#include "XmlReader.h"
#include <string>
#include <stack>
#include <algorithm>
/*
   function   21  79
   if         30  33
   if         37  40
   while      50  61
   if         53  53
   if         55  55
   else       56  57
   if         57  57
   if         59  59
   if         66  66
   if         71  71
   if         73  76
*/
//----< return current element string >------------------------------

std::string XmlReader::element()
{
  // find tag - assumes _position points to character after
  // opening "<" on entry
  localposition = _position;
  _tag = extractIdentifier(localposition);

  // is declaration?
  std::string decTag = "?xml";
  if(_tag.compare("?xml") == 0)
  {
    size_t locpos = _xml.find("?>");
    return _xml.substr(_position-1,locpos-_position+3); 
  }

  // is comment?
  if(_tag.compare("!--") == 0)
  {
    size_t locpos = _xml.find("-->");
    return _xml.substr(_position-1,locpos-_position+4); 
  }

  // find end of element </tag>
  size_t locpos1 = localposition;

  // note: tracks element scope with tagStack, so will correctly
  // return nested elements with the same tag name
  std::stack<std::string> tagStack;
  tagStack.push(_tag);
  while(true)
  {
    locpos1 = _xml.find(_tag,locpos1);
    if(locpos1 >= _xml.size())
      break;
    if(_xml[locpos1-1]=='/' && _xml[locpos1 + _tag.size()] == '>')  // modified 2/15/2012
      tagStack.pop();
    else if(_xml[locpos1-1]=='<')
      tagStack.push(_tag);
    if(tagStack.size() == 0)
      break;
    ++locpos1;
  }

  // find end element of self-closing tag, e.g., <tag />
  size_t locpos2 = _xml.find(">",localposition);
  if(_xml[locpos2-1] != '/')
    locpos2 = _xml.size();

  // find end element </tag>
  localposition = std::min(locpos1,locpos2);
  if(localposition >= _xml.size())
    throw std::exception("malformed XML");
  if(localposition == locpos1)
  {
    localposition = _xml.find('>',localposition);
    return _xml.substr(_position-1, localposition - _position +2);
  }
  return _xml.substr(_position-1, localposition - _position + 2);
}