#ifndef OAEMFIEDL_IFIELDMAPLOADER_HXX
#define OAEMFIEDL_IFIELDMAPLOADER_HXX

#include <TVector3.h>
#include <TDirectory.h>

namespace COMET{
    class IFieldMapLoader;
    class IFieldMapList;
}

/// Loads fieldmaps from command line arguments for convenience in executables
/** This class defines an interface to load in an arbitrary number of field maps 
 * into the global map.  This interface should be used for all executables that 
 * deal with the electromagnetic field, like plotting or combining fields.  
 */
class COMET::IFieldMapLoader{

    public:
        IFieldMapLoader();
        virtual ~IFieldMapLoader(){}

        /// Process the argument and carry out the change to the argument 
        /// IFieldMapList.
        /// \param argument the input argument letter from getopt
        /// \param optArgument the option that accompanies the argument
        /// \param fieldList the field list that the option will effect
        /// \return 0=pass,1=fail,2=bad fieldlist, 3=arg not found, 4=bad option
        int ProcessArgument(const char& argument, 
                            const char* optArgument, 
                            IFieldMapList* fieldList);
        /// Return the opt string for all input options
        std::string GetOptString() { return "f:R:t:r:s:";};
        /// Print the usage message for all options relating to field input
        std::string UsageMessage();
        /// Process an input string into an output TRotation
        bool StringToRotation(TRotation& rotation, 
                              std::stringstream& input);
        /// Initialise the argument fieldmap list and the global COMETField 
        /// mananger
        bool InitAllFields(IFieldMapList* fieldList);
        /// Write the fieldList and the description of the global field to the 
        /// current file
        bool WriteAllFields(IFieldMapList* fieldList);

};
#endif // OAEMFIEDL_IFIELDMAPLOADER_HXX