gehgassi_app/gehGassiApp/gehGassi.LocalNotifications/Platforms/iOS/LocalNotificationDelegate.cs

using System;
using System.Globalization;
using Foundation;
using UIKit;
using UserNotifications;


namespace gehGassi.LocalNotifications.Platforms
{
    public class LocalNotificationDelegate : UNUserNotificationCenterDelegate
    {
        

        public override void DidReceiveNotificationResponse(UNUserNotificationCenter center, UNNotificationResponse response, Action completionHandler)
        {
	        Console.WriteLine("**-----**-----**-----**----** LocalNotifications DidReceiveNotificationResponse **-----**-----**-----**----**");
			try
            {
                if (response is null)
                    return;
                
                if (!response.IsDefaultAction)
                    return;

                if (response.Notification.Request.Content.Badge != null)
                {
                    UIApplication.SharedApplication.InvokeOnMainThread(() =>
                    {
                        nint appBadges = UIApplication.SharedApplication.ApplicationIconBadgeNumber - response.Notification.Request.Content.Badge.Int32Value;
                        UIApplication.SharedApplication.ApplicationIconBadgeNumber = appBadges;
                    });
                }

                NSDictionary dictionary = response.Notification.Request.Content.UserInfo;
                IosNotification iosNotification = GetiOSNotification(dictionary);

                if (iosNotification != null)
                    NotificationService.OnPlatformNotificationTapped(iosNotification.Payload, iosNotification.NotificationId, iosNotification.IsLocal);

                completionHandler?.Invoke();
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error in DidReceiveNotificationResponse : " + ex.Message);
            }
        }

        public override void WillPresentNotification(UNUserNotificationCenter center, UNNotification notification, Action<UNNotificationPresentationOptions> completionHandler)
        {
	        Console.WriteLine("**-----**-----**-----**----** LocalNotifications WillPresentNotification **-----**-----**-----**----**");
			try
            {
                //default value
                UNNotificationPresentationOptions presentationOptions = UNNotificationPresentationOptions.None;
                UNNotificationContent notificationContent = notification?.Request.Content;

                if (notificationContent != null)
                {
                    NSDictionary dictionary = notificationContent.UserInfo;

                    IosNotification iosNotification = GetiOSNotification(dictionary);
                    NotificationService.OnPlatformNotificationReceived(iosNotification.Payload, iosNotification.NotificationId, iosNotification.IsLocal);

                    NSNumber _presentAlert = (NSNumber)notification.Request.Content.UserInfo[NotificationService.PRESENT_ALERT];
                    NSNumber _playSound = (NSNumber)notification.Request.Content.UserInfo[NotificationService.PLAY_SOUND];
                    NSNumber _showBadge = (NSNumber)notification.Request.Content.UserInfo[NotificationService.SHOW_BADGE];

                    if (_presentAlert != null && _presentAlert.BoolValue)
                        presentationOptions |= UNNotificationPresentationOptions.Alert;
                    if (_playSound != null && _playSound.BoolValue)
                        presentationOptions |= UNNotificationPresentationOptions.Sound;
                    if (_showBadge != null && _showBadge.BoolValue)
                        presentationOptions |= UNNotificationPresentationOptions.Badge;
                }

                completionHandler?.Invoke(presentationOptions);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error in WillPresentNotification : " + ex.Message);
            }
        }

        private IosNotification GetiOSNotification(NSDictionary dictionary)
        {
	        string payload = dictionary[NotificationService.PAYLOAD]?.ToString();
	        int? notificationId = (dictionary[NotificationService.NOTIFICATION_ID] as NSNumber)?.Int32Value;
	        bool isFromFirebase = false;
	        int? isLocalNumber = (dictionary[NotificationService.NOTIFICATION_ISLOCAL] as NSNumber)?.Int32Value;
	        bool isLocal = isLocalNumber.HasValue && isLocalNumber.Value == 1;

	        if (string.IsNullOrEmpty(payload) && !notificationId.HasValue)
	        {
		        var error = new NSError();
		        var jsonData = NSJsonSerialization.Serialize(dictionary, NSJsonWritingOptions.PrettyPrinted, out error);
		        var jsonText = new NSString(jsonData, NSStringEncoding.UTF8);

		        // Re-Get Payload & NotificatioinId from Firebase
		        payload = jsonText;

		        string notifId = dictionary[NotificationService.NOTIFICATION_ID_FIREBASE]?.ToString();
		        if (!string.IsNullOrEmpty(notifId))
		        {
			        notificationId = new NSNumber(int.Parse(notifId)).Int32Value;
			        isFromFirebase = true;
		        }
	        }


	        return new IosNotification(notificationId, payload, isLocal);
        }

        private class IosNotification
        {
            public int? NotificationId { get; }
            public string Payload { get; }
            public bool IsLocal { get; }

            public IosNotification(int? notificationId, string payload, bool isLocal)
            {
                NotificationId = notificationId;
                Payload = payload;
                IsLocal = isLocal;
            }
        }
    }
}