#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooExponential.h"
#include "RooChebychev.h"
#include "RooAddPdf.h"
#include "RooArgSet.h"
#include "RooExtendPdf.h"

#include "TFile.h"
#include "TString.h"

using namespace RooFit;

#define Blind

#ifdef Blind
#define ExtendPdf
#endif

Double_t xMin  = 4766;
Double_t xMax  = 5966;
Double_t xbMin = 5166;
Double_t xbMax = 5526;

int BkgFit()
{
  
  RooRealVar mass("mass","mass",xMin,xMax);
  mass.setRange("allRange",xMin,xMax);
  mass.setRange("lowerSB",xMin,xbMin); 
  mass.setRange("upperSB",xbMax,xMax);

#ifdef Blind
  TString fitRange = "lowerSB,upperSB";
#else
  TString fitRange = "allRange";
#endif

  RooRealVar aCheb("aCheb","aCheb",-2.0164e-01,-10.,10.);
  RooChebychev *Cheb = new RooChebychev("Cheb","Cheb",mass,aCheb);

  RooRealVar aExpo("aExpo","aExpo",-4.8184e-03,-10.,10.);
  RooExponential *Expo = new RooExponential("Expo","Expo",mass,aExpo);
  
  RooRealVar nCheb("nCheb","nCheb",8000,-10000,10000); //8.4738e+03
  RooRealVar nExpo("nExpo","nExpo",700,-10000,10000); //6.9946e+02

#ifdef ExtendPdf
  RooExtendPdf *ExtExpo = new RooExtendPdf("ExtExpo","ExtExpo",*Expo,nExpo,fitRange);
  RooExtendPdf *ExtCheb = new RooExtendPdf("ExtCheb","ExtCheb",*Cheb,nCheb,fitRange);
  
  RooAddPdf *CombModel = new RooAddPdf("CombModel","CombModel",RooArgList(*ExtExpo,*ExtCheb));
#else
  RooAddPdf *CombModel = new RooAddPdf("CombModel","CombModel",RooArgList(*Cheb,*Expo),RooArgList(nCheb,nExpo));
#endif

  TFile *file = new TFile("BkgCombModel.root","OPEN");
  RooDataSet *CombModelData = (RooDataSet*)file->Get("CombModelData");

  CombModel->fitTo(*CombModelData,Extended(kTRUE),Save(),Range(fitRange),PrintLevel(3));

  RooPlot *frame = mass.frame("mass","mass");
  CombModelData->plotOn(frame,Binning(30));
  CombModel->plotOn(frame,LineColor(kBlue),Range(fitRange),NormRange(fitRange));
  frame->Draw();

  return 0;
}