#include <set>
#include <string>
#include <vector>
#include <stdexcept>
#include <expat.h>
#include "housestylewriter.h"
#include "contexthandler.h"

using namespace std;

HouseStyleWriter::HouseStyleWriter(vector<ContextMatch> &v) :
  hswd(new HouseStyleWriterData())
{
  set<size_t> elementSet;
  size_t vectorsize = v.size();
  for (size_t i = 0; i < vectorsize; ++i)
        elementSet.insert(v[i].elementCount);
  
  hswd->setState(STATE_UNKNOWN);
  hswd->v = v;
  hswd->elementSet = elementSet;

  XML_SetUserData(p, hswd.get());
  XML_SetElementHandler(p, start, end);
  XML_SetCharacterDataHandler(p, characterdata);
  XML_SetXmlDeclHandler(p, xmldecl);
  XML_SetCdataSectionHandler(p, cdatastart, cdataend);
  XML_SetDefaultHandler(p, defaulthandler); 
}

HouseStyleWriter::~HouseStyleWriter()
{
}

string HouseStyleWriter::getOutput()
{
  return hswd->output;
}

void XMLCALL HouseStyleWriter::start(void *data, const XML_Char *el, const XML_Char **attr)
{
  HouseStyleWriterData *hswd;
  hswd = (HouseStyleWriterData *)data;
  hswd->setState(STATE_ON_START);
     
  if (hswd->textnode.size())
  {
    if (hswd->elementSet.count(hswd->getCount()))
      modify(hswd->v, hswd->textnode, hswd->getCount());
    hswd->output += xmliseTextNode(hswd->textnode);
    hswd->textnode = "";
  }

  hswd->output += '<';
  hswd->output += el;
  for (; *attr; attr += 2)
  {
    hswd->output += ' ';
    hswd->output += *attr;
    hswd->output += "=\"";
    hswd->output += xmliseAttribute(*(attr + 1));
    hswd->output += '"';
  }
  hswd->output += '>';
}

void XMLCALL HouseStyleWriter::end(void *data, const XML_Char *el)
{
  HouseStyleWriterData *hswd;
  hswd = (HouseStyleWriterData *)data;
  //++(hswd->elementCount);
  hswd->setState(STATE_ON_END);
     
  if (hswd->textnode.size())
  {
    if (hswd->elementSet.count(hswd->getCount()))
      modify(hswd->v, hswd->textnode, hswd->getCount());
    hswd->output += xmliseTextNode(hswd->textnode);
    hswd->textnode = "";
  }
  hswd->output += "</";
  hswd->output += el;
  hswd->output += '>';
}

void XMLCALL HouseStyleWriter::characterdata(void *data, const XML_Char *s, int len)
{
  HouseStyleWriterData *hswd;
  hswd = (HouseStyleWriterData *)data;
  hswd->textnode.append(s, len);
}

void XMLCALL HouseStyleWriter::xmldecl(
  void *data,
  const XML_Char *version,
  const XML_Char *encoding,
  int standalone)
{
  HouseStyleWriterData *hswd;
  hswd = (HouseStyleWriterData *)data;
  hswd->output += "<?xml version=\"";
  hswd->output += version;
  hswd->output += "\" encoding=\"UTF-8\"";
  if (standalone != -1)
  {
    hswd->output += " standalone=\"";
    hswd->output += (standalone) ? "yes" : "no";
    hswd->output += "\"";
  }
  hswd->output += "?>";
}

void XMLCALL HouseStyleWriter::cdatastart(void *data)
{
  HouseStyleWriterData *hswd;
  hswd = (HouseStyleWriterData *)data;
  hswd->setState(STATE_ON_CDATA_START);

  if (hswd->textnode.size())
  {
    if (hswd->elementSet.count(hswd->getCount()))
      modify(hswd->v, hswd->textnode, hswd->getCount());
    hswd->output += hswd->textnode;
    hswd->textnode = "";
  }
  
  hswd->output += "<![CDATA[";
}

void XMLCALL HouseStyleWriter::cdataend(void *data)
{
  HouseStyleWriterData *hswd;
  hswd = (HouseStyleWriterData *)data;
  hswd->setState(STATE_ON_CDATA_END);

  if (hswd->textnode.size())
  {
    if (hswd->elementSet.count(hswd->getCount()))
      modify(hswd->v, hswd->textnode, hswd->getCount());
    hswd->output += hswd->textnode;
    hswd->textnode = "";
  }
  
  hswd->output += "]]>";
}

void XMLCALL HouseStyleWriter::defaulthandler(
  void *data,
  const XML_Char *s,
  int len)
{
  HouseStyleWriterData *hswd;
  hswd = (HouseStyleWriterData *)data;
  hswd->output.append(s, len);
}

void HouseStyleWriter::modify(
  vector<ContextMatch> &v,
  string &buffer,
  unsigned elementCount)
{
  int vectorsize, os_adjust, exclusion;
  vectorsize = v.size();
  os_adjust = exclusion = 0;
  string cmp1, cmp2;
  
  for (int i = 0; i < vectorsize; ++i)
  {
    unsigned vectorElementCount = v[i].elementCount;
    if (vectorElementCount < elementCount)
      continue;
    else if (vectorElementCount > elementCount)
      break;
    else if (vectorElementCount == elementCount)
    {
          int offset = (int)v[i].offset + os_adjust;
          
          if (offset < exclusion)
            continue;

          // check match is as expected
          try {
            cmp1 = v[i].match;
            cmp2 = buffer.substr(offset, v[i].match.size());
          }
          catch (std::exception& e)
          {
            continue;
          }
          
          if (cmp1.compare(cmp2))
            continue;
          
          buffer.replace(offset, v[i].match.size(), v[i].replace.c_str());
          
          os_adjust += v[i].replace.size() - v[i].match.size();
          exclusion = offset + v[i].replace.size();
    }
  }
}