MyFirebaseMessagingService.kt

class MyFirebaseMessagingService : FirebaseMessagingService() {

    override fun onMessageReceived(remoteMessage: RemoteMessage) {
        // Check if message contains a data payload.
        remoteMessage.data.isNotEmpty().let {
            Log.d(TAG, "Message data payload: ${remoteMessage.data}")

            // Get Message details
            val title = remoteMessage.data["title"]
            val message = remoteMessage.data["message"]

            // Check that 'Automatic Date and Time' settings are turned ON.
            // If it's not turned on, Return
            if (!isTimeAutomatic(applicationContext)) {
                Log.d(TAG, "`Automatic Date and Time` is not enabled")
                return
            }

            // Check whether notification is scheduled or not
            val isScheduled = remoteMessage.data["isScheduled"]?.toBoolean()
            isScheduled?.let {
                if (it) {
                    // This is Scheduled Notification, Schedule it
                    val scheduledTime = remoteMessage.data["scheduledTime"]
                    scheduleAlarm(scheduledTime, title, message)
                } else {
                    // This is not scheduled notification, show it now
                    showNotification(title!!, message!!)
                }
            }
        }
    }