// Part of BNC, a utility for retrieving decoding and
// converting GNSS data streams from NTRIP broadcasters.
//
// Copyright (C) 2007
// German Federal Agency for Cartography and Geodesy (BKG)
// http://www.bkg.bund.de
// Czech Technical University Prague, Department of Geodesy
// http://www.fsv.cvut.cz
//
// Email: euref-ip@bkg.bund.de
//
// 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, version 2.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

/* -------------------------------------------------------------------------
 * BKG NTRIP Client
 * -------------------------------------------------------------------------
 *
 * Class:      RTCM3Decoder
 *
 * Purpose:    RTCM3 Decoder
 *
 * Author:     L. Mervart
 *
 * Created:    24-Aug-2006
 *
 * Changes:    
 *
 * -----------------------------------------------------------------------*/

#include <iostream>
#include <math.h>
#include <string.h>

#include "RTCM3Decoder.h"
#include "RTCM3coDecoder.h"
#include "bncconst.h"
#include "bncapp.h"
#include "bncutils.h" /* Weber, for latencies */

using namespace std;

#ifndef isinf
#  define isinf(x) 0
#endif

// Error Handling
////////////////////////////////////////////////////////////////////////////
void RTCM3Error(const char*, ...) {
}

// Constructor
////////////////////////////////////////////////////////////////////////////
RTCM3Decoder::RTCM3Decoder(const QString& staID) : GPSDecoder() {

  const int LEAPSECONDS = 14; /* only needed for approx. time */

  QSettings settings;
  _checkMountPoint = settings.value("messTypes").toString();
  _corrLate = settings.value("corrLate").toInt();
  _staID = staID;

  // Ensure, that the Decoder uses the "old" convention for the data structure for Rinex2. Perlt
  _Parser.rinex3 = 0;

  time_t tim;
  tim = time(0) - ((10*365+2+5)*24*60*60 + LEAPSECONDS);

  memset(&_Parser, 0, sizeof(_Parser));
  _Parser.GPSWeek = tim/(7*24*60*60);
  _Parser.GPSTOW  = tim%(7*24*60*60);

  connect(this, SIGNAL(newGPSEph(gpsephemeris*)), 
          (bncApp*) qApp, SLOT(slotNewGPSEph(gpsephemeris*)));
  connect(this, SIGNAL(newGlonassEph(glonassephemeris*)), 
          (bncApp*) qApp, SLOT(slotNewGlonassEph(glonassephemeris*)));

  // Sub-Decoder for Clock and Orbit Corrections
  // -------------------------------------------
  _coDecoder = new RTCM3coDecoder(staID);

  // Mode can be either observations or corrections
  // ----------------------------------------------
  _mode = unknown;
}

// Destructor
////////////////////////////////////////////////////////////////////////////
RTCM3Decoder::~RTCM3Decoder() {
  delete _coDecoder;
}

// 
////////////////////////////////////////////////////////////////////////////
t_irc RTCM3Decoder::Decode(char* buffer, int bufLen) {

  bool decoded = false;

  // Try to decode Clock and Orbit Corrections
  // -----------------------------------------
  if (_mode == unknown || _mode == corrections) {
    if ( _coDecoder->Decode(buffer, bufLen) == success ) {
      decoded = true;

      // Latency, Weber
      // -------
      if ( _corrLate == 2 ) {
        if (0<_coDecoder->_epochList.size()) {
          for (int ii=0;ii<_coDecoder->_epochList.size();ii++) {
            int week;
            double sec;
            double secGPS = _coDecoder->_epochList[ii];
            leapsecGPSWeeks(week, sec);
            double dt = fabs(sec - secGPS);
            const double secPerWeek = 7.0 * 24.0 * 3600.0;
            if (dt > 0.5 * secPerWeek) {
              if (sec > secGPS) {
                sec  -= secPerWeek;
              } else {
                sec  += secPerWeek;
              }
            }
            QString late;
            late = QString("%1 ").arg(int((sec - secGPS)*100.)/100.);
            if (late != "") {
              emit(newMessage(QString(_staID + ": Latency " + late + "sec").toAscii() ) );
            }
          }
        }
      }
      _coDecoder->_epochList.clear();

      if (_mode == unknown) {
        _mode = corrections;
//      emit(newMessage( (_staID + " : mode set to corrections").toAscii() ));
      }
    }
  }

  // Remaining part decodes the Observations
  // ---------------------------------------
  if (_mode == unknown || _mode == observations || _checkMountPoint == _staID || _checkMountPoint == "ALL") {
    for (int ii = 0; ii < bufLen; ii++) {
    
      _Parser.Message[_Parser.MessageSize++] = buffer[ii];
      if (_Parser.MessageSize >= _Parser.NeedBytes) {
    
