/**
 * Class that represents a Quaternion
 * Author: Alfredo Morales Pinzón
 * Date: October 7, 2014
 */

#ifndef __Quaternion_h__
#define __Quaternion_h__

//-----------------
// C++
//-----------------
#include <math.h>

//-----------------
// OWN
//-----------------
#include <Airways/MathLib/TempAirwaysAppli_MathLib_Export.h>
#include "vec3.h"

// Namespaces
using namespace std;

//------------------------------------------------------------------------------
// Class that represents a Quaterion with all its operations
//------------------------------------------------------------------------------
class TempAirwaysAppli_MathLib_EXPORT Quaternion
{
public:

	//------------------------------------------------------------
	//Builder
	//------------------------------------------------------------

	/*
	 * Class builder
	 */
	Quaternion( );

	/*
	 * Class builder using two vectors
	 * @param v1 is the first vector
	 * @param v2 is the second vector
	 */
	Quaternion(Vec3 v1, Vec3 v2);

	/*
	 * Class builder using theta and w vector
	 * @param nTheta is the theta angle
	 * @param nW is the w vector
	 */
	Quaternion(float nTheta, Vec3 nW);

	/*
	 * Class builder using r and im
	 * @param nR in the real part of the quaternion
	 * @param nI, nJ and nK are the imaginary parts of the quaternion
	 */
	Quaternion(float nR, float nI, float nJ, float nK);

	//------------------------------------------------------------
	//Destructor
	//------------------------------------------------------------

	~Quaternion();

	//------------------------------------------------------------
	//Public methods
	//------------------------------------------------------------

	/**
	 * Method that returns the real (r) component
	 * @return the r component
	 */
	float getR();

	/**
	 * Method that returns the i component
	 * @return the i component
	 */
	float getI();

	/**
	 * Method that returns the j component
	 * @return the j component
	 */
	float getJ();

	/**
	 * Method that returns the k component
	 * @return the k component
	 */
	float getK();

	/**
	 * Method that returns the w vector
	 * @return the w vector
	 */
	Vec3 getW();

	/**
	 * Method that returns the conjugate of the quaternion
	 * @return the conjugate of the quaternion
	 */
	Quaternion conjugate( );

	/**
	 * Method that returns a vector transformed by the quaternion
	 * @param vector to be rotated
	 * @return the transformed vector
	 */
	Vec3 rotateVector(Vec3 vector);

	//------------------------------------------------------------
	//Operators
	//------------------------------------------------------------

	/*
	 * Definition of operator *
	 * @param is the quaternion to be multiplied with
	 * @return the multiplication quaternion
	 */
	Quaternion operator*(Quaternion q);

	/**
	 * Definition of operator []
	 * @param Position of the quanternion to be returned. Position 0 corresponds
	 * to the real component and 1, 2, and 3 to the complex components.
	 * @param The value on the specified position is returned.
	 *
	 */
	const float& operator[](unsigned int i) const;

	/**
	 * Operator to print
	 */
	friend std::ostream& operator<<(std::ostream& os, const Quaternion& coord);


private:

	//------------------------------------------------------------
	//Private methods
	//------------------------------------------------------------


	//------------------------------------------------------------
	//Atributes
	//------------------------------------------------------------

	/**
	 * Real part of the quaternion
	 */
	float r;

	/**
	 * Angle between vectors
	 */
	float theta;

	/**
	 * Rotation vector
	 */
	Vec3 w;

	/**
	 * Vector the quaternion
	 */
	Vec3 im;

};

//------------------------------------------------------------------------------
#endif