/**
* @file GenericLocalFeatureSelection.h
* @brief This class provides a generic chooser function for different descriptors, which are derived from LocalFeature.
* @author Eric Bach
* @date 26.10.2011
*/

#ifndef _NICE_OBJREC_LOCALFEATURESELECTION_INCLUDE
#define _NICE_OBJREC_LOCALFEATURESELECTION_INCLUDE

#include "vislearning/features/localfeatures/LocalFeatureRepresentation.h"

// color-descriptor
#include "vislearning/features/localfeatures/LocalFeatureRGBSift.h"
#include "vislearning/features/localfeatures/LocalFeatureOpponnentSift.h"
// non-color-descriptor
#include "vislearning/features/localfeatures/LocalFeatureSift.h"


/** NOTE: This class only returns Descriptors, which NEED given positions. NO Descriptors calculate there own positions. **/

namespace OBJREC {

class GenericLocalFeatureSelection
{
  public:
    /** LocalFeature Selector
    * @brief This methode switches between the different LocalFeature-Types. One has to set the "localfeature_type" on a valid value and the methode returns a LocalFeatureRepresentation derived Object.
    * @param[in] Config* - A pointer to the given configfile, which must contain "section" - "localfeature_type"
    * @param[in] string  - This string defines the value for "section" in the configfile.
    * @return LocalFeatureRepresentation* - The LocalFeatureRepresentation which contains the selected LocalFeature-Type.
    */
    static LocalFeature *selectLocalFeature ( const NICE::Config *conf, std::string section = "Features" )
    {
      // return Value
      LocalFeature *lf = NULL;

      // string which defines the localfeature_type (for Ex. RGB, OppSift, Sift...)
      std::string localfeature_type = conf->gS ( section, "localfeature_type", "not defined" );

      // The prefix NICE_* indicates that this implementation comes from a NICE-Developer.
      // Extern implementations can be added without NICE_* in this selection-class.
      if ( localfeature_type == "NICE_SIFT" )
      {
        lf = new LocalFeatureSift ( conf );
      }
      else if ( localfeature_type == "NICE_RGBSIFT" )
      {
        lf = new LocalFeatureRGBSift ( conf );
      }
      else if ( localfeature_type == "NICE_OPPSIFT" )
      {
        lf = new LocalFeatureOpponnentSift ( conf );
      }

      // no correct localfeature_type was given
      if ( lf == NULL )
        fthrow ( NICE::Exception, "Local feature type not found: " << localfeature_type );

      return lf;
    }
};
}

#endif