/***************************************************************************
      gpsdata.cpp  -  Data structures for GPS data
                             -------------------
    begin                : 2004-04-14
    copyright            : (C) 2004 by Lars Luthman
    email                : larsl@users.sourceforge.net
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#include <limits>
#include <stdexcept>

#include <qfile.h>

#include "gpsdata.h"


QString GPSObject::xmlify(const QString& str) {
  QString tmp = str;
  tmp.replace("&", "&amp;");
  tmp.replace("<", "&lt;");
  tmp.replace(">", "&gt;");
  tmp.replace("\"", "&quot;");
  tmp.replace("\'", "&apos;");
  return tmp;
}


void GPSObject::writeXML(QTextStream& stream) {
  if (!name.isEmpty())
    stream<<"<name>"<<xmlify(name)<<"</name>\n";
  if (!cmt.isEmpty())
    stream<<"<cmt>"<<xmlify(cmt)<<"</cmt>\n";
  if (!desc.isEmpty())
    stream<<"<desc>"<<xmlify(desc)<<"</desc>\n";
  if (!src.isEmpty())
    stream<<"<src>"<<xmlify(src)<<"</src>\n";
  if (!url.isEmpty())
    stream<<"<url>"<<xmlify(url)<<"</url>\n";
  if (!urlname.isEmpty())
    stream<<"<urlname>"<<xmlify(urlname)<<"</urlname>\n";
}


GPSPoint::GPSPoint() {
  ele = -std::numeric_limits<double>::max();
}


void GPSPoint::writeXML(QTextStream& stream) {
  GPSObject::writeXML(stream);
  if (ele != -std::numeric_limits<double>::max())
    stream<<"<ele>"<<ele<<"</ele>\n";
  if (!sym.isEmpty())
    stream<<"<sym>"<<xmlify(sym)<<"</sym>\n";
}


GPSExtended::GPSExtended()
  : xMin(std::numeric_limits<double>::max()),
    xMax(-std::numeric_limits<double>::max()),
    yMin(std::numeric_limits<double>::max()),
    yMax(-std::numeric_limits<double>::max()),
    number(std::numeric_limits<int>::max()) {
  
}


void GPSExtended::writeXML(QTextStream& stream) {
  GPSObject::writeXML(stream);
  if (number != std::numeric_limits<int>::max())
    stream<<"<number>"<<number<<"</number>\n";
}


void Waypoint::writeXML(QTextStream& stream) {
  stream<<"<wpt lat=\""<<lat<<"\" lon=\""<<lon<<"\">\n";
  GPSPoint::writeXML(stream);
  stream<<"</wpt>\n";
}


void Route::writeXML(QTextStream& stream) {
  stream<<"<rte>\n";
  GPSExtended::writeXML(stream);
  for (int i = 0; i < points.size(); ++i) {
    stream<<"<rtept lat=\""<<points[i].lat
	  <<"\" lon=\""<<points[i].lon<<"\">\n";
    points[i].writeXML(stream);
    stream<<"</rtept>\n";
  }
  stream<<"</rte>\n";
}


void Track::writeXML(QTextStream& stream) {
  stream<<"<trk>\n";
  GPSExtended::writeXML(stream);
  for (int i = 0; i < segments.size(); ++i) {
    stream<<"<trkseg>\n";
    for (int j = 0; j < segments[i].points.size(); ++j) {
      stream<<"<trkpt lat=\""<<segments[i].points[j].lat
      <<"\" lon=\""<<segments[i].points[j].lon<<"\">\n";
      segments[i].points[j].writeXML(stream);
      stream<<"</trkpt>\n";
    }
    stream<<"</trkseg>\n";
  }
  stream<<"</trk>\n";
}


GPSData::GPSData() {
  xMin = std::numeric_limits<double>::max();
  xMax = -std::numeric_limits<double>::max();
  yMin = std::numeric_limits<double>::max();
  yMax = -std::numeric_limits<double>::max();
  nextWaypoint = 0;
  nextRoute = 0;
  nextTrack = 0;
}


