/*
 * EffRigCollection.cpp
 *
 *  Created on: 10/ago/2009
 *      Author: Nicola Mori
 */

/*! @file EffRigCollection.cpp The EffRigCollection class implementation file. */

#include "EffRigCollection.h"

#include "TGraphAsymmErrors.h"

extern "C" {
/*! @brief Fortran routine by Sergio Ricciarini which computes errors on the efficiency.
 *
 * This routine has been developed to carefully evaluate the error bars on the efficiency,
 * which must have a value between 0 and 1. See the appendix of Sergio's PhD thesis for more
 * details.
 * The important thing is that the computed efficiency will have the unphysical value 1.1
 * if there are less than 8 events in the efficiency sample (eg., the sample used to compute the
 * efficiency). This is necessary to have a reliable estimate of the errors.
 *
 * @param sel Pointer to an Int_t variable containing the number of events in the efficiency sample.
 * @param det Pointer to an Int_t variable containing the number of events in the efficiency sample
 *            which satisfied the set of cuts  for which the efficiency is being measured.
 * @param eff Pointer to a Double_t variable where the computed efficiency will be returned.
 * @param errLow Pointer to a Double_t variable where the length of the lower error bar will
 *               be returned.
 * @param errHigh Pointer to a Double_t variable where the length of the upper error bar will
 *               be returned.
 * @return Not clear at this point... ignore it.
 */
bool efficiency_(Int_t* sel, Int_t* det, Double_t* eff, Double_t* errLow, Double_t* errHigh);
}

EffRigCollection::EffRigCollection(const char *collectionName, TString outFileBase, TString rigBinsFile, int errMethod, bool owns) :
  EffCollection(collectionName, outFileBase, errMethod, owns), _bins(0), _selVector(0), _detVector(0), _outUp(0), _outDown(0) {

  ifstream rigBinListFile;
  rigBinListFile.open(rigBinsFile);

  TString auxString;
  while (!rigBinListFile.eof()) {
    rigBinListFile >> auxString;
    if (auxString != "") {
      _bins.push_back(auxString.Atof());
    }
  }
  rigBinListFile.close();

  _selVector.resize(_bins.size() - 1, 0);
  _detVector.resize(_bins.size() - 1, 0);
}

int EffRigCollection::ApplyCut(PamLevel2 *event) {

  _nEv++;
  if (_selCollection.ApplyCut(event) == CUTOK) {
    // Check if the event is inside the rigidity range
    // NOTE: at this point a TrkPhSinCut should be already performed,
    //       since we are going to retrieve rigidity.

    float rig = event->GetTrack(0)->GetTrkTrack()->GetRigidity();

    if (rig >= _bins[0]) {
      int i = 1;
      while (rig >= _bins[i] && i < (int) _bins.size()) {
        i++;
      }
      i--;

      if (i < (int) (_selVector.size())) {
        _selVector[i]++;
        _sel++;
        if (_detCollection.ApplyCut(event) == CUTOK) {
          _detVector[i]++;
          _det++;
          _nGood++;
          return CUTOK;
        }
      }
      else
        _outUp++;

    }
    else {
      _outDown++;
      return 0;
    }
  }

  return 0;
}

void EffRigCollection::Finalize() {

  // Print the report
  EffCollection::Finalize();
  cout << "    Events below the minimum rigidity: " << _outDown << "\n";
  cout << "    Events above the maximum rigidity: " << _outUp << "\n";

  // Compute the error
  Int_t sel[_selVector.size()];
  Int_t det[_detVector.size()];
  Double_t eff[_selVector.size()];
  Double_t errLow[_selVector.size()];
  Double_t errHigh[_selVector.size()];
  for (unsigned int i = 0; i < _selVector.size(); i++) {
    sel[i] = (Int_t) _selVector[i];
    det[i] = (Int_t) _detVector[i];
  }

  TGraphAsymmErrors errGraph;
  errGraph.SetName(GetName());
  errGraph.SetMarkerColor(kRed);
  errGraph.SetMarkerStyle(7);
  errGraph.GetYaxis()->SetRangeUser(0, 1.2);


  if (_errMethod == EFFERR_ROOT) {
    double binning[_bins.size()];
    for (unsigned int i = 0; i < _bins.size(); i++)
      binning[i] = _bins[i];

    TH1I pass("pass", "pass", _bins.size() - 1, binning);
    TH1I total("total", "total", _bins.size() - 1, binning);
    for (unsigned int i = 0; i < _selVector.size(); i++) {
      for (int j = 0; j < det[i]; j++)
        pass.Fill((binning[i + 1] + binning[i]) / 2.);
      for (int j = 0; j < sel[i]; j++)
        total.Fill((binning[i + 1] + binning[i]) / 2.);
    }

    errGraph.BayesDivide(&pass, &total);
    Double_t graphX;
    double currBin;
    int currPoint = 0;

    for (unsigned int i = 0; i < _selVector.size(); i++) {
      errGraph.GetPoint(currPoint, graphX, eff[i]);
      currBin = (binning[i + 1] + binning[i]) / 2.;
      if (currBin == graphX) {
        if (_selVector[i] < 8) {
          eff[i] = 1.1;
          errLow[i] = errHigh[i] = 0.;
          errGraph.SetPoint(currPoint, graphX, 1.1);
          float halfBin = (binning[i + 1] - binning[i]) / 2.;
          errGraph.SetPointError(currPoint, halfBin, halfBin, 0., 0.);
        }
        currPoint++;
      }
    }

  }
  if (_errMethod == EFFERR_SERGIO) {
    for (unsigned int i = 0; i < _selVector.size(); i++) {
      efficiency_(&(sel[i]), &(det[i]), &(eff[i]), &(errLow[i]), &(errHigh[i]));

      float R = (_bins[i] + _bins[i + 1]) / 2.;
      float halfBin = (_bins[i + 1] - _bins[i]) / 2.;
      errGraph.SetPoint(i, R, eff[i]);
      errGraph.SetPointError(i, halfBin, halfBin, errLow[i], errHigh[i]);

    }

  }

  // Write the output files
  if (_outFileBase != "") {
    ofstream outTextFile((_outFileBase + "-" + GetName() + "-rig.txt").Data(), ios_base::out);
    streamsize newPrec = 4;
    outTextFile.precision(newPrec);
    outTextFile.setf(ios::fixed, ios::floatfield);
    for (unsigned int i = 0; i < _selVector.size(); i++) {
      outTextFile << setw(10) << _bins[i] << setw(10) << _bins[i + 1] << setw(10) << _detVector[i] << setw(10)
          << _selVector[i];
      if (_selVector[i] != 0)
        outTextFile << setw(10) << eff[i] << setw(10) << errLow[i] << setw(10) << errHigh[i] << "\n";
      else
        outTextFile << setw(10) << 0. << setw(10) << 0. << setw(10) << 0.;
      if (i < _selVector.size() - 1) //Avoids to print an empty line at the end of the file
        outTextFile << endl;

    }

    outTextFile.close();

    TFile outRootFile((_outFileBase + "-" + GetName() + "-rig.root"), "RECREATE");
    outRootFile.cd();
    errGraph.Write();
    outRootFile.Close();

  }

}