// <file>
//     <copyright see="prj:///doc/copyright.txt"/>
//     <license see="prj:///doc/license.txt"/>
//     <author name="Daniel Grunwald"/>
//     <version>$Revision$</version>
// </file>

using ICSharpCode.SharpDevelop.Editor;
using System;
using System.IO;
using System.Text;
using ICSharpCode.Core;
using ICSharpCode.Core.WinForms;
using ICSharpCode.NRefactory.Ast;
using ICSharpCode.NRefactory.AstBuilder;
using ICSharpCode.SharpDevelop.DefaultEditor.Gui.Editor;
using ICSharpCode.SharpDevelop.Dom;
using ICSharpCode.SharpDevelop.Dom.Refactoring;
using ICSharpCode.SharpDevelop.Gui;
using ICSharpCode.SharpDevelop.Project;

namespace ICSharpCode.SharpDevelop.Editor.Commands
{
	public abstract class PasteAsCommand : AbstractMenuCommand
	{
		public override void Run()
		{
			string clipboardText = ClipboardWrapper.GetText();
			if (string.IsNullOrEmpty(clipboardText))
				return;
			
			IViewContent viewContent = WorkbenchSingleton.Workbench.ActiveViewContent;
			if (viewContent == null || !(viewContent is ITextEditorProvider)) {
				return;
			}
			
			ITextEditor textEditor = ((ITextEditorProvider)viewContent).TextEditor;
			if (textEditor == null) {
				return;
			}
			
			using (textEditor.Document.OpenUndoGroup())
				Run(textEditor, clipboardText);
		}
		
		protected abstract void Run(ITextEditor editor, string clipboardText);
		
		protected string GetIndentation(IDocument document, int line)
		{
			return DocumentUtilitites.GetWhitespaceAfter(document, document.GetLine(line).Offset);
		}
	}
	
	/// <summary>
	/// Pastes the clipboard text as a comment.
	/// 
	/// Does the following:
	/// - Take clipboard text
	/// - Get current indentation
	/// - Wrap first line using 'IAmbience.WrapComment'
	/// - If it's too long (according to the column ruler position), word-break
	/// - Insert it
	/// </summary>
	public class PasteAsCommentCommand : PasteAsCommand
	{
		protected override void Run(ITextEditor editor, string clipboardText)
		{
			string indentation = GetIndentation(editor.Document, editor.Caret.Line);
			IAmbience ambience = AmbienceService.GetCurrentAmbience();
			int maxLineLength = editor.Options.VerticalRulerColumn - VisualIndentationLength(editor, indentation);
			StringWriter insertedText = new StringWriter();
			insertedText.NewLine = DocumentUtilitites.GetLineTerminator(editor.Document, editor.Caret.Line);
			using (StringReader reader = new StringReader(clipboardText)) {
				string line;
				while ((line = reader.ReadLine()) != null) {
					AppendTextLine(indentation, ambience, maxLineLength, insertedText, line);
				}
			}
			IDocument document = editor.Document;
			int insertionPos = document.GetLine(editor.Caret.Line).Offset + indentation.Length;
			document.Insert(insertionPos, insertedText.ToString());
		}
		
		void AppendTextLine(string indentation, IAmbience ambience, int maxLineLength, StringWriter insertedText, string line)
		{
			const int minimumLineLength = 10;
			string commentedLine;
			while (true) {
				commentedLine = ambience.WrapComment(line);
				int commentingOverhead = commentedLine.Length - line.Length;
				if (commentingOverhead < 0 || (maxLineLength - commentingOverhead) < minimumLineLength)
					break;
				if (commentedLine.Length > maxLineLength) {
					int pos = FindWrapPositionBefore(line, maxLineLength - commentingOverhead);
					if (pos < minimumLineLength)
						break;
					insertedText.WriteLine(ambience.WrapComment(line.Substring(0, pos)));
					insertedText.Write(indentation);
					line = line.Substring(pos + 1);
				} else {
					break;
				}
			}
			insertedText.WriteLine(commentedLine);
			insertedText.Write(indentation); // indentation for next line
		}
		
		int FindWrapPositionBefore(string line, int pos)
		{
			return line.LastIndexOf(' ', pos);
		}
		
		int VisualIndentationLength(ITextEditor editor, string indentation)
		{
			int length = 0;
			foreach (char c in indentation) {
				if (c == '\t')
					length += editor.Options.IndentationSize;
				else
					length += 1;
			}
			return length;
		}
	}
	
	/// <summary>
	/// Pastes the clipboard text as a string.
	/// 
	/// Does the following:
	/// - Take clipboard text
	/// - Convert to string literal using CodeGenerator
	/// - Insert it
	/// </summary>
	public class PasteAsStringCommand : PasteAsCommand
	{
		protected override void Run(ITextEditor editor, string clipboardText)
		{
			CodeGenerator codeGenerator = ParserService.CurrentProjectContent.Language.CodeGenerator;
			if (codeGenerator == null)
				codeGenerator = LanguageProperties.CSharp.CodeGenerator;
			Expression expression = null;
			using (StringReader reader = new StringReader(clipboardText)) {
				string line;
				while ((line = reader.ReadLine()) != null) {
					Expression newExpr = new PrimitiveExpression(line);
					if (expression == null) {
						expression = newExpr;
					} else {
						expression = expression
							.Operator(BinaryOperatorType.Concat,
							          ExpressionBuilder.Identifier("Environment").Member("NewLine"))
							.Operator(BinaryOperatorType.Concat,
							          newExpr);
					}
				}
			}
			if (expression == null)
				return;
			string indentation = GetIndentation(editor.Document, editor.Caret.Line);
			editor.Document.Insert(editor.Caret.Offset, codeGenerator.GenerateCode(expression, indentation).Trim());
		}
	}
}