QgsRect* GPSData::getExtent() const {
  return new QgsRect(xMin, yMin, xMax, yMax);
}


int GPSData::getNumberOfWaypoints() const {
  return waypoints.size();
}


int GPSData::getNumberOfRoutes() const {
  return routes.size();
}


int GPSData::getNumberOfTracks() const {
  return tracks.size();
}


GPSData::WaypointIterator GPSData::waypointsBegin() {
  return waypoints.begin();
}


GPSData::RouteIterator GPSData::routesBegin() {
  return routes.begin();
}


GPSData::TrackIterator GPSData::tracksBegin() {
  return tracks.begin();
}


GPSData::WaypointIterator GPSData::waypointsEnd() {
  return waypoints.end();
}


GPSData::RouteIterator GPSData::routesEnd() {
  return routes.end();
}


GPSData::TrackIterator GPSData::tracksEnd() {
  return tracks.end();
}


GPSData::WaypointIterator GPSData::addWaypoint(double lat, double lon, 
                 QString name, double ele) {
  Waypoint wpt;
  wpt.lat = lat;
  wpt.lon = lon;
  wpt.name = name;
  wpt.ele = ele;
  return addWaypoint(wpt);
}


GPSData::WaypointIterator GPSData::addWaypoint(const Waypoint& wpt) {
  xMax = xMax > wpt.lon ? xMax : wpt.lon;
  xMin = xMin < wpt.lon ? xMin : wpt.lon;
  yMax = yMax > wpt.lat ? yMax : wpt.lat;
  yMin = yMin < wpt.lat ? yMin : wpt.lat;
  WaypointIterator iter = waypoints.insert(waypoints.end(), wpt);
  iter->id = nextWaypoint++;
  return iter;
}


GPSData::RouteIterator GPSData::addRoute(QString name) {
  Route rte;
  rte.name = name;
  return addRoute(rte);
}


GPSData::RouteIterator GPSData::addRoute(const Route& rte) {
  xMax = xMax > rte.xMax ? xMax : rte.xMax;
  xMin = xMin < rte.xMin ? xMin : rte.xMin;
  yMax = yMax > rte.yMax ? yMax : rte.yMax;
  yMin = yMin < rte.yMin ? yMin : rte.yMin;
  RouteIterator iter = routes.insert(routes.end(), rte);
  iter->id = nextRoute++;
  return iter;
}


GPSData::TrackIterator GPSData::addTrack(QString name) {
  Track trk;
  trk.name = name;
  return addTrack(trk);
}
  

GPSData::TrackIterator GPSData::addTrack(const Track& trk) {
  xMax = xMax > trk.xMax ? xMax : trk.xMax;
  xMin = xMin < trk.xMin ? xMin : trk.xMin;
  yMax = yMax > trk.yMax ? yMax : trk.yMax;
  yMin = yMin < trk.yMin ? yMin : trk.yMin;
  TrackIterator iter = tracks.insert(tracks.end(), trk);
  iter->id = nextTrack++;
  return iter;
}


void GPSData::removeWaypoints(std::list<int> const & ids) {
  std::list<int> ids2 = ids;
  ids2.sort();
  std::list<int>::const_iterator iter = ids2.begin();
  WaypointIterator wIter;
  for (wIter = waypoints.begin(); 
       wIter != waypoints.end() && iter != ids2.end(); ) {
    WaypointIterator tmpIter = wIter;
    ++tmpIter;
    if (wIter->id == *iter) {
      waypoints.erase(wIter);
      ++iter;
    }
    wIter = tmpIter;
  }
}
  

void GPSData::removeRoutes(std::list<int> const & ids) {
  std::list<int> ids2 = ids;
  ids2.sort();
  std::list<int>::const_iterator iter = ids2.begin();
  RouteIterator rIter;
  for (rIter = routes.begin(); rIter != routes.end() && iter != ids2.end(); ) {
    RouteIterator tmpIter = rIter;
    ++tmpIter;
    if (rIter->id == *iter) {
      routes.erase(rIter);
      ++iter;
    }
    rIter = tmpIter;
  }  
}
  

