// 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:      t_rnxObsFile
 *
 * Purpose:    Reads RINEX Observation File
 *
 * Author:     L. Mervart
 *
 * Created:    24-Jan-2012
 *
 * Changes:    
 *
 * -----------------------------------------------------------------------*/

#include <iostream>
#include <iomanip>
#include "rnxobsfile.h"
#include "bncutils.h"

using namespace std;

// Constructor
////////////////////////////////////////////////////////////////////////////
t_rnxObsFile::t_rnxObsHeader::t_rnxObsHeader() {
  _antNEU.ReSize(3); 
  _xyz.ReSize(3);    
  _antNEU  = 0.0;
  _xyz     = 0.0;
  _version = 0.0;
}

// Destructor
////////////////////////////////////////////////////////////////////////////
t_rnxObsFile::t_rnxObsHeader::~t_rnxObsHeader() {
}

// Read Header
////////////////////////////////////////////////////////////////////////////
t_irc t_rnxObsFile::t_rnxObsHeader::read(QTextStream* stream) {
  while (stream->status() == QTextStream::Ok && !stream->atEnd()) {
    QString line = stream->readLine();
    if (line.isEmpty()) {
      continue;
    }
    QString value = line.left(60).trimmed();
    QString key   = line.mid(60).trimmed();
    if      (key == "END OF HEADER") {
      break;
    }
    else if (key == "RINEX VERSION / TYPE") {
      QTextStream in(value.toAscii(), QIODevice::ReadOnly);
      in >> _version;
    }
    else if (key == "MARKER NAME") {
      _markerName = value;
    }
    else if (key == "ANT # / TYPE") {
      _antennaName = value.mid(20);
    }
    else if (key == "APPROX POSITION XYZ") {
      QTextStream in(value.toAscii(), QIODevice::ReadOnly);
      in >> _xyz[0] >> _xyz[1] >> _xyz[2];
    }
    else if (key == "ANTENNA: DELTA H/E/N") {
      QTextStream in(value.toAscii(), QIODevice::ReadOnly);
      in >> _antNEU[2] >> _antNEU[1] >> _antNEU[0];
    }
    else if (key == "# / TYPES OF OBSERV") {
      QTextStream in(value.toAscii(), QIODevice::ReadOnly);
      int nTypes;
      in >> nTypes;
      for (int ii = 0; ii < nTypes; ii++) {
        QString hlp;
        in >> hlp;
        _obsTypes << hlp;
      }
    }
  }

  return success;
}

// Constructor
////////////////////////////////////////////////////////////////////////////
t_rnxObsFile::t_rnxObsFile(QString fileName) {
  expandEnvVar(fileName);
  _file   = new QFile(fileName);
  _file->open(QIODevice::ReadOnly | QIODevice::Text);
  _stream = new QTextStream();
  _stream->setDevice(_file);
  _header.read(_stream);
}

// Destructor
////////////////////////////////////////////////////////////////////////////
t_rnxObsFile::~t_rnxObsFile() {
  delete _stream;
  delete _file;
}

// Retrieve single Epoch
////////////////////////////////////////////////////////////////////////////
const t_rnxObsFile::t_epo* t_rnxObsFile::nextEpoch() {

  _currEpo.clear();

  if (version() < 3.0) {
    return nextEpochV2();
  }
  else {
    return nextEpochV3();
  }
}

// Retrieve single Epoch (RINEX Version 3)
////////////////////////////////////////////////////////////////////////////
const t_rnxObsFile::t_epo* t_rnxObsFile::nextEpochV3() {
  while (_stream->status() == QTextStream::Ok && !_stream->atEnd()) {

    QString line = _stream->readLine();

    if (line.isEmpty()) {
      continue;
    }

    QTextStream in(line.mid(1).toAscii());

    // Epoch Time
    // ----------
    int    year, month, day, hour, min, flag;
    double sec;
    in >> year >> month >> day >> hour >> min >> sec >> flag;
    _currEpo.tt.set(year, month, day, hour, min, sec);

    // Number of Satellites
    // --------------------
    int numSat;
    readInt(line, 32, 3, numSat);
  
    _currEpo.satObs.resize(numSat);

    // Observations
    // ------------
    for (int iSat = 0; iSat < numSat; iSat++) {
      line = _stream->readLine();
      _currEpo.satObs[iSat].prn = line.mid(0,3);
      for (int iType = 0; iType < _header.nTypes(); iType++) {
        int pos = 16*iType;
        readDbl(line, pos,     14, _currEpo.satObs[iSat][iType]);
        readInt(line, pos + 14, 1, _currEpo.satObs[iSat].lli);
        readInt(line, pos + 15, 1, _currEpo.satObs[iSat].snr);
      }
    }
  }

  return 0;
}

// Retrieve single Epoch (RINEX Version 2)
////////////////////////////////////////////////////////////////////////////
const t_rnxObsFile::t_epo* t_rnxObsFile::nextEpochV2() {
  while (_stream->status() == QTextStream::Ok && !_stream->atEnd()) {

    QString line = _stream->readLine();

    if (line.isEmpty()) {
      continue;
    }

    QTextStream in(line.toAscii());

    // Epoch Time
    // ----------
    int    year, month, day, hour, min, flag;
    double sec;
    in >> year >> month >> day >> hour >> min >> sec >> flag;
    if      (year <  80) {
      year += 2000;
    }
    else if (year < 100) {
      year += 1900;
    }
    _currEpo.tt.set(year, month, day, hour, min, sec);

    // Number of Satellites
    // --------------------
    int numSat;
    readInt(line, 29, 3, numSat);
  
    _currEpo.satObs.resize(numSat);

    // Read Satellite Numbers
    // ----------------------
    int pos = 32;
    for (int iSat = 0; iSat < numSat; iSat++) {
      if (iSat > 0 && iSat % 12 == 0) {
        line = _stream->readLine();
        pos = 32;
      }
      QString prn = line.mid(pos, 3);
      pos += 3;

      _currEpo.satObs[iSat].prn = prn;
      _currEpo.satObs[iSat].ReSize(_header.nTypes());
    }

    // Read Observation Records
    // ------------------------
    for (int iSat = 0; iSat < numSat; iSat++) {
      line = _stream->readLine();
      pos  = 0;
      QString prn = _currEpo.satObs[iSat].prn;
      for (int iType = 0; iType < _header.nTypes(); iType++) {
        if (iType > 0 && iType % 5 == 0) {
          line = _stream->readLine();
          pos  = 0;
        }
        readDbl(line, pos,     14, _currEpo.satObs[iSat][iType]);
        readInt(line, pos + 14, 1, _currEpo.satObs[iSat].lli);
        readInt(line, pos + 15, 1, _currEpo.satObs[iSat].snr);
        pos += 16;
      }
    }

    return &_currEpo;
  }

  return 0;
}