source: branches/2389-EpsLexicase/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/IndentEngine/TextPasteIndentEngine.cs

//
// TextPasteIndentEngine.cs
//
// Author:
//       Matej Miklečić <matej.miklecic@gmail.com>
//
// Copyright (c) 2013 Matej Miklečić (matej.miklecic@gmail.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using ICSharpCode.NRefactory.Editor;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;

namespace ICSharpCode.NRefactory.CSharp
{
  /// <summary>
  ///     Represents a decorator of an IStateMachineIndentEngine instance
  ///     that provides logic for text paste events.
  /// </summary>
  public class TextPasteIndentEngine : IDocumentIndentEngine, ITextPasteHandler
  {

    #region Properties

    /// <summary>
    ///     An instance of IStateMachineIndentEngine which handles
    ///     the indentation logic.
    /// </summary>
    IStateMachineIndentEngine engine;
    /// <summary>
    ///     Text editor options.
    /// </summary>
    internal readonly TextEditorOptions textEditorOptions;
    internal readonly CSharpFormattingOptions formattingOptions;
    #endregion

    #region Constructors

    /// <summary>
    ///     Creates a new TextPasteIndentEngine instance.
    /// </summary>
    /// <param name="decoratedEngine">
    ///     An instance of <see cref="IStateMachineIndentEngine"/> to which the
    ///     logic for indentation will be delegated.
    /// </param>
    /// <param name="textEditorOptions">
    ///    Text editor options for indentation.
    /// </param>
    /// <param name="formattingOptions">
    ///     C# formatting options.
    /// </param>
    public TextPasteIndentEngine(IStateMachineIndentEngine decoratedEngine, TextEditorOptions textEditorOptions, CSharpFormattingOptions formattingOptions)
    {
      this.engine = decoratedEngine;
      this.textEditorOptions = textEditorOptions;
      this.formattingOptions = formattingOptions;

      this.engine.EnableCustomIndentLevels = false;
    }

    #endregion

    #region ITextPasteHandler

    /// <inheritdoc />
    string ITextPasteHandler.FormatPlainText(int offset, string text, byte[] copyData)
    {
      if (copyData != null && copyData.Length == 1) {
        var strategy = TextPasteUtils.Strategies [(PasteStrategy)copyData [0]];
        text = strategy.Decode(text);
      }
      engine.Update(offset);
      if (engine.IsInsideStringLiteral) {
        int idx = text.IndexOf('"');
        if (idx > 0) {
          var o = offset;
          while (o < engine.Document.TextLength) {
            char ch = engine.Document.GetCharAt(o);
            engine.Push(ch); 
            if (NewLine.IsNewLine(ch))
              break;
            o++;
            if (!engine.IsInsideStringLiteral)
              return TextPasteUtils.StringLiteralStrategy.Encode(text);
          }
          return TextPasteUtils.StringLiteralStrategy.Encode(text.Substring(0, idx)) + text.Substring(idx);
        }
        return TextPasteUtils.StringLiteralStrategy.Encode(text);

      } else if (engine.IsInsideVerbatimString) {

        int idx = text.IndexOf('"');
        if (idx > 0) {
          var o = offset;
          while (o < engine.Document.TextLength) {
            char ch = engine.Document.GetCharAt(o);
            engine.Push(ch); 
            o++;
            if (!engine.IsInsideVerbatimString)
              return TextPasteUtils.VerbatimStringStrategy.Encode(text);
          }
          return TextPasteUtils.VerbatimStringStrategy.Encode(text.Substring(0, idx)) + text.Substring(idx);
        }

        return TextPasteUtils.VerbatimStringStrategy.Encode(text);
      }
      var line = engine.Document.GetLineByOffset(offset);
      var pasteAtLineStart = line.Offset == offset;
      var indentedText = new StringBuilder();
      var curLine = new StringBuilder();
      var clonedEngine = engine.Clone();
      bool isNewLine = false, gotNewLine = false;
      for (int i = 0; i < text.Length; i++) {
        var ch = text [i];
        if (clonedEngine.IsInsideVerbatimString || clonedEngine.IsInsideMultiLineComment) {
          clonedEngine.Push(ch);
          curLine.Append(ch);
          continue;
        }

