/// 
/// For questions or suggestions about this module please contact the 
/// current responsible and CC in the oaAnalysis package manager.
///
/// 26-Nov-2012: Current responsible for this module is, 
/// Steve Dennis (stephen.dennis [*a*t*] warwick.ac.uk)
///

#ifndef TTruthVerticesModule_hxx_seen
#define TTruthVerticesModule_hxx_seen

// Root
#include <TObject.h>
// oaEvent
#include <ICOMETEvent.hxx>
// oaAnalysis
#include "IAnalysisTruthModuleBase.hxx"
#include "IoaAnalysisUtils.hxx"
#include "EoaAnalysis.hxx"

namespace COMET
{
  class ITruthVerticesModule;
  OA_EXCEPTION(ETruthVerticesModule,EoaAnalysis);
  OA_EXCEPTION(EUndefinedParticleCategoryVertex,ETruthVerticesModule);
}

/// oaAnalysis module for storing the truth information for primary
/// vertices in events
class COMET::ITruthVerticesModule : public IAnalysisTruthModuleBase
{
  public:
    
    class ITruthVertex;
    
    ITruthVerticesModule(const char* name = "Vertices", 
                                     const char* title = "True Primary Vertex information"
                                     );
    virtual ~ITruthVerticesModule();
    
    virtual Bool_t IsEnabledByDefault() const	{	return kTRUE;	}
    virtual void InitializeBranches();
    virtual bool FillTree(COMET::ICOMETEvent&);
    virtual Bool_t ProcessFirstEvent(COMET::ICOMETEvent&);
    
    
  private:
    
    /// The maximum number of vertices that the module will save in
    /// a single event
    const unsigned int fMaxNVertices;
    
    
  public:

    //--------------------------------------------------------------
    // Tree Entries
    
    Int_t fNVtx;		///< The total number of vertices recorded

    
    Int_t fNVtxFGD1;		///< The number of vertices recorded in FGD 1

    
    Int_t fNVtxFGD2;		///< The number of vertices recorded in FGD 2

    
    Int_t fNVtxP0D;		///< The number of vertices recorded in the P0D

    
    Int_t fNVtxDsECal;		///< The number of vertices recorded in the Downstream ECal

    
    Int_t fNVtxBrlECal;		///< The number of vertices recorded in the Barrel ECal

    
    Int_t fNVtxP0DECal;		///< The number of vertices recorded in the P0D ECal

    
    Int_t fNVtxTPC1;		///< The number of vertices recorded in TPC 1

    
    Int_t fNVtxTPC2;		///< The number of vertices recorded in TPC 2

    
    Int_t fNVtxTPC3;		///< The number of vertices recorded in TPC 3

    
    Int_t fNVtxSMRD;		///< The number of vertices recorded in the SMRD

    
    Int_t fNVtxRestOfOffAxis;		///< The number of vertices recorded in the rest of the off-axis detector

    
    Int_t fNVtxINGRID;		///< The number of vertices recorded in INGRID

    
    Int_t fNVtxOther;		///< The number of vertices recorded anywhere which does not fall  into the other available categories


    
    
    /// The array is sorted by the vertices ID number to enable more
    /// efficient retrieval by analysis tools.
    TClonesArray *fVertices;///< The TClonesArray storing the ITruthVertex objects holding the information relating to each vertex.
    
  private:
    
    ClassDef(ITruthVerticesModule, 1);
};



/// Class used by the Truth Vertices Module to store information relating
/// to an individual true primary vertex.
class COMET::ITruthVerticesModule::ITruthVertex : public TObject
{
  public:
    
    ITruthVertex();
    
    virtual ~ITruthVertex() {};
    
    /// Compare the values of the vertices' IDs so that a
    /// TClonesArray can be sorted in order of increasing ID.
    Int_t Compare(const TObject* obj) const;
    
    /// Make the object sortable so that a TClonesArray can be
    /// sorted in ID order.
    Bool_t IsSortable() const	{	return kTRUE;	}
    
    // Vertex information
    
    
    Int_t ID;		///<  A number which uniquely identifies this vertex within the event.
    ///< This ID is the interface between the Truth Vertices module
    ///< and other oaAnalysis modules. Other modules should use this
    ///< number to reference trajectories.
    
    TLorentzVector Position;		///< Position and time of the vertex


    std::string Generator;	///< The generator that created the vertex. eg: "genie:mean@free-spill"



    
    std::string ReactionCode;///< The Reaction code according to the generator
    ///< For Genie this will be of the form:
    ///< "nu:14;tgt:1000260560;N:2112;proc:Weak[CC],QES;"
    ///< For Neut it will be an integer, see definitions here:
    ///< http://www.t2k.org/asg/xsec/niwgdocs/neut_xsecs/neutmodesC.h/view


    
    
    COMET::IoaAnalysisUtils::ESubdetector Subdetector;///< Subdetector which the vertex occurs in.
    ///< There are also
    ///< values for INGRID, rest of the off-zxis detector, and 
    ///< Other.
    
    
    Double_t Fiducial;///< The distance inside the local fiducial volume [mm].
    ///< Not currently set for any detector other than the P0D.

    
    
    Int_t NPrimaryTraj;///< The number of primary trajectories
    ///< (ie: the number of primary
    ///< particles exiting the interaction vertex).
    
    std::vector< Int_t > PrimaryTrajIDs; ///< ID numbers which uniquely identify the trajectories of the  primary particles of the vertex within the event.


    
    // The PDG number of the incoming neutrino. Set to 0 in the
    // absence of a neutrino.
    Int_t NeutrinoPDG;///< The PDG number of the incoming neutrino. Set to 0 in the absence of a neutrino.

    // The four-momentum of the incoming neutrino.
    // Set to (-999999.9, -999999.9, -999999.9, -999999.9) in the
    // absence of a neutrino.
    TLorentzVector NeutrinoMomentum;///< The four-momentum of the incoming neutrino. Set to (-999999.9, -999999.9, -999999.9, -999999.9) in the absence of a neutrino.

    // The (extended for nuclei) PDG number of the target.
    // Set to 0 in the absence of a target.
    Int_t TargetPDG;///< The (extended for nuclei) PDG number of the target. Set to 0 in the absence of a target.

    
    TLorentzVector TargetMomentum;///< The four-momentum of the target.
    ///< Set to (-999999.9, -999999.9, -999999.9, -999999.9) in the
    ///< absence of a target.

  
  private:
    
    ClassDef(ITruthVerticesModule::ITruthVertex, 1);
};

#endif