feat(UXAssist): public ModFeature lifecycle registry

UXAssist/Common/ModFeatures/IModFeature.cs

@@ -0,0 +1,10 @@
+namespace UXAssist.Common.ModFeatures;
+
+public interface IModFeature
+{
+    void Init();
+    void Start();
+    void Uninit();
+    void OnInputUpdate();
+    void OnUpdate();
+}

UXAssist/Common/ModFeatures/ModFeatureAttribute.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace UXAssist.Common.ModFeatures;
+
+[AttributeUsage(AttributeTargets.Class, Inherited = false)]
+public sealed class ModFeatureAttribute : Attribute
+{
+    public string Name { get; }
+    public int Order { get; set; }
+
+    public ModFeatureAttribute(string name = null)
+    {
+        Name = name;
+    }
+}

UXAssist/Common/ModFeatures/ModFeatureRegistry.cs

@@ -0,0 +1,79 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+
+namespace UXAssist.Common.ModFeatures;
+
+public static class ModFeatureRegistry
+{
+    private static readonly List<Type> _staticFeatures = [];
+    private static readonly List<IModFeature> _instanceFeatures = [];
+    private static readonly HashSet<Assembly> _discoveredAssemblies = [];
+
+    public static void Discover(Assembly assembly)
+    {
+        if (!_discoveredAssemblies.Add(assembly)) return;
+
+        var staticTypes = Util.GetTypesFiltered(assembly, t =>
+            t.IsClass && t.IsAbstract && t.IsSealed &&
+            Attribute.IsDefined(t, typeof(ModFeatureAttribute)));
+
+        foreach (var type in staticTypes.OrderBy(GetOrder))
+        {
+            if (!_staticFeatures.Contains(type))
+                _staticFeatures.Add(type);
+        }
+    }
+
+    public static void Register<T>() where T : class, IModFeature, new()
+    {
+        var instance = new T();
+        _instanceFeatures.Add(instance);
+    }
+
+    public static void InitAll()
+    {
+        ForEachStatic("Init");
+        foreach (var f in _instanceFeatures) f.Init();
+    }
+
+    public static void StartAll()
+    {
+        ForEachStatic("Start");
+        foreach (var f in _instanceFeatures) f.Start();
+    }
+
+    public static void UninitAll()
+    {
+        ForEachStatic("Uninit");
+        foreach (var f in _instanceFeatures) f.Uninit();
+    }
+
+    public static void OnInputUpdateAll()
+    {
+        ForEachStatic("OnInputUpdate");
+        foreach (var f in _instanceFeatures) f.OnInputUpdate();
+    }
+
+    public static void OnUpdateAll()
+    {
+        ForEachStatic("OnUpdate");
+        foreach (var f in _instanceFeatures) f.OnUpdate();
+    }
+
+    private static void ForEachStatic(string methodName)
+    {
+        foreach (var type in _staticFeatures)
+        {
+            var method = type.GetMethod(methodName,
+                BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static);
+            method?.Invoke(null, null);
+        }
+    }
+
+    private static int GetOrder(Type type)
+    {
+        return type.GetCustomAttribute<ModFeatureAttribute>()?.Order ?? 0;
+    }
+}