CmdPal: Refactor TopLevelCommandManager to use IExtensionService implementations

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/BuiltInsCommandProvider.cs

@@ -2,6 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using Microsoft.CmdPal.UI.ViewModels.Commands;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
@@ -18,8 +19,7 @@ public sealed partial class BuiltInsCommandProvider : CommandProvider
     private readonly FallbackReloadItem _fallbackReloadItem = new();
     private readonly FallbackLogItem _fallbackLogItem = new();
     private readonly NewExtensionPage _newExtension = new();
-
-    private readonly IRootPageService _rootPageService;
+    private readonly GoHomeDockCommand _goHomeDockCommand = new();
 
     public override ICommandItem[] TopLevelCommands() =>
         [
@@ -41,22 +41,16 @@ public override IFallbackCommandItem[] FallbackCommands() =>
             _fallbackLogItem,
         ];
 
-    public BuiltInsCommandProvider(IRootPageService rootPageService)
+    public BuiltInsCommandProvider()
     {
         Id = "com.microsoft.cmdpal.builtin.core";
         DisplayName = Properties.Resources.builtin_display_name;
         Icon = IconHelpers.FromRelativePath("Assets\\Square44x44Logo.altform-unplated_targetsize-256.png");
-
-        _rootPageService = rootPageService;
     }
 
     public override ICommandItem[]? GetDockBands()
     {
-        var rootPage = _rootPageService.GetRootPage();
-        List<ICommandItem> bandItems = new();
-        bandItems.Add(new WrappedDockItem(rootPage, Properties.Resources.builtin_command_palette_title));
-
-        return bandItems.ToArray();
+        return [new WrappedDockItem(_goHomeDockCommand, Properties.Resources.builtin_command_palette_title)];
     }
 
     public override void InitializeWithHost(IExtensionHost host) => BuiltinsExtensionHost.Instance.Initialize(host);

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/GoHomeDockCommand.cs

@@ -0,0 +1,23 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+
+namespace Microsoft.CmdPal.UI.ViewModels.Commands;
+
+/// <summary>
+/// A lightweight command used as a dock band item that navigates the user
+/// back to the Command Palette home page when invoked.
+/// </summary>
+internal sealed partial class GoHomeDockCommand : InvokableCommand
+{
+    public GoHomeDockCommand()
+    {
+        Name = Properties.Resources.builtin_command_palette_title;
+        Icon = IconHelpers.FromRelativePath("Assets\\Square44x44Logo.altform-unplated_targetsize-256.png");
+    }
+
+    public override ICommandResult Invoke() => CommandResult.GoHome();
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Gallery/ExtensionGalleryViewModel.cs

@@ -13,6 +13,7 @@
 using Microsoft.CmdPal.Common.WinGet.Models;
 using Microsoft.CmdPal.Common.WinGet.Services;
 using Microsoft.CmdPal.UI.ViewModels.Properties;
+using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 using Microsoft.Extensions.Logging;
 
@@ -50,7 +51,7 @@ private static readonly CompositeFormat LabelGalleryExtensionsFound
             "Failed to check WinGet package status");
 
     private readonly IExtensionGalleryService _galleryService;
-    private readonly IExtensionService _extensionService;
+    private readonly IEnumerable<IExtensionService> _extensionServices;
     private readonly ILogger<ExtensionGalleryViewModel> _logger;
     private readonly ExtensionGalleryItemViewModelFactory _galleryExtensionViewModelFactory;
     private readonly IWinGetPackageManagerService? _winGetPackageManagerService;
@@ -162,7 +163,7 @@ public string ItemCounterText
 
