Pluginize Webhooks and support Payouts (#5421)

Co-authored-by: d11n <mail@dennisreimann.de>

BTCPayServer/HostedServices/Webhooks/WebhookProvider.cs

@@ -0,0 +1,45 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+using BTCPayServer.Data;
+using Microsoft.Extensions.Logging;
+
+namespace BTCPayServer.HostedServices.Webhooks;
+
+public abstract class WebhookProvider<T>(EventAggregator eventAggregator, ILogger logger, WebhookSender webhookSender)
+    : EventHostedServiceBase(eventAggregator, logger), IWebhookProvider
+{
+    public abstract Dictionary<string, string> GetSupportedWebhookTypes();
+
+    protected abstract WebhookSender.WebhookDeliveryRequest CreateDeliveryRequest(T evt, WebhookData webhook);
+
+    public abstract WebhookEvent CreateTestEvent(string type, params object[] args);
+
+    protected abstract StoreWebhookEvent GetWebhookEvent(T evt);
+    
+    protected override void SubscribeToEvents()
+    {
+        Subscribe<T>();
+        base.SubscribeToEvents();
+    }
+    protected override async Task ProcessEvent(object evt, CancellationToken cancellationToken)
+    {
+        if (evt is T tEvt)
+        {
+            if (GetWebhookEvent(tEvt) is not { } webhookEvent)
+                return;
+
+            var webhooks = await webhookSender.GetWebhooks(webhookEvent.StoreId, webhookEvent.Type);
+            foreach (var webhook in webhooks)
+            {
+                webhookSender.EnqueueDelivery(CreateDeliveryRequest(tEvt, webhook));
+            }
+
+            EventAggregator.Publish(CreateDeliveryRequest(tEvt, null));
+        }
+
+        await base.ProcessEvent(evt, cancellationToken);
+    }
+    
+}