implement message subscribing and worker

dotnet/AipsCore/Infrastructure/DI/AipsRegistrationExtensions.cs

@@ -20,7 +20,15 @@ public static class AipsRegistrationExtensions
 
         services.AddSingleton<IRabbitMqConnection, RabbitMqConnection>();
         services.AddSingleton<IMessagePublisher, RabbitMqPublisher>();
+        services.AddSingleton<IMessageSubscriber, RabbitMqSubscriber>();
         
         return services;
     }
+
+    public static IServiceCollection AddAipsMessageHandlers(this IServiceCollection services)
+    {
+        services.AddMessageHandlersFromAssembly(typeof(IMessage).Assembly);
+
+        return services;
+    }
 }

dotnet/AipsCore/Infrastructure/DI/MessageHandlerRegistrationExtensions.cs

@@ -0,0 +1,36 @@
+using System.Reflection;
+using AipsCore.Application.Abstract.MessageBroking;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace AipsCore.Infrastructure.DI;
+
+public static class MessageHandlerRegistrationExtensions
+{
+    public static IServiceCollection AddMessageHandlersFromAssembly(this IServiceCollection services, Assembly assembly)
+    {
+        var handlerInterface = typeof(IMessageHandler<>);
+        
+        var types = assembly.GetTypes()
+            .Where(t => t is { IsAbstract: false, IsInterface: false });
+
+        foreach (var type in types)
+        {
+            var interfaces = type.GetInterfaces();
+
+            foreach (var @interface in interfaces)
+            {
+                if (!@interface.IsGenericType)
+                    continue;
+
+                var genericDef = @interface.GetGenericTypeDefinition();
+
+                if (handlerInterface != genericDef)
+                    continue;
+                
+                services.AddTransient(@interface, type);
+            }
+        }
+
+        return services;
+    }
+}