//____________________________________________________________________________
/*!

\class   GAstro

\brief   A class for astronomical calculation
         Astronomical algorithms implemented in this library are based on
          J. Meeus, Astronomical Algorithms, Willmann-Bell, Incorporated, 1991.
         Equatorial coordinates refer to 2000.0 epoch

\author  Carla Distefano <distefano_c@lns.infn.it>
         LNS-INFN, Catania

\created February 1, 2016

\cpright  Copyright (c) 2016-2019, The KM3NeT Collaboration
          For the full text of the license see $GSEAGEN/LICENSE
*/
//____________________________________________________________________________

#ifndef _GASTRO__
#define _GASTRO__

#include <iostream>
#include <string>

using namespace std;

class GAstro {

  public:
    GAstro(double Latitude, double Longitude);
    GAstro(double Latitude, double Longitude, double UTMConvergeAngle, bool UseUTMSystem);
    ~GAstro();

    void SetCoordinates(double Latitude, double Longitude);

    double GST(double MJD);     // returns GST in radians
    double LST(double MJD);     // returns LST in radians

    void Eq2Hor(double LST, double RA, double Dec, double * Azimuth, double * Altitude);
    void Hor2Eq(double Altitude, double Azimuth, double LST, double * RA, double * Dec);

    void Gal2Eq(string Equinox, double GalLat, double GalLong, double * RA, double * Dec);
    void Eq2Gal(string Equinox, double RA, double Dec, double * GalLat, double * GalLong);


    void Hor2Direction(double Azimuth, double Altitude, double * vx, double * vy, double * vz);
    void Direction2Hor(double vx, double vy, double vz,double * Azimuth, double * Altitude);//// implementare

    void CalcPrecession(double MJD0, double MJD, double RA0, double Dec0, double *RA, double *Dec);
    void CalcNutation(double MJD, double RA0, double Dec0, double *RA, double *Dec);

    void CalcSrcDirMJD(double MJD, double RA, double Dec, double * vx, double * vy, double * vz);
    void CalcSrcDirMJD(double MJD, double RA, double Dec, double * CosTheta, double * Phi);

    void CalcSrcDirLST(double LST, double RA, double Dec, double * vx, double * vy, double * vz);
    void CalcSrcDirLST(double LST, double RA, double Dec, double * CosTheta, double * Phi);

    static double CalcMJD(string Date); // Date in format dd-mm-yyyy,hh:mm:ss
    static double CalcMJD(int month, int day, int hour, int min, int sec, int year);

    static double CalcDate(double MJD, string * Date);

    static void CalcTimeStamp(double MJD, unsigned int * TimeStampSec, unsigned int * TimeStampTick);
    static double CalcMJDFromTimeStamp(unsigned int TimeStampSec, unsigned int TimeStampTick);

  private:

    double fLatitude;           // site latitude in rad
    double fLongitude;          // site longitude in rad, positive westwards from the meridian of Greenwich, and negative to the east.
    double fUTMConvergeAngle;   // convergence angle of UTM system, in rad
    bool   fUseUTMSystem;       // if true use the UTM reference system
};

#endif // _GASTRO__