/*
The MIT License (MIT)

Copyright (c) 2012 Juan Ramón

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#ifndef Calibrate_h
#define Calibrate_h

	#include <math.h>

	/**
	 * \brief Library for coordinates transformations. Calculates the equivalent coordinates between both coordinate systems equatorial and horizontal.
	 *
	 * It's based on Toshimi Taki's matrix method for coordinates transformation: http://www.geocities.jp/toshimi_taki/matrix/matrix.htm
	 * Contains the necessary methods for setting the initial time, the reference objects, the transformation matrix, and to 
	 * calculate the equivalent vectors between both coordinate systems.
	 */
	class Calibrate{
		private:

			/**
			 * Constant of multiplication for the solar and sidereal time relation.
			 */
			double _k;

			/**
			 * Initial timestamp for the observations.
			 */			
			double _t0;

			/**
			 * Indicators for definition of the three reference objects.
			 */
			bool _isSetR1, _isSetR2, _isSetR3;

			/**
			 * Auxiliary matrices.
			 */
			double _lmn1[3], _LMN1[3], _lmn2[3], _LMN2[3], _lmn3[3], _LMN3[3];

			/**
			 * Transformation matrix. Transform vectors from equatorial to horizontal system.
			 */
			double _T[3][3];

			/**
			 * Inverse transformation matrix. Transform vectors from horizontal to equatorial system.
			 */
			double _iT[3][3];

			/**
			 * If the three reference objects have been defined, it calculates the transformation matrix from them.
			 */
			void _setT();

			/**
			 * Obtains a vector in polar notation from the equatorial coordinates and the observation time.
			 *
			 * \param ar Right ascension.
			 * \param dec Declination.
			 * \param t Timestamp of the observation.
			 * \param *EVC Pointer to array: Returns the three dimensional vector in polar notation.
			 */
			void _setEVC(double ar, double dec, double t, double* EVC);

			/**
			 * Obtains a vector in polar notation from the horizontal coordinates and observation time.
			 *
			 * \param ac Azimuth (horizontal coordinates).
			 * \param alt Altitude (horizontal coordinates).
			 * \param t Timestamp of the observation.
			 * \param *HVC Pointer to array: Returns the three dimensional vector in polar notation.
			 */			
			void _setHVC(double ac, double alt, double* HVC);

			/**
			 * Calculates the 3x3 inverse matrix.
			 * 
			 * \param m[3][3] Input matrix.
			 * \param res[3][3] Pointer to array: Returns the inverse matrix.
			 */
			void _inv(double m[3][3], double res[3][3]);

			/**
			 * Calculates the product of 3x3 matrices.
			 * 
			 * \param m1[3][3] Input matrix 1.
			 * \param m2[3][3] Input matrix 2.
			 * \param res[3][3] Pointer to array: Returns the result matrix.
			 */
			void _m_prod(double m1[3][3], double m2[3][3], double res[3][3]);

		public:

			/**
			 * Class constructor.
			 */
			Calibrate();

			/**
			 * Sets the initial time.
			 *
			 * This parameter is used in order to consider time passing on horizontal coordinates system.
			 *
			 * \param t0 Unix Timestamp of the initial observation time.
			 */
			void setTime(double t0);

			/**
			 * Sets the first reference object from the coordinates in both coordinates systems for 
			 * that object.
			 *
			 * \param ar Right Ascension (equatorial coordinates).
			 * \param dec Declination (equatorial coordinates).
			 * \param t Unix Timestamp of the Observation.
			 * \param ac Azimuth (horizontal coordinates).
			 * \param alt Altitude (horizontal coordinates).
			 */
			void setRef_1(double ar, double dec, double t, double ac, double alt);

			/**
			 * Sets the second reference object from the coordinates in both coordinates systems for 
			 * that object.
			 *
			 * \param ar Right Ascension (equatorial coordinates).
			 * \param dec Declination (equatorial coordinates).
			 * \param t Unix Timestamp of the Observation.
			 * \param ac Azimuth (horizontal coordinates).
			 * \param alt Altitude (horizontal coordinates).
			 */
			void setRef_2(double ar, double dec, double t, double ac, double alt);

			/**
			 * Sets the third reference object from the coordinates in both coordinates systems for 
			 * that object.
			 *
			 * \param ar Right Ascension (equatorial coordinates).
			 * \param dec Declination (equatorial coordinates).
			 * \param t Unix Timestamp of the Observation.
			 * \param ac Azimuth (horizontal coordinates).
			 * \param alt Altitude (horizontal coordinates).
			 */
			void setRef_3(double ar, double dec, double t, double ac, double alt);

			/**
			 * Third reference object calculated from the two others ones.
			 * 
			 * Calculates the cross product of the two first reference objects in both coordinates systems, in order 
			 * to obtain the third one.
			 * These two first objects must have 90º from each other, approximately (from 60º to 120º is enough to obtain
			 * goods results).
			 */
			void autoRef_3();

			/**
			 * Indicates if the three reference objects has been calculated.
			 * 
			 * \return Boolean.
			 */
			bool isConfigured();


			/**
			 * Horizontal coordinates calculated from the equatorial ones and time.
			 *
			 * \param ar Right Ascension (equatorial coordinates).
			 * \param dec Declination (equatorial coordinates)
			 * \param t Unix Timestamp of the Observation.
			 * \param *ac Pointer to double: Returns the azimuth (horizontal coordiantes).
			 * \param *alt Pointer to double: Returns the altitude (horizontal coordinates).
			 */
			void getHCoords(double ar, double dec, double t, double *ac, double *alt);

			/**
			 * Equatorial coordinates calculated from the horizontal ones and time.
			 *
			 * \param ac Azimuth (horizontal coordinates).
			 * \param alt Altitude (horizontal coordinates).
			 * \param t Unix Timestamp of the Observation.
			 * \param *ar Pointer to double: Returns the right ascension (equatorial coordinates).
			 * \param *dec Pointer to double: Returns the declination (equatorial coordinates).
			 */
			void getECoords(double ac, double alt, double t, double *ar, double *dec);
	};

#endif