#include <iostream>
#include <RooArgSet.h>
#include <RooChebychev.h>
#include <RooDataHist.h>
#include <RooPlot.h>
#include <RooRealVar.h>
#include <TApplication.h>
#include <TCanvas.h>

using namespace RooFit;


int FitSample2() {

	// Model
	RooRealVar x("x","x",5000,8500);

	// Polynomial
	RooRealVar a1("a1","a1",0.18,0.08,0.28);
	RooRealVar a2("a2","a2",0.11,0.01,0.21);
	RooRealVar a3("a3","a3",0.04,-0.05,0.12);
	RooRealVar a4("a4","a4",0.01,-0.08,0.10);
	RooChebychev model("model","Model",x,RooArgSet(a1,a2,a3,a4));

	RooDataHist* data = SampleData(x);
	//model.fitTo(*data);


	// -------------------- Debug graphs --------------------
	TCanvas* canvas1 = new TCanvas("canvas1","signal",600,600);
	canvas1->Divide(1,2);

	canvas1->cd(1);
	RooPlot* xframe = x.frame();
	data->plotOn(xframe);
	model.plotOn(xframe);
	xframe->Draw();

	canvas1->cd(2);
	RooPlot* xframe2 = x.frame();
	xframe2->addPlotable(xframe->residHist(), "P");
	xframe2->Draw();

	/*// Likelihood PLots
	TCanvas* canvas2 = new TCanvas("canvas2","signal",600,600);
	canvas2->Divide(2,2);
	RooAbsReal* modelnll = model.createNLL(*data);

	canvas2->cd(1);
	RooPlot* a1frame = a1.frame();
	modelnll->plotOn(a1frame,ShiftToZero());
	a1frame->Draw();

	canvas2->cd(2);
	RooPlot* a2frame = a2.frame();
	modelnll->plotOn(a2frame,ShiftToZero());
	a2frame->Draw();

	canvas2->cd(3);
	RooPlot* a3frame = a3.frame();
	modelnll->plotOn(a3frame,ShiftToZero());
	a3frame->Draw();

	canvas2->cd(4);
	RooPlot* a4frame = a4.frame();
	modelnll->plotOn(a4frame,ShiftToZero());
	a4frame->Draw();*/

	return 0;
}

RooDataHist* SampleData(RooRealVar x) {

	// Model
	x.setBins(100);

	// Polynomial
	RooRealVar dataGenA1("dataGenA1","a1",0.18);
	RooRealVar dataGenA2("dataGenA2","a2",0.11);
	RooRealVar dataGenA3("dataGenA3","a3",0.04);
	RooRealVar dataGenA4("dataGenA4","a4",0.01);
	RooChebychev dataGenModel("dataGenModel","Generating Model",x,RooArgSet(dataGenA1,dataGenA2,dataGenA3,dataGenA4));

 	// Generate data
	return dataGenModel.generateBinned(x,2500000,kTRUE);
}

int main(int argc, char* argv[]) {
	TApplication* rootapp = new TApplication("example",&argc, argv);
	FitSample2();
	rootapp->Run(kTRUE);
	return 0;
}