Added plugin hot reloading (#377)

app/MindWork AI Studio/Layout/MainLayout.razor.cs

@@ -94,6 +94,9 @@ public partial class MainLayout : LayoutComponentBase, IMessageBusReceiver, IDis
             // Load (but not start) all plugins, without waiting for them:
             var pluginLoadingTimeout = new CancellationTokenSource(TimeSpan.FromSeconds(5));
             _ = PluginFactory.LoadAll(pluginLoadingTimeout.Token);
+            
+            // Set up hot reloading for plugins:
+            PluginFactory.SetUpHotReloading();
         }
         
         // Register this component with the message bus:

app/MindWork AI Studio/Pages/Plugins.razor.cs

@@ -5,7 +5,7 @@ using Microsoft.AspNetCore.Components;
 
 namespace AIStudio.Pages;
 
-public partial class Plugins : ComponentBase
+public partial class Plugins : ComponentBase, IMessageBusReceiver
 {
     private const string GROUP_ENABLED = "Enabled";
     private const string GROUP_DISABLED = "Disabled";
@@ -23,6 +23,9 @@ public partial class Plugins : ComponentBase
 
     protected override async Task OnInitializedAsync()
     {
+        this.MessageBus.RegisterComponent(this);
+        this.MessageBus.ApplyFilters(this, [], [ Event.PLUGINS_RELOADED ]);
+        
         this.groupConfig = new TableGroupDefinition<IPluginMetadata>
         {
             Expandable = true,
@@ -53,4 +56,27 @@ public partial class Plugins : ComponentBase
         await this.SettingsManager.StoreSettings();
         await this.MessageBus.SendMessage<bool>(this, Event.CONFIGURATION_CHANGED);
     }
+    
+    #region Implementation of IMessageBusReceiver
+
+    public string ComponentName => nameof(Plugins);
+    
+    public Task ProcessMessage<T>(ComponentBase? sendingComponent, Event triggeredEvent, T? data)
+    {
+        switch (triggeredEvent)
+        {
+            case Event.PLUGINS_RELOADED:
+                this.InvokeAsync(this.StateHasChanged);
+                break;
+        }
+        
+        return Task.CompletedTask;
+    }
+
+    public Task<TResult?> ProcessMessageWithResult<TPayload, TResult>(ComponentBase? sendingComponent, Event triggeredEvent, TPayload? data)
+    {
+        return Task.FromResult<TResult?>(default);
+    }
+
+    #endregion
 }

app/MindWork AI Studio/Program.cs

@@ -1,5 +1,6 @@
 using AIStudio.Agents;
 using AIStudio.Settings;
+using AIStudio.Tools.PluginSystem;
 using AIStudio.Tools.Services;
 
 using Microsoft.AspNetCore.Server.Kestrel.Core;
@@ -209,6 +210,7 @@ internal sealed class Program
         await serverTask;
         
         RUST_SERVICE.Dispose();
+        PluginFactory.Dispose();
         programLogger.LogInformation("The AI Studio server was stopped.");
     }
 }

app/MindWork AI Studio/Tools/Event.cs

@@ -8,6 +8,7 @@ public enum Event
     STATE_HAS_CHANGED,
     CONFIGURATION_CHANGED,
     COLOR_THEME_CHANGED,
+    PLUGINS_RELOADED,
     
     // Update events:
     USER_SEARCH_FOR_UPDATE,

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

@@ -0,0 +1,33 @@
+namespace AIStudio.Tools.PluginSystem;
+
+public static partial class PluginFactory
+{
+    public static void SetUpHotReloading()
+    {
+        LOG.LogInformation($"Start hot reloading plugins for path '{HOT_RELOAD_WATCHER.Path}'.");
+        try
+        {
+            var messageBus = Program.SERVICE_PROVIDER.GetRequiredService<MessageBus>();
+        
+            HOT_RELOAD_WATCHER.IncludeSubdirectories = true;
+            HOT_RELOAD_WATCHER.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName;
+            HOT_RELOAD_WATCHER.Filter = "*.lua";
+            HOT_RELOAD_WATCHER.Changed += async (_, args) =>
+            {
+                LOG.LogInformation($"File changed: {args.FullPath}");
+                await LoadAll();
+                await messageBus.SendMessage<bool>(null, Event.PLUGINS_RELOADED);
+            };
+            
+            HOT_RELOAD_WATCHER.EnableRaisingEvents = true;
+        }
+        catch (Exception e)
+        {
+            LOG.LogError(e, "Error while setting up hot reloading.");
+        }
+        finally
+        {
+            LOG.LogInformation("Hot reloading plugins set up.");
+        }
+    }
+}

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

@@ -1,5 +1,3 @@
-using System.Reflection;
-
 using Microsoft.Extensions.FileProviders;
 
 namespace AIStudio.Tools.PluginSystem;

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

@@ -16,6 +16,8 @@ public static partial class PluginFactory
     private static readonly string PLUGINS_ROOT = Path.Join(DATA_DIR, "plugins");
     
     private static readonly string INTERNAL_PLUGINS_ROOT = Path.Join(PLUGINS_ROOT, ".internal");
+    
+    private static readonly FileSystemWatcher HOT_RELOAD_WATCHER = new(PLUGINS_ROOT);
 
     private static readonly List<IPluginMetadata> AVAILABLE_PLUGINS = [];
     
@@ -45,6 +47,8 @@ public static partial class PluginFactory
             return;
         }
         
+        AVAILABLE_PLUGINS.Clear();
+        
         //
         // 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.
@@ -136,4 +140,9 @@ public static partial class PluginFactory
             _ => new NoPlugin("This plugin type is not supported yet. Please try again with a future version of AI Studio.")
         };
     }
+    
+    public static void Dispose()
+    {
+        HOT_RELOAD_WATCHER.Dispose();
+    }
 }

app/MindWork AI Studio/wwwroot/changelog/v0.9.39.md

@@ -2,5 +2,6 @@
 - Added a feature flag for the plugin system. This flag is disabled by default and can be enabled inside the app settings. Please note that this feature is still in development; there are no plugins available yet.
 - Added the Lua library we use for the plugin system to the about page.
 - Added the plugin overview page. This page shows all installed plugins and allows you to enable or disable them. It is only available when the plugin preview feature is enabled.
+- Added hot reloading for plugins. When any plugin is changed, the app will automatically reload the plugin without needing to restart the app.
 - Fixed the preview tooltip component not showing the correct position when used inside a scrollable container.
 - Upgraded to Rust 1.85.1