Display command-line help from Core and extensions

Closes wixtoolset/issues#6211

4 files changed, 54 insertions, 32 deletions

diff --git a/src/WixToolset.Core/CommandLine/CommandLine.cs b/src/WixToolset.Core/CommandLine/CommandLine.cs
index 02bc32e9..5439eb39 100644
--- a/src/WixToolset.Core/CommandLine/CommandLine.cs
+++ b/src/WixToolset.Core/CommandLine/CommandLine.cs
@@ -118,7 +118,7 @@ namespace WixToolset.Core.CommandLine
                 extension.PostParse();
             }
 
-            return command ?? new HelpCommand();
+            return command ?? new HelpCommand(extensions);
         }
 
         private bool TryParseCommand(string arg, ICommandLineParser parser, IEnumerable<IExtensionCommandLine> extensions, out ICommandLineCommand command)
@@ -134,7 +134,7 @@ namespace WixToolset.Core.CommandLine
                     case "h":
                     case "help":
                     case "-help":
-                        command = new HelpCommand();
+                        command = new HelpCommand(extensions);
                         break;
 
                     case "version":
diff --git a/src/WixToolset.Core/CommandLine/CommandLineParser.cs b/src/WixToolset.Core/CommandLine/CommandLineParser.cs
index 11e5751d..2ee1e9ae 100644
--- a/src/WixToolset.Core/CommandLine/CommandLineParser.cs
+++ b/src/WixToolset.Core/CommandLine/CommandLineParser.cs
@@ -27,7 +27,7 @@ namespace WixToolset.Core.CommandLine
 
         public bool IsSwitch(string arg)
         {
-            return !String.IsNullOrEmpty(arg) && ('/' == arg[0] || '-' == arg[0]);
+            return !String.IsNullOrEmpty(arg) && '-' == arg[0];
         }
 
         public string GetArgumentAsFilePathOrError(string argument, string fileType)
@@ -74,7 +74,7 @@ namespace WixToolset.Core.CommandLine
 
         public string GetNextArgumentAsDirectoryOrError(string commandLineSwitch)
         {
-            if (this.TryGetNextNonSwitchArgumentOrError(out var arg) && this.TryGetDirectory(commandLineSwitch, this.Messaging, arg, out var directory))
+            if (this.TryGetNextNonSwitchArgumentOrError(out var arg) && this.TryGetDirectory(commandLineSwitch, arg, out var directory))
             {
                 return directory;
             }
@@ -85,7 +85,7 @@ namespace WixToolset.Core.CommandLine
 
         public bool GetNextArgumentAsDirectoryOrError(string commandLineSwitch, IList<string> directories)
         {
-            if (this.TryGetNextNonSwitchArgumentOrError(out var arg) && this.TryGetDirectory(commandLineSwitch, this.Messaging, arg, out var directory))
+            if (this.TryGetNextNonSwitchArgumentOrError(out var arg) && this.TryGetDirectory(commandLineSwitch, arg, out var directory))
             {
                 directories.Add(directory);
                 return true;
@@ -124,7 +124,14 @@ namespace WixToolset.Core.CommandLine
 
         public bool TryGetNextSwitchOrArgument(out string arg)
         {
-            return TryDequeue(this.RemainingArguments, out arg);
+            if (this.RemainingArguments.Count > 0)
+            {
+                arg = this.RemainingArguments.Dequeue();
+                return true;
+            }
+
+            arg = null;
+            return false;
         }
 
         private bool TryGetNextNonSwitchArgumentOrError(out string arg)
@@ -139,24 +146,7 @@ namespace WixToolset.Core.CommandLine
             return result;
         }
 
-        private static bool IsValidArg(string arg)
-        {
-            return !(String.IsNullOrEmpty(arg) || '/' == arg[0] || '-' == arg[0]);
-        }
-
-        private static bool TryDequeue(Queue<string> q, out string arg)
-        {
-            if (q.Count > 0)
-            {
-                arg = q.Dequeue();
-                return true;
-            }
-
-            arg = null;
-            return false;
-        }
-
-        private bool TryGetDirectory(string commandlineSwitch, IMessaging messageHandler, string arg, out string directory)
+        private bool TryGetDirectory(string commandlineSwitch, string arg, out string directory)
         {
             directory = null;
 
