- tweak: refactor funny

Nebula.Shared/ServiceManager.cs

@@ -0,0 +1,44 @@
+using System.Reflection;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Nebula.Shared;
+
+public static class ServiceExt
+{
+    public static void AddServices(this IServiceCollection services)
+    {
+        foreach (var (type, inference) in GetServicesWithHelpAttribute(Assembly.GetExecutingAssembly()))
+        {
+            if (inference is null)
+            {
+                services.AddSingleton(type);
+            }
+            else
+            {
+                services.AddSingleton(inference, type);
+            }
+        }
+    }
+    
+    private static IEnumerable<(Type,Type?)> GetServicesWithHelpAttribute(Assembly assembly) {
+        foreach(Type type in assembly.GetTypes())
+        {
+            var attr = type.GetCustomAttribute<ServiceRegisterAttribute>();
+            if (attr is not null) {
+                yield return (type, attr.Inference);
+            }
+        }
+    }
+}
+
+public sealed class ServiceRegisterAttribute : Attribute
+{
+    public Type? Inference { get; }
+    public bool IsSingleton { get; }
+
+    public ServiceRegisterAttribute(Type? inference = null, bool isSingleton = true)
+    {
+        IsSingleton = isSingleton;
+        Inference = inference;
+    }
+}