void GPSData::removeTracks(std::list<int> const & ids) {
  std::list<int> ids2 = ids;
  ids2.sort();
  std::list<int>::const_iterator iter = ids2.begin();
  TrackIterator tIter;
  for (tIter = tracks.begin(); tIter != tracks.end() && iter != ids2.end(); ) {
    TrackIterator tmpIter = tIter;
    ++tmpIter;
    if (tIter->id == *iter) {
      tracks.erase(tIter);
      ++iter;
    }
    tIter = tmpIter;
  }  
}


void GPSData::writeXML(QTextStream& stream) {
  stream.setEncoding(QTextStream::UnicodeUTF8);
  stream<<"<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
  <<"<gpx version=\"1.0\" creator=\"Quantum GIS\">\n";
  for (WaypointIterator wIter = waypoints.begin(); 
       wIter != waypoints.end(); ++wIter)
    wIter->writeXML(stream);
  for (RouteIterator rIter = routes.begin(); rIter != routes.end(); ++rIter)
    rIter->writeXML(stream);
  for (TrackIterator tIter = tracks.begin(); tIter != tracks.end(); ++tIter)
    tIter->writeXML(stream);
  stream<<"</gpx>\n";
  stream<<flush;
}


GPSData* GPSData::getData(const QString& filename) {
  // if the data isn't there already, try to load it
  if (dataObjects.find(filename) == dataObjects.end()) {
    QFile file(filename);
    GPSData* data = new GPSData;
    std::cerr<<"Loading file "<<filename<<std::endl;
    GPXHandler handler(*data);
    bool failed = false;
    
    // SAX parsing
    XML_Parser p = XML_ParserCreate(NULL);
    XML_SetUserData(p, &handler);
    XML_SetElementHandler(p, GPXHandler::start, GPXHandler::end);
    XML_SetCharacterDataHandler(p, GPXHandler::chars);
    long int bufsize = 10*1024*1024;
    char* buffer = new char[bufsize];
    file.open(IO_ReadOnly);
    int atEnd = 0;
    while (!file.atEnd()) {
      long int readBytes = file.readBlock(buffer, bufsize);
      if (file.atEnd())
  atEnd = 1;
      if (!XML_Parse(p, buffer, readBytes, atEnd)) {
  std::cerr<<"Parse error at line "
     <<XML_GetCurrentLineNumber(p)<<": "
     <<XML_ErrorString(XML_GetErrorCode(p))<<std::endl;
  failed = true;
  break;
      }
    }
    delete [] buffer;
    XML_ParserFree(p);
    if (failed)
      return 0;
    
    dataObjects[filename] = std::pair<GPSData*, unsigned>(data, 0);
  }
  else
    std::cerr<<filename<<" is already loaded"<<std::endl;
  
  // return a pointer and increase the reference count for that filename
  DataMap::iterator iter = dataObjects.find(filename);
  ++(iter->second.second);
  return (GPSData*)(iter->second.first);
}


void GPSData::releaseData(const QString& filename) {
  
  /* decrease the reference count for the filename (if it is used), and erase
     it if the reference count becomes 0 */
  DataMap::iterator iter = dataObjects.find(filename);
  if (iter != dataObjects.end()) {
    std::cerr<<"unrefing "<<filename<<std::endl;
    if (--(iter->second.second) == 0) {
      std::cerr<<"No one's using "<<filename<<", I'll erase it"<<std::endl;
      delete iter->second.first;
      dataObjects.erase(iter);
    }
  }
}


// we have to initialize the static member
GPSData::DataMap GPSData::dataObjects;




bool GPXHandler::startElement(const XML_Char* qName, const XML_Char** attr) {
  //std::cerr<<"<"<<qName<<">"<<std::endl;
  if (!std::strcmp(qName, "gpx")) {
    parseModes.push(ParsingDocument);
    mData = GPSData();
  }
    
