bilal-fazlani · drewburlingame · May 27, 2020
diff --git a/CommandDotNet.Example/CommandDotNet.Example.csproj b/CommandDotNet.Example/CommandDotNet.Example.csproj
@@ -8,6 +8,7 @@
     <ProjectReference Include="..\CommandDotNet.FluentValidation\CommandDotNet.FluentValidation.csproj" />
     <ProjectReference Include="..\CommandDotNet.NewerReleasesAlerts\CommandDotNet.NewerReleasesAlerts.csproj" />
     <ProjectReference Include="..\CommandDotNet.NameCasing\CommandDotNet.NameCasing.csproj" />
+    <ProjectReference Include="..\CommandDotNet.ReadLineRepl\CommandDotNet.ReadLineRepl.csproj" />
     <ProjectReference Include="..\CommandDotNet\CommandDotNet.csproj" />
   </ItemGroup>
   <ItemGroup>

diff --git a/CommandDotNet.Example/Examples.cs b/CommandDotNet.Example/Examples.cs
@@ -14,27 +14,6 @@ namespace CommandDotNet.Example
                            "Example: %AppName% [debug] [parse] [log:info] cancel-me")]
     internal class Examples
     {
-        private static bool _inSession;
-
-        [DefaultMethod]
-        public void StartSession(
-            CommandContext context,
-            InteractiveSession interactiveSession, 
-            [Option(ShortName = "i")] bool interactive)
-        {
-            if (interactive && !_inSession)
-            {
-                context.Console.WriteLine("start session");
-                _inSession = true;
-                interactiveSession.Start();
-            }
-            else
-            {
-                context.Console.WriteLine($"no session {interactive} {_inSession}");
-                context.ShowHelpOnExit = true;
-            }
-        }
-
         [SubCommand]
         public Git Git { get; set; } = null!;
 

diff --git a/CommandDotNet.Example/InteractiveMiddleware.cs b/CommandDotNet.Example/InteractiveMiddleware.cs
diff --git a/CommandDotNet.Example/Program.cs b/CommandDotNet.Example/Program.cs
@@ -2,6 +2,7 @@
 using CommandDotNet.Diagnostics;
 using CommandDotNet.FluentValidation;
 using CommandDotNet.NameCasing;
+using CommandDotNet.ReadLineRepl;
 
 namespace CommandDotNet.Example
 {
@@ -24,7 +25,7 @@ public static AppRunner GetAppRunner(NameValueCollection? appSettings = null)
                 .UseLog2ConsoleDirective()
                 .UseNameCasing(Case.KebabCase)
                 .UseFluentValidation()
-                .UseInteractiveMode("Example")
+                .UseRepl(replConfig: new ReplConfig {AppName = "Example", ReplOption = {LongName = "interactive", ShortName = 'i'}})
                 .UseDefaultsFromAppSetting(appSettings, includeNamingConventions: true);
         }
     }

