Dalamud/Dalamud/Plugin/PluginManager.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using Serilog;

namespace Dalamud.Plugin
{
    public class PluginManager {
        private readonly Dalamud dalamud;
        private readonly string pluginDirectory;
        private readonly string defaultPluginDirectory;

        public List<IDalamudPlugin> Plugins;

        public PluginManager(Dalamud dalamud, string pluginDirectory, string defaultPluginDirectory) {
            this.dalamud = dalamud;
            this.pluginDirectory = pluginDirectory;
            this.defaultPluginDirectory = defaultPluginDirectory;
        }

        public void UnloadPlugins() {
            if (this.Plugins == null)
                return;

            for (var i = 0; i < this.Plugins.Count; i++) {
                this.Plugins[i].Dispose();
                this.Plugins[i] = null;
            }
        }

        public void LoadPlugins() {
            LoadPluginsAt(new DirectoryInfo(this.defaultPluginDirectory));
            LoadPluginsAt(new DirectoryInfo(this.pluginDirectory));
        }

        private void LoadPluginsAt(DirectoryInfo folder) {
            if (folder.Exists)
            { 
                Log.Debug("Loading plugins at {0}", folder);

                var pluginDlls = folder.GetFiles("*.dll", SearchOption.AllDirectories);

                var assemblies = new List<Assembly>(pluginDlls.Length); 
                foreach (var dllFile in pluginDlls) 
                { 
                    Log.Debug("Loading assembly at {0}", dllFile);
                    var assemblyName = AssemblyName.GetAssemblyName(dllFile.FullName);
                    var pluginAssembly = Assembly.Load(assemblyName); 
                    assemblies.Add(pluginAssembly); 
                }

                var interfaceType = typeof(IDalamudPlugin);
                var foundImplementations = new List<Type>();
                foreach (var assembly in assemblies) {
                    if (assembly != null) {
                        Log.Debug("Loading types for {0}", assembly.FullName);
                        var types = assembly.GetTypes();
                        foreach (var type in types) {
                            if (type.IsInterface || type.IsAbstract) {
                                continue;
                            }

                            if (type.GetInterface(interfaceType.FullName) != null) {
                                foundImplementations.Add(type);
                            }
                        }
                    }
                }

                this.Plugins = new List<IDalamudPlugin>(foundImplementations.Count); 
                foreach (var pluginType in foundImplementations) 
                { 
                    var plugin = (IDalamudPlugin)Activator.CreateInstance(pluginType);

                    var dalamudInterface = new DalamudPluginInterface(this.dalamud, pluginType.Assembly.GetName().Name);

                    plugin.Initialize(dalamudInterface);
                    Log.Information("Loaded plugin: {0}", plugin.Name);
                    this.Plugins.Add(plugin); 
                }
            }
        }
    }
}