refactor: Improving architecture (current stand)

app/src/main/java/app/myzel394/alibi/NotificationHelper.kt

@@ -7,10 +7,13 @@ import android.os.Build
 import androidx.annotation.RequiresApi
 
 object NotificationHelper {
+    const val RECORDER_CHANNEL_ID = "recorder"
+    const val RECORDER_CHANNEL_NOTIFICATION_ID = 1
+
     @RequiresApi(Build.VERSION_CODES.O)
     fun createChannels(context: Context) {
         val channel = NotificationChannel(
-            "recorder",
+            RECORDER_CHANNEL_ID,
             context.resources.getString(R.string.notificationChannels_recorder_name),
             android.app.NotificationManager.IMPORTANCE_LOW,
         )
@@ -19,4 +22,5 @@ object NotificationHelper {
         val notificationManager = context.getSystemService(NotificationManager::class.java)
         notificationManager.createNotificationChannel(channel)
     }
+
 }

app/src/main/java/app/myzel394/alibi/db/AppSettings.kt

@@ -2,7 +2,13 @@ package app.myzel394.alibi.db
 
 import android.media.MediaRecorder
 import android.os.Build
+import android.util.Log
+import com.arthenica.ffmpegkit.FFmpegKit
+import com.arthenica.ffmpegkit.ReturnCode
 import kotlinx.serialization.Serializable
+import java.io.File
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter.ISO_DATE_TIME
 
 @Serializable
 data class AppSettings(
@@ -27,6 +33,103 @@ data class AppSettings(
     }
 }
 
+@Serializable
+data class LastRecording(
+    val folderPath: String,
+    @Serializable(with = LocalDateTimeSerializer::class)
+    val recordingStart: LocalDateTime,
+    val maxDuration: Long,
+    val intervalDuration: Long,
+    val fileExtension: String,
+    val forceExactMaxDuration: Boolean,
+) {
+    val fileFolder: File
+        get() = File(folderPath)
+
+    val filePaths: List<File>
+        get() =
+            File(folderPath).listFiles()?.filter {
+                val name = it.nameWithoutExtension
+
+                name.toIntOrNull() != null
+            }?.toList() ?: emptyList()
+
+    val hasRecordingAvailable: Boolean
+        get() = filePaths.isNotEmpty()
+
+    private fun stripConcatenatedFileToExactDuration(
+        outputFile: File
+    ) {
+        // Move the concatenated file to a temporary file
+        val rawFile = File("$folderPath/${outputFile.nameWithoutExtension}-raw.${fileExtension}")
+        outputFile.renameTo(rawFile)
+
+        val command = "-sseof ${maxDuration / -1000} -i $rawFile -y $outputFile"
+
+        val session = FFmpegKit.execute(command)
+
+        if (!ReturnCode.isSuccess(session.returnCode)) {
+            Log.d(
+                "Audio Concatenation",
+                String.format(
+                    "Command failed with state %s and rc %s.%s",
+                    session.getState(),
+                    session.getReturnCode(),
+                    session.getFailStackTrace()
+                )
+            )
+
+            throw Exception("Failed to strip concatenated audio")
+        }
+    }
+
+    suspend fun concatenateFiles(forceConcatenation: Boolean = false): File {
+        val paths = filePaths.joinToString("|")
+        val fileName = recordingStart
+            .format(ISO_DATE_TIME)
+            .toString()
+            .replace(":", "-")
+            .replace(".", "_")
+        val outputFile = File("$fileFolder/$fileName.${fileExtension}")
+
+        if (outputFile.exists() && !forceConcatenation) {
+            return outputFile
+        }
+
+        val command = "-i 'concat:$paths' -y" +
+                " -acodec copy" +
+                " -metadata title='$fileName' " +
+                " -metadata date='${recordingStart.format(ISO_DATE_TIME)}'" +
+                " -metadata batch_count='${filePaths.size}'" +
+                " -metadata batch_duration='${intervalDuration}'" +
+                " -metadata max_duration='${maxDuration}'" +
+                " $outputFile"
+
+        val session = FFmpegKit.execute(command)
+
+        if (!ReturnCode.isSuccess(session.returnCode)) {
+            Log.d(
+                "Audio Concatenation",
+                String.format(
+                    "Command failed with state %s and rc %s.%s",
+                    session.getState(),
+                    session.getReturnCode(),
+                    session.getFailStackTrace()
+                )
+            )
+
+            throw Exception("Failed to concatenate audios")
+        }
+
+        val minRequiredForPossibleInExactMaxDuration = maxDuration / intervalDuration
+        if (forceExactMaxDuration && filePaths.size > minRequiredForPossibleInExactMaxDuration) {
+            stripConcatenatedFileToExactDuration(outputFile)
+        }
+
+        return outputFile
+    }
+}
+
 @Serializable
 data class AudioRecorderSettings(
     val maxDuration: Long = 30 * 60 * 1000L,

app/src/main/java/app/myzel394/alibi/db/AppSettingsSerializer.kt

@@ -1,10 +1,17 @@
 package app.myzel394.alibi.db
 
 import androidx.datastore.core.Serializer
+import kotlinx.serialization.KSerializer
 import kotlinx.serialization.SerializationException
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 import kotlinx.serialization.json.Json
 import java.io.InputStream
 import java.io.OutputStream
+import java.time.LocalDateTime
 
 class AppSettingsSerializer: Serializer<AppSettings> {
     override val defaultValue: AppSettings = AppSettings.getDefaultInstance()
@@ -31,3 +38,15 @@ class AppSettingsSerializer: Serializer<AppSettings> {
         )
     }
 }
+
+class LocalDateTimeSerializer: KSerializer<LocalDateTime> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("LocalDateTime", PrimitiveKind.STRING)
+
+    override fun deserialize(decoder: Decoder): LocalDateTime {
+        return LocalDateTime.parse(decoder.decodeString())
+    }
+
+    override fun serialize(encoder: Encoder, value: LocalDateTime) {
+        encoder.encodeString(value.toString())
+    }
+}