        var delimiterLength = NewLine.GetDelimiterLength(ch, i + 1 < text.Length ? text[i + 1] : ' ');
        if (delimiterLength > 0) {
          isNewLine = true;
          if (gotNewLine || pasteAtLineStart) {
            if (curLine.Length > 0 || formattingOptions.EmptyLineFormatting == EmptyLineFormatting.Indent)
              indentedText.Append(clonedEngine.ThisLineIndent);
          }
          indentedText.Append(curLine);
          indentedText.Append(textEditorOptions.EolMarker);
          curLine.Length = 0;
          gotNewLine = true;
          i += delimiterLength - 1;
          // textEditorOptions.EolMarker[0] is the newLineChar used by the indentation engine.
          clonedEngine.Push(textEditorOptions.EolMarker[0]);
        } else {
          if (isNewLine) {
            if (ch == '\t' || ch == ' ') {
              clonedEngine.Push(ch);
              continue;
            }
            isNewLine = false;
          }
          curLine.Append(ch);
          clonedEngine.Push(ch);
        }
        if (clonedEngine.IsInsideVerbatimString || clonedEngine.IsInsideMultiLineComment && 
            !(clonedEngine.LineBeganInsideVerbatimString || clonedEngine.LineBeganInsideMultiLineComment)) {
          if (gotNewLine) {
            if (curLine.Length > 0 || formattingOptions.EmptyLineFormatting == EmptyLineFormatting.Indent)
              indentedText.Append(clonedEngine.ThisLineIndent);
          }
          pasteAtLineStart = false;
          indentedText.Append(curLine);
          curLine.Length = 0;
          gotNewLine = false;
          continue;
        }
      }
      if (gotNewLine && (!pasteAtLineStart || curLine.Length > 0)) {
        indentedText.Append(clonedEngine.ThisLineIndent);
      }
      if (curLine.Length > 0) {
        indentedText.Append(curLine);
      }
      return indentedText.ToString();
    }

    /// <inheritdoc />
    byte[] ITextPasteHandler.GetCopyData(ISegment segment)
    {
      engine.Update(segment.Offset);
      
      if (engine.IsInsideStringLiteral) {
        return new[] { (byte)PasteStrategy.StringLiteral };
      } else if (engine.IsInsideVerbatimString) {
        return new[] { (byte)PasteStrategy.VerbatimString };
      }
      
      return null;
    }

    #endregion

    #region IDocumentIndentEngine

    /// <inheritdoc />
    public IDocument Document {
      get { return engine.Document; }
    }

    /// <inheritdoc />
    public string ThisLineIndent {
      get { return engine.ThisLineIndent; }
    }

    /// <inheritdoc />
    public string NextLineIndent {
      get { return engine.NextLineIndent; }
    }

    /// <inheritdoc />
    public string CurrentIndent {
      get { return engine.CurrentIndent; }
    }

    /// <inheritdoc />
    public bool NeedsReindent {
      get { return engine.NeedsReindent; }
    }

    /// <inheritdoc />
    public int Offset {
      get { return engine.Offset; }
    }

    /// <inheritdoc />
    public TextLocation Location {
      get { return engine.Location; }
    }

    /// <inheritdoc />
    public bool EnableCustomIndentLevels {
      get { return engine.EnableCustomIndentLevels; }
      set { engine.EnableCustomIndentLevels = value; }
    }
    
    /// <inheritdoc />
    public void Push(char ch)
    {
      engine.Push(ch);
    }

    /// <inheritdoc />
    public void Reset()
    {
      engine.Reset();
    }

    /// <inheritdoc />
    public void Update(int offset)
    {
      engine.Update(offset);
    }

    #endregion

    #region IClonable

    public IDocumentIndentEngine Clone()
    {
      return new TextPasteIndentEngine(engine, textEditorOptions, formattingOptions);
    }

    object ICloneable.Clone()
    {
      return Clone();
    }

    #endregion

  }

  /// <summary>
  ///     Types of text-paste strategies.
  /// </summary>
  public enum PasteStrategy : byte
  {
    PlainText = 0,
    StringLiteral = 1,
    VerbatimString = 2
  }

