/***************************************************************************
                          ksmoon.h  -  K Desktop Planetarium
                             -------------------
    begin                : Sun Aug 26 2001
    copyright            : (C) 2001 by Jason Harris
    email                : kstars@30doradus.org
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef KSMOON_H_
#define KSMOON_H_

#include "ksplanetbase.h"
#include "dms.h"

/**@class KSMoon
	*A subclass of SkyObject that provides information
	*needed for the Moon.  Specifically, KSMoon provides a moon-specific
	*findPosition() function.  Also, there is a method findPhase(), which returns
	*the lunar phase as a floating-point number between 0.0 and 1.0.
	*@short Provides necessary information about the Moon.
	*@author Jason Harris
	*@version 1.0
	*/

class KStarsData;
class KSSun;

class KSMoon : public KSPlanetBase  {
public:
    /**
    	*Default constructor.  Set name="Moon".
    	*/
    KSMoon(KStarsData *kd);

    /**Destructor (empty). */
    ~KSMoon();

    /**
    	*Determine the phase angle of the moon, and assign the appropriate
    	*moon image
    	*@param Sun The current Sun object.
    	*/
    void findPhase( const KSSun *Sun );

    /**@return the moon's current phase angle, as a dms angle
    	*/
    dms phase( void ) const { return Phase; }

    /**@return the illuminated fraction of the Moon as seen from Earth
    	*/
    double illum( void ) const { return 0.5*(1.0 - cos( phase().radians() ) ); }

    /**@return a short string describing the moon's phase
    	*/
    QString phaseName( void ) const;

    /** reimplemented from KSPlanetBase
    	*/
    virtual bool loadData();

protected:
    /**Reimplemented from KSPlanetBase, this function employs unique algorithms for
    	*estimating the lunar coordinates.  Finding the position of the moon is
    	*much more difficult than the other planets.  For one thing, the Moon is
    	*a lot closer, so we can detect smaller deviations in its orbit.  Also,
    	*the Earth has a significant effect on the Moon's orbit, and their
    	*interaction is complex and nonlinear.  As a result, the positions as
    	*calculated by findPosition() are only accurate to about 10 arcseconds
    	*(10 times less precise than the planets' positions!)
    	*@short moon-specific coordinate finder
    	*@param num KSNumbers pointer for the target date/time
    	*@note we don't use the Earth pointer here
    	*/
    virtual bool findGeocentricPosition( const KSNumbers *num, const KSPlanetBase* );

private:
    dms Phase;
    static bool data_loaded;
    static int instance_count;

    /**@class MoonLRData
    	*Encapsulates the Longitude and radius terms of the sums
    	*used to compute the moon's position.
    	*@short Moon Longitude and radius data object
    	*@author Mark Hollomon
    	*@version 1.0
    	*/
    class MoonLRData {
    public:
        int nd;
        int nm;
        int nm1;
        int nf;
        double Li;
        double Ri;

        MoonLRData( int pnd, int pnm, int pnm1, int pnf, double pLi, double pRi ):
        nd(pnd), nm(pnm), nm1(pnm1), nf(pnf), Li(pLi), Ri(pRi) {}
    };

    static QList<MoonLRData*> LRData;

    /**@class MoonBData
    	*Encapsulates the Latitude terms of the sums
    	*used to compute the moon's position.
    	*@short Moon Latitude data object
    	*@author Mark Hollomon
    	*@version 1.0
    	*/
    class MoonBData {
    public:
        int nd;
        int nm;
        int nm1;
        int nf;
        double Bi;

        MoonBData( int pnd, int pnm, int pnm1, int pnf, double pBi ):
        nd(pnd), nm(pnm), nm1(pnm1), nf(pnf), Bi(pBi) {}
    };

    static QList<MoonBData*> BData;
};

#endif
