/**
* @file TConvolution.hh
* @brief .
*
* @author 
*
* @date 
*/
#ifndef TCONVOLUTION_HH
#define TCONVOLUTION_HH

#include <iostream>

class TH1;
class TVirtualFFT;

/** */
class TConvolution {
public:
  enum BufStrat { None=0, Extend=1, Mirror=2, Flat=3 } ;

  TConvolution(Int_t Ndim = 1, Int_t NbinsX = 30, Int_t NbinsY = 30, 
	       TConvolution::BufStrat bs = TConvolution::Mirror,
	       Double_t bufFracX = 0.1, Double_t bufFracY = 0.1,
	       Option_t* opt = "EX");
  TConvolution(const TH1* histoA, const TH1* histoB, 
	       TConvolution::BufStrat bs = TConvolution::Mirror,
	       Double_t bufFracX = 0.1, Double_t bufFracY = 0.1,
	       Option_t* opt = "EX");
  TConvolution(const TConvolution& other);
  virtual ~TConvolution();

  static std::string BufStratToString(BufStrat bs);
  static BufStrat StringToBufStrat(std::string sbs);
  static std::string CommaSeparatedListOfBufStrats();

  void SetBufferStrategy(TConvolution::BufStrat bs);
  void SetBufferFraction(Double_t bufFracX = 0,
			 Double_t bufFracY = 0);
  void SetShiftA(TH1* histo, 
		 Double_t shiftValX = 0, Double_t shiftValY = 0);
  void SetShiftB(TH1* histo, 
		 Double_t shiftValX = 0, Double_t shiftValY = 0);

  void SetHistoA(const TH1* histo);
  void SetHistoB(const TH1* histo);
  void Convolve(TH1* result);

  void DiagnosticPlot(std::string transform, 
		      std::string name);

private:
  Int_t fDim;

  // FFT objects
  Option_t* fFFTOpt;
  TVirtualFFT* fFFTr2cA;
  TVirtualFFT* fFFTr2cB;
  TVirtualFFT* fFFTc2r;

  // handy holders
  Int_t* fIndex;

  // buffer parameters
  BufStrat fBufStrat; //< Buffer stategy
  Double_t* fBufFrac; //< Buffer fraction in x & y
  Int_t* fNbin; //< N bins within histo range in x & y
  Int_t* fNbuf; //< N buffer bins in x & y
  Int_t* fNtot; //< N total bins in x & y

  // shift parameters
  Int_t* fShiftBinA; //< x & y shift bin for histo A
  Int_t* fShiftBinB; //< x & y shift bin for histo B
  Double_t* fShiftValA; //< x & y shift value for histo A
  Double_t* fShiftValB; //< x & y shift value for histo B

  bool is2D() const;
  bool CheckConsistency(const TH1* histoA, const TH1* histoB);
  void CalcNumberOfBins();
  void InitFFT();

  void CalcShiftBins(const TH1* histo, 
		     const Double_t* ShiftVal,
		     Int_t* zeroBin);

  void ScanHisto(const TH1* histo, 
		 Int_t* zeroBin,
		 TVirtualFFT* fft);


  void MultiplyAndTransform();
  void complexProduct(Double_t re1, Double_t im1, 
		      Double_t re2, Double_t im2,
		      Double_t& re, Double_t& im);
  void ScanResult(TH1* histo) const;

  TH1 * GetTransformedHisto(const char* name, const char* title, 
			    TVirtualFFT* fft, Option_t* option);
  void debugFFT(const char* name, TVirtualFFT * fft, 
		bool isComplex);
  
  ClassDef(TConvolution,1);
};

std::ostream& operator<<(std::ostream& os, const TConvolution::BufStrat& sfo);

#endif