  /// <summary>
  ///     Defines some helper methods for dealing with text-paste events.
  /// </summary>
  public static class TextPasteUtils
  {
    /// <summary>
    ///     Collection of text-paste strategies.
    /// </summary>
    public static TextPasteStrategies Strategies = new TextPasteStrategies();

    /// <summary>
    ///     The interface for a text-paste strategy.
    /// </summary>
    public interface IPasteStrategy
    {
      /// <summary>
      ///     Formats the given text according with this strategy rules.
      /// </summary>
      /// <param name="text">
      ///    The text to format.
      /// </param>
      /// <returns>
      ///     Formatted text.
      /// </returns>
      string Encode(string text);

      /// <summary>
      ///     Converts text formatted according with this strategy rules
      ///     to its original form.
      /// </summary>
      /// <param name="text">
      ///     Formatted text to convert.
      /// </param>
      /// <returns>
      ///     Original form of the given formatted text.
      /// </returns>
      string Decode(string text);

      /// <summary>
      ///     Type of this strategy.
      /// </summary>
      PasteStrategy Type { get; }
    }

    /// <summary>
    ///     Wrapper that discovers all defined text-paste strategies and defines a way
    ///     to easily access them through their <see cref="PasteStrategy"/> type.
    /// </summary>
    public sealed class TextPasteStrategies
    {
      /// <summary>
      ///     Collection of discovered text-paste strategies.
      /// </summary>
      IDictionary<PasteStrategy, IPasteStrategy> strategies;

      /// <summary>
      ///     Uses reflection to find all types derived from <see cref="IPasteStrategy"/>
      ///     and adds an instance of each strategy to <see cref="strategies"/>.
      /// </summary>
      public TextPasteStrategies()
      {
        strategies = Assembly.GetExecutingAssembly()
             .GetTypes()
        .Where(t => typeof(IPasteStrategy).IsAssignableFrom(t) && t.IsClass)
        .Select(t => (IPasteStrategy)t.GetProperty("Instance").GetValue(null, null))
        .ToDictionary(s => s.Type);
      }

      /// <summary>
      ///     Checks if there is a strategy of the given type and returns it.
      /// </summary>
      /// <param name="strategy">
      ///     Type of the strategy instance.
      /// </param>
      /// <returns>
      ///     A strategy instance of the requested type,
      ///     or <see cref="DefaultStrategy"/> if it wasn't found.
      /// </returns>
      public IPasteStrategy this [PasteStrategy strategy] {
        get {
          if (strategies.ContainsKey(strategy)) {
            return strategies [strategy];
          }
          
          return DefaultStrategy;
        }
      }
    }

    /// <summary>
    ///     Doesn't do any formatting. Serves as the default strategy.
    /// </summary>
    public class PlainTextPasteStrategy : IPasteStrategy
    {

      #region Singleton

      public static IPasteStrategy Instance {
        get {
          return instance ?? (instance = new PlainTextPasteStrategy());
        }
      }

      static PlainTextPasteStrategy instance;

      protected PlainTextPasteStrategy()
      {
      }

      #endregion

      /// <inheritdoc />
      public string Encode(string text)
      {
        return text;
      }

      /// <inheritdoc />
      public string Decode(string text)
      {
        return text;
      }

      /// <inheritdoc />
      public PasteStrategy Type {
        get { return PasteStrategy.PlainText; }
      }
    }

    /// <summary>
    ///     Escapes chars in the given text so that they don't
    ///     break a valid string literal.
    /// </summary>
    public class StringLiteralPasteStrategy : IPasteStrategy
    {

      #region Singleton

      public static IPasteStrategy Instance {
        get {
          return instance ?? (instance = new StringLiteralPasteStrategy());
        }
      }

      static StringLiteralPasteStrategy instance;

      protected StringLiteralPasteStrategy()
      {
      }

      #endregion

      /// <inheritdoc />
      public string Encode(string text)
      {
        return CSharpOutputVisitor.ConvertString(text);
      }