     public ExtensionGalleryViewModel(
         IExtensionGalleryService galleryService,
-        IExtensionService extensionService,
+        IEnumerable<IExtensionService> extensionServices,
         ILogger<ExtensionGalleryViewModel> logger,
         ExtensionGalleryItemViewModelFactory galleryExtensionViewModelFactory,
         IWinGetPackageManagerService? winGetPackageManagerService = null,
@@ -171,7 +172,7 @@ public ExtensionGalleryViewModel(
         TaskScheduler? uiScheduler = null)
     {
         _galleryService = galleryService;
-        _extensionService = extensionService;
+        _extensionServices = extensionServices;
         _logger = logger;
         _galleryExtensionViewModelFactory = galleryExtensionViewModelFactory;
         _winGetPackageManagerService = winGetPackageManagerService;
@@ -347,17 +348,23 @@ private async Task CheckInstalledAsync(
         List<ExtensionGalleryItemViewModel> snapshot;
         try
         {
-            var installedExtensions = refreshInstalledExtensions
-                ? await RunInBackgroundAsync(
-                    () => _extensionService.RefreshInstalledExtensionsAsync(includeDisabledExtensions: true),
-                    cancellationToken)
-                : await RunInBackgroundAsync(
-                    () => _extensionService.GetInstalledExtensionsAsync(includeDisabledExtensions: true),
-                    cancellationToken);
+            var allInstalledExtensions = new List<Common.Services.IExtensionWrapper>();
+            foreach (var service in _extensionServices)
+            {
+                var extensions = refreshInstalledExtensions
+                    ? await RunInBackgroundAsync(
+                        () => service.RefreshInstalledExtensionsAsync(includeDisabledExtensions: true),
+                        cancellationToken)
+                    : await RunInBackgroundAsync(
+                        () => service.GetInstalledExtensionsAsync(includeDisabledExtensions: true),
+                        cancellationToken);
+                allInstalledExtensions.AddRange(extensions);
+            }
+
             cancellationToken.ThrowIfCancellationRequested();
 
             var installedPfns = new HashSet<string>(
-                installedExtensions
+                allInstalledExtensions
                     .Select(e => e.PackageFamilyName)
                     .Where(pfn => !string.IsNullOrEmpty(pfn)),
                 StringComparer.OrdinalIgnoreCase);

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Services/BuiltInExtensionService.cs

@@ -0,0 +1,77 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Common.Services;
+using Microsoft.CommandPalette.Extensions;
+using Windows.Foundation;
+
+namespace Microsoft.CmdPal.UI.ViewModels.Services;
+
+/// <summary>
+/// Extension service that manages in-process built-in command providers
+/// registered in the DI container as <see cref="ICommandProvider"/>.
+/// </summary>
+public sealed class BuiltInExtensionService : IExtensionService
+{
+    private readonly IEnumerable<ICommandProvider> _commandProviders;
+    private readonly TaskScheduler _taskScheduler;
+    private readonly List<IExtensionWrapper> _wrappers = [];
+
+#pragma warning disable CS0067 // Events are required by the interface but not raised by this implementation
+    public event TypedEventHandler<IExtensionService, IEnumerable<CommandProviderWrapper>>? OnProviderAdded;
+
+    public event TypedEventHandler<IExtensionService, IEnumerable<CommandProviderWrapper>>? OnProviderRemoved;
+#pragma warning restore CS0067
+
+    public BuiltInExtensionService(IEnumerable<ICommandProvider> commandProviders, TaskScheduler taskScheduler)
+    {
+        _commandProviders = commandProviders;
+        _taskScheduler = taskScheduler;
+    }
+
+    public Task<IEnumerable<CommandProviderWrapper>> LoadProvidersAsync(CancellationToken ct)
+    {
+        ct.ThrowIfCancellationRequested();
+
+        var wrappers = new List<CommandProviderWrapper>();
+        foreach (var provider in _commandProviders)
+        {
+            wrappers.Add(new CommandProviderWrapper(provider, _taskScheduler));
+        }
+
+        return Task.FromResult<IEnumerable<CommandProviderWrapper>>(wrappers);
+    }
+
+    public Task SignalStopAsync()
+    {
+        // Built-in providers are in-proc and don't need explicit stop signaling.
+        return Task.CompletedTask;
+    }
+
+    public Task<IEnumerable<IExtensionWrapper>> GetInstalledExtensionsAsync(bool includeDisabledExtensions = false)
+    {
+        return Task.FromResult<IEnumerable<IExtensionWrapper>>(_wrappers);
+    }
+
+    public Task<IEnumerable<IExtensionWrapper>> RefreshInstalledExtensionsAsync(bool includeDisabledExtensions = false)
+    {
+        // Built-in set is fixed at startup; refresh is a no-op.
+        return GetInstalledExtensionsAsync(includeDisabledExtensions);
+    }
+
+    public IExtensionWrapper? GetInstalledExtension(string extensionUniqueId)
+    {
+        return _wrappers.FirstOrDefault(w => w.ExtensionUniqueId == extensionUniqueId);
+    }
+
+    public void EnableExtension(string extensionUniqueId)
+    {
+        // TODO: persist enabled state in settings
+    }
+
+    public void DisableExtension(string extensionUniqueId)
+    {
+        // TODO: persist disabled state in settings
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Services/IExtensionService.cs