app/src/main/java/app/myzel394/alibi/enums/RecorderState.kt

@@ -0,0 +1,7 @@
+package app.myzel394.alibi.enums
+
+enum class RecorderState {
+    IDLE,
+    RECORDING,
+    PAUSED,
+}

app/src/main/java/app/myzel394/alibi/services/AudioRecorderService.kt

@@ -0,0 +1,55 @@
+package app.myzel394.alibi.services
+
+import android.media.MediaRecorder
+import android.os.Build
+
+class AudioRecorderService: IntervalRecorderService() {
+    var recorder: MediaRecorder? = null
+        private set
+
+    val filePath: String
+        get() = "$folder/$counter.${settings.fileExtension}"
+
+    private fun createRecorder(): MediaRecorder {
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            MediaRecorder(this)
+        } else {
+            MediaRecorder()
+        }.apply {
+            setAudioSource(MediaRecorder.AudioSource.MIC)
+            setOutputFile(filePath)
+            setOutputFormat(settings.outputFormat)
+            setAudioEncoder(settings.encoder)
+            setAudioEncodingBitRate(settings.bitRate)
+            setAudioSamplingRate(settings.samplingRate)
+        }
+    }
+
+    private fun resetRecorder() {
+        runCatching {
+            recorder?.let {
+                it.stop()
+                it.release()
+            }
+        }
+    }
+
+    override fun startNewCycle() {
+        super.startNewCycle()
+
+        val newRecorder = createRecorder().also {
+            it.prepare()
+        }
+
+        resetRecorder()
+
+        newRecorder.start()
+        recorder = newRecorder
+    }
+
+    override fun getAmplitudeAmount(): Int {
+        return 100
+    }
+
+    override fun getAmplitude(): Int = recorder?.maxAmplitude ?: 0
+}

app/src/main/java/app/myzel394/alibi/services/ExtraRecorderInformationService.kt

@@ -0,0 +1,85 @@
+package app.myzel394.alibi.services
+
+import android.os.Handler
+import android.os.Looper
+import java.util.Timer
+import java.util.TimerTask
+import java.util.concurrent.Executors
+import java.util.concurrent.ScheduledExecutorService
+import java.util.concurrent.TimeUnit
+
+abstract class ExtraRecorderInformationService: RecorderService() {
+    abstract fun getAmplitudeAmount(): Int
+    abstract fun getAmplitude(): Int
+
+    private var recordingTime = 0L
+    private lateinit var recordingTimeTimer: ScheduledExecutorService
+
+    var amplitudes = mutableListOf<Int>()
+        private set
+    private lateinit var amplitudesTimer: Timer
+
+    private val handler = Handler(Looper.getMainLooper())
+
+    var onRecordingTimeChange: ((Long) -> Unit)? = null
+    var onAmplitudeChange: ((List<Int>) -> Unit)? = null
+
+    private fun createRecordingTimeTimer() {
+        recordingTimeTimer = Executors.newSingleThreadScheduledExecutor().also {
+            it.scheduleAtFixedRate(
+                {
+                    recordingTime += 1000
+                },
+                0,
+                1000,
+                TimeUnit.MILLISECONDS
+            )
+        }
+    }
+
+    private fun updateAmplitude() {
+        amplitudes.add(getAmplitude())
+
+        // Delete old amplitudes
+        if (amplitudes.size > getAmplitudeAmount()) {
+            amplitudes.drop(amplitudes.size - getAmplitudeAmount())
+        }
+
+        handler.postDelayed(::updateAmplitude, 100)
+    }
+
+    private fun createAmplitudesTimer() {
+        amplitudesTimer = Timer().also {
+            it.scheduleAtFixedRate(
+                object: TimerTask() {
+                    override fun run() {
+                        updateAmplitude()
+                    }
+                },
+                0,
+                100,
+            )
+        }
+    }
+
+    override fun start() {
+        createRecordingTimeTimer()
+        createAmplitudesTimer()
+    }
+
+    override fun pause() {
+        recordingTimeTimer.shutdown()
+        amplitudesTimer.cancel()
+    }
+
+    override fun resume() {
+        createRecordingTimeTimer()
+        createAmplitudesTimer()
+    }
+
+    override fun stop() {
+        recordingTimeTimer.shutdown()
+        amplitudesTimer.cancel()
+    }
+
+}

