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

/* $Id$ */

///////////////////////////////////////////////////////////
//                                                       //
//  Class to generate the particles for the MC           //
//  The base class is empty                              //
//                                                       //
///////////////////////////////////////////////////////////

#include <TArrayF.h>
#include <TLorentzVector.h>
#include <TMCProcess.h>

#include "AliRndm.h"

class AliVertexGenerator;
class AliCollisionGeometry;
class AliGenEventHeader;
class AliStack;
class TGenerator;



typedef enum { kNoSmear, kPerEvent, kPerTrack }  VertexSmear_t;
typedef enum { kExternal, kInternal, kContainer} VertexSource_t;


class AliGenerator : public TNamed, public AliRndm
{

 public:

    AliGenerator();
    AliGenerator(Int_t npart);
    virtual ~AliGenerator();
    virtual void Init();
    virtual void SetOrigin(Float_t ox, Float_t oy, Float_t oz);
    virtual void SetOrigin(const TLorentzVector &o);
    virtual void SetSigma(Float_t sx, Float_t sy, Float_t sz);
    virtual void SetSigmaZ(Float_t sz) {fOsigma[2] = sz;}
    virtual void SetMomentumRange(Float_t pmin=0, Float_t pmax=1.e10);
    virtual void SetPtRange(Float_t ptmin=0, Float_t ptmax=1.e10);
    virtual void SetPhiRange(Float_t phimin = 0., Float_t phimax = 360.);
    virtual void SetYRange(Float_t ymin=-100, Float_t ymax=100);
    virtual void SetVRange(Float_t vxmin, Float_t vxmax,
			   Float_t vymin, Float_t vymax,
			   Float_t vzmin, Float_t vzmax);
    virtual void SetNumberParticles(Int_t npart=100) {fNpart=npart;}
    virtual Int_t NumberParticles() const {return fNpart;}
    virtual void SetThetaRange(Float_t thetamin=0, Float_t thetamax=180);
    virtual void GenerateN(Int_t ntimes);
    virtual void Generate()=0;
    virtual void SetParentWeight(Float_t wgt) {fParentWeight=wgt;}
    virtual void SetChildWeight(Float_t wgt)  {fChildWeight=wgt;}    
    virtual void SetAnalog(Int_t flag=1) {fAnalog=flag;}	
    virtual void SetVertexSmear(VertexSmear_t smear) {fVertexSmear = smear;}
    virtual void SetCutVertexZ(Float_t cut=999999.) {fCutVertexZ = cut;}
    virtual void SetVertexSource(VertexSource_t source = kInternal) {fVertexSource = source;}
    virtual void SetVertex(Float_t vx, Float_t vy, Float_t vz, Float_t t = 0)
    {fVertex[0] = vx; fVertex[1] = vy; fVertex[2] = vz; fTime = t;}
    void SetVertexGenerator(AliVertexGenerator* vertexGenerator)
      {fVertexGenerator = vertexGenerator; fVertexSource = kExternal; fVertexSmear = kPerEvent;}
    void SetPileUpTimeWindow(Float_t pileUpTimeW) {fPileUpTimeWindow = pileUpTimeW;}
    virtual void SetTime(Float_t time)
	{fTime = time;}
    virtual void SetTimeOrigin(Float_t timeorig)
        {fTimeOrigin = timeorig;}
    
    virtual void SetTrackingFlag(Int_t flag=1) {fTrackIt=flag;}
    void Vertex();
    void VertexExternal();
    virtual void VertexInternal();
    virtual void FinishRun();
    virtual void SetMC(TGenerator *theMC) {fMCEvGen =theMC;}
    virtual TGenerator* GetMC() const {return fMCEvGen;}
    virtual void AddHeader(AliGenEventHeader* /*header*/) {;}
    virtual void SetContainer(AliGenerator* container) {fContainer = container;}
    virtual void SetEventPlane(Float_t evPlane) {fEvPlane = evPlane; }

  // Getters

    virtual void GetOrigin(Float_t &ox, Float_t &oy, Float_t &oz) const
	{ox=fOrigin.At(0);oy=fOrigin.At(1);oz=fOrigin.At(2);}
    virtual void GetOrigin(TLorentzVector &o) const
	{o[0]=fOrigin.At(0);o[1]=fOrigin.At(1);o[2]=fOrigin.At(2);o[3]=0;}
  // Stack 
    void SetStack (AliStack *stack) {fStack = stack;}
    AliStack* GetStack(){return fStack;}
  // Collision Geometry
    virtual Bool_t ProvidesCollisionGeometry() const {return kFALSE;}
    virtual Bool_t NeedsCollisionGeometry()    const {return kFALSE;}    
    virtual AliCollisionGeometry* CollisionGeometry() const {return fCollisionGeometry;}
    virtual void SetCollisionGeometry(AliCollisionGeometry* geom) {fCollisionGeometry = geom;}