  // top level objects
  else if (!std::strcmp(qName, "wpt")) {
    parseModes.push(ParsingWaypoint);
    mWpt = Waypoint();
    for (int i = 0; attr[2*i] != NULL; ++i) {
      if (!std::strcmp(attr[2*i], "lat"))
  mWpt.lat = QString(attr[2*i+1]).toDouble();
      else if (!std::strcmp(attr[2*i], "lon"))
  mWpt.lon = QString(attr[2*i+1]).toDouble();
    }
    mObj = &mWpt;
  }
  else if (!std::strcmp(qName, "rte")) {
    parseModes.push(ParsingRoute);
    mRte = Route();
    mObj = &mRte;
  }
  else if (!std::strcmp(qName, "trk")) {
    parseModes.push(ParsingTrack);
    mTrk = Track();
    mObj = &mTrk;
  }
    
  // common properties
  else if (!std::strcmp(qName, "name")) {
    if (parseModes.top() == ParsingWaypoint ||
  parseModes.top() == ParsingRoute ||
  parseModes.top() == ParsingTrack) {
      mString = &mObj->name;
      mCharBuffer = "";
      parseModes.push(ParsingString);
    }
    else
      parseModes.push(ParsingUnknown);
  }
  else if (!std::strcmp(qName, "cmt")) {
    if (parseModes.top() == ParsingWaypoint ||
  parseModes.top() == ParsingRoute ||
  parseModes.top() == ParsingTrack) {
      mString = &mObj->cmt;
      mCharBuffer = "";
      parseModes.push(ParsingString);
    }
    else
      parseModes.push(ParsingUnknown);
  }
  else if (!std::strcmp(qName, "desc")) {
    if (parseModes.top() == ParsingWaypoint ||
  parseModes.top() == ParsingRoute ||
  parseModes.top() == ParsingTrack) {
      mString = &mObj->desc;
      mCharBuffer = "";
      parseModes.push(ParsingString);
    }
    else
      parseModes.push(ParsingUnknown);
  }
  else if (!std::strcmp(qName, "src")) {
    if (parseModes.top() == ParsingWaypoint ||
  parseModes.top() == ParsingRoute ||
  parseModes.top() == ParsingTrack) {
      mString = &mObj->src;
      mCharBuffer = "";
      parseModes.push(ParsingString);
    }
    else
      parseModes.push(ParsingUnknown);
  }
  else if (!std::strcmp(qName, "url")) {
    if (parseModes.top() == ParsingWaypoint ||
  parseModes.top() == ParsingRoute ||
  parseModes.top() == ParsingTrack) {
      mString = &mObj->url;
      mCharBuffer = "";
      parseModes.push(ParsingString);
    }
    else
      parseModes.push(ParsingUnknown);
  }
  else if (!std::strcmp(qName, "urlname")) {
    if (parseModes.top() == ParsingWaypoint ||
  parseModes.top() == ParsingRoute ||
  parseModes.top() == ParsingTrack) {
      mString = &mObj->urlname;
      mCharBuffer = "";
      parseModes.push(ParsingString);
    }
    else
      parseModes.push(ParsingUnknown);
  }
    
  // waypoint-specific attributes
  else if (!std::strcmp(qName, "ele")) {
    if (parseModes.top() == ParsingWaypoint) {
      mDouble = &mWpt.ele;
      mCharBuffer = "";
      parseModes.push(ParsingDouble);
    }
    else
      parseModes.push(ParsingUnknown);
  }
  else if (!std::strcmp(qName, "sym")) {
    if (parseModes.top() == ParsingWaypoint) {
      mString = &mWpt.sym;
      mCharBuffer = "";
      parseModes.push(ParsingString);
    }
    else
      parseModes.push(ParsingUnknown);
  }
    
  // route/track-specific attributes
  else if (!std::strcmp(qName, "number")) {
    if (parseModes.top() == ParsingRoute) {
      mInt = &mRte.number;
      mCharBuffer = "";
      parseModes.push(ParsingInt);
    }
    else if (parseModes.top() == ParsingTrack) {
      mInt = &mTrk.number;
      parseModes.push(ParsingInt);
    }
    else
      parseModes.push(ParsingUnknown);
  }    
    
