class LightManager(context: Context) : SensorEventListener {

    private val sensorManager: SensorManager? = context.getSystemService(Context.SENSOR_SERVICE) as SensorManager?
    private val lightSensor: Sensor?
    private var handlerThread: HandlerThread? = null
    val lightValue: BehaviorSubject<Int> = BehaviorSubject.create<Int>()

    init {
        this.lightSensor = sensorManager?.getDefaultSensor(Sensor.TYPE_LIGHT)
        this.handlerThread = HandlerThread(LightManager::class.java.simpleName)
        this.handlerThread?.start()
        val handler = Handler(this.handlerThread?.looper)
        this.sensorManager?.registerListener(this, this.lightSensor, SensorManager.SENSOR_DELAY_NORMAL, handler)
    }

    fun onStop() {
        sensorManager?.unregisterListener(this)
        this.handlerThread?.takeIf { it.isAlive }?.quitSafely()
    }

    override fun onAccuracyChanged(p0: Sensor?, p1: Int) = Unit

    override fun onSensorChanged(event: SensorEvent?): Unit = event?.values?.get(0)?.toInt()?.let {
        this.lightValue.onNext(it)
    } ?: kotlin.run { }

}