app/src/main/java/app/myzel394/alibi/services/IntervalRecorderService.kt

@@ -0,0 +1,117 @@
+package app.myzel394.alibi.services
+
+import android.media.MediaRecorder
+import app.myzel394.alibi.db.AudioRecorderSettings
+import app.myzel394.alibi.db.LastRecording
+import java.io.File
+import java.util.Timer
+import java.util.TimerTask
+import java.util.concurrent.Executor
+import java.util.concurrent.Executors
+import java.util.concurrent.ScheduledExecutorService
+import java.util.concurrent.TimeUnit
+
+abstract class IntervalRecorderService: ExtraRecorderInformationService() {
+    protected var counter = 0
+        private set
+    protected lateinit var folder: File
+    lateinit var settings: Settings
+        protected set
+
+    private lateinit var cycleTimer: ScheduledExecutorService
+
+    fun createLastRecording(): LastRecording = LastRecording(
+        folderPath = folder.absolutePath,
+        recordingStart = recordingStart,
+        maxDuration = settings.maxDuration,
+        fileExtension = settings.fileExtension,
+        intervalDuration = settings.intervalDuration,
+        forceExactMaxDuration = settings.forceExactMaxDuration,
+    )
+
+    // Make overrideable
+    open fun startNewCycle() {
+        deleteOldRecordings()
+    }
+
+    private fun createTimer() {
+        cycleTimer = Executors.newSingleThreadScheduledExecutor().also {
+            it.scheduleAtFixedRate(
+                {
+                    startNewCycle()
+                },
+                0,
+                settings.intervalDuration,
+                TimeUnit.MILLISECONDS
+            )
+        }
+    }
+
+    override fun start() {
+        folder.mkdirs()
+
+        createTimer()
+    }
+
+    override fun pause() {
+        cycleTimer.shutdown()
+    }
+
+    override fun resume() {
+        createTimer()
+    }
+
+    override fun stop() {
+        cycleTimer.shutdown()
+    }
+
+    private fun deleteOldRecordings() {
+        val timeMultiplier = settings.maxDuration / settings.intervalDuration
+        val earliestCounter = counter - timeMultiplier
+
+        folder.listFiles()?.forEach { file ->
+            val fileCounter = file.nameWithoutExtension.toIntOrNull() ?: return
+
+            if (fileCounter < earliestCounter) {
+                file.delete()
+            }
+        }
+    }
+
+    data class Settings(
+        val maxDuration: Long,
+        val intervalDuration: Long,
+        val forceExactMaxDuration: Boolean,
+        val bitRate: Int,
+        val samplingRate: Int,
+        val outputFormat: Int,
+        val encoder: Int,
+    ) {
+        val fileExtension: String
+            get() = when(outputFormat) {
+                MediaRecorder.OutputFormat.AAC_ADTS -> "aac"
+                MediaRecorder.OutputFormat.THREE_GPP -> "3gp"
+                MediaRecorder.OutputFormat.MPEG_4 -> "mp4"
+                MediaRecorder.OutputFormat.MPEG_2_TS -> "ts"
+                MediaRecorder.OutputFormat.WEBM -> "webm"
+                MediaRecorder.OutputFormat.AMR_NB -> "amr"
+                MediaRecorder.OutputFormat.AMR_WB -> "awb"
+                MediaRecorder.OutputFormat.OGG -> "ogg"
+                else -> "raw"
+            }
+
+        companion object {
+            fun from(audioRecorderSettings: AudioRecorderSettings): Settings {
+                return Settings(
+                    intervalDuration = audioRecorderSettings.intervalDuration,
+                    bitRate = audioRecorderSettings.bitRate,
+                    samplingRate = audioRecorderSettings.getSamplingRate(),
+                    outputFormat = audioRecorderSettings.getOutputFormat(),
+                    encoder = audioRecorderSettings.getEncoder(),
+                    maxDuration = audioRecorderSettings.maxDuration,
+                    forceExactMaxDuration = audioRecorderSettings.forceExactMaxDuration,
+                )
+            }
+        }
+    }
+}

app/src/main/java/app/myzel394/alibi/services/RecorderService.kt

@@ -1,324 +1,94 @@
 package app.myzel394.alibi.services
 
+import android.app.Notification
 import android.app.PendingIntent
 import android.app.Service
-import android.content.ComponentName
-import android.content.Context
 import android.content.Intent
-import android.content.ServiceConnection
-import android.media.MediaRecorder
 import android.os.Binder
-import android.os.Build
-import android.os.Handler
 import android.os.IBinder
-import android.os.Looper
-import android.util.Log
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.DisposableEffect
-import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateListOf
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
-import androidx.compose.ui.platform.LocalContext
 import androidx.core.app.NotificationCompat
-import androidx.core.content.ContextCompat
 import app.myzel394.alibi.MainActivity
+import app.myzel394.alibi.NotificationHelper
 import app.myzel394.alibi.R
-import app.myzel394.alibi.dataStore
+import app.myzel394.alibi.enums.RecorderState
-import app.myzel394.alibi.db.AudioRecorderSettings
-import com.arthenica.ffmpegkit.FFmpegKit
-import com.arthenica.ffmpegkit.ReturnCode
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.SupervisorJob
-import kotlinx.coroutines.cancel
-import kotlinx.coroutines.flow.collectLatest
-import kotlinx.coroutines.launch
-import java.io.File
 import java.time.LocalDateTime
 import java.time.ZoneId
-import java.time.format.DateTimeFormatter.ISO_DATE_TIME
 import java.util.Date
+import java.util.concurrent.Executors
+import java.util.concurrent.ScheduledExecutorService
+import java.util.concurrent.TimeUnit
 
-import java.util.UUID
+abstract class RecorderService: Service() {
+    private val binder = RecorderBinder()
 
-const val AMPLITUDE_UPDATE_INTERVAL = 100L
+    private var isPaused: Boolean = false
 
-class RecorderService: Service() {
+    lateinit var recordingStart: LocalDateTime
-    private val binder = LocalBinder()
-    private val handler = Handler(Looper.getMainLooper())
-    private var job = SupervisorJob()
-    private var scope = CoroutineScope(Dispatchers.IO + job)
-
-    private var mediaRecorder: MediaRecorder? = null
-    private var onError: MediaRecorder.OnErrorListener? = null
-    private var onAmplitudeUpdate: () -> Unit = {}
-
-    private var counter = 0
-    var maxAmplitudes = 1000
-
-    var settings: Settings? = null
         private set
 
-    var fileFolder: String? = null
+    var state = RecorderState.RECORDING
-        private set
-    val isRecording = mutableStateOf(false)
-
-    val amplitudes = mutableStateListOf<Int>()
-
-    var recordingStart: LocalDateTime? = null
         private set
 
