// $Id$
//====================================================================
//  AIDA Detector description implementation for LCD
//--------------------------------------------------------------------
//
//  Author     : M.Frank
//
//====================================================================

// Framework include files
#include "DDG4/Geant4SensitiveDetector_inline.h"
#include "DDG4/Factories.h"

// Geant4 include files
#include "G4OpticalPhoton.hh"
#include "G4VProcess.hh"

using namespace std;
using namespace DD4hep::Geometry;

/*
 *   DD4hep::Simulation namespace declaration
 */
namespace DD4hep {  namespace Simulation {

  /// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  ///               Geant4GenericSD<Calorimeter>
  /// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  struct Calorimeter {};
  /// Method for generating hit(s) using the information of G4Step object.
  template <> bool Geant4GenericSD<Calorimeter>::buildHits(G4Step* step,G4TouchableHistory*) {
    StepHandler     h(step);
    Position        pos     = 0.5 * (h.prePos() + h.postPos());
    HitContribution contrib = Geant4Hit::extractContribution(step);
    Geant4CalorimeterHit* hit=find(collection(0),HitPositionCompare<Geant4CalorimeterHit>(pos));

    if ( !hit ) {
      collection(0)->insert(hit=new Geant4CalorimeterHit(pos));
    }
    hit->truth.push_back(contrib);
    hit->energyDeposit += contrib.deposit;
    return true;
  }
  typedef Geant4GenericSD<Calorimeter> Geant4Calorimeter;
}}    // End namespace DD4hep::Simulation

DECLARE_GEANT4SENSITIVEDETECTOR(Geant4Calorimeter);

/*
 *   DD4hep::Simulation namespace declaration
 */
namespace DD4hep {  namespace Simulation {

  /// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  ///               Geant4GenericSD<OpticalCalorimeter>
  /// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  enum { Edep_type=0, Cerenkov_type=1 };
  struct OpticalCalorimeter {};
  template <> class Geant4GenericSD<OpticalCalorimeter> : public Geant4GenericSD<Calorimeter>  {
  public:
    /// Constructor. The sensitive detector element is identified by the detector name
    Geant4GenericSD(const string& name, LCDD& lcdd)
      : Geant4GenericSD<Calorimeter>(name,lcdd) {          }

    /// Initialize the sensitive detector for the usage of a single hit collection
    bool defineCollection(const string& coll_name) {
      Geant4SensitiveDetector::defineCollection("Edep_" + coll_name);
      Geant4SensitiveDetector::defineCollection("Ceren_" + coll_name);
      return true;
    }

    /// Method for generating hit(s) using the information of G4Step object.
    virtual G4bool ProcessHits(G4Step* step,G4TouchableHistory* history) {
      G4Track * track =  step->GetTrack();
      // check that particle is optical photon:
      if( track->GetDefinition() != G4OpticalPhoton::OpticalPhotonDefinition() )  {
	return this->Geant4GenericSD<Calorimeter>::ProcessHits(step,history);
      }
      else if ( track->GetCreatorProcess()->G4VProcess::GetProcessName() != "Cerenkov")  {
	track->SetTrackStatus(fStopAndKill);
	return false;
      }
      else {
	StepHandler h(step);
	HitContribution contrib = Geant4Hit::extractContribution(step);
	Position        pos     = h.prePos();
	Geant4CalorimeterHit* hit=find(collection(Cerenkov_type),HitPositionCompare<Geant4CalorimeterHit>(pos));
	if ( !hit ) {
	  collection(Cerenkov_type)->insert(hit=new Geant4CalorimeterHit(pos));
	}
	hit->energyDeposit += contrib.deposit;
	hit->truth.push_back(contrib);
	track->SetTrackStatus(fStopAndKill); // don't step photon any further
	return true;
      }
    }
  };
  typedef Geant4GenericSD<OpticalCalorimeter> Geant4OpticalCalorimeter;
}}    // End namespace DD4hep::Simulation

DECLARE_GEANT4SENSITIVEDETECTOR(Geant4OpticalCalorimeter);