Added a banner when a user calls just winapp (#187)

<img width="1734" height="1308" alt="image"
src="https://github.com/user-attachments/assets/11e41a90-e541-43ad-8da3-3f32b4f1639e"
/>

---------

Co-authored-by: Nikola Metulev <[email protected]>

Author: nmetulev

src/winapp-CLI/WinApp.Cli/Commands/WinAppRootCommand.cs

@@ -27,7 +27,7 @@ public WinAppRootCommand(
         GetWinappPathCommand getWinappPathCommand,
         CertCommand certCommand,
         SignCommand signCommand,
-        ToolCommand toolCommand) : base("Windows App Development CLI tool")
+        ToolCommand toolCommand) : base("Setup Windows SDK and Windows App SDK for use in your app, create MSIX packages, generate manifests and certificates, and use build tools.")
     {
         Subcommands.Add(initCommand);
         Subcommands.Add(restoreCommand);

src/winapp-CLI/WinApp.Cli/Helpers/BannerHelper.cs

@@ -0,0 +1,117 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using System.Reflection;
+
+namespace WinApp.Cli.Helpers;
+
+/// <summary>
+/// Provides banner display functionality for the CLI.
+/// ASCII art is pre-computed for optimal startup performance.
+/// </summary>
+internal static class BannerHelper
+{
+    // Stylized "winapp" text in block letters
+    private static readonly string[] TitleBlockArt =
+    {
+        @"▄▄              ▀▀                          ",
+        @" ▀█▄    ██   ██ ██  ████▄  ▀▀█▄ ████▄ ████▄ ",
+        @"  ▄█▀   ██ █ ██ ██  ██ ██ ▄█▀██ ██ ██ ██ ██ ",
+        @"▄█▀      ██▀██  ██▄ ██ ██ ▀█▄██ ████▀ ████▀ ",
+        @"                                ██    ██    ",
+        @"                                ▀▀    ▀▀    ",
+    };
+
+    // Simple ASCII fallback for the title
+    private static readonly string[] TitleAsciiArt =
+    {
+        @"           _                          ",
+        @" __      _(_)_ __   __ _ _ __  _ __   ",
+        @" \ \ /\ / / | '_ \ / _` | '_ \| '_ \  ",
+        @"  \ V  V /| | | | | (_| | |_) | |_) | ",
+        @"   \_/\_/ |_|_| |_|\__,_| .__/| .__/  ",
+        @"                        |_|   |_|     ",
+    };
+
+    // ANSI color codes for gradient effect (Blue -> Purple, Windows-themed)
+    private static readonly string[] GradientColors =
+    {
+        "\x1b[38;5;39m",   // Bright Blue
+        "\x1b[38;5;33m",   // Blue
+        "\x1b[38;5;63m",   // Blue-Purple
+        "\x1b[38;5;99m",   // Purple
+        "\x1b[38;5;135m",  // Light Purple
+        "\x1b[38;5;141m",  // Lavender
+    };
+
+    private const string ResetColor = "\x1b[0m";
+
+    /// <summary>
+    /// Displays the CLI banner with version information.
+    /// </summary>
+    public static void DisplayBanner()
+    {
+        var useColor = UiSymbols.UseEmoji; // Same check - modern terminals support both
+        var version = GetVersionString();
+        
+        Console.WriteLine();
+        
+        if (useColor)
+        {
+            DisplayColorBanner(version);
+        }
+        else
+        {
+            DisplayPlainBanner(version);
+        }
+        
+        Console.WriteLine();
+    }
+
+    private static void DisplayColorBanner(string version)
+    {
+        var titleLines = TitleBlockArt;
+        
+        // Display each line with a gradient color
+        for (int i = 0; i < titleLines.Length; i++)
+        {
+            var color = GradientColors[i % GradientColors.Length];
+            Console.WriteLine($"  {color}{titleLines[i]}{ResetColor}");
+        }
+        
+        Console.WriteLine();
+        Console.WriteLine($"  \x1b[90mWindows App Development CLI · Version {version}{ResetColor}");
+    }
+
+    private static void DisplayPlainBanner(string version)
+    {
+        foreach (var line in TitleAsciiArt)
+        {
+            Console.WriteLine($"  {line}");
+        }
+        
+        Console.WriteLine();
+        Console.WriteLine($"  Windows App Development CLI - Version {version}");
+    }
+
+    /// <summary>
+    /// Gets the version string from the assembly.
+    /// </summary>
+    private static string GetVersionString()
+    {
+        var assembly = Assembly.GetExecutingAssembly();
+        
+        // Try to get informational version first (includes git info if available)
+        var infoVersion = assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>()?.InformationalVersion;
+        if (!string.IsNullOrEmpty(infoVersion))
+        {
+            // Remove git hash suffix if present (e.g., "0.1.8+abc123" -> "0.1.8")
+            var plusIndex = infoVersion.IndexOf('+');
+            return plusIndex >= 0 ? infoVersion[..plusIndex] : infoVersion;
+        }
+        
+        // Fall back to assembly version
+        var version = assembly.GetName().Version;
+        return version != null ? $"{version.Major}.{version.Minor}.{version.Build}" : "0.0.0";
+    }
+}

src/winapp-CLI/WinApp.Cli/Program.cs

@@ -66,6 +66,15 @@ static async Task<int> Main(string[] args)
 
         var rootCommand = serviceProvider.GetRequiredService<WinAppRootCommand>();
 
+        // If no arguments provided, display banner and show help
+        if (args.Length == 0)
+        {
+            BannerHelper.DisplayBanner();
+            // Show help by invoking with --help
+            await rootCommand.Parse(["--help"]).InvokeAsync();
+            return 0;
+        }
+
         var parseResult = rootCommand.Parse(args);
 
         try
@@ -76,13 +85,6 @@ static async Task<int> Main(string[] args)
 
             CommandCompletedEvent.Log(parseResult.CommandResult, returnCode);
 
-            if (args.Length == 0)
-            {
-                // Temporary special case: If no arguments are provided, return 0 to indicate success.
-                // This is because winget's validation currently doesn't like us returning failure here.
-                returnCode = 0;
-            }
-
             return returnCode;
         }
         catch (Exception ex)