package cadencechords.modules.metronome

import android.media.AudioAttributes
import android.media.SoundPool
import expo.modules.kotlin.modules.Module
import expo.modules.kotlin.modules.ModuleDefinition
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Job
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch

class MetronomeModule : Module() {
  private var bpm: Int = 120
  private var job: Job? = null
  private var isRunning: Boolean = false
  private var soundPool: SoundPool? = null
  private var soundId: Int = 0

  override fun definition() = ModuleDefinition {
    Name("Metronome")

    OnCreate {
      setUpSoundPool()
    }

    OnDestroy {
      soundPool?.release()
      soundPool = null
      job?.cancel()
    }

    Function("setBpm") { bpm: Int ->
      this@MetronomeModule.bpm = bpm
      if (isRunning) {
        stop()
        start()
      }
    }

    Function("start") {
      start()
    }

    Function("stop") {
      stop()
    }
  }

  private fun playSound() {
    soundPool!!.play(soundId, 1f, 1f, 0, 0, 1f)
  }

  private fun setUpSoundPool() {
    val audioAttributes = AudioAttributes.Builder()
      .setUsage(AudioAttributes.USAGE_MEDIA)
      .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
      .build()
    soundPool = SoundPool.Builder()
      .setMaxStreams(1)
      .setAudioAttributes(audioAttributes)
      .build()

    soundId = soundPool!!.load(appContext.reactContext, R.raw.low, 1)
  }

  private fun start() {
    if (isRunning) return

    if (soundPool == null) setUpSoundPool()

    playSound()
    isRunning = true

    job = CoroutineScope(Dispatchers.Default).launch {
      while(isRunning) {
        val intervalMillis = (60000 / bpm).toLong()
        delay(intervalMillis)

        if (isRunning) {
          playSound()
        }
      }
    }
  }

  private fun stop() {
    isRunning = false
    job?.cancel()
  }
}