoute).collectAsState()
 
     Box(
         modifier =
@@ -455,13 +458,30 @@ private fun ConnectedCallUI(
                     )
                 }
                 IconButton(
-                    onClick = onToggleSpeaker,
+                    onClick = onCycleAudioRoute,
                     modifier = Modifier.size(56.dp),
                 ) {
                     Icon(
-                        imageVector = if (isSpeakerOn) Icons.Default.VolumeUp else Icons.Default.VolumeOff,
+                        imageVector =
-                        contentDescription = stringRes(if (isSpeakerOn) R.string.call_earpiece else R.string.call_speaker),
+                            when (currentAudioRoute) {
-                        tint = if (isSpeakerOn) Color.Cyan else Color.White,
+                                AudioRoute.EARPIECE -> Icons.Default.VolumeOff
+                                AudioRoute.SPEAKER -> Icons.Default.VolumeUp
+                                AudioRoute.BLUETOOTH -> Icons.Default.BluetoothAudio
+                            },
+                        contentDescription =
+                            stringRes(
+                                when (currentAudioRoute) {
+                                    AudioRoute.EARPIECE -> R.string.call_earpiece
+                                    AudioRoute.SPEAKER -> R.string.call_speaker
+                                    AudioRoute.BLUETOOTH -> R.string.call_bluetooth
+                                },
+                            ),
+                        tint =
+                            when (currentAudioRoute) {
+                                AudioRoute.EARPIECE -> Color.White
+                                AudioRoute.SPEAKER -> Color.Cyan
+                                AudioRoute.BLUETOOTH -> Color(0xFF2196F3)
+                            },
                         modifier = Modifier.size(28.dp),
                     )
                 }

amethyst/src/main/res/values/strings.xml

@@ -793,6 +793,7 @@
     <string name="call_camera_off">Camera off</string>
     <string name="call_speaker">Speaker</string>
     <string name="call_earpiece">Earpiece</string>
+    <string name="call_bluetooth">Bluetooth</string>
     <string name="call_voice">Voice call</string>
     <string name="call_video">Video call</string>
     <string name="call_failed_start">Failed to start call</string>