-    val filePaths: List<File>
+    var onStateChange: ((RecorderState) -> Unit)? = null
-        get() = File(fileFolder!!).listFiles()?.filter {
-            val name = it.nameWithoutExtension
 
-            if (name.toIntOrNull() == null) {
+    protected abstract fun start()
-                return@filter false
+    protected abstract fun pause()
+    protected abstract fun resume()
+    protected abstract fun stop()
+
+    override fun onBind(p0: Intent?): IBinder? = binder
+
+    inner class RecorderBinder: Binder() {
+        fun getService(): RecorderService = this@RecorderService
     }
 
-            val extension = it.extension
+    fun changeState(newState: RecorderState) {
-
+        if (state == newState) {
-            extension == settings!!.fileExtension
+            return
-        }?.toList() ?: emptyList()
-
-    override fun onBind(p0: Intent?): IBinder = binder
-
-    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        when (intent?.action) {
-            Actions.START.toString() -> start()
-            Actions.STOP.toString() -> stop()
         }
 
-        return super.onStartCommand(intent, flags, startId)
+        when (newState) {
+            RecorderState.RECORDING -> {
+                if (isPaused) {
+                    resume()
+                    isPaused = false
+                } else {
+                    start()
+                }
+            }
+            RecorderState.PAUSED -> {
+                pause()
+                isPaused = true
+            }
+            else -> throw IllegalStateException("$newState is not a valid state. Destroy or recreate the service instead.")
+        }
+
+        state = newState
+        onStateChange?.invoke(newState)
+    }
+
+    override fun onCreate() {
+        super.onCreate()
+
+        val notification = buildNotification()
+
+        startForeground(NotificationHelper.RECORDER_CHANNEL_NOTIFICATION_ID, notification)
+
+        recordingStart = LocalDateTime.now()
+        start()
     }
 
     override fun onDestroy() {
         super.onDestroy()
 
-        scope.cancel()
-    }
-
-    fun setOnAmplitudeUpdateListener(onAmplitudeUpdate: () -> Unit) {
-        this.onAmplitudeUpdate = onAmplitudeUpdate
-    }
-
-    private fun start() {
-        reset()
-        fileFolder = getRandomFileFolder(this)
-
-        // Create folder
-        File(this.fileFolder!!).mkdirs()
-
-        scope.launch {
-            dataStore.data.collectLatest { preferenceSettings ->
-                if (settings == null) {
-                    settings = Settings.from(preferenceSettings.audioRecorderSettings)
-                    recordingStart = LocalDateTime.now()
-                    isRecording.value = true
-
-                    showNotification()
-                    startNewRecording()
-                    updateAmplitude()
-                }
-            }
-        }
-    }
-
-    private fun resetCoroutineScope() {
-        // Reset `scope`
-        scope.cancel()
-        job = SupervisorJob()
-        scope = CoroutineScope(Dispatchers.IO + job)
-    }
-
-    private fun stop() {
-        isRecording.value = false
-        mediaRecorder?.apply {
-            runCatching {
         stop()
-                release()
-            }
-        }
 