@@ -0,0 +1,67 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Common.Services;
+using Windows.Foundation;
+
+namespace Microsoft.CmdPal.UI.ViewModels.Services;
+
+public interface IExtensionService
+{
+    /// <summary>
+    /// Loads command providers managed by this service. Returns providers that
+    /// are immediately ready. Slow or late providers arrive via <see cref="OnProviderAdded"/>.
+    /// </summary>
+    /// <param name="ct">Cancellation token owned by the caller to cancel in-flight loading.</param>
+    /// <returns>Command provider wrappers that are started and ready for command loading.</returns>
+    Task<IEnumerable<CommandProviderWrapper>> LoadProvidersAsync(CancellationToken ct);
+
+    /// <summary>
+    /// Signals running providers managed by this service to stop/dispose.
+    /// </summary>
+    Task SignalStopAsync();
+
+    /// <summary>
+    /// Gets the currently cached installed extensions managed by this service.
+    /// </summary>
+    /// <param name="includeDisabledExtensions">True to include disabled extensions in the result.</param>
+    /// <returns>A sequence of installed extensions from the current in-memory cache.</returns>
+    Task<IEnumerable<IExtensionWrapper>> GetInstalledExtensionsAsync(bool includeDisabledExtensions = false);
+
+    /// <summary>
+    /// Forces a fresh scan of installed extensions and updates the in-memory cache.
+    /// </summary>
+    /// <param name="includeDisabledExtensions">True to include disabled extensions in the result.</param>
+    /// <returns>A sequence of installed extensions after the cache has been rebuilt.</returns>
+    Task<IEnumerable<IExtensionWrapper>> RefreshInstalledExtensionsAsync(bool includeDisabledExtensions = false);
+
+    /// <summary>
+    /// Gets a cached installed extension by its unique id.
+    /// </summary>
+    /// <param name="extensionUniqueId">The unique id of the extension to look up.</param>
+    /// <returns>The cached extension if found; otherwise, null.</returns>
+    IExtensionWrapper? GetInstalledExtension(string extensionUniqueId);
+
+    /// <summary>
+    /// Enables an installed extension by unique id.
+    /// </summary>
+    /// <param name="extensionUniqueId">The unique id of the extension to enable.</param>
+    void EnableExtension(string extensionUniqueId);
+
+    /// <summary>
+    /// Disables an installed extension by unique id.
+    /// </summary>
+    /// <param name="extensionUniqueId">The unique id of the extension to disable.</param>
+    void DisableExtension(string extensionUniqueId);
+
+    /// <summary>
+    /// Raised when one or more providers become available (late start, new package install, etc.).
+    /// </summary>
+    event TypedEventHandler<IExtensionService, IEnumerable<CommandProviderWrapper>>? OnProviderAdded;
+
+    /// <summary>
+    /// Raised when one or more providers are removed (package uninstall, etc.).
+    /// </summary>
+    event TypedEventHandler<IExtensionService, IEnumerable<CommandProviderWrapper>>? OnProviderRemoved;
+}