/**
* \file CbmRichRadiusCorrection.h
*
* \brief This class performs a correction of A and B parameters for ellipse fit or
* radius correction for circle fit.
*
* \author Semen Lebedev
* \date 2012
**/
#ifndef CBM_RICH_RADIUS_CORRECTION
#define CBM_RICH_RADIUS_CORRECTION

#include "CbmRichRingLight.h"
#include "TROOT.h"
#include "TDirectory.h"
#include "TFile.h"
#include "TH2D.h"
#include "TSystem.h"

#include <string>
#include <iostream>

using std::string;
using std::cout;
using std::endl;

/**
* \file CbmRichRadiusCorrection.h
*
* \brief This class performs a radius correction.
*
* \author Semen Lebedev
* \date 2012
**/
class CbmRichRadiusCorrection
{
public:

   /**
    * \brief Perform A and B parameters correction.
    * \param[in] RICH ring.
    */
   static void DoCorrection(
         CbmRichRingLight* ring)
   {
      if ( NULL == fhMapAaxisXY || NULL == fhMapBaxisXY){
         Init();
      }
      if ( NULL == fhMapAaxisXY || NULL == fhMapBaxisXY) return;

      double centerX = ring->GetCenterX();
      double centerY = ring->GetCenterY();
      double axisA = ring->GetAaxis() + fhMapAaxisXY->GetBinContent(fhMapAaxisXY->FindBin(centerX,centerY));
      double axisB = ring->GetBaxis() + fhMapBaxisXY->GetBinContent(fhMapBaxisXY->FindBin(centerX,centerY));

      ring->SetAaxis(axisA);
      ring->SetBaxis(axisB);
   }

private:
   /**
    * \brief Initialize histograms for radius correction procedure.
    * This procedure will be invoked automatically before first correction
    * is made.
    */
   static void Init()
   {
      string fileName = gSystem->Getenv("VMCWORKDIR");
      fileName += "/parameters/rich/radius_correction_map_compact.root";

      TDirectory *current = gDirectory;
      TFile *file = new TFile(fileName.c_str(), "READ");

      if (NULL == file || !file->IsOpen()) {
         cout << " -E- Read correction maps " << endl;
         cout << " -E- Could not open input file " << fileName << endl;
         return;
      } else {
         cout <<" -I- Map Correction input file: "<< fileName << endl;
      }

      gROOT->cd();

      fhMapAaxisXY = (TH2D*) file->Get("fh_mapaxisAXY")->Clone();
      fhMapBaxisXY = (TH2D*) file->Get("fh_mapaxisBXY")->Clone();

      file->Close();
      delete file;
      current->cd();
   }

   static TH2D* fhMapAaxisXY;
   static TH2D* fhMapBaxisXY;
};

#endif