Improving performance of Adding and Removing Packaged Apps (#4521) (#4900)

* Merging in Theme changes and moving win32Tests to Microsoft.Plugin.Program.UnitTests

* Fixing message format for exception

* Changing test structure.  Need to add unit tests.

* Updating packagerepository comment based on pr feedback

* Fixing potential race condition in ListRepository.  Now internally implemented as a concurrent dictionary.

* Removing unecessary implementation of IRepository interface as this is implemented by the base class.

* Restoring checks for invalid uwp apps based on PR feedback. This was accidentally removed when moving the initialize outside the constructor.

* Fixing comments

* Adding newline to end of file for IProgramRepository

src/modules/launcher/Plugins/Microsoft.Plugin.Program/Storage/IProgramRepository.cs

@@ -0,0 +1,11 @@
+using Windows.ApplicationModel;
+
+namespace Microsoft.Plugin.Program.Storage
+{
+    internal interface IProgramRepository
+    {
+        void IndexPrograms();
+        void Load();
+        void Save();
+    }
+}

src/modules/launcher/Plugins/Microsoft.Plugin.Program/Storage/PackageRepository.cs

@@ -0,0 +1,89 @@
+using Microsoft.Plugin.Program.Logger;
+using Microsoft.Plugin.Program.Programs;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Windows.ApplicationModel;
+using Wox.Infrastructure.Storage;
+
+namespace Microsoft.Plugin.Program.Storage
+{
+    /// <summary>
+    /// A repository for storing packaged applications such as UWP apps or appx packaged desktop apps.
+    /// This repository will also monitor for changes to the PackageCatelog and update the repository accordingly
+    /// </summary>
+    internal class PackageRepository : ListRepository<UWP.Application>, IProgramRepository
+    {
+        private IStorage<IList<UWP.Application>> _storage;
+
+        private IPackageCatalog _packageCatalog;
+        public PackageRepository(IPackageCatalog packageCatalog, IStorage<IList<UWP.Application>> storage)
+        {
+            _storage = storage ?? throw new ArgumentNullException("storage", "StorageRepository requires an initialized storage interface");
+            _packageCatalog = packageCatalog ?? throw new ArgumentNullException("packageCatalog", "PackageRepository expects an interface to be able to subscribe to package events");
+            _packageCatalog.PackageInstalling += OnPackageInstalling;
+            _packageCatalog.PackageUninstalling += OnPackageUninstalling;
+        }
+
+        public void OnPackageInstalling(PackageCatalog p, PackageInstallingEventArgs args)
+        {
+            if (args.IsComplete)
+            {
+
+                try
+                {
+                    var uwp = new UWP(args.Package);
+                    uwp.InitializeAppInfo(args.Package.InstalledLocation.Path);
+                    foreach (var app in uwp.Apps)
+                    {
+                        Add(app);
+                    }
+                }
+                //InitializeAppInfo will throw if there is no AppxManifest.xml for the package. 
+                //Note there are sometimes multiple packages per product and this doesn't necessarily mean that we haven't found the app.
+                //eg. "Could not find file 'C:\\Program Files\\WindowsApps\\Microsoft.WindowsTerminalPreview_2020.616.45.0_neutral_~_8wekyb3d8bbwe\\AppxManifest.xml'."
+
+                catch (System.IO.FileNotFoundException e)
+                {
+                    ProgramLogger.LogException($"|UWP|OnPackageInstalling|{args.Package.InstalledLocation}|{e.Message}", e);
+                }
+            }
+        }
+
+        public void OnPackageUninstalling(PackageCatalog p, PackageUninstallingEventArgs args)
+        {
+            if (args.Progress == 0)
+            {
+                //find apps associated with this package. 
+                var uwp = new UWP(args.Package);
+                var apps = Items.Where(a => a.Package.Equals(uwp)).ToArray();
+                foreach (var app in apps)
+                {
+                    Remove(app);
+                }
+            }
+        }
+
+        public void IndexPrograms()
+        {
+            var windows10 = new Version(10, 0);
+            var support = Environment.OSVersion.Version.Major >= windows10.Major;
+
+            var applications = support ? Programs.UWP.All() : new Programs.UWP.Application[] { };
+            Set(applications);
+        }
+
+        public void Save()
+        {
+            _storage.Save(Items);
+        }
+
+        public void Load()
+        {
+            var items = _storage.TryLoad(new Programs.UWP.Application[] { });
+            Set(items);
+        }
+    }
+}