        // RTCM message types
        // ------------------
          for (int kk = 0; kk < _Parser.typeSize; kk++) {
            _typeList.push_back(_Parser.typeList[kk]);
          }
          _Parser.typeSize = 0;
    
        while(int rr = RTCM3Parser(&_Parser)) {

          // GNSS Observations
          // -----------------
          if (rr == 1 || rr == 2) {
                  decoded = true;
    
            if (!_Parser.init) {
              HandleHeader(&_Parser);
              _Parser.init = 1;
            }
            
            if (rr == 2) {
//            std::cerr << "No valid RINEX! All values are modulo 299792.458!\n";
              emit(newMessage( (_staID + ": No valid RINEX! All values are modulo 299792.458!").toAscii() ));
            }
            
            for (int ii = 0; ii < _Parser.Data.numsats; ii++) {
              p_obs obs = new t_obs();
              _obsList.push_back(obs);
              if      (_Parser.Data.satellites[ii] <= PRN_GPS_END) {
                obs->_o.satSys = 'G';
                obs->_o.satNum = _Parser.Data.satellites[ii];
              }
              else if (_Parser.Data.satellites[ii] <= PRN_GLONASS_END) {
                obs->_o.satSys = 'R';
                obs->_o.satNum = _Parser.Data.satellites[ii] - PRN_GLONASS_START + 1;
              }
              else {
                obs->_o.satSys = 'S';
                obs->_o.satNum = _Parser.Data.satellites[ii] - PRN_WAAS_START + 20;
              }
              obs->_o.GPSWeek  = _Parser.Data.week;
              obs->_o.GPSWeeks = _Parser.Data.timeofweek / 1000.0;
            
              for (int jj = 0; jj < _Parser.numdatatypesGPS; jj++) {
                int v = 0;
                // sepearated declaration and initalization of df and pos. Perlt
                int df;
                int pos;
                df = _Parser.dataflag[jj];
                pos = _Parser.datapos[jj];
                if ( (_Parser.Data.dataflags[ii] & df)
                     && !isnan(_Parser.Data.measdata[ii][pos])
                     && !isinf(_Parser.Data.measdata[ii][pos])) {
                  v = 1;
                }
                else {
                  df = _Parser.dataflagGPS[jj];
                  pos = _Parser.dataposGPS[jj];
                  if ( (_Parser.Data.dataflags[ii] & df)
                       && !isnan(_Parser.Data.measdata[ii][pos])
                       && !isinf(_Parser.Data.measdata[ii][pos])) {
                  v = 1;
                  }
                }
                if (!v) { 
                  continue; 
                }
                else
                {
		  int isat = (_Parser.Data.satellites[ii] < 120 
			      ? _Parser.Data.satellites[ii] 
			      : _Parser.Data.satellites[ii] - 80);
		  
                  // variables df and pos are used consequently. Perlt
                  if      (df & GNSSDF_C1DATA) {
                    obs->_o.C1 = _Parser.Data.measdata[ii][pos];
                  }
                  else if (df & GNSSDF_C2DATA) {
                    obs->_o.C2 = _Parser.Data.measdata[ii][pos];
                  }
                  else if (df & GNSSDF_P1DATA) {
                    obs->_o.P1 = _Parser.Data.measdata[ii][pos];
                  }
                  else if (df & GNSSDF_P2DATA) {
                    obs->_o.P2 = _Parser.Data.measdata[ii][pos];
                  }
                  else if (df & (GNSSDF_L1CDATA|GNSSDF_L1PDATA)) {
                    obs->_o.L1            = _Parser.Data.measdata[ii][pos];
                    obs->_o.SNR1          = _Parser.Data.snrL1[ii];
		    obs->_o.lock_timei_L1 = _Parser.lastlockl1[isat];
                  }
                  else if (df & (GNSSDF_L2CDATA|GNSSDF_L2PDATA)) {
                    obs->_o.L2            = _Parser.Data.measdata[ii][pos];
                    obs->_o.SNR2          = _Parser.Data.snrL2[ii];
		    obs->_o.lock_timei_L2 = _Parser.lastlockl2[isat];
                  }
                  else if (df & (GNSSDF_S1CDATA|GNSSDF_S1PDATA)) {
                    obs->_o.S1   = _Parser.Data.measdata[ii][pos];
                  }
                  else if (df & (GNSSDF_S2CDATA|GNSSDF_S2PDATA)) {
                    obs->_o.S2   = _Parser.Data.measdata[ii][pos];
                  }
                }
              }
            }
          }
    
          // GPS Ephemeris
          // -------------
          else if (rr == 1019) {
            decoded = true;
            gpsephemeris* ep = new gpsephemeris(_Parser.ephemerisGPS);
            emit newGPSEph(ep);
          }
    
          // GLONASS Ephemeris
          // -----------------
          else if (rr == 1020) {
            decoded = true;
            glonassephemeris* ep = new glonassephemeris(_Parser.ephemerisGLONASS);
            emit newGlonassEph(ep);
          }
        }
      }
    }
    if (_mode == unknown && decoded) {
      _mode = observations;
//    emit(newMessage( (_staID + " : mode set to observations").toAscii() ));
    }
  }

  if (decoded) {
    return success;
  }
  else {
    return failure;
  }
}