#include "TSystem.h"
#include "TROOT.h"
#include "TFile.h"
#include "TH1D.h"
#include "RooRealVar.h"
#include "RooCategory.h"
#include "RooDataHist.h"
#include "RooGenericPdf.h"
#include "RooAddPdf.h"
#include "RooPlot.h"
#include "RooSimultaneous.h"
#include "TCanvas.h"
#include <map>


void test_minimal() {
  
  ////////
  // ROOFIT INCLUSION
  gSystem->Load("libRooFit");
  using namespace RooFit;

  ////////
  // VARIABLE AND INTERVAL DEFINITIONS
  double minx = 139.75;
  double maxx = 164.75;
  // Variable
  RooRealVar* x = new RooRealVar("x", "x", minx,maxx);

  ////////
  // EXECUTION OPTIONS
  bool simultaneous = false;

  ////////
  // LOAD HISTOGRAM DATA
  TH1D* h_data;
  RooDataHist* data;
  RooAddPdf* pdf_all;
  // Open files
  TFile* file_data;
  file_data = new TFile("testFit.root");
  // Fill histograms and create RooDataHists
  h_data = (TH1D*)file_data->Get("deltaM_7");
  data = new RooDataHist("Data mass distribution", "", RooArgList(*x), h_data);

  ////////
  // CREATE SIMULTANEOUS OBJECTS

  // Fit categories
  RooCategory* sim_names = new RooCategory("sim_names","sim_names"); 
  sim_names->defineType("bin_7");

  // Data
  std::map<string,RooDataHist*> histMap;
  histMap.insert(std::make_pair("bin_7",data));
  RooDataHist* sim_data = new RooDataHist("sim data", "sim data", RooArgList(*x),*sim_names, histMap);

  // PDFs
  RooSimultaneous* sim_pdf = new RooSimultaneous("sim pdf","sim pdf",*sim_names);
  // Define signal pdf --> modified gaussian
  RooRealVar*    mean  = new RooRealVar("mean_7","mean_7",145,140,150);
  RooRealVar*    sigma = new RooRealVar("sigma_7","sigma_7",0.4,0.3,1);
  RooGenericPdf* pdf_sig = new RooGenericPdf("pdf_sig_7", "pdf_sig_7",
					     "exp(-0.5*pow(abs((@0-@1)/@2),(1.+1./(1.+0.5*abs((@0-@1)/@2)))))",
					     RooArgSet(*x,*mean,*sigma));
  // Define background pdfs --> power * exponential
  RooRealVar*    alpha = new RooRealVar("alpha_7","alpha_7",0.5,0.2,1.5);
  RooRealVar*    beta  = new RooRealVar("beta_7","beta_7",0.03,0.001,0.2);
  RooGenericPdf* pdf_bkg = new RooGenericPdf("pdf_bkg_7", "pdf_bkg_7",
					     "pow(@0-139.57,@1)*exp(-@2*(@0-139.57))",
					     RooArgSet(*x,*alpha,*beta));
  // Define composite pdf
  RooRealVar*    nsig = new RooRealVar("nsig_7","nsig_7", 100, 1, 1000000);
  RooRealVar*    nbkg = new RooRealVar("nbkg_7","nbkg_7", 100, 1, 1000000);
  pdf_all = new RooAddPdf("pdf_all_7","pdf_sig_7+pdf_bkg_7",RooArgList(*pdf_sig,*pdf_bkg),RooArgList(*nsig,*nbkg));
  // Add PDF to the simultaneous one
  sim_pdf->addPdf(*pdf_all,"bin_7");

  ////////
  // PERFORM FIT
  if(simultaneous) sim_pdf->fitTo(*sim_data,Minos(RooArgSet(*alpha,*beta,*mean,*sigma,*nsig,*nbkg)),Hesse(kTRUE),Range(minx,maxx));
  else pdf_all->fitTo(*data,Minos(RooArgSet(*alpha,*beta,*mean,*sigma,*nsig,*nbkg)),Hesse(kTRUE),Range(minx,maxx));

  ////////
  // PLOTS
  TCanvas *canvas = new TCanvas();
  // Plot
  RooPlot *dataPlot = new RooPlot("Data mass distribution", "", *x, minx, maxx, 200);
  data->plotOn(dataPlot);
  pdf_all->plotOn(dataPlot,LineColor(2));
  pdf_all->paramOn(dataPlot,Layout(0.55,0.92,0.60));
  dataPlot->Draw();
  canvas->cd();
}