iOS AudioRecorder

AudioRecorder.ios.kt

package com.app.animalcare.client.common.utils.audio

import io.github.aakira.napier.Napier
import kotlinx.cinterop.*
import platform.AVFAudio.*
import platform.CoreAudioTypes.kAudioFormatMPEG4AAC
import platform.Foundation.NSError
import platform.Foundation.NSURL

data class LocalUrl(
    val url: NSURL,
)

@OptIn(ExperimentalForeignApi::class, BetaInteropApi::class)
internal actual class AudioRecorder {

    private var recorder: AVAudioRecorder? = null
    var delegateProtocol: AVAudioRecorderDelegateProtocol? = null

    private inline fun createRecorder(url: NSURL, error: CPointer<ObjCObjectVar<NSError?>>?): AVAudioRecorder {
        AVAudioSession.sharedInstance().apply {
            setCategory(AVAudioSessionCategoryPlayAndRecord, error)
            setActive(true, error)
        }
        val settings = mapOf<Any?, Any?>(
            AVFormatIDKey to kAudioFormatMPEG4AAC.toInt(),
            AVSampleRateKey to 12000,
            AVNumberOfChannelsKey to 1,
            AVEncoderAudioQualityKey to AVAudioQualityHigh
        )
        Napier.d { "Url is $url, ${url.path}" }
        return url.usePinned {
            AVAudioRecorder(it.get(), settings, error)
        }
    }

    actual fun start(url: LocalUrl): Boolean {
        if (recorder != null) {
            recorder?.stop()
            recorder = null
        }

        return memScoped {
            val err = allocPointerTo<ObjCObjectVar<NSError?>>()

            createRecorder(url = url.url, error = err.value).also {
                val error = err.value?.pointed?.value
                if (error == null) {
                    Napier.i { "Audio recorder successfully initialized" }

                    it.delegate = delegateProtocol
                    it.prepareToRecord()
                    it.record()

                    recorder = it
                } else {
                    Napier.e { "Error while creating audio recorder: ${error.code}, ${error.description}" }
                }
            }
            return err.value?.pointed?.value == null
        }
    }

    actual fun stop() {
        recorder?.stop()
        recorder = null
    }
}