#include "TFile.h"
#include "TH1F.h"
#include "TH2F.h"
#include "TCanvas.h"
#include "TStopwatch.h"
#include "TROOT.h"
#include "TSystem.h"
#include "TTree.h"
#include "TString.h"


void printCand(TLorentzVector l, TVector3 p)
{
  cout <<"vtx("<<p.X()<<"/"<<p.Y()<<"/"<<p.Z()<<") p4("<<l.Px()<<"/"<<l.Py()<<"/"<<l.Pz()<<")="<<l.Vect().Mag()<<endl;
}


void ana_psi2s_fit(TString fname, int nevts=0)
{
    TStopwatch timer;
    timer.Start();

	gROOT->LoadMacro("$VMCWORKDIR/gconfig/rootlogon.C");rootlogon();
    
    TCanvas *c1=new TCanvas("c1","c1",600,600);
	
	PndEventReader evr(fname);
	
	if (nevts==0) nevts=evr.GetEntries();
	    
    // **** create and setup some histos for QA plots
    //
    TH1F *jpsimass = new TH1F("jpsimass","J/psi cands",100,3.1-0.3,3.1+0.3);
    TH1F *jpsi2mass = new TH1F("jpsi2mass","J/psi cands 4C fit",100,3.1-0.3,3.1+0.3);
    
    TH1F *ppmass = new TH1F("ppmass","pbarp cands",100,3.68598-0.5,3.68598+0.5);
    TH1F *pp2mass = new TH1F("pp2mass","pbarp fitted",100,3.68598-0.5,3.68598+0.5);
    
   // **** create all the particle lists we'll need for rebuilding the decay tree
    //
    TCandList pip, pim, ep, em;
    TCandList jpsi,pp;
    
    TPidMassSelector *jpsiMSel       = new TPidMassSelector("jpsiSelector" , 3.096 , 0.3);
    
    TLorentzVector ini(0,0,6.23164,7.24015);
    
	int i=0,j=0;
		
    // **** loop over all _events_
    //
	while (evr.GetEvent() && ++i<nevts)
	{
		if (!(i%100)) 
		cout <<"evt "<<i<<endl;
		
		evr.FillList(pip,"PionLoosePlus");
		evr.FillList(pim,"PionLooseMinus");
		evr.FillList(ep, "ElectronLoosePlus");
		evr.FillList(em, "ElectronLooseMinus");
		
		jpsi.Combine(ep,em);
		
		for (j=0;j<jpsi.GetLength();++j) 
		{
		   jpsimass->Fill(jpsi[j].M());
		}
		
		// for the 4C fit we need to add the daughters individually
		pp.Combine(jpsi,pip,pim);
		
		for (j=0;j<pp.GetLength();++j)
		{
			ppmass->Fill(pp[j].M());
			
			//do the 4C fit on the pbar p System
			Pnd4CFitter fitter(pp[j],ini);
			
			fitter.FitConserveMasses();
			
			TCandidate *ppfit=fitter.FittedCand(pp[j]);
			pp2mass->Fill(ppfit->M());
			
			TCandidate *epfit=fitter.FittedCand(*(pp[j].Daughter(0)->Daughter(0)));
			TCandidate *emfit=fitter.FittedCand(*(pp[j].Daughter(0)->Daughter(1)));
			
			TLorentzVector sum=epfit->P4()+emfit->P4();
			
			jpsi2mass->Fill(sum.Mag());
			
		}
    }
    
    // **** plot all that stuff
    //
    
    c1->Divide(2,2);

    c1->cd(1); jpsimass->Draw();
    c1->cd(2); jpsi2mass->Draw();
	c1->cd(3); ppmass->Draw();
    c1->cd(4); pp2mass->Draw();
    c1->cd();
    
    timer.Stop();
    Double_t rtime = timer.RealTime();
    Double_t ctime = timer.CpuTime();
    
    printf("RealTime=%f seconds, CpuTime=%f seconds\n",rtime,ctime);
    
}