diff --git a/CommandDotNet.ReadLineRepl/CommandDotNet.ReadLineRepl.csproj b/CommandDotNet.ReadLineRepl/CommandDotNet.ReadLineRepl.csproj
@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <AssemblyTitle>CommandDotNet.ReadLineRepl</AssemblyTitle>
+        <Description>Provides an interactive session using the GNU style readline package</Description>
+    </PropertyGroup>
+    <ItemGroup>
+        <Compile Remove="output\**" />
+    </ItemGroup>
+    <ItemGroup>
+        <EmbeddedResource Remove="output\**" />
+    </ItemGroup>
+    <ItemGroup>
+        <None Remove="output\**" />
+    </ItemGroup>
+    <ItemGroup>
+        <PackageReference Include="ReadLine" Version="2.0.1" />
+        <PackageReference Include="Nullable" Version="1.2.1">
+            <PrivateAssets>all</PrivateAssets>
+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+        </PackageReference>
+    </ItemGroup>
+    <ItemGroup>
+        <ProjectReference Include="..\CommandDotNet\CommandDotNet.csproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/CommandDotNet.ReadLineRepl/MiddlewareSteps.cs b/CommandDotNet.ReadLineRepl/MiddlewareSteps.cs
@@ -0,0 +1,9 @@
+using CommandDotNet.Execution;
+
+namespace CommandDotNet.ReadLineRepl
+{
+    public static class MiddlewareSteps
+    {
+        public static MiddlewareStep ReplSession { get; } = CommandDotNet.Execution.MiddlewareSteps.Help.CheckIfShouldShowHelp - 1000;
+    }
+}
diff --git a/CommandDotNet.ReadLineRepl/ReplConfig.cs b/CommandDotNet.ReadLineRepl/ReplConfig.cs
@@ -0,0 +1,51 @@
+using System;
+using CommandDotNet.Builders;
+
+namespace CommandDotNet.ReadLineRepl
+{
+    public class ReplConfig
+    {
+        private Func<CommandContext, string>? _sessionInitMessage;
+        private Func<CommandContext, string>? _sessionHelpMessage;
+
+        public string? AppName { get; set; }
+
+        public ReplOption ReplOption { get; set; } = new ReplOption();
+
+        public Func<CommandContext, string> GetSessionInitMessage
+        {
+            get => _sessionInitMessage ?? BuildSessionInit ;
+            set => _sessionInitMessage = value ?? throw new ArgumentNullException(nameof(value));
+        }
+
+
+        public Func<CommandContext, string> GetSessionHelpMessage
+        {
+            get => _sessionHelpMessage ?? BuildSessionHelp;
+            set => _sessionHelpMessage = value ?? throw new ArgumentNullException(nameof(value));
+        }
+
+        private string BuildSessionInit(CommandContext context)
+        {
+            var appInfo = AppInfo.GetAppInfo();
+            return @$"{AppName ?? appInfo.FileName} {appInfo.Version}
+Type 'help' to see interactive options
+{BuildSessionHelp(context)}";
+        }
+
+        private string BuildSessionHelp(CommandContext context)
+        {
+            return @"Type '-h' or '--help' for the list of commands
+Type 'exit', 'quit' or 'Ctrl+C + Enter' to exit.";
+        }
+    }
+
+    public class ReplOption
+    {
+        public string? LongName { get; set; }
+        public char? ShortName { get; set; }
+        public string? Description { get; set; }
+
+        internal bool IsRequested => LongName is { } || ShortName is { };
+    }
+}
diff --git a/CommandDotNet.ReadLineRepl/ReplMiddleware.cs b/CommandDotNet.ReadLineRepl/ReplMiddleware.cs
@@ -0,0 +1,82 @@
+using System;
+using System.Threading.Tasks;
+using CommandDotNet.Execution;
+
+namespace CommandDotNet.ReadLineRepl
+{
+    public static class ReplMiddleware
+    {
+        public static AppRunner UseRepl(this AppRunner appRunner, ReplConfig? replConfig = null)
+        {
+            ReadLine.HistoryEnabled = true;
+
+            replConfig ??= new ReplConfig();
+            return appRunner.Configure(c =>
+            {
+                c.UseMiddleware(ReplSession, MiddlewareSteps.ReplSession);
+                // use the existing appRunner to reuse the configuration.
+                c.UseParameterResolver(ctx => new ReplSession(appRunner, replConfig, ctx));
+
+                var config = new Config(appRunner, replConfig);
+                c.Services.Add(config);
+
+                var replOption = replConfig.ReplOption;
+                if (replOption?.IsRequested ?? false)
+                {
+                    var option = new Option(replOption!.LongName, replOption.ShortName, TypeInfo.Flag, ArgumentArity.Zero)
+                    {
+                        Description = replOption.Description
+                    };
+                    config.Option = option;
+
+                    c.BuildEvents.OnCommandCreated += args =>
+                    {
+                        var builder = args.CommandBuilder;
+
+                        // do not include option if already in a session
+                        if (!config.InSession && builder.Command.IsRootCommand())
+                        {
+                            builder.AddArgument(option);
+                        }
+                    };
+                }
+            });
+        }
+
+        private class Config
+        {
+            public AppRunner AppRunner { get; }
+            public ReplConfig ReplConfig { get; }
+            public bool InSession { get; set; }
+            public Option? Option { get; set; }
+
+            public Config(AppRunner appRunner, ReplConfig replConfig)
+            {
+                AppRunner = appRunner ?? throw new ArgumentNullException(nameof(appRunner));
+                ReplConfig = replConfig ?? throw new ArgumentNullException(nameof(replConfig));
+            }
+        }
+
+        private static Task<int> ReplSession(CommandContext ctx, ExecutionDelegate next)
+        {
+            var parseResult = ctx.ParseResult!;
+            var cmd = parseResult.TargetCommand;
+            if (cmd.IsRootCommand() 
+                && !cmd.IsExecutable 
+                && parseResult.ParseError is null 
+                && !parseResult.HelpWasRequested())
+            {
+                var config = ctx.AppConfig.Services.GetOrThrow<Config>();
+                var option = config.Option;
+                if (!config.InSession && (option is null || cmd.HasInputValues(option.Name)))
+                {
+                    config.InSession = true;
+                    new ReplSession(config.AppRunner, config.ReplConfig, ctx).Start();
+                    return ExitCodes.Success;
+                }
+            }
+
+            return next(ctx);
+        }
+    }
+}
diff --git a/CommandDotNet.Example/InteractiveSession.cs → CommandDotNet.ReadLineRepl/ReplSession.cs b/CommandDotNet.Example/InteractiveSession.cs → CommandDotNet.ReadLineRepl/ReplSession.cs
@@ -1,20 +1,19 @@
 using System;
 using System.Linq;
-using CommandDotNet.Builders;
 using CommandDotNet.Tokens;
 
