#ifndef _GeoCal_h
#define _GeoCal_h
#include <cmath>
#include <math.h>
#include "DVector.h"
#include "DMatrix.h"
//extern "C" {
// #include "SCsabertime.h"
//} 

class GeoCal {
public:
     GeoCal();

     // Calculate line of sight vector in Spacecraft Coords)
     DVector cal_SC_los_vector(double scanAng);

     void  cal_ECIvector_SCtoMoon(int year,int month,double sec, DVector &, DVector &);
     void cal_ECI_lunar_vector (int year,int month,double sec, double &, 
     double &, DVector &);
     
     // Calculate line of sight vector in Orbit Coords)
     DVector cal_ORB_los_vector(double scanAng,double roll,double pitch,
     double yaw);

     //Calculate horizontal elevation angle
     void cal_horizontal_elevation_angle(double scanAng,
                                       double roll,double pitch, double yaw,
				       double &elevAngle);

     //Calculate trans matrix from SC coords to ECI coords 
     DMatrix matrix_SCtoECI(double *quat);
     
     //Calculate trans matrix from ORB coords to ECF coords
     DMatrix matrix_ORBtoECF(DVector &velECF, DVector &posECF);
     DMatrix matrix_ORBtoECF2(DVector &velECF, DVector &posECF);
     
     //Convert unit vector in ORB to ECF
     int unitVectorORBtoECF(DMatrix &matrixORBtoECF,DVector &unitposORB,
         DVector &unitposECF,DVector &scVelECF);
	   

     //Calculate line of sight vector in ECF Coords)
     DVector cal_ECF_los_vector(DMatrix &tran, DVector &losSC);

     //Calculate the mean greenwich sidereal time in radians  (SUN.FOR)
     void cal_mean_greenwich_sidereal_time(int year,int doy,double sec,
     					   double &, double &,double &);
     //Cal mean greenwich sidereal time in radians 			   
     void cal_mean_greenwich_sidereal_time(int year,int doy,double sec);
     
     //Calculate the true of date greenwich sidereal time in radians
     void cal_greenwich_sidereal_time(int year,int doy,double sec,double &,
     				double &,double &,double &,double &,double &,double &);

     //Calculate solar zenith angle
     void cal_solar_zenith(double gstm,double sdec,double srasn,
                           double rlat,double rlong, double &solarZenith);
     //Calculate solar zenith angle and solar local time
     //void cal_solar_zenith(double gstm,double sdec,double srasn, double rlat,double rlong, double &solarZenith, double &SolarLT);
     //Calculate solar zenith angle 
     void cal_solar_zenith_method2(int day,double hours, double rlat,
                                   double rlong, double &solarZenith);


     void cal_solar_zenith(DVector &vECF, double dlat,double dlong,
                           double &solarZenith);

     void cal_solarLT(double sec,double dlong,double &SolarLT);
//void cal_solar_zenith_solarLT(double gstm,double sdec,double srasn, double dlat,double dlong, double &solarZenith,double &SolarLT);
     //Calculate julianCenturyEpoch1900
     double julianCenturyEpoch1900(int yr,int doy,double sec);

				   
     //Calculate sun-earth distance 
     void cal_sun_earth(int year,int doy,double sec, double &rsun_e);
     double r2r(double x);
     
     //Convert ECI vector to ECF vector
     DVector convert_ECItoECF(int year,int doy,double sec,
     		      DVector &posECI);
//     DVector GeoCal::convert_ECItoECF(int year,int doy,double sec,
//     		      DVector &posECI);
     		      //DVector &posECI, DVector &velECI,int Velocity_req);
     //DVector GeoCal::convert_ECItoECF(SABER_TIME &utcTime,DVector &posECI);
           //DVector &velECI, int Velocity_req);

     //convert the result of atan2(y,x) from -pi to pi to the range
     //of 0 to 2pi
     double datan0(double y, double x);
     
     //Calculate tangent point in ECI 
     DVector calTpECF(DVector &losECF, DVector &ORBposECF);
     //DVector calTpECI(DVector &losECI, DVector &SCposECI,int &notan);
     DVector calTpECI(DVector &losECI, DVector &SCposECI, double gmst,double &lat,double &lon,double &altitude,int &notan);

     void calCart2LLA_F1999(DVector &cartXYZ, double gmst, double &lat, double &lon, double &alt, int &notan);
     double calDeltaT(double t, double p, double u, double v);
     DVector calTpECI(DVector &losECI, DVector &SCposECI, int &notan);

     //Convert ECF to geodetic coordinates 
     void calECF2Geodetic(DVector &TpECF, double &Tplat, double &Tplon,
                                double &Tpalt);
     double Angle_los_moonScan(DVector &losECI,DVector &lunarECI);

     ~GeoCal();        // destructor

protected:
     int size;
     void init(const double*, int);
};
#endif