  // route points
  else if (!std::strcmp(qName, "rtept")) {
    if (parseModes.top() == ParsingRoute) {
      mRtept = Routepoint();
      for (int i = 0; attr[2*i] != NULL; ++i) {
  if (!std::strcmp(attr[2*i], "lat"))
    mRtept.lat = QString(attr[2*i+1]).toDouble();
  else if (!std::strcmp(attr[2*i], "lon"))
    mRtept.lon = QString(attr[2*i+1]).toDouble();
      }
      parseModes.push(ParsingRoutepoint);
    }
    else
      parseModes.push(ParsingUnknown);
  }
    
  // track segments and points
  else if (!std::strcmp(qName, "trkseg")) {
    if (parseModes.top() == ParsingTrack) {
      mTrkseg = TrackSegment();
      parseModes.push(ParsingTrackSegment);
    }
    else
      parseModes.push(ParsingUnknown);
  }
  else if (!std::strcmp(qName, "trkpt")) {
    if (parseModes.top() == ParsingTrackSegment) {
      mTrkpt = Trackpoint();
      for (int i = 0; attr[2*i] != NULL; ++i) {
  if (!std::strcmp(attr[2*i], "lat"))
    mTrkpt.lat = QString(attr[2*i+1]).toDouble();
  else if (!std::strcmp(attr[2*i], "lon"))
    mTrkpt.lon = QString(attr[2*i+1]).toDouble();
      }
      parseModes.push(ParsingTrackpoint);
    }
    else
      parseModes.push(ParsingUnknown);
  }
    
  // unknown
  else
    parseModes.push(ParsingUnknown);
    
  return true;
}


void GPXHandler::characters(const XML_Char* chars, int len) {
  // This is horrible.
#ifdef XML_UNICODE
  for (int i = 0; i < len; ++i)
    mCharBuffer += QChar(chars[i]);
#else
  mCharBuffer += QString::fromUtf8(chars, len);
#endif
}


bool GPXHandler::endElement(const std::string& qName) {
  if (parseModes.top() == ParsingWaypoint) {
    mData.addWaypoint(mWpt);
  }
  else if (parseModes.top() == ParsingRoute) {
    mData.addRoute(mRte);
  }
  else if (parseModes.top() == ParsingTrack) {
    mData.addTrack(mTrk);
  }
  else if (parseModes.top() == ParsingRoutepoint) {
    mRte.points.push_back(mRtept);
    mRte.xMin = (mRte.xMin < mRtept.lon ? mRte.xMin : mRtept.lon);
    mRte.xMax = (mRte.xMax > mRtept.lon ? mRte.xMax : mRtept.lon);
    mRte.yMin = (mRte.yMin < mRtept.lat ? mRte.yMin : mRtept.lat);
    mRte.yMax = (mRte.yMax > mRtept.lat ? mRte.yMax : mRtept.lat);
  }
  else if (parseModes.top() == ParsingTrackSegment) {
    mTrk.segments.push_back(mTrkseg);
  }
  else if (parseModes.top() == ParsingTrackpoint) {
    mTrkseg.points.push_back(mTrkpt);
    mTrk.xMin = (mTrk.xMin < mTrkpt.lon ? mTrk.xMin : mTrkpt.lon);
    mTrk.xMax = (mTrk.xMax > mTrkpt.lon ? mTrk.xMax : mTrkpt.lon);
    mTrk.yMin = (mTrk.yMin < mTrkpt.lat ? mTrk.yMin : mTrkpt.lat);
    mTrk.yMax = (mTrk.yMax > mTrkpt.lat ? mTrk.yMax : mTrkpt.lat);
  }
  else if (parseModes.top() == ParsingDouble) {
    *mDouble = QString(mCharBuffer).toDouble();
    mCharBuffer = "";
  }
  else if (parseModes.top() == ParsingInt) {
    *mInt = QString(mCharBuffer).toInt();
    mCharBuffer = "";
  }
  else if (parseModes.top() == ParsingString) {
    *mString = mCharBuffer;
    mCharBuffer = "";
  }
  parseModes.pop();
  
  return true;
}