// @(#)root/foam:$Id$
// Author: S. Jadach <mailto:Stanislaw.jadach@ifj.edu.pl>, P.Sawicki <mailto:Pawel.Sawicki@ifj.edu.pl>

#ifndef ROOT_TFoamCell
#define ROOT_TFoamCell

#include "TRef.h"

class TFoamVect;


class TFoamCell : public TObject {
   //   static, the same for all cells!
private:
   Short_t  fDim;                   ///< Dimension of the vector space
   //   MEMBERS
private:
   //--- linked tree organization ---
   Int_t    fSerial;                ///< Serial number
   Int_t    fStatus;                ///< Status (active, inactive)

   // For backwards compatibility. The TFoam v1 and v2 classes use these
   // members. Getting rid of them and doing a schema evolution rule for
   // TFoamCell doesn't seem to work, because the TRefs can't be dereferenced
   // at that point yet.
   TRef fParent;    ///< Pointer to parent cell
   TRef fDaught0;   ///< Pointer to daughter 1
   TRef fDaught1;   ///< Pointer to daughter 2

   Int_t fParentIdx = -1;    ///< Serial number of parent cell
   Int_t fDaught0Idx = -1;   ///< Serial number of daughter 1
   Int_t fDaught1Idx = -1;   ///< Serial number of daughter 2

   // Note: the fCells member doesn't take part in IO because it will be filled by the TFoam object.
   TFoamCell** fCells = nullptr;    ///<! Array of ALL cells, owned by the TFoam object
   //--- M.C. sampling and choice of the best edge ---
private:
   Double_t fXdiv;                  ///< Factor for division
   Int_t    fBest;                  ///< Best Edge for division
   //--- Integrals of all kinds ---
   Double_t fVolume;                ///< Cartesian Volume of cell
   Double_t fIntegral;              ///< Integral over cell (estimate from exploration)
   Double_t fDrive;                 ///< Driver  integral, only for cell build-up
   Double_t fPrimary;               ///< Primary integral, only for MC generation

public:
   TFoamCell();                          // Default Constructor for ROOT streamers
   TFoamCell(Int_t);                     // User Constructor
   TFoamCell(TFoamCell const&) = delete;      // Copy Constructor
   TFoamCell(TFoamCell &&) = delete;
   ~TFoamCell() override;                // Destructor
   void  Fill(Int_t, TFoamCell*, TFoamCell*, TFoamCell*);    // Assigns values of attributes
   TFoamCell&  operator=(const TFoamCell&) = delete;   // Substitution operator (never used)
   TFoamCell&  operator=(TFoamCell &&) = delete;
   //--------------- Geometry ----------------------------------
   Double_t  GetXdiv() const { return fXdiv;}          // Pointer to Xdiv
   Int_t     GetBest() const { return fBest;}          // Pointer to Best
   void      SetBest(Int_t    Best){ fBest =Best;}     // Set Best edge candidate
   void      SetXdiv(Double_t Xdiv){ fXdiv =Xdiv;}     // Set x-division for best edge cand.
   void      GetHcub(  TFoamVect&, TFoamVect&) const;  // Get position and size vectors (h-cubical subspace)
   void      GetHSize( TFoamVect& ) const;             // Get size only of cell vector  (h-cubical subspace)
   //--------------- Integrals/Volumes -------------------------
   void      CalcVolume();                             // Calculates volume of cell
   Double_t  GetVolume() const { return fVolume;}      // Volume of cell
   Double_t  GetIntg() const { return fIntegral;}      // Get Integral
   Double_t  GetDriv() const { return fDrive;}         // Get Drive
   Double_t  GetPrim() const { return fPrimary;}       // Get Primary
   void      SetIntg(Double_t Intg){ fIntegral=Intg;}  // Set true integral
   void      SetDriv(Double_t Driv){ fDrive   =Driv;}  // Set driver integral
   void      SetPrim(Double_t Prim){ fPrimary =Prim;}  // Set primary integral
   //--------------- linked tree organization ------------------
   Int_t     GetStat() const { return fStatus;}        // Get Status
   void      SetStat(Int_t Stat){ fStatus=Stat;}       // Set Status

   // For backwards compatibility, fall back to the TRefs if the index is not set.
   TFoamCell* GetPare() const { return fParentIdx >= 0 ? fCells[fParentIdx] : (TFoamCell*) fParent.GetObject(); }    // Get Pointer to parent cell
   TFoamCell* GetDau0() const { return fDaught0Idx >= 0 ? fCells[fDaught0Idx] : (TFoamCell*) fDaught0.GetObject(); } // Get Pointer to 1-st daughter vertex
   TFoamCell* GetDau1() const { return fDaught1Idx >= 0 ? fCells[fDaught1Idx] : (TFoamCell*) fDaught1.GetObject(); } // Get Pointer to 2-nd daughter vertex

   void      SetDau0(TFoamCell* Daug){ fDaught0Idx = Daug ? Daug->fSerial : -1;}  // Set pointer to 1-st daughter
   void      SetDau1(TFoamCell* Daug){ fDaught1Idx = Daug ? Daug->fSerial : -1;}  // Set pointer to 2-nd daughter
   void      SetSerial(Int_t Serial){ fSerial=Serial;}    // Set serial number
   Int_t     GetSerial() const { return fSerial;}         // Get serial number
   void      SetCells(TFoamCell** cells) { fCells = cells;} // Set the pointer to the cells array
   TFoamCell** GetCells() const { return fCells;}           // Return the pointer to the cells array
   //--- other ---
   void Print(Option_t *option) const override ;                   // Prints cell content

   ClassDefOverride(TFoamCell,2)  //Single cell of FOAM
};
#endif