//some standard C++ includes
#include <iostream>
#include <stdlib.h>
#include <string>
#include <vector>
#include <chrono>
#include <cmath>
#include <math.h>
#include <iterator>
#include <algorithm>
#include <fstream>


//some ROOT includes
#include "TInterpreter.h"
#include "TROOT.h"
#include "TH1F.h"
#include "TH2D.h"
#include "TFile.h"
#include "TMath.h"
#include "TTree.h"
#include "TBranch.h"
#include "TVector3.h"

//"art" includes (canvas, and gallery)
#include "canvas/Utilities/InputTag.h"
#include "gallery/Event.h"
#include "gallery/ValidHandle.h"
#include "canvas/Persistency/Common/FindMany.h"
#include "canvas/Persistency/Common/FindOne.h"
#include "gallery/Handle.h"

//"larsoft" object includes
#include "lardataobj/RecoBase/OpFlash.h"
#include "lardataobj/RecoBase/OpHit.h"
#include "lardataobj/RawData/RawDigit.h"
#include "lardataobj/RecoBase/Hit.h"
#include "lardataobj/RecoBase/Track.h"
#include "lardataobj/RecoBase/SpacePoint.h"
#include "lardataobj/AnalysisBase/T0.h"
#include "lardataobj/MCBase/MCTrack.h"
#include "lardataobj/MCBase/MCStep.h"

//(timing information for the beam)
#include "lardataobj/RawData/TriggerData.h"
#include "larcoreobj/SimpleTypesAndConstants/geo_types.h"
#include "larcoreobj/SimpleTypesAndConstants/RawTypes.h"

//"larreco" reconstruction for MCS.
#include "larreco/RecoAlg/TrajectoryMCSFitter.h"

using namespace art;
using namespace std;
using namespace std::chrono;








void readTTree() {
    
    // read the Tree generated by tree2w and fill one histogram
    // we are only interested by the destep branch
    
    // note that we use "new" to create the TFile and TTree objects because we
    // want to keep these objects alive when we leave this function
    TFile *f = new TFile("/pnfs/uboone/scratch/users/abhat/gallery_output.root");
    TTree *t1 = (TTree*)f->Get("SCEtree");
    static Float_t mctrack_startX;
    static Float_t mctrack_startY;
    TBranch *b_mctrack_startX = t1->GetBranch("mctrack_startX");
    TBranch *b_mctrack_startY = t1->GetBranch("mctrack_startY");
    
    
    b_mctrack_startX->SetAddress(&mctrack_startX);
    b_mctrack_startY->SetAddress(&mctrack_startY);
    
    
    
    //create one histogram
    TH2D* h_track_start1 = new TH2D("h_track_start1","End Point of Tracks;X-Coordinate (cm);Y-Coordinate (cm)",100,-10,270,100,-130,130);
    h_track_start1->SetMarkerStyle(20);
    h_track_start1->SetMarkerColor(2);
    //read only the destep branch for all entries
    Int_t nentries = (Int_t)t1->GetEntries();
    for (Int_t i=0;i<nentries;i++) {
        b_mctrack_startX->GetEntry(i);
        b_mctrack_startY->GetEntry(i);
        // fill the histogram with the destep entry
        h_track_start1->Fill(b_mctrack_startX,b_mctrack_startY);
    }
    
    // we do not close the file; we want to keep the generated histograms;
    // we fill a 3-d scatter plot with the particle step coordinates
    TCanvas* canvas = new TCanvas("canvas","Hit Info!",1500,500);
    h_track_start1->Draw("P");

    TLine *l1 = new TLine(-10,-116.5,270,-116.5);
    TLine *l2 = new TLine(-10,116.5,270,116.5);
    l1->Draw();
    l2->Draw("SAME");


}