-namespace CommandDotNet.Example
+namespace CommandDotNet.ReadLineRepl
 {
-    public class InteractiveSession
+    public class ReplSession
     {
         private readonly AppRunner _appRunner;
-        private readonly string _appName;
+        private readonly ReplConfig _replConfig;
         private readonly CommandContext _context;
 
-        public InteractiveSession(AppRunner appRunner, string appName, CommandContext context)
+        public ReplSession(AppRunner appRunner, ReplConfig replConfig, CommandContext context)
         {
             _appRunner = appRunner;
-            _appName = appName;
+            _replConfig = replConfig;
             _context = context;
         }
 
@@ -29,7 +28,10 @@ public void Start()
                 pressedCtrlC = true;
             };
 
-            PrintSessionInit();
+            var sessionInitMessage = _replConfig.GetSessionInitMessage(_context);
+            var sessionHelpMessage = _replConfig.GetSessionHelpMessage(_context);
+
+            console.WriteLine(sessionInitMessage);
 
             bool pendingNewLine = false;
             void Write(string? value = null)
@@ -56,7 +58,7 @@ void EnsureNewLine()
             {
                 EnsureNewLine();
                 Write(">>>");
-                var input = console.In.ReadLine();
+                var input = ReadLine.Read();
                 if (input is null || pressedCtrlC)
                 {
                     pressedCtrlC = false;
@@ -79,7 +81,7 @@ void EnsureNewLine()
                         case "quit":
                             return;
                         case "help":
-                            PrintSessionHelp();
+                            console.WriteLine(sessionHelpMessage);
                             continue;
                     }
                     if (singleArg == Environment.NewLine)
@@ -93,22 +95,5 @@ void EnsureNewLine()
             }
             EnsureNewLine();
         }
-
-        private void PrintSessionInit()
-        {
-            var appInfo = AppInfo.GetAppInfo(_context);
-            var console = _context.Console;
-            console.WriteLine($"{_appName} {appInfo.Version}");
-            console.WriteLine("Type 'help' to see interactive options");
-            console.WriteLine("Type '-h' or '--help' to options for commands");
-            console.WriteLine("Type 'exit', 'quit' or 'Ctrl+C' to exit.");
-        }
-
-        private void PrintSessionHelp()
-        {
-            var console = _context.Console;
-            console.WriteLine("Type '-h' or '--help' to options for commands");
-            console.WriteLine("Type 'exit', 'quit' or 'Ctrl+C' to exit.");
-        }
     }
 }
diff --git a/CommandDotNet.sln b/CommandDotNet.sln
@@ -40,6 +40,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "CommandDotNet.Example.Tests
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CommandDotNet.DataAnnotations", "CommandDotNet.DataAnnotations\CommandDotNet.DataAnnotations.csproj", "{558AA426-06D4-4FC9-B2E5-B6742F0A5D77}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CommandDotNet.ReadLineRepl", "CommandDotNet.ReadLineRepl\CommandDotNet.ReadLineRepl.csproj", "{1149E03F-FF07-448A-BB42-82876459B138}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -94,6 +96,10 @@ Global
 		{558AA426-06D4-4FC9-B2E5-B6742F0A5D77}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{558AA426-06D4-4FC9-B2E5-B6742F0A5D77}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{558AA426-06D4-4FC9-B2E5-B6742F0A5D77}.Release|Any CPU.Build.0 = Release|Any CPU
+		{1149E03F-FF07-448A-BB42-82876459B138}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{1149E03F-FF07-448A-BB42-82876459B138}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{1149E03F-FF07-448A-BB42-82876459B138}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{1149E03F-FF07-448A-BB42-82876459B138}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE