Show relevant error for invalid command line args.

Also fixes the unreported but apparently broken error display for other errors, like invalid games. The originally-caught exceptions were nested in an Autofac exception and have to be unwrapped to restore the original behavior.

Fixes #127

Focus.Apps.EasyNpc/App.xaml.cs

@@ -1,12 +1,16 @@
 using Autofac;
+using Autofac.Core;
 using CommandLine;
+using CommandLine.Text;
 using Focus.Apps.EasyNpc.Configuration;
 using Focus.Apps.EasyNpc.Main;
 using Focus.Apps.EasyNpc.Reports;
 using Focus.ModManagers;
 using Serilog;
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Windows;
 
 namespace Focus.Apps.EasyNpc
@@ -16,11 +20,21 @@ namespace Focus.Apps.EasyNpc
     /// </summary>
     public partial class App : Application
     {
+        private IDisposable? container;
+
         private void Application_Startup(object sender, StartupEventArgs e)
         {
             Console.WriteLine("Application started");
             Parser.Default.ParseArguments<CommandLineOptions>(e.Args)
-                .WithParsed(Start);
+                .WithParsed(Start)
+                .WithNotParsed(DisplayErrors);
+        }
+
+        private void DisplayErrors(IEnumerable<Error> errors)
+        {
+            var sentenceBuilder = SentenceBuilder.Create();
+            var errorMessages = errors.Select(e => sentenceBuilder.FormatError(e));
+            Warn(StartupWarnings.InvalidCommandLine(errorMessages), true);
         }
 
         private void Start(CommandLineOptions options)
@@ -36,46 +50,51 @@ private void Start(CommandLineOptions options)
             if (isVortex && string.IsNullOrEmpty(options.VortexManifest) &&
                 !Warn(StartupWarnings.MissingVortexManifest))
             {
-                Current.Shutdown();
                 return;
             }
 
             var container = AppContainer.Build(options, startupInfo);
+            this.container = container;
             var logger = container.Resolve<ILogger>();
             var mainWindow = MainWindow = new MainWindow(logger, container);
             if (isFirstLaunch && string.IsNullOrEmpty(Settings.Default.DefaultModRootDirectory))
                 Settings.Default.DefaultModRootDirectory = container.Resolve<IModManagerConfiguration>().ModsDirectory;
             try
             {
-                if (options.PostBuild)
+                try
                 {
-                    var postBuildReportViewModel = container.Resolve<PostBuildReportViewModel>();
-                    mainWindow.DataContext = postBuildReportViewModel;
-                    _ = postBuildReportViewModel.UpdateReport();
+                    if (options.PostBuild)
+                    {
+                        var postBuildReportViewModel = container.Resolve<PostBuildReportViewModel>();
+                        mainWindow.DataContext = postBuildReportViewModel;
+                        _ = postBuildReportViewModel.UpdateReport();
+                    }
+                    else
+                    {
+                        var mainViewModelFactory = container.Resolve<MainViewModel.Factory>();
+                        var mainViewModel = mainViewModelFactory(isFirstLaunch);
+                        mainWindow.DataContext = mainViewModel;
+                    }
                 }
-                else
+                catch (DependencyResolutionException ex)
                 {
-                    var mainViewModelFactory = container.Resolve<MainViewModel.Factory>();
-                    var mainViewModel = mainViewModelFactory(isFirstLaunch);
-                    mainWindow.DataContext = mainViewModel;
+                    if (ex.InnerException is not null)
+                        throw ex.InnerException;
+                    throw;
                 }
                 mainWindow.Show();
             }
             catch (MissingGameDataException ex)
             {
                 Warn(StartupWarnings.MissingGameData(ex.GameId, ex.GameName), true);
-                container.Dispose();
-                Current.Shutdown();
             }
             catch (UnsupportedGameException ex)
             {
                 Warn(StartupWarnings.UnsupportedGame(ex.GameId, ex.GameName), true);
-                container.Dispose();
-                Current.Shutdown();
             }
         }
 
-        private static bool Warn(StartupWarning warning, bool isFatal = false)
+        private bool Warn(StartupWarning warning, bool isFatal = false)
         {
             var model = new StartupWarningViewModel
             {
@@ -87,7 +106,13 @@ private static bool Warn(StartupWarning warning, bool isFatal = false)
             {
                 DataContext = model
             };
-            return warningWindow.ShowDialog() == true;
+            var ignored = warningWindow.ShowDialog() == true;
+            if (!ignored)
+            {
+                container?.Dispose();
+                Current.Shutdown();
+            }
+            return ignored;
         }
     }
 }

Focus.Apps.EasyNpc/Main/StartupWarningWindow.xaml

@@ -48,6 +48,25 @@
                         </ControlTemplate>
                         <Style x:Key="ListItemStyle" TargetType="TextBlock" BasedOn="{StaticResource ParagraphStyle}"/>
 
+                        <DataTemplate DataType="{x:Type main:InvalidCommandLineContent}">
+                            <ui:SimpleStackPanel>
+                                <TextBlock Style="{StaticResource ParagraphStyle}">
+                                    <Run Text="{StaticResource AppName}"/> was started with invalid command-line arguments and cannot continue. The errors are listed below.
+                                </TextBlock>
+                                <ItemsControl ItemsSource="{Binding ErrorMessages}">
+                                    <ItemsControl.ItemTemplate>
+                                        <DataTemplate>
+                                            <ContentControl Template="{StaticResource ListItem}" Tag="•">
+                                                <TextBlock Style="{StaticResource FirstParagraphStyle}" Text="{Binding}"/>
+                                            </ContentControl>
+                                        </DataTemplate>
+                                    </ItemsControl.ItemTemplate>
+                                </ItemsControl>
+                                <TextBlock Style="{StaticResource ParagraphStyle}">
+                                    Please correct these settings in your mod manager and restart the app.
+                                </TextBlock>
+                            </ui:SimpleStackPanel>
+                        </DataTemplate>
                         <DataTemplate DataType="{x:Type main:MissingVortexManifestContent}">
                             <ui:SimpleStackPanel>
                                 <TextBlock Style="{StaticResource ParagraphStyle}">

Focus.Apps.EasyNpc/Main/StartupWarnings.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 
 namespace Focus.Apps.EasyNpc.Main
 {
@@ -16,6 +18,12 @@ public class StartupWarnings
             Description = new MissingVortexManifestContent(),
         };
 
+        public static StartupWarning InvalidCommandLine(IEnumerable<string> errorMessages) => new()
+        {
+            Title = "Invalid options",
+            Description = new InvalidCommandLineContent { ErrorMessages = errorMessages },
+        };
+
         public static StartupWarning MissingGameData(string gameId, string gameName) => new()
         {
             Title = "Game not found",
@@ -29,6 +37,11 @@ public class StartupWarnings
         };
     }
 
+    public class InvalidCommandLineContent
+    {
+        public IEnumerable<string> ErrorMessages { get; init; } = Enumerable.Empty<string>();
+    }
+
     public class MissingVortexManifestContent
     {
         public string ExtensionUrl { get; private init; } = "https://www.nexusmods.com/site/mods/265";