/****************************************************************\
| This file is part of the PAX example files for CDF             |
| -------------------------------------------------------------- | 
|   Author of the last change: $Author: erdmann $                 
|   Date of last change:       $Date: 2003/11/18 15:13:17 $   
|   Revision number:           $Revision: 1.2 $        
\****************************************************************/
//
//! example interface: fill CDF StnElectrons into PAX event interpretation
//
#include "TPAXAnaModule.hh"

#include "PAX/PAXexperimentclass.hh"
#include "PAX/PAXfourvector.hh"
#include "PAX/PAXinterpret.hh"
#include "PAX/PAXiterator.hh"
#include "PAX/PAXphysicsmap.hh"
#include "PAX/PAXvertex.hh"

#include <Stntuple/obj/TStnElectronBlock.hh>
#include <Stntuple/data/TCalTower.hh>

bool  TPAXAnaModule::FillElectrons(PaxEventInterpret* ei, int currentevent){

  bool vertexOK   = 0;
  bool electronOK = 0;
  bool eventOK    = 1;
  
  // fill the vertices from the VertexBlock into the event interpretation

  vertexOK = FillVertices(ei, currentevent);

  // fill the electrons from the StnElectronBlock into the event interpretation    

  if (fElectronData)
    {
      // set name of event interpretation

      ei->SetPaxName("electrons");

      // read Stntuple data
      
      fElectronData->GetEntry(currentevent);

      // loop over all CDF electrons

      int nelectrons = fElectronData->NElectrons();

      for (Int_t i=0; i<nelectrons; i++) 
	{
	  // access CDF electron

	  TStnElectron* cdf_electron = fElectronData->Electron(i);   

	  // create empty pax fourvector

	  PaxFourVector* pax_electron = new PaxFourVector;	    	    	    

	  // add fourvector to the event interpretation

	  ei->Add(pax_electron);

	  // set kinematics, charge, name, particle identification

	  pax_electron->SetPx((double) cdf_electron->Momentum()->Px());
	  pax_electron->SetPy((double) cdf_electron->Momentum()->Py());
	  pax_electron->SetPz((double) cdf_electron->Momentum()->Pz());
	  pax_electron->SetE ((double) cdf_electron->Momentum()->E());
	  pax_electron->SetCharge((double) cdf_electron->Charge());
	  pax_electron->SetPaxName("electron");

	  int ipdg = 11;
	  if ( pax_electron->GetCharge() > 0 ) ipdg = -ipdg;
	  pax_electron->SetParticleId( ipdg );

	  // ----------------------------------------------------------------
	  
	  // in order to enable access to the original CDF data within PAX, 
	  // register an experiment relation to the instance of the TStnElectron
	  // class

  	  string experiment_class_manager; 

	  // create empty experiment relation 

	  PaxExperimentClassRelations* experiment_class_relation 
	    = new PaxExperimentClassRelations; 

	  // add a manager with pax vertex under the name of the CDF class
	  // to the pax electron

	  experiment_class_manager = "TStnElectron"; 
	  pax_electron->map_experimentclass_relations
	    ->Add( experiment_class_manager, experiment_class_relation ); 

	  // register CDF electron instance with the experiment class relation

	  PaxExperimentClass* ec = new PaxExperiment<TStnElectron>(cdf_electron); 
	  experiment_class_relation->Add(i,ec); 

	  // also register an experiment relation to the eta-phi assignment 
	  // of the calorimeter tower TCalTower

	  if (fCalData)
	    {
	      TCalTower* tower = fCalData->Tower(cdf_electron->SeedIEta(), 
						 cdf_electron->SeedIPhi());

	      // create empty experiment relation 

              PaxExperimentClassRelations* tower_relation 
		= new PaxExperimentClassRelations; 

	      // add a manager with pax electron under the name of the CDF class

	      experiment_class_manager = "TCalTower"; 
              pax_electron->map_experimentclass_relations
		->Add( experiment_class_manager, tower_relation ); 

	      // register CDF tower instance with the experiment class relation

              PaxExperimentClass* ec = new PaxExperiment<TCalTower>( tower ); 
              tower_relation->Add( tower->EtaPhi(), ec ); 
            }
	}
      electronOK = 1;
    }
  else
    {
      cerr << "ElectronBlock was not found in the STNTUPLE!!" << endl; 
      electronOK = 0;
    }

  //------------------------------------------------------------

  // connect all calorimeter towers to the primary vertex

  if (vertexOK & electronOK)
    {
      // iterator for vertices

      PaxIterator<PaxVertex*>* iter_vx = ei->vertex->GetIterator();

      // search for the primary vertex

      PaxVertex* primary_vertex = 0;

      iter_vx->First();

      while ( !primary_vertex && !iter_vx->IsDone() )
	{ 
	  if (iter_vx->CurrentItem()->GetPaxName() == "primary vertex")
	    primary_vertex = iter_vx->CurrentItem();

	  iter_vx->Next();
	}

      // connect all towers to the primary vertex:
      // here we set the begin vertex relations of all fourvectors,
      // as well as the outgoing fourvector relations of the vertex

      if ( primary_vertex ) 
	{
	  PaxIterator < PaxFourVector* >* iter_fv 
	    = ei->fourvector->GetIterator();

	  for ( iter_fv->First(); !iter_fv->IsDone(); iter_fv->Next() )
	    iter_fv->CurrentItem()->begin_vertex_relations->
	      Add( primary_vertex, iter_fv->CurrentItem() );
	} 
    }

  eventOK = vertexOK && electronOK;
  return eventOK;
}

//_____________________________________________________________________________