Building a Refactoring Plug-in for VS.NET - the Sequel

using System;
using Microsoft.Office.Core;
using Extensibility;
using System.Runtime.InteropServices;
using EnvDTE;
using System.IO;

namespace RefactorAddIn
{
	/// <summary>
	/// CollectionGenerator
	/// Version: 0.1   draft
	/// Copyright 2004 (c) Stephan Meyn
	/// Role:
	/// Responsibilities:
	/// <list type="bullet">
	/// <item></item>
	/// </list>
	/// 
	/// 
	/// </summary>
	public class CollectionGenerator: VSPlugIn	
	{
		
		private CodeClass sourceClass;
		#region public Attributes
		public override string cmdName
		{
			get
			{
				return "GenerateCollection";
			}
		}
		public override string qualifiedName
		{
			get
			{
				return "RefactorAddIn.Connect.GenerateCollection";
			}
		}
		public override string shortDescription{get { return "Generate Collection Class";} }
		public override string longDescription { get {return "Generates Code for a collection class for current class"; }}
		public override int position { get {return  1;} }
		public override int iconId { get {return 54;} }


		#endregion

		#region construction
		public CollectionGenerator(_DTE applicationObject, AddIn addInInstance)
			: base(applicationObject, addInInstance)
		{		}
		#endregion

		#region public methods
		protected override EnvDTE.vsCommandStatus doQueryStatus()
		{
			vsCommandStatus status = vsCommandStatus.vsCommandStatusInvisible;
	
			CodeElement selection = selectedElement(vsCMElement.vsCMElementClass);

			if (selection != null)
			{
				// Show MenuItem
				status = (vsCommandStatus)vsCommandStatus.vsCommandStatusSupported|vsCommandStatus.vsCommandStatusEnabled; 					
			}
			else 
				status = (vsCommandStatus)vsCommandStatus.vsCommandStatusInvisible;
			return status;
		}
		protected override bool doExec()
		{
			CodeClass selection = selectedElement(vsCMElement.vsCMElementClass) as CodeClass;
			if (selection != null)
				return generateCollectionClass(selection);
			else 
				return false;
		}

		#endregion

		#region private methods

		/// <summary>
		/// print out what is currently selected
		/// </summary>
		[Obsolete]private void whatIsSelected()
		{

			Object obj = _applicationObject.SelectedItems.SelectionContainer.Item(1);
				if (obj == null) return;
				
				CodeElement e = obj as CodeElement;
				if (e is CodeClass)
				{
					CodeClass cc =e as CodeClass;
					message("Selected is CodeClass {0}",  cc.Name);
				}
				else if (e is CodeAttribute)
				{
					CodeAttribute cc = e as CodeAttribute;
					message("Selected is CodeAttribute {0}",  cc.Name);
				}
				else if (e is CodeProperty)
				{
					CodeProperty cc = e as CodeProperty;
					message("Selected is CodeProperty {0}",  cc.Name);
				}
				else 
				{
					message("Selected[{0}] is {1}", e.Name, e.Kind);
				}
			
		}


		private bool generateCollectionClass(CodeClass classElement)
		{
			sourceClass = classElement;
			try
			{
				string baseClassName = classElement.Name;
				CollectionBuilder gen = new CollectionBuilder(baseClassName);
				string classCode = gen.Generate();
				InsertNewCodeFileForClass(gen.CollectionClassName, classCode);
//				System.Windows.Forms.Clipboard.SetDataObject(classCode, true);
//				message("the code has been placed onto the clipboard");
			} 
			catch (Exception ex)
			{
				string msg = ex.Message;
				message (msg);
			}
			return true;
		}

		/// <summary>
		/// insert a new class item
		/// </summary>
		/// <remarks>Doesn't worl as AddClass is not implemented</remarks>
		/// <param name="CollectionClassName"></param>
		/// <param name="classCode"></param>
		private void InsertNewCodeFileForClass(string CollectionClassName, string classCode)
		{
			//a replacement for this call.
//			CodeClass result = projectItem.ContainingProject.CodeModel.AddClass(
//				CollectionClassName, CollectionClassName+".cs", 0, 0,0,vsCMAccess.vsCMAccessPublic);
			string sourceClassPath =sourceClass.ProjectItem.Document.Path;
			string targetPathRoot = System.IO.Path.GetDirectoryName(sourceClassPath);
			string newFileName = uniqueFileName(CollectionClassName + ".cs", targetPathRoot);
			using (StreamWriter sw = File.CreateText(newFileName))
			{
				sw.WriteLine ("using System.Collections;");
				sw.WriteLine();
				sw.WriteLine(classCode);
			}
			
			ProjectItems items = projectItem.ContainingProject.ProjectItems;
			items.AddFromFile(newFileName);
		}
		/// <summary>
		/// generate a unique filename to avoid clashes with existing filenames
		/// </summary>
		/// <returns></returns>
		private string uniqueFileName(string proposedFileName, string targetDirectory)
		{
			string extension = Path.GetExtension(proposedFileName);
			string baseFileName = Path.GetFileNameWithoutExtension(proposedFileName);
			int verNumber = 0;
			string fileName = proposedFileName;
			string result = Path.Combine(targetDirectory, fileName);
			while (File.Exists(result))
			{
				verNumber++;
				fileName = string.Format("{0}_{1}{2}",baseFileName, verNumber, extension);
				result =Path.Combine(targetDirectory, fileName);
			}
			return result;
		}
		#endregion
	}
}