Implemented plugin loading

app/MindWork AI Studio/Tools/PluginSystem/PluginFactory.cs

@@ -1,3 +1,5 @@
+using System.Text;
+
 using AIStudio.Settings;
 
 using Lua;
@@ -9,10 +11,81 @@ public static partial class PluginFactory
     private static readonly ILogger LOG = Program.LOGGER_FACTORY.CreateLogger("PluginFactory");
     private static readonly string DATA_DIR = SettingsManager.DataDirectory!;
     private static readonly string PLUGINS_ROOT = Path.Join(DATA_DIR, "plugins");
+    private static readonly Dictionary<IPluginMetadata, string> AVAILABLE_PLUGINS = new();
+    private static readonly SettingsManager SETTINGS = Program.SERVICE_PROVIDER.GetRequiredService<SettingsManager>();
     
-    public static async Task LoadAll()
+    /// <summary>
+    /// A list of all available plugins.
+    /// </summary>
+    public static IEnumerable<IPluginMetadata> AvailablePlugins => AVAILABLE_PLUGINS.Keys;
+    
+    /// <summary>
+    /// A list of all enabled plugins.
+    /// </summary>
+    public static IEnumerable<IPluginMetadata> EnabledPlugins => AVAILABLE_PLUGINS.Keys.Where(x => SETTINGS.ConfigurationData.EnabledPlugins.Contains(x.Id));
+    
+    /// <summary>
+    /// A list of all disabled plugins.
+    /// </summary>
+    public static IEnumerable<IPluginMetadata> DisabledPlugins => AVAILABLE_PLUGINS.Keys.Where(x => !SETTINGS.ConfigurationData.EnabledPlugins.Contains(x.Id));
+    
+    /// <summary>
+    /// Try to load all plugins from the plugins directory.
+    /// </summary>
+    /// <remarks>
+    /// Loading plugins means:<br/>
+    /// - Parsing and checking the plugin code<br/>
+    /// - Check for forbidden plugins<br/>
+    /// - Creating a new instance of the allowed plugin<br/>
+    /// - Read the plugin metadata<br/>
+    /// <br/>
+    /// Loading a plugin does not mean to start the plugin, though.
+    /// </remarks>
+    public static async Task LoadAll(CancellationToken cancellationToken = default)
     {
+        LOG.LogInformation("Start loading plugins.");
+        if (!Directory.Exists(PLUGINS_ROOT))
+        {
+            LOG.LogInformation("No plugins found.");
+            return;
+        }
         
+        //
+        // The easiest way to load all plugins is to find all `plugin.lua` files and load them.
+        // By convention, each plugin is enforced to have a `plugin.lua` file.
+        //
+        var pluginMainFiles = Directory.EnumerateFiles(PLUGINS_ROOT, "plugin.lua", SearchOption.AllDirectories);
+        foreach (var pluginMainFile in pluginMainFiles)
+        {
+            if (cancellationToken.IsCancellationRequested)
+                break;
+            
+            LOG.LogInformation($"Try to load plugin: {pluginMainFile}");
+            var code = await File.ReadAllTextAsync(pluginMainFile, Encoding.UTF8, cancellationToken);
+            var plugin = await Load(pluginMainFile, code, cancellationToken);
+            
+            switch (plugin)
+            {
+                case NoPlugin noPlugin when noPlugin.Issues.Any():
+                    LOG.LogError($"Was not able to load plugin: '{pluginMainFile}'. Reason: {noPlugin.Issues.First()}");
+                    continue;
+                
+                case NoPlugin:
+                    LOG.LogError($"Was not able to load plugin: '{pluginMainFile}'. Reason: Unknown.");
+                    continue;
+                
+                case { IsValid: false }:
+                    LOG.LogError($"Was not able to load plugin '{pluginMainFile}', because the Lua code is not a valid AI Studio plugin. There are {plugin.Issues.Count()} issues to fix.");
+                    continue;
+
+                case { IsMaintained: false }:
+                    LOG.LogWarning($"The plugin '{pluginMainFile}' is not maintained anymore. Please consider to disable it.");
+                    break;
+            }
+            
+            LOG.LogInformation($"Successfully loaded plugin: '{pluginMainFile}' (Id='{plugin.Id}', Type='{plugin.Type}', Name='{plugin.Name}', Version='{plugin.Version}', Authors='{string.Join(", ", plugin.Authors)}')");
+            AVAILABLE_PLUGINS.Add(new PluginMetadata(plugin), pluginMainFile);
+        }
     }
     
     public static async Task<PluginBase> Load(string path, string code, CancellationToken cancellationToken = default)
@@ -30,6 +103,10 @@ public static partial class PluginFactory
         {
             return new NoPlugin($"Was not able to parse the plugin: {e.Message}");
         }
+        catch (LuaRuntimeException e)
+        {
+            return new NoPlugin($"Was not able to run the plugin: {e.Message}");
+        }
         
         if (!state.Environment["TYPE"].TryRead<string>(out var typeText))
             return new NoPlugin("TYPE does not exist or is not a valid string.");