#ifndef  OAEVENT_ITRACKIDMAP_HXX
#define  OAEVENT_ITRACKIDMAP_HXX

#include <IDatum.hxx>
#include <map>

namespace COMET { class ITrackIDMap; }

/// Class to store mapping from generated track IDs to input track IDs
class COMET::ITrackIDMap:public COMET::IDatum{

    public:

        ITrackIDMap(int minNew=0, const char* name="TrackID_Mapping")
            :IDatum(name), fMinNewTrkID(minNew) {};
        typedef std::map<int,int> TrackIDMapping;
        
        /// Set the minimum ID for any new track IDs
        /// This should correspond to the largest found track ID in the previous
        /// section (i.e. read in from an input file).
        void SetMinNewTrackID(int newValue) {fMinNewTrkID = newValue;};
        /// Get
        const int GetMinNewTrkID()const {return fMinNewTrkID;};
        /// Add an explict mapping to the track ID map.
        void Add(int oldID, int newID) {fNewToGlobal[oldID] = newID;};
        /// Check if the mapping exists.
        /// If no mapping exists, create a new track ID for this ID.
        int Get(int oldID) {
            if (oldID == 0) return oldID;
            if (fNewToGlobal.find(oldID) == fNewToGlobal.end()) {
                fNewToGlobal[oldID] = oldID + fMinNewTrkID;
            }
            return fNewToGlobal[oldID];
        }

        virtual void ls(Option_t* opt = "") const;

    private:

        TrackIDMapping fNewToGlobal;    
        int fMinNewTrkID;

        ClassDef(ITrackIDMap,1)
};

#endif  // OAEVENT_ITRACKIDMAP_HXX