From 504c75692a997791c1ed89d2d40478b0476ca8e6 Mon Sep 17 00:00:00 2001
From: Johnny Shaw <johnny.shaw@live.com>
Date: Wed, 3 May 2023 19:05:37 -0600
Subject: [PATCH] better missing feature handling

---
 VMPlex/App.xaml.cs | 59 ++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 52 insertions(+), 7 deletions(-)

diff --git a/VMPlex/App.xaml.cs b/VMPlex/App.xaml.cs
index 2010b72..f7eea39 100644
--- a/VMPlex/App.xaml.cs
+++ b/VMPlex/App.xaml.cs
@@ -30,25 +30,70 @@ static private void CheckCapability()
             // Before we show any other windows check that we can access the
             // management service, if we can't then exit.
             //
-            bool capable = false;
+            var state = GetVsmsState();
+            if (state == VsmsState.NoPermission)
+            {
+                UI.MessageBox.Show(
+                   System.Windows.MessageBoxImage.Error,
+                    "Virtual System Management",
+                    "VMPlex is unable to interact with the Virtual Machine Management Service. " +
+                    "Please run as administrator or add your user to the Hyper-V Administrators group.");
+                Environment.Exit(0xdead);
+            }
+            else if (state == VsmsState.NotInstalled)
+            {
+                var res = UI.MessageBox.Show(
+                    System.Windows.MessageBoxImage.Error,
+                    "Virtual System Management",
+                    "VMPlex is unable to interact with the Virtual Machine Management Service. " +
+                    "Please ensure that Windows Hyper-V is enabled on this machine. " +
+                    "Open Windows Optional Features now?",
+                    MessageBoxButton.YesNo);
+                if (res == MessageBoxResult.Yes)
+                {
+                    LaunchOptionalFeaturesDialog();
+                }
+                Environment.Exit(0xdead);
+            }
+        }
+
+        private enum VsmsState
+        {
+            Ok,
+            NoPermission,
+            NotInstalled,
+        }
+
+        static private VsmsState GetVsmsState()
+        {
             try
             {
                 var vsms = new WmiScope(@"root\virtualization\v2")
                     .GetInstance<IMsvm_VirtualSystemManagementService>();
-                capable = (vsms != null);
+                return vsms != null ? VsmsState.Ok : VsmsState.NoPermission;
             }
             catch
             {
+                return VsmsState.NotInstalled;
             }
+        }
 
-            if (!capable)
+        static private void LaunchOptionalFeaturesDialog()
+        {
+            try
+            {
+                var p = new Process();
+                p.StartInfo.FileName = "OptionalFeatures.exe";
+                p.StartInfo.UseShellExecute = true;
+                p.Start();
+            }
+            catch (Exception ex)
             {
                 UI.MessageBox.Show(
                    System.Windows.MessageBoxImage.Error,
-                    "Virtual System Management",
-                    "VMPlex is unable to interact with the Virtual Machine Management Service. " +
-                    "Please run as administrator or add your user to the Hyper-V Administrators group.");
-                Environment.Exit(0xdead);
+                    "VMPlex Workstation",
+                    "Failed to launch OptionalFeatures.exe\n\n" +
+                    ex.Message);
             }
         }