/**
  * @RDE_HEADER@
  * LtsCoordinate
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by Norbert Thoden, ESVG, 2024-08-27
  */


#include "lts_coordinate.h"
#include <QLineF>

namespace LtsCoordTrans
{

static long s_conversion_counter = 0; // counts conversion

//
std::function<double(double, double, double, bool*)> LtsCoordinate::m_getElevationCB;

//------------------------------------------------------------------------------
// class LtsCoordinate
//------------------------------------------------------------------------------
void LtsCoordinate::setElevationCallback(const elevationCbFunc &elevationCB)
{
  m_getElevationCB = elevationCB;
}

bool LtsCoordinate::hasElevationCallback()
{
  return m_getElevationCB != nullptr;
}

double LtsCoordinate::elevationAt(double defaultElevation, bool *bIsCovered) const
{
  // shall we cache bIsCovered also?
  // no. If bIsCovered is provided, we explicitly call m_getElevationCB
  // if not, we benefit from cache (m_elevation);
  if (!bIsCovered)
    if (!std::isnan(m_elevation))
      return m_elevation;
  if (m_getElevationCB)
      m_elevation = m_getElevationCB(m_geo.lon(), m_geo.lat(), defaultElevation, bIsCovered);
  return m_elevation;
}

void LtsCoordinate::setZValueAccordingElevation(double defaultElevation)
{
  m_geo.z(elevationAt(defaultElevation));
}

double LtsCoordinate::elevationAt(const LtsCoordinate &coordinate, double defaultElevation, bool *bIsCovered)
{
  return coordinate.elevationAt(defaultElevation, bIsCovered);
}

void LtsCoordinate::replaceZValueByElevationIfValue(double zValueToBeReplaced, double defaultElevation)
{
  // 2024-10: Norbert Thoden
  // if (qFuzzyCompare(m_geo.z(), zValueToBeReplaced)) did not work with NaN as expected
  // qFuzzyCompare(std::nan(""), std::nan("")) will return 'false' !!!
  // so check NaN explicit:

  if ((std::isnan(zValueToBeReplaced) && std::isnan(m_geo.z()))  ||
      qFuzzyCompare(m_geo.z(), zValueToBeReplaced))
    setZValueAccordingElevation(defaultElevation);
}

double LtsCoordinate::angleDegreeUtm2D(const LtsCoordinate &coord1, const LtsCoordinate &coord2)
{
  const LtsCoordTrans::UtmCoordinate &utm1 = coord1.utmCoordinate();                     // implicit coord1.zone will be set
  const LtsCoordTrans::UtmCoordinate &utm2 = coord2.utmCoordinateDiffZone(utm1.zone);

  const QPointF& offsetUtm = utm2.toPoint() - utm1.toPoint();
  QLineF poly(QPointF(), offsetUtm);
  const double angle = poly.angle();


  // QLineF::angle()
  //        270
  //         |
  //         |
  // 180 --------- 0
  //         |
  //         |
  //        90

  // desired:
  //         0
  //         |
  //         |
  // 270 --------- 90
  //         |
  //         |
  //        180

  return fmod(angle+90.0, 360);
}

const UtmCoordinate &LtsCoordinate::utmCoordinateInternal(int zone) const
{
  if (zone == -1)
  {
    if (!hasUtm())
      convertGeoToUtm();
    return m_utm2D;                 // <- return
  }
  utmCoordinateDiffZone(zone);      // ensure m_utm2D_differentZone
  return m_utm2D_differentZone;     // <- return
}

void LtsCoordinate::convertGeoToUtm() const
{
  // geo -> utm
  int zone = -1;
  // avoid working with NaN
  if (std::isnan(m_geo.lon()) || std::isnan(m_geo.lat()))
  {
    fprintf(stderr, "Error while fromGeographic, value is NaN\n");
    m_utm2D = LtsCoordTrans::UtmCoordinate();
    return;
  }

#ifdef LTS_DEBUG
  ++s_conversion_counter;
#endif // LTS_DEBUG

  m_utm2D = LtsCoordTrans::UtmCoordinate::fromGeographic(m_geo.lon(), m_geo.lat(), zone);
  Q_ASSERT_X(m_utm2D.zone > 0, "LtsCoordinate", "zone has to be set");
}

QString LtsCoordinate::mgrs(int prec, bool withSpaces) const
{
  utmCoordinateInternal();      // ensure m_utm2D
  QString tmp = m_utm2D.mgrs(prec, withSpaces);
  return tmp;
}

QString LtsCoordinate::mgrsWithZ(int prec, bool withSpaces) const
{
  double ele = elevationAt();
  QString tmp = mgrs(prec, withSpaces) + QStringLiteral(" z=") + QString::number(ele, 'f', 2);
  return tmp;
}


QString LtsCoordinate::toString(bool fullAndExpensive) const
{
  if (fullAndExpensive)
  {
    utmCoordinateInternal();      // ensure m_utm2D
    elevationAt();                // ensure m_elevation
  }
  std::ostringstream stream;
  stream << "LtsCoordinate(m_geo=" << m_geo
         << ", m_utm2D.x " << m_utm2D.x << ", m_utm2D.y " << m_utm2D.y << ", m_utm2D.zone " << m_utm2D.zone;
  if (!qFuzzyIsNull(m_utm2D.x) || !qFuzzyIsNull(m_utm2D.y))
    stream << ", m_utm2D.mgrs '" << m_utm2D.mgrs().toUtf8().constData() << "'";
  stream << ", elevation " << std::fixed << std::setprecision(3) << m_elevation               // << std::fixed << std::setprecision(3) -> 3 decimal places
         << ")";
  return QString::fromStdString(stream.str());
}

void LtsCoordinate::resetConversionCounter()
{
  s_conversion_counter = 0;
}
long LtsCoordinate::getConversionCounter()
{
  return s_conversion_counter;
}


// output operator:
std::ostream &operator<<(std::ostream &stream, const LtsCoordinate &value)
{
  stream << value.toString().toStdString();
  return stream;
}

} // namespace LtsCoordTrans