////////////////////////////////////////////////////////////////////
/// \class RAT::DS::MCParticle
///
/// \brief  This class represents a primary particle for the event.
///
/// \author Stan Seibert <volsung@physics.utexas.edu>\n
///         Phil G Jones <p.g.jones@qmul.ac.uk>
///
/// REVISION HISTORY:\n
///  2013-1-21 : P. Jones - Refactor as part of ds review.
///
/// \details This class describes the state of one of the initial particles in this event.
///         Secondaries created during simulation are not included here.
///
////////////////////////////////////////////////////////////////////
#ifndef __RAT_DS_MCParticle__
#define __RAT_DS_MCParticle__

#include <TObject.h>
#include <TVector3.h>
#include <Math/Vector3D.h>

namespace RAT
{
namespace DS
{

class MCParticle : public TObject {
public:
  /// Construct a MCParticle
  MCParticle(): TObject(), pdgCode(0), mcTime(0), kineticEnergy(0), vertexID(0), metaInfo("") { }

  /// Set the position of the particle
  ///
  /// @param[in] pos of the particle
  void SetPosition( const TVector3& pos ) { position = ROOT::Math::XYZVectorF(pos.X(), pos.Y(), pos.Z()); }

  /// Get the position of the particle
  ///
  /// @return position of the particle
  TVector3 GetPosition() const { return TVector3(position.X(), position.Y(), position.Z()); }

  /// Set the polarisation of the particle
  ///
  /// @param[in] pol of the particle
  void SetPolarisation( const TVector3& pol ) { polarisation = ROOT::Math::XYZVectorF(pol.X(), pol.Y(), pol.Z()); }

  /// Get the polarisation of the particle
  ///
  /// @return polarisation of the particle
  TVector3 GetPolarisation() const { return TVector3(polarisation.X(), polarisation.Y(), polarisation.Z()); }

  /// Set the momentum of the particle
  ///
  /// @param[in] mom of the particle
  void SetMomentum( const TVector3& mom ) { momentum = ROOT::Math::XYZVectorF(mom.X(), mom.Y(), mom.Z()); }

  /// Get the momentum of the particle
  ///
  /// @return momentum of the particle
  TVector3 GetMomentum() const { return TVector3(momentum.X(), momentum.Y(), momentum.Z()); }

  /// Set the Particle Data Group, PDG, code of the particle
  ///
  /// @param[in] code
  void SetPDGCode( const Int_t code ) { pdgCode = code; }

  /// Get the Particle Data Group, PDG, Code of the particle
  ///
  /// @return code
  Int_t GetPDGCode() const { return pdgCode; }

  /// Set the time of the particle
  ///
  /// @param[in] time of the particle
  void SetTime( const Double_t time ) { mcTime = time; }

  /// Get the time of the particle
  ///
  /// @return time of the particle
  Double_t GetTime() const { return mcTime; }

  /// Set the kinetic energy of the particle
  ///
  /// @param[in] energy (kinetic) of the particle
  void SetKineticEnergy( const Double_t energy ) { kineticEnergy = energy; }

  /// Get the kinetic energy of the particle
  ///
  /// @return kinetic energy of the particle
  Double_t GetKineticEnergy() const { return kineticEnergy; }

  /// Set the Vertex ID to which this particle belongs
  ///
  /// @param[in] id of the vertex
  void SetVertexID( const Int_t id ) { vertexID = id; }

  /// Get the Vertex ID to which this particle belongs
  ///
  /// @return id
  Int_t GetVertexID() const { return vertexID; }

  /// Set the meta information of this particle
  ///
  /// @param[in] info of the vertex
  void SetMetaInfo( const std::string info ) { metaInfo = info; }

  /// Get the meta information (general purpose user string) of this particle
  ///
  /// @return metaInfo
  std::string GetMetaInfo() const { return metaInfo; }




  // This ROOT macro adds dictionary methods to this class.
  // The number should be incremented whenever this class's members are changed.
  // It assumes this class has no virtual methods, use ClassDef if change this.
  ClassDefNV( MCParticle, 6 );
protected:
  ROOT::Math::XYZVectorF position; ///< Initial position
  ROOT::Math::XYZVectorF polarisation; ///< Initial polarisation
  ROOT::Math::XYZVectorF momentum; ///< Initial momentum
  Int_t pdgCode; ///< Particle Data Group code
  Double_t mcTime; ///< Initial time in the event mc system
  Double32_t kineticEnergy; ///< Initial Kinetic energy
  Int_t vertexID; ///< Vertex to which this particle belongs
  std::string metaInfo;
};

} // namespace DS

} // namespace RAT

#endif