//-*- Mode: C++ -*-
  // *****************************************************************************
  //                                                                             *
  // @Autors: I.Kulakov; M.Zyzak; I.Kisel                                        *
  // @e-mail: I.Kulakov@gsi.de; M.Zyzak@gsi.de; I.Kisel@compeng.uni-frankfurt.de *
  //                                                                             *
  // *****************************************************************************

#ifndef ITSCATRIPLETS_H
#define ITSCATRIPLETS_H

#include "ITSCADoublets.h"

#include <vector>
using std::vector;

class ITSCATriplet {
 public:
  ITSCATriplet():fParam(), fLevel(-1){}
  ITSCATriplet( const ITSCADoublet& s1, const ITSCADoublet& s2, const AliHLTTPCCATrackParam& param ):fParam(param), fLevel(0) {
    fIHit[0] = s1.IHit(0); fIHit[1] = s1.IHit(1); fIHit[2] = s2.IHit(1);
  }
  ITSCATriplet( const TES& ih0, const TES& ih1, const TES& ih2, const AliHLTTPCCATrackParam& param ):fParam(param), fLevel(0) {
    fIHit[0] = ih0; fIHit[1] = ih1; fIHit[2] = ih2;
  }
  
    // accessors
  const TES& IHit( int IH ) const { return fIHit[IH]; }
  int ISta( int IH ) const { return fIHit[IH].s; }
  
  const AliHLTTPCCATrackParam& Param() const { return fParam; }
  
  float QMomentum() const { return fParam.QMomentum(); }
  float QMomentumErr() const { return sqrt( fParam.Err2QMomentum() ); } // qp err
  
  char&       Level()       { return fLevel; };
  const char& Level() const { return fLevel; };

  vector<unsigned int>&       INeighbours()       { return fINeighbours; };
  const vector<unsigned int>& INeighbours() const { return fINeighbours; };

    // check wether a is neighbour from the right to this
  bool IsRightNeighbour( float pick, const ITSCATriplet& a ){
    if ( IHit(1) != a.IHit(0) || IHit(2) != a.IHit(1) )
      return false;
    if ( fabs(QMomentum() - a.QMomentum()) > pick * (QMomentumErr() + a.QMomentumErr()) )
      return false; // neighbours must have same qp
    return true;
  }

 private:
  TES fIHit[3]; // index of hit on station
  AliHLTTPCCATrackParam fParam;

  char fLevel;

  vector<unsigned int> fINeighbours; // index of neighbour triplets on their station
};

class ITSCATriplets: public ITSCAStationArray<ITSCATriplet> {
 public:
  ITSCATriplets( int nSta, const ITSCAHits* hits ):ITSCAStationArray<ITSCATriplet>( nSta,hits ){};
};

#endif