/*
	Reaction.h
	Reaction is a class which implements either a decay or scattering reaction. As such it requires either
	3 (decay) or 4 (scattering) nuclei to perform any calcualtions. I also links together the target, which provides
	energy loss calculations, with the kinematics. Note that Reaction does not own the LayeredTarget.

	--GWM Jan. 2021
*/
#ifndef REACTION_H
#define REACTION_H

#include "Nucleus.h"
#include "LayeredTarget.h"

namespace Mask {

	class Reaction {
	public:
		Reaction();
		Reaction(int zt, int at, int zp, int ap, int ze, int ae);
		~Reaction();
		bool Calculate();
		void SetNuclei(int zt, int at, int zp, int ap, int ze, int ae);
		void SetNuclei(const Nucleus* nucs);
		void SetBeamKE(double bke);
		void SetEjectileThetaType(int type);
	
		inline void SetLayeredTarget(LayeredTarget* targ) { target = targ; };
		inline void SetPolarRxnAngle(double theta) { m_theta = theta; };
		inline void SetAzimRxnAngle(double phi) { m_phi = phi; };
		inline void SetExcitation(double ex) { m_ex = ex; };
		inline void SetTarget(const Nucleus& nuc) { reactants[0] = nuc; };
		inline void SetTarget(int z, int a) { reactants[0] = Nucleus(z, a); };
		inline void SetProjectile(const Nucleus& nuc) { reactants[1] = nuc; };
		inline void SetProjectile(int z, int a) { reactants[1] = Nucleus(z, a); };
		inline void SetEjectile(const Nucleus& nuc) { reactants[2] = nuc; };
		inline void SetEjectile(int z, int a) { reactants[2] = Nucleus(z, a); };
		inline void SetResidual(const Nucleus& nuc) { reactants[3] = nuc; };
		inline void SetResidual(int z, int a) { reactants[3] = Nucleus(z, a); };
		inline void SetRxnLayer(int layer) { rxnLayer = layer; };
		inline void TurnOffResidualEloss() { resid_elossFlag = false; };
		inline void TurnOnResidualEloss() { resid_elossFlag = true; };
		inline bool IsDecay() { return decayFlag; };
		inline const Nucleus* GetNuclei() const { return &(reactants[0]); };
		inline const Nucleus& GetProjectile() const { return reactants[1]; };
		inline const Nucleus& GetTarget() const { return reactants[0]; };
		inline const Nucleus& GetEjectile() const { return reactants[2]; };
		inline const Nucleus& GetResidual() const { return reactants[3]; };
		inline int GetRxnLayer() { return rxnLayer; };
		inline void ResetTarget() { reactants[0].SetVectorCartesian(0,0,0, reactants[0].GetGroundStateMass()); }
		inline void ResetProjectile() { reactants[1].SetVectorCartesian(0,0,0, reactants[1].GetGroundStateMass()); }
		inline void ResetEjectile() { reactants[2].SetVectorCartesian(0,0,0, reactants[2].GetGroundStateMass()); }
		inline void ResetResidual() { reactants[3].SetVectorCartesian(0,0,0, reactants[3].GetGroundStateMass()); }
	
	private:
		void CalculateDecay(); //target -> light_decay (eject) + heavy_decay(resid)
		void CalculateReaction(); //target + project -> eject + resid
		void CalculateReactionThetaLab();
		void CalculateReactionThetaCM();
	
		Nucleus reactants[4]; //0=target, 1=projectile, 2=ejectile, 3=residual
		LayeredTarget* target; //not owned by Reaction
	
		double m_bke, m_theta, m_phi, m_ex;
	
		int rxnLayer;
		int m_eject_theta_type; 
	
		bool decayFlag, nuc_initFlag, resid_elossFlag;
	
		static constexpr int lab = 0;
		static constexpr int center_of_mass = 1;
	
	};

}

#endif