      /// <inheritdoc />
      public string Decode(string text)
      {
        var result = new StringBuilder();
        bool isEscaped = false;

        for (int i = 0; i < text.Length; i++) {
          var ch = text[i];
          if (isEscaped) {
            switch (ch) {
              case 'a':
                result.Append('\a');
                break;
              case 'b':
                result.Append('\b');
                break;
              case 'n':
                result.Append('\n');
                break;
              case 't':
                result.Append('\t');
                break;
              case 'v':
                result.Append('\v');
                break;
              case 'r':
                result.Append('\r');
                break;
              case '\\':
                result.Append('\\');
                break;
              case 'f':
                result.Append('\f');
                break;
              case '0':
                result.Append(0);
                break;
              case '"':
                result.Append('"');
                break;
              case '\'':
                result.Append('\'');
                break;
              case 'x':
                char r;
                if (TryGetHex(text, -1, ref i, out r)) {
                  result.Append(r);
                  break;
                }
                goto default;
              case 'u':
                if (TryGetHex(text, 4, ref i, out r)) {
                  result.Append(r);
                  break;
                }
                goto default;
              case 'U':
                if (TryGetHex(text, 8, ref i, out r)) {
                  result.Append(r);
                  break;
                }
                goto default;
              default:
                result.Append('\\');
                result.Append(ch);
                break;
            }
            isEscaped = false;
            continue;
          }
          if (ch != '\\') {
            result.Append(ch);
          }
          else {
            isEscaped = true;
          }
        }

        return result.ToString();
      }

      static bool TryGetHex(string text, int count, ref int idx, out char r)
      {
        int i;
        int total = 0;
        int top = count != -1 ? count : 4;

        for (i = 0; i < top; i++) {
          int c = text[idx + 1 + i];

          if (c >= '0' && c <= '9')
            c = (int) c - (int) '0';
          else if (c >= 'A' && c <= 'F')
            c = (int) c - (int) 'A' + 10;
          else if (c >= 'a' && c <= 'f')
            c = (int) c - (int) 'a' + 10;
          else {
            r = '\0';
            return false;
          }
          total = (total * 16) + c;
        }

        if (top == 8) {
          if (total > 0x0010FFFF) {
            r = '\0';
            return false;
          }

          if (total >= 0x00010000)
            total = ((total - 0x00010000) / 0x0400 + 0xD800);
        }
        r = (char)total;
        idx += top;
        return true;
      }

      /// <inheritdoc />
      public PasteStrategy Type {
        get { return PasteStrategy.StringLiteral; }
      }
    }

    /// <summary>
    ///     Escapes chars in the given text so that they don't
    ///     break a valid verbatim string.
    /// </summary>
    public class VerbatimStringPasteStrategy : IPasteStrategy
    {

      #region Singleton

      public static IPasteStrategy Instance {
        get {
          return instance ?? (instance = new VerbatimStringPasteStrategy());
        }
      }

      static VerbatimStringPasteStrategy instance;

      protected VerbatimStringPasteStrategy()
      {
      }

      #endregion

      static readonly Dictionary<char, IEnumerable<char>> encodeReplace = new Dictionary<char, IEnumerable<char>> {
        { '\"', "\"\"" },
      };

      /// <inheritdoc />
      public string Encode(string text)
      {
        return string.Concat(text.SelectMany(c => encodeReplace.ContainsKey(c) ? encodeReplace [c] : new[] { c }));
      }

      /// <inheritdoc />
      public string Decode(string text)
      {
        bool isEscaped = false;
        return string.Concat(text.Where(c => !(isEscaped = !isEscaped && c == '"')));
      }

      /// <inheritdoc />
      public PasteStrategy Type {
        get { return PasteStrategy.VerbatimString; }
      }
    }

    /// <summary>
    ///     The default text-paste strategy.
    /// </summary>
    public static IPasteStrategy DefaultStrategy = PlainTextPasteStrategy.Instance;
    /// <summary>
    ///     String literal text-paste strategy.
    /// </summary>
    public static IPasteStrategy StringLiteralStrategy = StringLiteralPasteStrategy.Instance;
    /// <summary>
    ///     Verbatim string text-paste strategy.
    /// </summary>
    public static IPasteStrategy VerbatimStringStrategy = VerbatimStringPasteStrategy.Instance;
  }
}