#ifndef __TCESCLUSTERFITTER__
#define __TCESCLUSTERFITTER__

/*

 Compute a CES chi2 and position from a list of ADC's.  
 A standard pedestal, gain, and threshold for ADC's is applied.

 Use:
 TCesClusterFitter calc;
 // fill raw ADC's into int adc[11];
 // bool wires is true for wire view
 // first strip is the detector channel number of the adc[0], 
 // nstrips is the number of valid ADC values in adc[0:nstrips-1]
 // only 11 strip clusters allowed
 int failed = calc.Fit(int* adc, bool wires=true, int firststrip, int nstrips);
 if(failed) cout << "failed" << endl;
 float rawE = calc.RawEnergy();
 float fitE = calc.FitEnergy();
 // the x or z reflects readout order
 // x direction = +phi for west, -phi for east, z = |CDF x|
 double cesXorZ = calc.Position();
 double cesXorZ = calc.Position();
 double chi2 = calc.Chi2();

*/

#include <iostream> 
#include <memory> 

class TCesClusterFitter
{
public :

  // constants
  double CESRADIUS;
  
  int    N_PHI_STRIP;
  double PHI_STRIP_OFFSET;
  double PHI_STRIP_PITCH;

  int    N_Z_STRIP1;
  int    N_Z_STRIP2;
  double Z_STRIP_OFFSET1;
  double Z_STRIP_OFFSET2;
  double Z_STRIP_PITCH1;
  double Z_STRIP_PITCH2;

  double GEV_TO_ADC_WIRE;   // GeV to Adc for strips
  double GEV_TO_ADC_STRIP;   // GeV to Adc for strips

  double CONST1;   // two factors determining one-channel E sigma
  double CONST2;   // 

  double DXMIN;  // tolerance to stop iteration

private :

  // frozen electron shower profile (1985 test beam)
  double _pos1[300];
  double _corrections[6][300];

  double _posMax; // position of the strip with highest pulse height
  double _fittedPosition; 
  
  double _strippos[129]; // strip boundaries 
  double _wirepos[33]; // strip boundaries 
  
  double _offset; 
  double _sinth; // sinTheta determined by the channel with highest ADC

  double _pos[12];  /* strip boundaries of channels in the cluster
		     * in mm
		     * projected with sinTheta to correct the widening effect
		     */
  double _rawPosition; // cluster centroid  
  double _rawEnergy;   // cluster sum energy 
  double _fitPosition; 
  double _e[11]; 
  double _fitEnergy; 
  double _chi2; 
  
  int ADCs[11];  // stores the ADC's of the 11 channels.
  int firstChan; // first strip number
  int nChan;    // number of strips 
  double qdiff[11];  // differences between measured and expected 

  void initArrays();

  int fitt2_strip(double x1, double delta, double R[2]);
  int fitt2_wire (double x1, double delta, double R[2]);
  
  int _verbose;
  bool _wires;
  
public:

  TCesClusterFitter();
  ~TCesClusterFitter();
  
  int Fit(int* adc, bool wires=true, int firststrip=0, int nstrips=11);

  double RawEnergy(){ return _rawEnergy;}
  double FitEnergy() { return _fitEnergy;}

  // position in readout direction
  double Position() {return _fitPosition;}
  // provide side (0=east) and get stntuple sign (x in -phi sense, z in CDFz)
  double Position(int side) 
          { return (side==0? -_fitPosition : _fitPosition ); }
  double Chi2() {return _chi2;}
  
  void SetVerbose(int i) { _verbose = i;}
};

#endif