#ifndef AliEventPoolManager_h
#define AliEventPoolManager_h

#include <vector>
#include <deque>
#include <Rtypes.h>
#include <Riostream.h>
#include <TObjArray.h>
#include <TFile.h>
#include <TMath.h>
#include <TRandom.h>
#include <TSystem.h>

// Generic event mixing classes
//
// Stores a buffer of tracks that updates continuously. The track type
// contained by the pools can be anything inheriting from
// TObject. Pools are updated based on maintaining a minimum fixed
// number of tracks. Multiplicity/centrality and z-vertex bins must be
// passed in at initialization. For example of implementation, see
// $ALICE_ROOT/PWGCF/Correlations/DPhi/AliAnalysisTaskPhiCorrelations.cxx
//
// Authors: A. Adare and C. Loizides

class AliEventPool : public TObject
{
 public:
 AliEventPool(Int_t d) 
   : fEvents(0),
    fNTracksInEvent(0),
    fEventIndex(0),
    fMixDepth(d), 
    fMultMin(-999), 
    fMultMax(+999), 
    fZvtxMin(-999), 
    fZvtxMax(+999), 
    fWasUpdated(0), 
    fMultBinIndex(0), 
    fZvtxBinIndex(0), 
    fDebug(0), 
    fTargetTrackDepth(0),
    fFirstFilled(0),
    fNTimes(0) {;}
  
 AliEventPool(Int_t d, Double_t multMin, Double_t multMax, 
		  Double_t zvtxMin, Double_t zvtxMax) 
   : fEvents(0),
    fNTracksInEvent(0),
    fEventIndex(0),
    fMixDepth(d), 
    fMultMin(multMin), 
    fMultMax(multMax), 
    fZvtxMin(zvtxMin),
    fZvtxMax(zvtxMax),
    fWasUpdated(0),
    fMultBinIndex(0), 
    fZvtxBinIndex(0),
    fDebug(0),
    fTargetTrackDepth(0),
    fFirstFilled(0),
    fNTimes(0) {;}
  ~AliEventPool() {;}
  
  Bool_t      EventMatchesBin(Int_t mult,    Double_t zvtx) const;
  Bool_t      EventMatchesBin(Double_t mult, Double_t zvtx) const;
  Bool_t      IsReady()                    const { return NTracksInPool() >= fTargetTrackDepth; }
  Bool_t      IsFirstReady()               const { return fFirstFilled;   }
  Int_t       GetNTimes()                  const { return fNTimes;        }
  Int_t       GetCurrentNEvents()          const { return fEvents.size(); }
  Int_t       GlobalEventIndex(Int_t j)    const;
  TObject    *GetRandomTrack()             const;
  TObjArray  *GetRandomEvent()             const;
  TObjArray  *GetEvent(Int_t i)            const;
  Int_t       MultBinIndex()               const { return fMultBinIndex; }
  Int_t       NTracksInEvent(Int_t iEvent) const;
  Int_t       NTracksInCurrentEvent()      const { return fNTracksInEvent.back(); }
  void        PrintInfo()                  const;
  Int_t       NTracksInPool()              const;
  Bool_t      WasUpdated()                 const { return fWasUpdated; }
  Int_t       ZvtxBinIndex()               const { return fZvtxBinIndex; }
  void        SetDebug(Bool_t b)                 { fDebug = b; }
  void        SetTargetTrackDepth(Int_t d)       { fTargetTrackDepth = d; }
  Int_t       SetEventMultRange(Int_t    multMin, Int_t multMax);
  Int_t       SetEventMultRange(Double_t multMin, Double_t multMax);
  Int_t       SetEventZvtxRange(Double_t zvtxMin, Double_t zvtxMax);
  void        SetMultBinIndex(Int_t iM) { fMultBinIndex = iM; }
  void        SetZvtxBinIndex(Int_t iZ) { fZvtxBinIndex = iZ; }
  Int_t       UpdatePool(TObjArray *trk);
  
protected:
  deque<TObjArray*>     fEvents;              //Holds TObjArrays of MyTracklets
  deque<int>            fNTracksInEvent;      //Tracks in event
  deque<int>            fEventIndex;          //Original event index
  Int_t                 fMixDepth;            //Number of evts. to mix with
  Double_t              fMultMin, fMultMax;   //Track multiplicity bin range
  Double_t              fZvtxMin, fZvtxMax;   //Event z-vertex bin range
  Bool_t                fWasUpdated;          //Evt. succesfully passed selection?
  Int_t                 fMultBinIndex;        //Multiplicity bin
  Int_t                 fZvtxBinIndex;        //Zvertex bin
  Int_t                 fDebug;               //If 1 then debug on
  Int_t                 fTargetTrackDepth;    //Number of tracks, once full
  Bool_t                fFirstFilled;         //Init to false
  Int_t                 fNTimes;              //Number of times init. condition reached

  ClassDef(AliEventPool,1) // Event pool class
};

class AliEventPoolManager : public TObject
{
public:
  AliEventPoolManager() 
    : fDebug(0),
    fNMultBins(0), 
    fNZvtxBins(0),
    fEvPool(0),
    fTargetTrackDepth(0) {;}
  AliEventPoolManager(Int_t maxEvts, Int_t minNTracks,
		   Int_t nMultBins, Double_t *multbins,
		   Int_t nZvtxBins, Double_t *zvtxbins);

  ~AliEventPoolManager() {;}
  
  // First uses bin indices, second uses the variables themselves.
  AliEventPool *GetEventPool(Int_t iMult, Int_t iZvtx) const;
  AliEventPool *GetEventPool(Int_t    centVal, Double_t zvtxVal) const;
  AliEventPool *GetEventPool(Double_t centVal, Double_t zvtxVal) const;

  Int_t       InitEventPools(Int_t depth, 
			     Int_t nmultbins, Double_t *multbins, 
			     Int_t nzvtxbins, Double_t *zvtxbins);
  void        SetTargetTrackDepth(Int_t d) { fTargetTrackDepth = d;} // Same as for G.E.P. class
  Int_t       UpdatePools(TObjArray *trk);
  void        SetDebug(Bool_t b) { fDebug = b; }

protected:
  Int_t      fDebug;                                    // If 1 then debug on
  Int_t      fNMultBins;                                // number mult bins
  Int_t      fNZvtxBins;                                // number vertex bins
  std::vector<std::vector<AliEventPool*> > fEvPool; // pool in bins of [fMultBin][fZvtxBin]
  Int_t      fTargetTrackDepth;                         // Required track size, same for all pools.

  ClassDef(AliEventPoolManager,1)
};
#endif