AlarmWrapperImp.kt

internal const val ARG_ID_KEY = "ALARM_ID_KEY"
internal const val ARG_REQUEST_CODE_KEY = "ALARM_REQUEST_CODE_KEY"
internal const val ARG_ALARM_TYPE = "ARG_ALARM_TYPE"

/**
 * @param appContext injected via DI 
 */

class AlarmWrapperImp(private val appContext: Context) : AlarmWrapper {
    private var alarmManager: AlarmManager? = null
    private lateinit var alarmIntent: PendingIntent

    init {
        alarmManager = appContext.getSystemService(Context.ALARM_SERVICE) as? AlarmManager
    }

    override fun setAlarm(alarmType: AlarmType, requestCode: String, id: String) {
        alarmIntent = Intent(appContext, AlarmReceiver::class.java).let { intent ->
            intent.putExtra(ARG_ID_KEY, id)
            intent.putExtra(ARG_REQUEST_CODE_KEY, requestCode)
            intent.putExtra(ARG_ALARM_TYPE, alarmType.name)

            // PendingIntent.getBroadcast(appContext, 1, intent, 0) Bug : I used same same request code for both alarms
            PendingIntent.getBroadcast(appContext, requestCode, intent, 0) 
        }

        when (alarmType) {
            AlarmType.TYPE1 -> {
                alarmManager?.set(
                    AlarmManager.ELAPSED_REALTIME_WAKEUP,
                    SystemClock.elapsedRealtime() + 60 * 1000,  // Wake up the device to fire a one-time (non-repeating) alarm in one minute
                    alarmIntent
                )
            }
            AlarmType.TYPE2 -> {
                alarmManager?.set(
                    AlarmManager.ELAPSED_REALTIME_WAKEUP,
                    SystemClock.elapsedRealtime() + 300 * 1000,  // 5 minutes
                    alarmIntent
                )
            }
            AlarmType.UNKNOWN -> throw IllegalArgumentException("unknown {${alarmType.name}} received")
        }
    }

    override fun cancelAlarm(alarmType: AlarmType, requestCode: String, id: String) {
        alarmIntent = Intent(appContext, AlarmReceiver::class.java).let { intent ->
            intent.putExtra(ARG_ID_KEY, id)
            intent.putExtra(ARG_REQUEST_CODE_KEY, requestCode)
            intent.putExtra(ARG_ALARM_TYPE, alarmType.name)
                                                            
            // to cancel the alarm, we need a same id.                                                              
            PendingIntent.getBroadcast(appContext, requestCode, intent, 0)
        }

        alarmManager?.cancel(alarmIntent)
    }
}