@@ -174,7 +164,7 @@ namespace WixToolset.Core.CommandLine
         {
             path = null;
 
-            if (!IsValidArg(arg))
+            if (String.IsNullOrEmpty(arg) || '-' == arg[0])
             {
                 this.Messaging.Write(ErrorMessages.FilePathRequired(commandlineSwitch));
             }
diff --git a/src/WixToolset.Core/CommandLine/HelpCommand.cs b/src/WixToolset.Core/CommandLine/HelpCommand.cs
index 78845189..3af442aa 100644
--- a/src/WixToolset.Core/CommandLine/HelpCommand.cs
+++ b/src/WixToolset.Core/CommandLine/HelpCommand.cs
@@ -3,27 +3,60 @@
 namespace WixToolset.Core.CommandLine
 {
     using System;
+    using System.Collections.Generic;
+    using System.Linq;
     using System.Threading;
     using System.Threading.Tasks;
+    using WixToolset.Extensibility;
     using WixToolset.Extensibility.Data;
     using WixToolset.Extensibility.Services;
 
     internal class HelpCommand : ICommandLineCommand
     {
+        private static readonly ExtensionCommandLineSwitch[] BuiltInSwitches = new ExtensionCommandLineSwitch[]
+        {
+            new ExtensionCommandLineSwitch { Switch = "build", Description = "Build a wixlib, package or bundle." },
+            new ExtensionCommandLineSwitch { Switch = "decompile", Description = "Decompile a package or bundle into source code." },
+        };
+
+        public HelpCommand(IEnumerable<IExtensionCommandLine> extensions)
+        {
+            this.Extensions = extensions;
+        }
+
         public bool ShowLogo => true;
 
         public bool StopParsing => true;
 
+        private IEnumerable<IExtensionCommandLine> Extensions { get; }
+
         public Task<int> ExecuteAsync(CancellationToken _)
         {
-            Console.WriteLine("TODO: Show list of available commands");
+            var commandLineSwitches = new List<ExtensionCommandLineSwitch>(BuiltInSwitches);
+            commandLineSwitches.AddRange(this.Extensions.SelectMany(e => e.CommandLineSwitches).OrderBy(s => s.Switch, StringComparer.Ordinal));
+
+            Console.WriteLine();
+            Console.WriteLine("Usage: wix [option]");
+            Console.WriteLine("Usage: wix [command]");
+            Console.WriteLine();
+            Console.WriteLine("Options:");
+            Console.WriteLine("  -h|--help         Show command line help.");
+            Console.WriteLine("  --version         Display WiX Toolset version in use.");
+            Console.WriteLine();
+
+            Console.WriteLine("Commands:");
+            foreach (var commandLineSwitch in commandLineSwitches)
+            {
+                Console.WriteLine("  {0,-17} {1}", commandLineSwitch.Switch, commandLineSwitch.Description);
+            }
+
+            Console.WriteLine();
+            Console.WriteLine("Run 'wix [command] --help' for more information on a command.");
+            AppCommon.DisplayToolFooter();
 
             return Task.FromResult(-1);
         }
 
-        public bool TryParseArgument(ICommandLineParser parseHelper, string argument)
-        {
-            return true; // eat any arguments
-        }
+        public bool TryParseArgument(ICommandLineParser parseHelper, string argument) => true; // eat any arguments
     }
 }
diff --git a/src/WixToolset.Core/CommandLine/VersionCommand.cs b/src/WixToolset.Core/CommandLine/VersionCommand.cs
index 6ce2a89d..01a7d0e6 100644
--- a/src/WixToolset.Core/CommandLine/VersionCommand.cs
+++ b/src/WixToolset.Core/CommandLine/VersionCommand.cs
@@ -16,8 +16,7 @@ namespace WixToolset.Core.CommandLine
 
         public Task<int> ExecuteAsync(CancellationToken cancellationToken)
         {
-            Console.WriteLine("wix version {0}", ThisAssembly.AssemblyInformationalVersion);
-            Console.WriteLine();
+            Console.WriteLine(ThisAssembly.AssemblyInformationalVersion);
 
             return Task.FromResult(0);
         }