//
// ********************************************************************
// * License and Disclaimer                                           *
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//
//  Gorad (Geant4 Open-source Radiation Analysis and Design)
//
//  Author : Makoto Asai (SLAC National Accelerator Laboratory)
//
//  Development of Gorad is funded by NASA Johnson Space Center (JSC)
//  under the contract NNJ15HK11B.
//
// ********************************************************************
//
// GRGeomImpBiasWorld.hh
//   Header file of a parallel world class that defines the geometry
//   of the geometry improtance biasing.
//
// History
//   September 8th, 2020 : first implementation
//
// ********************************************************************

#ifndef GRGeomImpBiasWorld_H
#define GRGeomImpBiasWorld_H 1

#include "G4VUserParallelWorld.hh"
#include "globals.hh"
#include "G4ThreeVector.hh"

class GRDetectorConstruction;
class G4VPhysicalVolume;
class G4Region;
class GRGeomImpBiasWorldStateNotifier;

class GRGeomImpBiasWorld : public G4VUserParallelWorld
{
  friend class GRGeomImpBiasWorldStateNotifier;

  public:
    GRGeomImpBiasWorld(G4String&,GRDetectorConstruction*);
    virtual ~GRGeomImpBiasWorld();
    virtual void Construct();
    virtual void ConstructSD();

  private:
    GRDetectorConstruction* detector;
    G4VPhysicalVolume* fWorld = nullptr;
    G4Region* biasingRegion = nullptr;
    GRGeomImpBiasWorldStateNotifier* stateNotifier;
    G4bool constructed = false;

  private:
    void Update();
};

#include "G4VStateDependent.hh"
#include "G4ApplicationState.hh"

class GRGeomImpBiasWorldStateNotifier : public G4VStateDependent
{
  public:
    GRGeomImpBiasWorldStateNotifier(GRGeomImpBiasWorld* bw)
    : biasWorld(bw)
    {;}
    virtual ~GRGeomImpBiasWorldStateNotifier()
    {;}
    virtual G4bool Notify(G4ApplicationState newState)
    {
      if(previousState == G4State_Idle && newState == G4State_GeomClosed)
      { biasWorld->Update(); }
      previousState = newState;
      return true;
    }
  private:
    GRGeomImpBiasWorld* biasWorld;
    G4ApplicationState previousState = G4State_PreInit;
};

#endif