add a simple plugin system

Pilz.Plugins/PluginManagerT.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Pilz.Plugins
+{
+    public class PluginManager<TPluginInterface, TPluginRuntimeInfo> where TPluginInterface : class where TPluginRuntimeInfo : PluginRuntimeInfo<TPluginInterface>
+    {
+        public static IEnumerable<TPluginRuntimeInfo> LoadPlugins(string[] paths)
+        {
+            var states = new List<TPluginRuntimeInfo>();
+
+            foreach (string path in paths)
+                states.Add(LoadPlugin(path));
+
+            return states;
+        }
+
+        public static TPluginRuntimeInfo LoadPlugin(string path)
+        {
+            var info = Activator.CreateInstance<TPluginRuntimeInfo>();
+            var irmplugin = typeof(TPluginInterface);
+            var loadContext = new PluginLoadContext(path);
+            Assembly? assembly = null;
+
+            if (File.Exists(path))
+            {
+                try
+                {
+                    assembly = loadContext.LoadFromAssemblyName(new AssemblyName(Path.GetFileNameWithoutExtension(path)));
+                }
+                catch
+                {
+                    info.Status = PluginStatus.ErrorAtLoading;
+                }
+            }
+            else
+                info.Status = PluginStatus.FileNotFound;
+
+            if (assembly != null)
+            {
+                foreach (var type in assembly.GetTypes())
+                {
+                    if (info.Plugin == null && irmplugin.IsAssignableFrom(type))
+                    {
+                        try
+                        {
+                            if (Activator.CreateInstance(type) is TPluginInterface plugin)
+                            {
+                                info.Plugin = plugin;
+                                info.Status = PluginStatus.Success;
+                            }
+                        }
+                        catch
+                        {
+                            info.Status = PluginStatus.ErrorAtInitializing;
+                        }
+                    }
+                }
+
+                if (info.Plugin == null)
+                    info.Status = PluginStatus.NoValidPlugin;
+            }
+
+            return info;
+        }
+    }
+}