FirebasePushTransport.cs

using System;
using System.Threading;
using Microsoft.Maui.Devices;
using Plugin.Firebase.CloudMessaging;
using Plugin.Firebase.CloudMessaging.EventArgs;
using Waher.Events;
using Waher.Networking.XMPP.Push;
 
namespace NeuroAccessMaui.Services.Push
{
    public sealed class FirebasePushTransport : IPushTransport
    {
        private bool isInitialized;
 
        public event EventHandlerAsync<TokenInformation>? TokenChanged;
 
        public Task InitializeAsync(CancellationToken CancellationToken)
        {
            CancellationToken.ThrowIfCancellationRequested();
 
            if (this.isInitialized)
                return Task.CompletedTask;
 
            this.isInitialized = true;
 
            try
            {
                CrossFirebaseCloudMessaging.Current.TokenChanged += this.OnTokenChanged;
            }
            catch (Exception ex)
            {
                ServiceRef.LogService.LogException(ex);
            }
 
            return Task.CompletedTask;
        }
 
        private async void OnTokenChanged(object? Sender, FCMTokenChangedEventArgs EventArgs)
        {
            try
            {
                string? Token = EventArgs?.Token;
                if (string.IsNullOrEmpty(Token))
                    return;
 
                TokenInformation TokenInformation = new()
                {
                    Token = Token,
                    Service = PushMessagingService.Firebase,
                    ClientType = ResolveClientType()
                };
 
                EventHandlerAsync<TokenInformation>? Handler = this.TokenChanged;
                if (Handler is not null)
                    await Handler.Raise(this, TokenInformation);
            }
            catch (Exception ex)
            {
                ServiceRef.LogService.LogException(ex);
            }
        }
 
        private static ClientType ResolveClientType()
        {
            if (DeviceInfo.Platform == DevicePlatform.Android)
                return ClientType.Android;
 
            if (DeviceInfo.Platform == DevicePlatform.iOS || DeviceInfo.Platform == DevicePlatform.MacCatalyst)
                return ClientType.iOS;
 
            return ClientType.Other;
        }
    }
}