implement message subscribing and worker

dotnet/AipsWorker/WorkerService.cs

@@ -0,0 +1,61 @@
+using System.Reflection;
+using AipsCore.Application.Abstract;
+using AipsCore.Application.Abstract.MessageBroking;
+using AipsCore.Application.Common.Message.TestMessage;
+using AipsWorker.Utilities;
+using Microsoft.Extensions.Hosting;
+
+namespace AipsWorker;
+
+public class WorkerService : BackgroundService
+{
+    private readonly IDispatcher _dispatcher;
+    private readonly SubscribeMethodUtility _subscribeMethodUtility;
+
+    public WorkerService(IMessageSubscriber subscriber, IDispatcher dispatcher)
+    {
+        _dispatcher = dispatcher;
+        _subscribeMethodUtility = new SubscribeMethodUtility(subscriber);
+    }
+
+    
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        
+        var messageTypes = GetAllMessageTypes();
+
+        foreach (var messageType in messageTypes)
+        {
+            var handleMethod = GetMessageHandleMethod(messageType);
+            
+            await _subscribeMethodUtility.SubscribeToMessageTypeAsync(messageType, this, handleMethod);
+        }
+    }
+
+    private IReadOnlyCollection<Type> GetAllMessageTypes()
+    {
+        var messageInterface = typeof(IMessage);
+        var assembly = messageInterface.Assembly;
+
+        return assembly
+            .GetTypes()
+            .Where(t =>
+                !t.IsAbstract &&
+                !t.IsInterface &&
+                messageInterface.IsAssignableFrom(t))
+            .ToList();
+    }
+
+    private async Task HandleMessage<T>(T message, CancellationToken ct) where T : IMessage
+    {
+        await _dispatcher.Execute(message, ct);
+    }
+    
+    private MethodInfo GetMessageHandleMethod(Type messageType)
+    {
+        return GetType()
+            .GetMethod(nameof(HandleMessage),
+                BindingFlags.Instance | BindingFlags.NonPublic)!
+            .MakeGenericMethod(messageType);
+    }
+}