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

#include <vector>
#include <itkConceptChecking.h>
#include <itkFunctionBase.h>
#include <fpa/Filters/Algorithm.h>
#include <fpa/Functors/BaseVertexFunction.h>

namespace fpa
{
  namespace Filters
  {
    /**
     */
    template< class _TTraits >
    class DijkstraBase
      : public fpa::Filters::Algorithm< _TTraits >
    {
    public:
      typedef _TTraits TTraits;
      fpaTraitsMacro( typename, TTraits );

      typedef fpa::Filters::Algorithm< TTraits > Superclass;
      typedef DijkstraBase                       Self;
      typedef itk::SmartPointer< Self >          Pointer;
      typedef itk::SmartPointer< const Self >    ConstPointer;

      typedef std::vector< TNode > TQueue;
      struct TQueueOrder
      {
        bool operator()( const TNode& a, const TNode& b ) const
          {
            return( b.Value < a.Value );
          }
      };

      typedef itk::FunctionBase< TOutputValue, TOutputValue > TScalarWeight;
      typedef fpa::Functors::BaseVertexFunction< TVertex, TOutputValue > TVertexWeight;

    protected:
      itkConceptMacro(
        Check_TOutputValue,
        ( itk::Concept::IsFloatingPoint< TOutputValue > )
        );

    public:
      itkTypeMacro( fpa::Filters::DijkstraBase, fpa::Filters::Algorithm );

      itkGetConstObjectMacro( ScalarWeight, TScalarWeight );
      itkGetObjectMacro( ScalarWeight, TScalarWeight );

      itkGetConstObjectMacro( VertexWeight, TVertexWeight );
      itkGetObjectMacro( VertexWeight, TVertexWeight );

    public:
      void SetWeightFunction( TScalarWeight* w );
      void SetWeightFunction( TVertexWeight* w );

    protected:
      DijkstraBase( );
      virtual ~DijkstraBase( );

      virtual void _UpdateOutputValue( TNode& n ) override;
      virtual void _QueueClear( ) override;
      virtual TNode _QueuePop( ) override;
      virtual void _QueuePush( const TNode& n ) override;
      virtual unsigned long _QueueSize( ) const override;
      virtual void _ComputeOutputValue( TNode& n ) override;

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

    protected:
      typename TScalarWeight::Pointer m_ScalarWeight;
      typename TVertexWeight::Pointer m_VertexWeight;

      TQueue       m_Queue;
      TQueueOrder m_QueueOrder;
    };

  } // ecapseman

} // ecapseman

#ifndef ITK_MANUAL_INSTANTIATION
#  include <fpa/Filters/DijkstraBase.hxx>
#endif // ITK_MANUAL_INSTANTIATION

#endif // __fpa__Filters__DijkstraBase__h__
// eof - $RCSfile$