    virtual Float_t GetEnergyCMS() const { return fEnergyCMS; }
    virtual void    SetEnergyCMS(Float_t energy = 0) { fEnergyCMS = energy; }
    virtual void    GetProjectile(TString& tar, Int_t& a, Int_t& z) const
    {tar = fProjectile; a = fAProjectile; z = fZProjectile;}    
    virtual void    GetTarget(TString& tar, Int_t& a, Int_t& z) const
    {tar = fTarget; a = fATarget; z = fZTarget;}    
    virtual void    SetProjectile(TString proj="", Int_t a = 0, Int_t z = 0)
	{fProjectile = proj; fAProjectile = a; fZProjectile = z;}
    virtual void    SetTarget(TString tar="", Int_t a = 0, Int_t z = 0)
	{fTarget = tar; fATarget = a; fZTarget = z;}
    
    virtual void    SetSeed(UInt_t seed);
    
 protected:
    virtual  void  PushTrack(Int_t done, Int_t parent, Int_t pdg,
                               Float_t *pmom, Float_t *vpos, Float_t *polar,
                               Float_t tof, TMCProcess mech, Int_t &ntr,
                               Float_t weight = 1, Int_t is = 0);
    virtual  void  PushTrack(Int_t done, Int_t parent, Int_t pdg,
                      Double_t px, Double_t py, Double_t pz, Double_t e,
                      Double_t vx, Double_t vy, Double_t vz, Double_t tof,
                      Double_t polx, Double_t poly, Double_t polz,
                      TMCProcess mech, Int_t &ntr, Float_t weight = 1, Int_t is = 0);
    virtual void   KeepTrack(Int_t itrack); 
    virtual void   SetHighWaterMark(Int_t nt);

 protected:
    TGenerator* fMCEvGen;      //!Pointer to the generator
    Float_t     fThetaMin;     //Minimum theta of generation in radians
    Float_t     fThetaMax;     //Maximum theta of generation in radians
    Float_t     fPhiMin;       //Minimum phi of generation in radians
    Float_t     fPhiMax;       //Maximum phi of generation in radians
    Float_t     fPMin;         //Minimum momentum of generation in GeV/c
    Float_t     fPMax;         //Minimum momentum of generation in GeV/c
    Float_t     fPtMin;        //Minimum transverse momentum
    Float_t     fPtMax;        //Maximum transverse momentum
    Float_t     fYMin;         //Minimum rapidity
    Float_t     fYMax;         //Maximum rapidity
    TArrayF     fVMin;         //Minimum Decaylength
    TArrayF     fVMax;         //Minimum Decaylength    
    Int_t       fNpart;        //Maximum number of particles per event
    Float_t     fParentWeight; //Parent Weight
    Float_t     fChildWeight;  //ChildWeight
    Int_t       fAnalog;       //Flag for anolog or pt-weighted generation
   //
    VertexSmear_t     fVertexSmear;  //Vertex Smearing mode
    VertexSource_t    fVertexSource; //Vertex source (internal/external)
    Float_t     fCutVertexZ;         //Vertex cut in units of sigma_z
    Float_t     fPileUpTimeWindow;   //Time window for pile-up events
    Int_t       fTrackIt;    // if 1, Track final state particles 
    AliVertexGenerator* fVertexGenerator;  //! Generator for the vertex
    TArrayF     fOrigin;     // Origin of event
    TArrayF     fOsigma;     // Sigma of the Origin of event
    TArrayF     fVertex;        //! Vertex of current event
    
    Float_t     fTimeOrigin; // Time0 origin in a run or event sample
    Float_t     fTime;       // Event time smeared around time0 origin using sigma vertex
    Float_t     fEvPlane;    // the event plane 

    AliStack*   fStack;         //! Local pointer to stack
    AliGenerator* fContainer;   //! Local pointer to container
    
    AliCollisionGeometry* fCollisionGeometry; //!Collision geometry
    /*************************************************************************/
    enum {kThetaRange    = BIT(14),
	  kVertexRange   = BIT(15),
	  kPhiRange      = BIT(16),
	  kPtRange       = BIT(17),
	  kYRange        = BIT(18),
	  kMomentumRange = BIT(19),
	  kEtaRange      = BIT(20)	  
    };

    Float_t     fEnergyCMS;    // Centre of mass energy
    Int_t        fAProjectile;   // Projectile A
    Int_t        fZProjectile;   // Projectile Z
    Int_t        fATarget;       // Target A
    Int_t        fZTarget;       // Target Z
    TString      fProjectile;    // Projectile
    TString      fTarget;        // Target

 private:
    AliGenerator(const AliGenerator &gen);
    AliGenerator & operator=(const AliGenerator &gen);

    ClassDef(AliGenerator,5) // Base class for event generators
};

#endif