////////////////////////////////////////////////////////////////////
/// \class GLG4Gen
///
/// \author Phil Jones <p.g.jones@qmul.ac.uk>
/// \author Nuno Barros <nfbarros@hep.upenn.edu> -- contact person
///
/// REVISION HISTORY:\n
///	inherited as part of the generic GLG4 software
///  31-Oct-2016 : N Barros - Introduced BeginOfRun and EndOfRun methods.
///  10-Feb-2017 : N Barros - Added instances of time, position and vertex generator pointers the GLG4Gen
///                         - Expanded GLG4Gen::BeginOfRun to propagate to underlying generators
///
////////////////////////////////////////////////////////////////////
#ifndef __GLG4Gen_h__
#define __GLG4Gen_h__

#include <globals.hh>
#include <RAT/ParameterMacros.hh>
#include <string>

class G4Event;
class G4Track;
class G4PrimaryVertex;
class GLG4TimeGen;
class GLG4VertexGen;
class GLG4PosGen;

// Base class for event generators
class GLG4Gen {

public:
  GLG4Gen(const G4String &name = "") : fNextTime(0.0),fTimeGen(0),fVertexGen(0),fPosGen(0), fName(name) { };
  virtual ~GLG4Gen();
  virtual void GenerateEvent(G4Event *event)=0;
  virtual double NextTime() const { return fNextTime; };
  virtual void SubtractTime(double time) { fNextTime -= time; };
  virtual G4String GetName() {return fName;}
  virtual void SetName(G4String name) {fName = name;}
  virtual void ResetTime(double offset=0.0)=0;
  virtual bool IsRepeatable() const =0;

  virtual void SetState(G4String state)=0;
  virtual G4String GetState() const =0;

  virtual void BeginOfRun();
  virtual void EndOfRun();

  // Optional methods for setting specific aspects of
  // event generator if applicable
  virtual void SetTimeState(G4String state) { (void)state; };
  virtual G4String GetTimeState() const { return ""; };
  virtual void SetVertexState(G4String state) { (void)state; };
  virtual G4String GetVertexState() const { return ""; };
  virtual void SetPosState(G4String state) { (void)state; };
  virtual G4String GetPosState() const { return ""; };
protected:
  double fNextTime;
  GLG4TimeGen *fTimeGen;
  GLG4VertexGen *fVertexGen;
  GLG4PosGen *fPosGen;
  G4String fName;

};


// Generic generator formed by combining separate time, vertex, and position
// generators.
class GLG4Gen_Combo : public GLG4Gen {
public:
  GLG4Gen_Combo();
  virtual ~GLG4Gen_Combo();
  virtual void GenerateEvent(G4Event *event);
  virtual void ResetTime(double offset=0.0);
  virtual bool IsRepeatable() const { return true; };

  virtual void SetState(G4String state);
  virtual G4String GetState() const;

  virtual void SetTimeState(G4String state);
  virtual G4String GetTimeState() const;
  virtual void SetVertexState(G4String state);
  virtual G4String GetVertexState() const;
  virtual void SetPosState(G4String state);
  virtual G4String GetPosState() const;


protected:
  G4String fStateStr;
};


// Creates a one-shot generator used to defer a long-lived track
// to a later event.
class GLG4Gen_DeferTrack : public GLG4Gen {
public:
  GLG4Gen_DeferTrack(const G4Track *track);
  virtual ~GLG4Gen_DeferTrack();
  virtual void GenerateEvent(G4Event *event);
  virtual void ResetTime(double offset=0.0) { __unused_parameter(offset); };
  virtual bool IsRepeatable() const { return false; };

  virtual void BeginOfRun() { };
  virtual void EndOfRun() { };

  virtual void SetState(G4String state);
  virtual G4String GetState() const;

protected:
  G4PrimaryVertex *fVertex;
};


#endif