Mixin context action

MixinContextAction

using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using ActiveMesa.R2P.ContextActions;
using ActiveMesa.R2P.Infrastructure;
using JetBrains.Application;
using JetBrains.Application.Progress;
using JetBrains.ProjectModel;
using JetBrains.ReSharper.Feature.Services.Bulbs;
using JetBrains.ReSharper.Feature.Services.CSharp.Bulbs;
using JetBrains.ReSharper.Intentions.Extensibility;
using JetBrains.ReSharper.Psi.CSharp;
using JetBrains.ReSharper.Psi.CSharp.Tree;
using JetBrains.ReSharper.Psi.ExtensionsAPI.Tree;
using JetBrains.ReSharper.Psi.Impl.CodeStyle;
using JetBrains.ReSharper.Psi.Tree;
using JetBrains.TextControl;
using JetBrains.Util;

namespace ActiveMesa.R2P.Mixin
{
  [ContextAction(Description="Injects a mixin", Group=ContextActionGroups.CSharp, Name = "Inject mixin")]
  public class ApplyMixinAction : ContextActionBase
  {
    private readonly ICSharpContextActionDataProvider provider;
    private IAttribute mixinAttribute;

    public ApplyMixinAction(ICSharpContextActionDataProvider provider)
    {
      this.provider = provider;
    }

    protected override Action<ITextControl> ExecutePsiTransaction(ISolution solution, IProgressIndicator progress)
    {
      // get the argument, if it exists
      string argument = this.With(x => mixinAttribute)
        .If(x => x.Arguments.Count == 1)
        .With(x => x.Arguments[0])
        .With(x => x.Expression)
        .With(x => x as ICSharpLiteralExpression)
        .With(x => x.ConstantValue)
        .If(x => x.IsString())
        .With(x => x.Value as string);

      if (argument != null)
      {
        var sb = new StringBuilder();
        sb.AppendLine("using System;")
          .AppendLine("using System.Collections.Generic;")
          .AppendLine("using System.Linq;")
          .AppendLine("public class Mixin {")
          .AppendLine("public IEnumerable<string> Invoke() {")
          .AppendLine(argument)
          .AppendLine("}")
          .AppendLine("}");
        var inpc = new CSharpInProcessCompiler();
        var t = inpc.CompileAndInstantiate(sb.ToString());
        var lines = (IEnumerable<string>) t.GetType().GetMethod("Invoke").Invoke(t, EmptyArray<object>.Instance);
        string allLines = Environment.NewLine + lines.Join(Environment.NewLine) + Environment.NewLine;

        var owner = mixinAttribute.GetContainingTypeDeclaration() as IClassLikeDeclaration;
        if (owner != null)
          return tc =>
            {
              tc.Document.InsertText(owner.RBrace.GetDocumentRange().TextRange.StartOffset, allLines);
            };
      }

      return null;
    }

    public override string Text
    {
      get { return "Apply mixin"; }
    }

    public override bool IsAvailable(IUserDataHolder cache)
    {
      mixinAttribute = provider.GetSelectedElement<IAttribute>(true, true);
      return mixinAttribute != null && mixinAttribute.Name.ShortName.Equals("Mixin");
    }
  }
}