/// \file
/// \ingroup tutorial_eve7 \\\PBR pbr_4trk.C
///  This example display only points in web browser
///
/// \macro_code
///

#include "TRandom.h"
#include "TParticle.h"
#include <ROOT/REveElement.hxx>
#include <ROOT/REveScene.hxx>
#include <ROOT/REveManager.hxx>
#include <ROOT/REveTrack.hxx>
#include <ROOT/REveTrackPropagator.hxx>

#include "TGeoManager.h"
#include "TGeoMaterial.h"
#include "TGeoMedium.h"
#include "TGeoVolume.h"
#include "TGeoTrack.h"
#include "TRandom.h"
#include "TTimer.h"
#include "TPad.h"

namespace REX = ROOT::Experimental;

void create_geo()
{
    if (gGeoManager) {
       delete gGeoManager;
    }

    new TGeoManager("Cylinder", "the simplest detector geometry");
    //--- define some materials
     TGeoMaterial *matVacuum = new TGeoMaterial("Vacuum", 0,0,0);
     TGeoMaterial *matAl = new TGeoMaterial("Al", 26.98,13,2.7);
 //   //--- define some media
     TGeoMedium *Vacuum = new TGeoMedium("Vacuum",1, matVacuum);
     TGeoMedium *Al = new TGeoMedium("Root Material",2, matAl);

     matVacuum->SetTransparency(90);

     TGeoVolume *top = gGeoManager->MakeBox("TOP",Vacuum,100,100,100);
     gGeoManager->SetTopVolume(top);
     top->SetFillColor(3);

     TGeoVolume *vol = gGeoManager->MakeTube("CYL",Al, 29.8,30,50);
     vol->SetFillColor(2);
     vol->SetLineWidth(1);

     top->AddNode(vol,1);

     gGeoManager->CloseGeometry();

//     auto cyl1 = new REX::REveGeoShape("Cylinder 1");
//     cyl1->SetShape(top);

//   gGeoManager->GetMasterVolume()->Draw();

//   top->Draw();
//   gPad->Modified();
//   gPad->Update();

} //END create_geo

void makeTracks(int N_Tracks, REX::REveElement* trackHolder)
{
   TRandom &r = *gRandom;
   auto prop = new REX::REveTrackPropagator();
   prop->SetMagFieldObj(new REX::REveMagFieldDuo(350, 3.5, -2.0));
   prop->SetMaxR(300);
   prop->SetMaxZ(600);
   prop->SetMaxOrbs(6);
   // Default is kHelix propagator.
   // prop->SetStepper(REX::REveTrackPropagator::kRungeKutta);

   double v = 0.5;
   double m = 5;

   for (int i = 0; i < N_Tracks; i++)
   {
      auto p = new TParticle();

      int pdg = 11 * (r.Integer(2) > 0 ? 1 : -1);
      p->SetPdgCode(pdg);

      p->SetProductionVertex(r.Uniform(-v,v), r.Uniform(-v,v), r.Uniform(-v,v), 1);
      p->SetMomentum(r.Uniform(-m,m), r.Uniform(-m,m), r.Uniform(-m,m)*r.Uniform(1, 3), 1);
      auto track = new REX::REveTrack(p, 1, prop);
      track->MakeTrack();
      track->SetMainColor(kBlue);
      track->SetName(Form("RandomTrack_%d", i));
      trackHolder->AddElement(track);
   }
}

void pbr_4trk()
{
   int Ntracks = 8;

   auto eveMng = REX::REveManager::Create();

   create_geo();  

   TFile* geom=TFile::Open("CylGeo.root");
   REX::REveGeoShapeExtract* gse = (REX::REveGeoShapeExtract*) geom->Get("Cylinder");
   REX::REveGeoShape *gGeomCyl=0;

   gse->Print();

   gGeomCyl = REX::REveGeoShape::ImportShapeExtract(gse, 0);
   geom->Close();
   delete geom;

   eveMng->GetGlobalScene()->AddElement(gGeomCyl);
//   gEve->AddGlobalElement(gGeomCyl);

   auto trackHolder = new REX::REveElement("Tracks");
   eveMng->GetEventScene()->AddElement(trackHolder);
   makeTracks(Ntracks, trackHolder);

   eveMng->Show();
}