/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 * See cxx source for full Copyright notice                               *
 **************************************************************************/

//-------------------------------------------------------------------------
//                      Class AliRsnDaughter
//  
//           A simple object which describes a reconstructed track
//           with some references to its related generated particle
//           and some facilities which could help in composing its
//           4-momentum, for resonance study.
// 
// author: A. Pulvirenti             (email: alberto.pulvirenti@ct.infn.it)
//-------------------------------------------------------------------------

#ifndef ALIRSNDAUGHTER_H
#define ALIRSNDAUGHTER_H

#include "AliPID.h"
#include <TVector3.h>
#include <TParticle.h>
#include <TLorentzVector.h>

class AliESDtrack;

class AliRsnDaughter : public TObject
{
public:
			       AliRsnDaughter();
	               AliRsnDaughter(const AliRsnDaughter &copy);
				
	virtual       ~AliRsnDaughter() { }
		
	Bool_t         Adopt(TParticle* particle);
	Bool_t         Adopt(const AliESDtrack* track, Bool_t checkRefit = kTRUE);
	TVector3       Get3Momentum() const 						  {TVector3 v(fP[0],fP[1],fP[2]); return v;}
	TLorentzVector Get4Momentum() const			            	  {TLorentzVector v(fP[0],fP[1],fP[2],GetEnergy()); return v;}
	Double_t       GetEnergy() const  				              {return TMath::Sqrt(fMass*fMass + GetP2());}
	UShort_t       GetIndex() const 							  {return fIndex;}
	Int_t          GetLabel() const 							  {return fLabel;}
	Double_t       GetMass() const                                {return fMass;}
	Int_t          GetMother() const							  {return fMother;}
	Short_t        GetMotherPDG() const 						  {return fMotherPDG;}
	UShort_t       GetPDG() const								  {return fPDG;}
	Double_t       GetPIDweight(Int_t i) const  				  {return ( (i>=0&&i<AliPID::kSPECIES)?fPIDwgt[i]:-1.0 );}
	Char_t         GetSign() const  							  {return fSign;}
	Double_t       GetP2() const								  {return fP[0]*fP[0] + fP[1]*fP[1] + fP[2]*fP[2];}
	Double_t       GetP() const 								  {return TMath::Sqrt(GetP2());}
	Double_t       GetPx() const								  {return fP[0];}
	Double_t       GetPy() const								  {return fP[1];}
	Double_t       GetPz() const								  {return fP[2];}
	Double_t       GetPt() const								  {return TMath::Sqrt(fP[0]*fP[0] + fP[1]*fP[1]);}
	Short_t        GetTruePDG() const							  {return fTruePDG;}
	TVector3       GetVertex() const							  {TVector3 v(fV[0],fV[1],fV[2]); return v;}
	Double_t       GetVx() const								  {return fV[0];}
	Double_t       GetVy() const								  {return fV[1];}
	Double_t       GetVz() const								  {return fV[2];}
	Double_t       GetVt() const								  {return TMath::Sqrt(fV[0]*fV[0] + fV[1]*fV[1]);}
	void           SetIndex(UShort_t value) 					  {fIndex = value;}
	void           SetIndex(Int_t value)						  {fIndex = (UShort_t)value;}
	void           SetLabel(Int_t l)							  {fLabel = l;}
	void           SetMass(Double_t m)                            {fMass = m;}
	void           SetMother(Int_t l)							  {fMother = l;}
	void           SetMotherPDG(Short_t pdg)					  {fMotherPDG = pdg;}
	void           SetPDG(UShort_t pdg)                           {fPDG = TMath::Abs(pdg);}
	void           SetPDG(Int_t pdg)                              {fPDG = (UShort_t)TMath::Abs(pdg);}
	void           SetPIDweights(const Double_t *pid)			  {Int_t i;for(i=0;i<AliPID::kSPECIES;i++)fPIDwgt[i]=pid[i];}
	void           SetPxPyPz(Double_t px,Double_t py,Double_t pz) {fP[0]=px;fP[1]=py;fP[2]=pz;}
	void           SetSign(Char_t value)						  {fSign = value;}
	void           SetSign(Int_t value) 						  {fSign = (Char_t)value;}
	void           SetTruePDG(Short_t pdg)  					  {fTruePDG = pdg;}
	void           SetVxVyVz(Double_t vx,Double_t vy,Double_t vz) {fV[0]=vx;fV[1]=vy;fV[2]=vz;}
	
	friend AliRsnDaughter operator+(AliRsnDaughter t1, AliRsnDaughter t2);
	
private:
	
	Char_t     fSign;                     // charge sign
	UShort_t   fPDG;                      // assigned PDG code from PID (0=undefined)
	UShort_t   fIndex;                    // reference index in AliESD container

	Double_t   fP[3];                     // vector momentum
	Double_t   fV[3];                     // production vertex
	Double_t   fMass;                     // mass
	
	Double_t   fPIDwgt[AliPID::kSPECIES]; // particle PID weights
	
	// The following data are useful for simulated events only
	// and can be left blank when using real or 'realistic' data
	
	Int_t      fLabel;        // GEANT label of corresponding particle
	Short_t    fTruePDG;      // PDG code of corresponding particle
	Int_t      fMother;       // GEANT label of mother particle
	Short_t    fMotherPDG;    // PDG code of mother particle
	
	ClassDef(AliRsnDaughter,1)
};

#endif