// =========================================================================
// @author Leonardo Florez Valencia
// @email florez-l@javeriana.edu.co
// =========================================================================
#ifndef __fpa__Common__OriginalRandomWalker__h__
#define __fpa__Common__OriginalRandomWalker__h__

#include <fpa/Config.h>
#include <vector>
#include <itkImage.h>
#include <itkImageToImageFilter.h>

namespace fpa
{
  namespace Common
  {
    /**
     */
    template< class _TImage, class _TLabels, class _TScalar = float >
    class OriginalRandomWalker
      : public itk::ImageToImageFilter< _TImage, _TLabels >
    {
    public:
      typedef _TImage  TImage;
      typedef _TLabels TLabels;
      typedef _TScalar TScalar;

      typedef OriginalRandomWalker                       Self;
      typedef itk::ImageToImageFilter< TImage, TLabels > Superclass;
      typedef itk::SmartPointer< Self >                  Pointer;
      typedef itk::SmartPointer< const Self >            ConstPointer;

      typedef itk::Image< TScalar, TImage::ImageDimension > TScalarImage;
      typedef typename TImage::IndexType  TIndex;
      typedef typename TImage::PixelType  TPixel;
      typedef typename TImage::RegionType TRegion;
      typedef typename TLabels::PixelType TLabel;

    public:
      itkNewMacro( Self );
      itkTypeMacro(
        fpa::Common::OriginalRandomWalker, itk::ImageToImageFilter
        );

      itkGetConstMacro( Beta, TScalar );
      itkSetMacro( Beta, TScalar );

      itkGetConstMacro( Epsilon, TScalar );
      itkSetMacro( Epsilon, TScalar );

      itkBooleanMacro( NormalizeWeights );
      itkGetConstMacro( NormalizeWeights, bool );
      itkSetMacro( NormalizeWeights, bool );

      fpaFilterInputMacro( InputLabels, TLabels );
      fpaFilterOutputMacro( OutputProbabilities, TScalarImage );

    public:
      void AddSeed( const TIndex& seed, const TLabel& label );

    protected:
      OriginalRandomWalker( );
      virtual ~OriginalRandomWalker( );

      virtual void GenerateData( ) override;

      static unsigned long _1D( const TIndex& idx, const TRegion& region );
      static TIndex _ND( const unsigned long& i, const TRegion& region );

    private:
      // Purposely not implemented
      OriginalRandomWalker( const Self& other );
      Self& operator=( const Self& other );

    protected:
      std::vector< TIndex > m_Seeds;
      std::vector< TLabel > m_Labels;

      TScalar m_Beta;
      TScalar m_Epsilon;
      bool m_NormalizeWeights;
    };

  } // ecapseman

} // ecapseman

#ifndef ITK_MANUAL_INSTANTIATION
#  include <fpa/Common/OriginalRandomWalker.hxx>
#endif // ITK_MANUAL_INSTANTIATION
#endif // __fpa__Common__OriginalRandomWalker__h__
// eof - $RCSfile$