text: /* ***** BEGIN LICENSE BLOCK *****
   * Distributed under the BSD license:
   *
   * Copyright (c) 2010, Ajax.org B.V.
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in the
   *       documentation and/or other materials provided with the distribution.
   *     * Neither the name of Ajax.org B.V. nor the
   *       names of its contributors may be used to endorse or promote products
   *       derived from this software without specific prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL AJAX.ORG B.V. BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * ***** END LICENSE BLOCK ***** */
  
  define(function(require, exports, module) {
  "use strict";
  
  var oop = require("../../lib/oop");
  var lang = require("../../lib/lang");
  var Range = require("../../range").Range;
  var BaseFoldMode = require("./fold_mode").FoldMode;
  var TokenIterator = require("../../token_iterator").TokenIterator;
  
  var FoldMode = exports.FoldMode = function(voidElements, optionalEndTags) {
      BaseFoldMode.call(this);
      // TODO folding support for optional end tags
      this.voidElements = oop.mixin(voidElements || {}, optionalEndTags || {});
  };
  oop.inherits(FoldMode, BaseFoldMode);
  
  var Tag = function() {
      this.tagName = "";
      this.closing = false;
      this.selfClosing = false;
      this.start = {row: 0, column: 0};
      this.end = {row: 0, column: 0};
  };
  
  function is(token, type) {
      return token.type.lastIndexOf(type + ".xml") > -1;
  }
  
  (function() {
  
      this.getFoldWidget = function(session, foldStyle, row) {
          var tag = this._getFirstTagInLine(session, row);
  
          if (!tag)
              return "";
  
          if (tag.closing || (!tag.tagName && tag.selfClosing))
              return foldStyle == "markbeginend" ? "end" : "";
  
          if (!tag.tagName || tag.selfClosing || this.voidElements.hasOwnProperty(tag.tagName.toLowerCase()))
              return "";
  
          if (this._findEndTagInLine(session, row, tag.tagName, tag.end.column))
              return "";
  
          return "start";
      };
  
      /*
       * returns a first tag (or a fragment) in a line
       */
      this._getFirstTagInLine = function(session, row) {
          var tokens = session.getTokens(row);
          var tag = new Tag();
  
          for (var i = 0; i < tokens.length; i++) {
              var token = tokens[i];
              if (is(token, "tag-open")) {
                  tag.end.column = tag.start.column + token.value.length;
                  tag.closing = is(token, "end-tag-open");
                  token = tokens[++i];
                  if (!token)
                      return null;
                  tag.tagName = token.value;
                  tag.end.column += token.value.length;
                  for (i++; i < tokens.length; i++) {
                      token = tokens[i];
                      tag.end.column += token.value.length;
                      if (is(token, "tag-close")) {
                          tag.selfClosing = token.value == '/>';
                          break;
                      }
                  }
                  return tag;
              } else if (is(token, "tag-close")) {
                  tag.selfClosing = token.value == '/>';
                  return tag;
              }
              tag.start.column += token.value.length;
          }
  
          return null;
      };
  
      this._findEndTagInLine = function(session, row, tagName, startColumn) {
          var tokens = session.getTokens(row);
          var column = 0;
          for (var i = 0; i < tokens.length; i++) {
              var token = tokens[i];
              column += token.value.length;
              if (column < startColumn)
                  continue;
              if (is(token, "end-tag-open")) {
                  token = tokens[i + 1];
                  if (token && token.value == tagName)
                      return true;
              }
          }
          return false;
      };
  
      /*
       * reads a full tag and places the iterator after the tag
       */
      this._readTagForward = function(iterator) {
          var token = iterator.getCurrentToken();
          if (!token)
              return null;
  
          var tag = new Tag();
          do {
              if (is(token, "tag-open")) {
                  tag.closing = is(token, "end-tag-open");
                  tag.start.row = iterator.getCurrentTokenRow();
                  tag.start.column = iterator.getCurrentTokenColumn();
              } else if (is(token, "tag-name")) {
                  tag.tagName = token.value;
              } else if (is(token, "tag-close")) {
                  tag.selfClosing = token.value == "/>";
                  tag.end.row = iterator.getCurrentTokenRow();
                  tag.end.column = iterator.getCurrentTokenColumn() + token.value.length;
                  iterator.stepForward();
                  return tag;
              }
          } while(token = iterator.stepForward());
  
          return null;
      };
      
      this._readTagBackward = function(iterator) {
          var token = iterator.getCurrentToken();
          if (!token)
              return null;
  
          var tag = new Tag();
          do {
              if (is(token, "tag-open")) {
                  tag.closing = is(token, "end-tag-open");
                  tag.start.row = iterator.getCurrentTokenRow();
                  tag.start.column = iterator.getCurrentTokenColumn();
                  iterator.stepBackward();
                  return tag;
              } else if (is(token, "tag-name")) {
                  tag.tagName = token.value;
              } else if (is(token, "tag-close")) {
                  tag.selfClosing = token.value == "/>";
                  tag.end.row = iterator.getCurrentTokenRow();
                  tag.end.column = iterator.getCurrentTokenColumn() + token.value.length;
              }
          } while(token = iterator.stepBackward());
  
          return null;
      };
      
      this._pop = function(stack, tag) {
          while (stack.length) {
              
              var top = stack[stack.length-1];
              if (!tag || top.tagName == tag.tagName) {
                  return stack.pop();
              }
              else if (this.voidElements.hasOwnProperty(tag.tagName)) {
                  return;
              }
              else if (this.voidElements.hasOwnProperty(top.tagName)) {
                  stack.pop();
                  continue;
              } else {
                  return null;
              }
          }
      };
      
      this.getFoldWidgetRange = function(session, foldStyle, row) {
          var firstTag = this._getFirstTagInLine(session, row);
          
          if (!firstTag)
              return null;
          
          var isBackward = firstTag.closing || firstTag.selfClosing;
          var stack = [];
          var tag;
          
          if (!isBackward) {
              var iterator = new TokenIterator(session, row, firstTag.start.column);
              var start = {
                  row: row,
                  column: firstTag.start.column + firstTag.tagName.length + 2
              };
              while (tag = this._readTagForward(iterator)) {
                  if (tag.selfClosing) {
                      if (!stack.length) {
                          tag.start.column += tag.tagName.length + 2;
                          tag.end.column -= 2;
                          return Range.fromPoints(tag.start, tag.end);
                      } else
                          continue;
                  }
                  
                  if (tag.closing) {
                      this._pop(stack, tag);
                      if (stack.length == 0)
                          return Range.fromPoints(start, tag.start);
                  }
                  else {
                      stack.push(tag);
                  }
              }
          }
          else {
              var iterator = new TokenIterator(session, row, firstTag.end.column);
              var end = {
                  row: row,
                  column: firstTag.start.column
              };
              
              while (tag = this._readTagBackward(iterator)) {
                  if (tag.selfClosing) {
                      if (!stack.length) {
                          tag.start.column += tag.tagName.length + 2;
                          tag.end.column -= 2;
                          return Range.fromPoints(tag.start, tag.end);
                      } else
                          continue;
                  }
                  
                  if (!tag.closing) {
                      this._pop(stack, tag);
                      if (stack.length == 0) {
                          tag.start.column += tag.tagName.length + 2;
                          return Range.fromPoints(tag.start, end);
                      }
                  }
                  else {
                      stack.push(tag);
                  }
              }
          }
          
      };
  
  }).call(FoldMode.prototype);
  
  });
  