Use System.CommandLine.Experimental instead of NDesk.Options

src/Pretzel.Logic/Commands/BakeBaseCommandArguments.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+using System.CommandLine;
+using System.IO.Abstractions;
+
+namespace Pretzel.Logic.Commands
+{
+    public abstract class BakeBaseCommandArguments : PretzelBaseCommandArguments, IBakeBaseCommandArguments
+    {
+        protected BakeBaseCommandArguments(IFileSystem fileSystem) : base(fileSystem) { }
+
+        protected override IEnumerable<Option> CreateOptions() => base.CreateOptions().Concat(new[]
+        {
+            new Option(new [] { "-c", "--cleantarget" }, "Delete the target directory (_site by default)")
+            {
+                Argument = new Argument<bool>()
+            },
+        });
+
+        public bool CleanTarget { get; set; }
+    }
+}

src/Pretzel.Logic/Commands/BaseCommandArguments.cs

@@ -0,0 +1,28 @@
+using Pretzel.Logic.Extensibility;
+using System;
+using System.Collections.Generic;
+using System.CommandLine;
+using System.Composition;
+using System.Linq;
+
+namespace Pretzel.Logic.Commands
+{
+    public abstract class BaseCommandArguments : ICommandArguments
+    {
+        readonly List<Option> options = new List<Option>();
+        [Export]
+        public IList<Option> Options => options;
+        public IList<ICommandArgumentsExtension> Extensions { get; } = new List<ICommandArgumentsExtension>();
+
+        internal void BuildOptions()
+        {
+            options.AddRange(CreateOptions());
+        }
+
+        protected abstract IEnumerable<Option> CreateOptions();
+
+        public virtual void BindingCompleted()
+        {
+        }
+    }
+}

src/Pretzel.Logic/Commands/BuiltInCommands.cs

@@ -0,0 +1,13 @@
+namespace Pretzel.Logic.Commands
+{
+    public static class BuiltInCommands
+    {
+        public const string Bake = "bake";
+        public const string Hungry = "hungry";
+        public const string Import = "import";
+        public const string Ingredient = "ingredient";
+        public const string Create = "create";
+        public const string Taste = "taste";
+        public const string Version = "version";
+    }
+}

src/Pretzel.Logic/Commands/CommandArgumentsAttribute.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Composition;
+
+namespace Pretzel.Logic.Commands
+{
+    [MetadataAttribute]
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
+    public sealed class CommandArgumentsAttribute : ExportAttribute
+    {
+        public CommandArgumentsAttribute() : base(typeof(ICommandArguments))
+        {
+        }
+    }
+}

src/Pretzel/Commands/CommandInfoAttribute.cs → src/Pretzel.Logic/Commands/CommandInfoAttribute.cs

@@ -1,14 +1,18 @@
 using System;
 using System.Composition;
 
-namespace Pretzel.Commands
+namespace Pretzel.Logic.Commands
 {
     [MetadataAttribute]
     [AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
     public sealed class CommandInfoAttribute : ExportAttribute
     {
         public string CommandName { get; set; }
 
+        public string CommandDescription { get; set; }
+
+        public Type CommandArgumentsType { get; set; }
+
         public CommandInfoAttribute() : base(typeof(ICommand))
         {
         }

src/Pretzel.Logic/Commands/IBakeBaseCommandArguments.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Linq;
+
+namespace Pretzel.Logic.Commands
+{
+    [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
+    public interface IBakeBaseCommandArguments : IPretzelBaseCommandArguments
+    {
+        bool CleanTarget { get; }
+    }
+}

src/Pretzel.Logic/Commands/IBakeCommandArguments.cs

@@ -0,0 +1,10 @@
+using System;
+using System.Linq;
+
+namespace Pretzel.Logic.Commands
+{
+    public interface IBakeCommandArguments : IBakeBaseCommandArguments
+    {
+
+    }
+}

src/Pretzel.Logic/Commands/ICommand.cs

@@ -0,0 +1,30 @@
+using System.Threading.Tasks;
+
+namespace Pretzel.Logic.Commands
+{
+    /// <summary>
+    /// Defines a custom command for pretzel. Implementors should be decorated with the <see cref="CommandInfoAttribute"/>
+    /// Also see <see cref="Command{T}"/> for easier implementation.
+    /// </summary>
+    public interface ICommand
+    {
+        /// <summary>
+        /// Executes the specified command with arguments provided defined in <see cref="CommandInfoAttribute.CommandArgumentsType"/>.
+        /// </summary>
+        /// <param name="arguments">The arguments.</param>
+        /// <returns></returns>
+        Task<int> Execute(ICommandArguments arguments);
+    }
+
+    /// <summary>
+    /// Defines a custom command for pretzel. Implementors should be decorated with the <see cref="CommandInfoAttribute"/>
+    /// </summary>
+    public abstract class Command<T> : ICommand where T : ICommandArguments
+    {
+        public Task<int> Execute(ICommandArguments arguments)
+            => Execute((T)arguments);
+
+        protected abstract Task<int> Execute(T arguments);
+    }
+
+}