         stopForeground(STOP_FOREGROUND_REMOVE)
         stopSelf()
     }
 
-    fun reset() {
+    private fun buildNotification(): Notification {
-        resetCoroutineScope()
+        return NotificationCompat.Builder(this, "recorder")
-        settings = null
-        recordingStart = null
-        counter = 0
-        amplitudes.clear()
-        isRecording.value = false
-
-        if (fileFolder != null) {
-            File(fileFolder!!).listFiles()?.forEach {
-                it.delete()
-            }
-
-            fileFolder = null
-        }
-    }
-
-    private fun stripConcatenatedFileToExactDuration(
-        outputFile: File
-    ) {
-        // Move the concatenated file to a temporary file
-        val rawFile = File("$fileFolder/${outputFile.nameWithoutExtension}-raw.${settings!!.fileExtension}")
-        outputFile.renameTo(rawFile)
-
-        val command = "-sseof ${settings!!.maxDuration / -1000} -i $rawFile -y $outputFile"
-
-        val session = FFmpegKit.execute(command)
-
-        if (!ReturnCode.isSuccess(session.returnCode)) {
-            Log.d(
-                "Audio Concatenation",
-                String.format(
-                    "Command failed with state %s and rc %s.%s",
-                    session.getState(),
-                    session.getReturnCode(),
-                    session.getFailStackTrace()
-                )
-            )
-
-            throw Exception("Failed to strip concatenated audio")
-        }
-    }
-
-    fun concatenateFiles(forceConcatenation: Boolean = false): File {
-        val paths = filePaths.joinToString("|")
-        val fileName = recordingStart!!
-            .format(ISO_DATE_TIME)
-            .toString()
-            .replace(":", "-")
-            .replace(".", "_")
-        val outputFile = File("$fileFolder/$fileName.${settings!!.fileExtension}")
-
-        if (outputFile.exists() && !forceConcatenation) {
-            return outputFile
-        }
-
-        val command = "-i 'concat:$paths' -y" +
-                " -acodec copy" +
-                " -metadata title='$fileName' " +
-                " -metadata date='${recordingStart!!.format(ISO_DATE_TIME)}'" +
-                " -metadata batch_count='${filePaths.size}'" +
-                " -metadata batch_duration='${settings!!.intervalDuration}'" +
-                " -metadata max_duration='${settings!!.maxDuration}'" +
-                " $outputFile"
-
-        val session = FFmpegKit.execute(command)
-
-        if (!ReturnCode.isSuccess(session.returnCode)) {
-            Log.d(
-                "Audio Concatenation",
-                String.format(
-                    "Command failed with state %s and rc %s.%s",
-                    session.getState(),
-                    session.getReturnCode(),
-                    session.getFailStackTrace()
-                )
-            )
-
-            throw Exception("Failed to concatenate audios")
-        }
-
-        val minRequiredForPossibleInExactMaxDuration = settings!!.maxDuration / settings!!.intervalDuration
-        if (settings!!.forceExactMaxDuration && filePaths.size > minRequiredForPossibleInExactMaxDuration) {
-            stripConcatenatedFileToExactDuration(outputFile)
-        }
-
-        return outputFile
-    }
-
-    private fun updateAmplitude() {
-        if (!isRecording.value || mediaRecorder == null) {
-            return
-        }
-
-        val amplitude = mediaRecorder!!.maxAmplitude
-        amplitudes.add(amplitude)
-
-        // Delete old amplitudes
-        if (amplitudes.size > maxAmplitudes) {
-            amplitudes.removeRange(0, amplitudes.size - maxAmplitudes)
-        }
-
-        onAmplitudeUpdate()
-        handler.postDelayed(::updateAmplitude, AMPLITUDE_UPDATE_INTERVAL)
-    }
-
-    private fun startNewRecording() {
-        if (!isRecording.value) {
-            return
-        }
-
-        deleteOldRecordings()
-
-        val newRecorder = createRecorder()
-
-        newRecorder.prepare()
-
-        runCatching {
-            mediaRecorder?.let {
-                it.stop()
-                it.release()
-            }
-        }
-
-        newRecorder.start()
-        mediaRecorder = newRecorder
-
-        counter++
-
-        handler.postDelayed(this::startNewRecording, settings!!.intervalDuration)
-    }
-
-    private fun deleteOldRecordings() {
-        val timeMultiplier = settings!!.maxDuration / settings!!.intervalDuration
-        val earliestCounter = counter - timeMultiplier
-
-        File(fileFolder!!).listFiles()?.forEach { file ->
-            val fileCounter = file.nameWithoutExtension.toIntOrNull() ?: return
-
-            if (fileCounter < earliestCounter) {
-                file.delete()
-            }
-        }
-    }
-
-    private fun createRecorder(): MediaRecorder {
-        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-            MediaRecorder(this)
-        } else {
-            MediaRecorder()
-        }.apply {
-            setAudioSource(MediaRecorder.AudioSource.MIC)
-            setOutputFile(getFilePath())
-            setOutputFormat(settings!!.outputFormat)
-            setAudioEncoder(settings!!.encoder)
-            setAudioEncodingBitRate(settings!!.bitRate)
-            setAudioSamplingRate(settings!!.samplingRate)
-
-            setOnErrorListener { mr, what, extra ->
-                onError?.onError(mr, what, extra)
-
-                this@RecorderService.stop()
-            }
-        }
-    }
-
-    private fun showNotification() {
-        if (!isRecording.value) {
-            return
-        }
-
-        val notification = NotificationCompat.Builder(this, "recorder")
             .setContentTitle("Recording Audio")
             .setContentText("Recording audio in background")
             .setSmallIcon(R.drawable.launcher_foreground)
@@ -328,7 +98,7 @@ class RecorderService: Service() {
             .setOnlyAlertOnce(true)
             .setUsesChronometer(true)
             .setChronometerCountDown(false)
-            .setWhen(Date.from(recordingStart!!.atZone(ZoneId.systemDefault()).toInstant()).time)
+            .setWhen(Date.from(recordingStart.atZone(ZoneId.systemDefault()).toInstant()).time)
             .setShowWhen(true)
             .setContentIntent(
                 PendingIntent.getActivity(
@@ -339,126 +109,5 @@ class RecorderService: Service() {
                 )
             )
             .build()
-
-        // show notification
-        startForeground(getNotificationId(), notification)
-    }
-
-    // To avoid int overflow, we'll use the number of seconds since 2023-01-01 01:01:01
-    private fun getNotificationId(): Int {
-        val offset = ZoneId.of("UTC").rules.getOffset(recordingStart!!)
-
-        return (
-                recordingStart!!.toEpochSecond(offset) -
-                        LocalDateTime.of(2023, 1, 1, 1, 1).toEpochSecond(offset)
-                ).toInt()
-    }
-
-    private fun getFilePath(): String = "$fileFolder/$counter.${settings!!.fileExtension}"
-
-    inner class LocalBinder: Binder() {
-        fun getService(): RecorderService = this@RecorderService
-    }
-
-    enum class Actions {
-        START,
-        STOP,
-    }
-
-    companion object {
-        fun getRandomFileFolder(context: Context): String {
-            // uuid
-            val folder = UUID.randomUUID().toString()
-
-            return "${context.externalCacheDir!!.absolutePath}/$folder"
-        }
-
-        fun startService(context: Context, connection: ServiceConnection?) {
-            Intent(context, RecorderService::class.java).also { intent ->
-                intent.action = Actions.START.toString()
-
-                ContextCompat.startForegroundService(context, intent)
-
-                if (connection != null) {
-                    context.bindService(intent, connection, Context.BIND_AUTO_CREATE)
     }
 }
-        }
-
-        fun stopService(context: Context) {
-            Intent(context, RecorderService::class.java).also { intent ->
-                intent.action = Actions.STOP.toString()
-
-                context.startService(intent)
-            }
-        }
-    }
-}
-
-data class Settings(
-    val maxDuration: Long,
-    val intervalDuration: Long,
-    val forceExactMaxDuration: Boolean,
-    val bitRate: Int,
-    val samplingRate: Int,
-    val outputFormat: Int,
-    val encoder: Int,
-) {
-    val fileExtension: String
-        get() = when(outputFormat) {
-            MediaRecorder.OutputFormat.AAC_ADTS -> "aac"
-            MediaRecorder.OutputFormat.THREE_GPP -> "3gp"
-            MediaRecorder.OutputFormat.MPEG_4 -> "mp4"
-            MediaRecorder.OutputFormat.MPEG_2_TS -> "ts"
-            MediaRecorder.OutputFormat.WEBM -> "webm"
-            MediaRecorder.OutputFormat.AMR_NB -> "amr"
-            MediaRecorder.OutputFormat.AMR_WB -> "awb"
-            MediaRecorder.OutputFormat.OGG -> "ogg"
-            else -> "raw"
-        }
-
-    companion object {
-        fun from(audioRecorderSettings: AudioRecorderSettings): Settings {
-            return Settings(
-                intervalDuration = audioRecorderSettings.intervalDuration,
-                bitRate = audioRecorderSettings.bitRate,
-                samplingRate = audioRecorderSettings.getSamplingRate(),
-                outputFormat = audioRecorderSettings.getOutputFormat(),
-                encoder = audioRecorderSettings.getEncoder(),
-                maxDuration = audioRecorderSettings.maxDuration,
-                forceExactMaxDuration = audioRecorderSettings.forceExactMaxDuration,
-            )
-        }
-    }
-}
-
-@Composable
-fun bindToRecorderService(): Pair<ServiceConnection, RecorderService?> {
-    val context = LocalContext.current
-    var service by remember { mutableStateOf<RecorderService?>(null) }
-
-    val connection = remember {
-        object : ServiceConnection {
-            override fun onServiceConnected(name: ComponentName?, binder: IBinder?) {
-                service = (binder as RecorderService.LocalBinder).getService()
-            }
-
-            override fun onServiceDisconnected(name: ComponentName?) {
-            }
-        }
-    }
-
-    DisposableEffect(Unit) {
-        Intent(context, RecorderService::class.java).also { intent ->
-            context.bindService(intent, connection, Context.BIND_AUTO_CREATE)
-        }
-
-        onDispose {
-            service?.let {
-                context.unbindService(connection)
-            }
-        }
-    }
-
-    return connection to service
-}

app/src/main/java/app/myzel394/alibi/ui/components/AudioRecorder/atoms/SaveRecordingButton.kt

@@ -0,0 +1,114 @@
+package app.myzel394.alibi.ui.components.AudioRecorder.atoms
+
+import android.util.Log
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Memory
+import androidx.compose.material.icons.filled.Save
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.LinearProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.unit.dp
+import app.myzel394.alibi.R
+import app.myzel394.alibi.services.RecorderService
+import app.myzel394.alibi.ui.BIG_PRIMARY_BUTTON_SIZE
+import kotlinx.coroutines.launch
+import java.io.File
+
+@Composable
+fun SaveRecordingButton(
+    modifier: Modifier = Modifier,
+    service: RecorderService,
+    onSaveFile: (File) -> Unit,
+    label: String = stringResource(R.string.ui_audioRecorder_action_save_label),
+) {
+    val context = LocalContext.current
+    val scope = rememberCoroutineScope()
+
+    var isProcessingAudio by remember { mutableStateOf(false) }
+
+    if (isProcessingAudio)
+        AlertDialog(
+            onDismissRequest = { },
+            icon = {
+               Icon(
+                   Icons.Default.Memory,
+                      contentDescription = null,
+               )
+            },
+            title = {
+                Text(
+                    stringResource(R.string.ui_audioRecorder_action_save_processing_dialog_title),
+                )
+            },
+             text = {
+                 Column(
+                     horizontalAlignment = Alignment.CenterHorizontally,
+                 ) {
+                     Text(
+                         stringResource(R.string.ui_audioRecorder_action_save_processing_dialog_description),
+                     )
+                        Spacer(modifier = Modifier.height(32.dp))
+                     LinearProgressIndicator()
+                 }
+            },
+            confirmButton = {}
+        )
+    Button(
+        modifier = Modifier
+            .padding(16.dp)
+            .fillMaxWidth()
+            .height(BIG_PRIMARY_BUTTON_SIZE)
+            .semantics {
+                contentDescription = label
+            }
+            .then(modifier),
+        onClick = {
+            isProcessingAudio = true
+            RecorderService.stopService(context)
+
+            scope.launch {
+                try {
+                    val file = service.concatenateFiles()
+
+                    onSaveFile(file)
+                } catch (error: Exception) {
+                    Log.getStackTraceString(error)
+                } finally {
+                    isProcessingAudio = false
+                }
+            }
+        },
+    ) {
+        Icon(
+            Icons.Default.Save,
+            contentDescription = null,
+            modifier = Modifier.size(ButtonDefaults.IconSize),
+        )
+        Spacer(modifier = Modifier.width(ButtonDefaults.IconSpacing))
+        Text(label)
+    }
+}

app/src/main/java/app/myzel394/alibi/ui/components/AudioRecorder/molecules/RecordingStatus.kt

@@ -5,6 +5,7 @@ import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.tween
 import androidx.compose.animation.expandHorizontally
 import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -12,15 +13,12 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Delete
-import androidx.compose.material.icons.filled.Save
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.Icon
@@ -35,9 +33,9 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
@@ -45,9 +43,9 @@ import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.unit.dp
 import app.myzel394.alibi.R
 import app.myzel394.alibi.services.RecorderService
-import app.myzel394.alibi.ui.BIG_PRIMARY_BUTTON_SIZE
 import app.myzel394.alibi.ui.components.AudioRecorder.atoms.ConfirmDeletionDialog
 import app.myzel394.alibi.ui.components.AudioRecorder.atoms.RealtimeAudioVisualizer
+import app.myzel394.alibi.ui.components.AudioRecorder.atoms.SaveRecordingButton
 import app.myzel394.alibi.ui.components.atoms.Pulsating
 import app.myzel394.alibi.ui.utils.KeepScreenOn
 import app.myzel394.alibi.ui.utils.formatDuration
@@ -60,31 +58,28 @@ import java.time.ZoneId
 @Composable
 fun RecordingStatus(
     service: RecorderService,
-    saveFile: (File) -> Unit,
+    onSaveFile: (File) -> Unit,
 ) {
     val context = LocalContext.current
 
     var now by remember { mutableStateOf(LocalDateTime.now()) }
 
-    val start = service.recordingStart!!
+    val progress = service.recordingTime.value!! / (service.settings!!.maxDuration / 1000f)
-    val duration = now.toEpochSecond(ZoneId.systemDefault().rules.getOffset(now)) - start.toEpochSecond(ZoneId.systemDefault().rules.getOffset(start))
-    val progress = duration / (service.settings!!.maxDuration / 1000f)
 
     LaunchedEffect(Unit) {
         while (true) {
             now = LocalDateTime.now()
-            delay(1000)
+            delay(900)
         }
     }
 
     // Only show animation when the recording has just started
-    val recordingJustStarted = duration < 1
+    val recordingJustStarted = service.recordingTime.value!! < 1
     var progressVisible by remember { mutableStateOf(!recordingJustStarted) }
     LaunchedEffect(Unit) {
         progressVisible = true
     }
 
-
     KeepScreenOn()
 
     Column(
@@ -102,7 +97,7 @@ fun RecordingStatus(
                 verticalAlignment = Alignment.CenterVertically,
                 horizontalArrangement = Arrangement.Center,
             ) {
-                val distance = Duration.between(service.recordingStart, now).toMillis()
+                val distance = Duration.between(service.recordingStart!!, now).toMillis()
 
                 Pulsating {
                     Box(
@@ -167,31 +162,12 @@ fun RecordingStatus(
                 Text(label)
             }
         }
-        val label = stringResource(R.string.ui_audioRecorder_action_save_label)
-        
         val alpha by animateFloatAsState(if (progressVisible) 1f else 0f, tween(1000))
-        Button(
+        SaveRecordingButton(
             modifier = Modifier
-                .padding(16.dp)
+                .alpha(alpha),
-                .fillMaxWidth()
+            service = service,
-                .height(BIG_PRIMARY_BUTTON_SIZE)
+            onSaveFile = onSaveFile,
-                .graphicsLayer(alpha = alpha)
-                .semantics {
-                    contentDescription = label
-                },
-            onClick = {
-                RecorderService.stopService(context)
-
-                saveFile(service.concatenateFiles())
-            },
-        ) {
-            Icon(
-                Icons.Default.Save,
-                contentDescription = null,
-                modifier = Modifier.size(ButtonDefaults.IconSize),
         )
-            Spacer(modifier = Modifier.width(ButtonDefaults.IconSpacing))
-            Text(label)
-        }
     }
 }

app/src/main/java/app/myzel394/alibi/ui/components/AudioRecorder/molecules/StartRecording.kt

@@ -8,6 +8,7 @@ import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.tween
 import androidx.compose.animation.expandHorizontally
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
@@ -49,6 +50,7 @@ import app.myzel394.alibi.db.AppSettings
 import app.myzel394.alibi.services.RecorderService
 import app.myzel394.alibi.ui.BIG_PRIMARY_BUTTON_SIZE
 import app.myzel394.alibi.ui.components.AudioRecorder.atoms.AudioVisualizer
+import app.myzel394.alibi.ui.components.AudioRecorder.atoms.SaveRecordingButton
 import app.myzel394.alibi.ui.components.atoms.PermissionRequester
 import app.myzel394.alibi.ui.utils.rememberFileSaverDialog
 import java.time.format.DateTimeFormatter
@@ -58,6 +60,7 @@ import java.time.format.FormatStyle
 fun StartRecording(
     connection: ServiceConnection,
     service: RecorderService? = null,
+    onStart: () -> Unit,
 ) {
     val context = LocalContext.current
     val saveFile = rememberFileSaverDialog("audio/*")
@@ -78,6 +81,16 @@ fun StartRecording(
             },
             onPermissionAvailable = {
                 RecorderService.startService(context, connection)
+
+                if (service == null) {
+                    onStart()
+                } else {
+                    // To avoid any leaks from the previous recording, we need to wait until it
+                    // fully started
+                    service.setOnStartedListener {
+                        onStart()
+                    }
+                }
             },
         ) { trigger ->
             val label = stringResource(R.string.ui_audioRecorder_action_start_label)
@@ -127,37 +140,22 @@ fun StartRecording(
                 .fillMaxWidth(),
             textAlign = TextAlign.Center,
         )
-        if (service?.recordingStart != null)
+        if (service?.hasRecordingAvailable == true)
             Column(
                 modifier = Modifier.weight(1f),
                 horizontalAlignment = Alignment.CenterHorizontally,
                 verticalArrangement = Arrangement.Bottom,
             ) {
-                Button(
+                SaveRecordingButton(
-                    modifier = Modifier
+                    service = service,
-                        .padding(16.dp)
+                    onSaveFile = saveFile,
-                        .fillMaxWidth()
+                    label = stringResource(
-                        .height(BIG_PRIMARY_BUTTON_SIZE),
-                    onClick = {
-                        saveFile(service.concatenateFiles())
-                    },
-                    colors = ButtonDefaults.textButtonColors(),
-                ) {
-                    Icon(
-                        Icons.Default.Save,
-                        contentDescription = null,
-                        modifier = Modifier
-                            .size(ButtonDefaults.IconSize),
-                    )
-                    Spacer(modifier = Modifier.width(ButtonDefaults.IconSpacing))
-                    Text(
-                        stringResource(
                         R.string.ui_audioRecorder_action_saveOldRecording_label,
-                            DateTimeFormatter.ofLocalizedDate(FormatStyle.FULL).format(service.recordingStart!!),
+                        DateTimeFormatter.ofLocalizedDate(FormatStyle.FULL).format(service.recordingStart),
                     ),
+
                 )
             }
-            }
         else
             Spacer(modifier = Modifier.weight(1f))
     }

app/src/main/java/app/myzel394/alibi/ui/models/AudioRecorderModel.kt

@@ -0,0 +1,69 @@
+package app.myzel394.alibi.ui.models
+
+import android.content.ComponentName
+import android.content.Context
+import android.content.Intent
+import android.content.ServiceConnection
+import android.os.IBinder
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.core.content.ContextCompat
+import androidx.lifecycle.ViewModel
+import app.myzel394.alibi.enums.RecorderState
+import app.myzel394.alibi.services.AudioRecorderService
+import app.myzel394.alibi.services.RecorderService
+
+class AudioRecorderModel: ViewModel() {
+    var recorderState by mutableStateOf(RecorderState.IDLE)
+        private set
+    var recordingTime by mutableStateOf<Long?>(null)
+        private set
+    var amplitudes by mutableStateOf<List<Int>?>(null)
+        private set
+
+    private var intent: Intent? = null
+    private var recorderService: RecorderService? = null
+
+    private val connection = object : ServiceConnection {
+        override fun onServiceConnected(className: ComponentName, service: IBinder) {
+            recorderService = ((service as RecorderService.RecorderBinder).getService() as AudioRecorderService).also {recorder ->
+                recorder.onStateChange = { state ->
+                    recorderState = state
+                }
+                recorder.onRecordingTimeChange = { time ->
+                    recordingTime = time
+                }
+                recorder.onAmplitudeChange = { amps ->
+                    amplitudes = amps
+                }
+            }
+        }
+
+        override fun onServiceDisconnected(arg0: ComponentName) {
+            recorderService = null
+            reset()
+        }
+    }
+
+    fun reset() {
+        recorderState = RecorderState.IDLE
+        recordingTime = null
+        amplitudes = null
+    }
+
+    fun startRecording(context: Context) {
+        runCatching {
+            context.unbindService(connection)
+        }
+
+        val intent = Intent(context, AudioRecorderService::class.java)
+        ContextCompat.startForegroundService(context, intent)
+        context.bindService(intent, connection, Context.BIND_AUTO_CREATE)
+    }
+
+    fun stopRecording(context: Context) {
+        context.stopService(intent)
+        context.unbindService(connection)
+    }
+}

app/src/main/java/app/myzel394/alibi/ui/screens/AudioRecorder.kt

@@ -30,7 +30,10 @@ fun AudioRecorder(
 ) {
     val saveFile = rememberFileSaverDialog("audio/aac")
     val (connection, service) = bindToRecorderService()
-    val isRecording = service?.isRecording?.value ?: false
+
+    var showRecorderStatus by remember {
+        mutableStateOf(service?.isRecording ?: false)
+    }
 
     Scaffold(
         topBar = {
@@ -58,10 +61,22 @@ fun AudioRecorder(
                 .fillMaxSize()
                 .padding(padding),
         ) {
-            if (isRecording)
+            if (showRecorderStatus && service?.recordingTime?.value != null)
-                RecordingStatus(service = service!!, saveFile = saveFile)
+                RecordingStatus(
+                    service = service,
+                    onSaveFile = {
+                        saveFile(it)
+                        showRecorderStatus = false
+                    }
+                )
             else
-                StartRecording(connection = connection, service = service)
+                StartRecording(
+                    connection = connection,
+                    service = service,
+                    onStart = {
+                        showRecorderStatus = true
+                    }
+                )
         }
     }
 }

app/src/main/java/app/myzel394/alibi/ui/screens/SettingsScreen.kt

@@ -51,7 +51,7 @@ fun SettingsScreen(
     navController: NavController
 ) {
     val (_, service) = bindToRecorderService()
-    val isRecording = service?.isRecording?.value ?: false
+    val isRecording = service?.isRecording ?: false
     val scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior(
         rememberTopAppBarState()
     )

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

@@ -23,6 +23,9 @@
     <string name="ui_audioRecorder_action_delete_confirm_title">Delete Recording?</string>
     <string name="ui_audioRecorder_action_delete_confirm_message">Are you sure you want to delete this recording?</string>
     <string name="ui_audioRecorder_action_save_label">Save Recording</string>
+    <string name="ui_audioRecorder_action_start_description">Alibi will continue recording in the background and store the last <xliff:g name="durationInMinutes">%s</xliff:g> minutes at your request</string>
+    <string name="ui_audioRecorder_action_save_processing_dialog_title">Processing</string>
+    <string name="ui_audioRecorder_action_save_processing_dialog_description">Processing Audio, do not close Alibi! You will be automatically prompted to save the file once it\'s ready</string>
 
     <string name="ui_welcome_explanation_title">Welcome to Alibi!</string>
     <string name="ui_welcome_explanation_message">Alibi is like a dashcam for your phone. It allows you to record your audio continuously and save the last 30 minutes when you need it.</string>
@@ -49,5 +52,4 @@
     <string name="ui_settings_option_samplingRate_description">Define how many samples per second are taken from the audio signal</string>
     <string name="ui_settings_option_samplingRate_explanation">Set the sampling rate</string>
     <string name="ui_settings_option_encoder_title">Encoder</string>
-    <string name="ui_audioRecorder_action_start_description">Alibi will continue recording in the background and store the last <xliff:g name="durationInMinutes">%s</xliff:g> minutes at your request</string>
 </resources>