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

#include <algorithm>
#include <limits>

// -------------------------------------------------------------------------
template< class _TTraits >
void fpa::Filters::DijkstraBase< _TTraits >::
SetWeightFunction( TScalarWeight* w )
{
  if( this->m_ScalarWeight.GetPointer( ) != w )
  {
    this->_Deassociate( this->m_ScalarWeight );
    this->m_ScalarWeight = w;
    this->_Associate( this->m_ScalarWeight );
    this->Modified( );

  } // fi
}

// -------------------------------------------------------------------------
template< class _TTraits >
void fpa::Filters::DijkstraBase< _TTraits >::
SetWeightFunction( TVertexWeight* w )
{
  if( this->m_VertexWeight.GetPointer( ) != w )
  {
    this->_Deassociate( this->m_VertexWeight );
    this->m_VertexWeight = w;
    this->_Associate( this->m_VertexWeight );
    this->Modified( );

  } // fi
}

// -------------------------------------------------------------------------
template< class _TTraits >
fpa::Filters::DijkstraBase< _TTraits >::
DijkstraBase( )
  : Superclass( )
{
  this->SetInitValue( TOutputValue( 0 ) );
}

// -------------------------------------------------------------------------
template< class _TTraits >
fpa::Filters::DijkstraBase< _TTraits >::
~DijkstraBase( )
{
}

// -------------------------------------------------------------------------
template< class _TTraits >
void fpa::Filters::DijkstraBase< _TTraits >::
_UpdateOutputValue( TNode& n )
{
  // Do nothing
}

// -------------------------------------------------------------------------
template< class _TTraits >
void fpa::Filters::DijkstraBase< _TTraits >::
_QueueClear( )
{
  this->m_Queue.clear( );
}

// -------------------------------------------------------------------------
template< class _TTraits >
typename fpa::Filters::DijkstraBase< _TTraits >::
TNode fpa::Filters::DijkstraBase< _TTraits >::
_QueuePop( )
{
  std::pop_heap(
    this->m_Queue.begin( ), this->m_Queue.end( ), this->m_QueueOrder
    );
  TNode n = this->m_Queue.back( );
  this->m_Queue.pop_back( );
  return( n );
}

// -------------------------------------------------------------------------
template< class _TTraits >
void fpa::Filters::DijkstraBase< _TTraits >::
_QueuePush( const TNode& n )
{
  bool push_needed =  ( n.Parent == n.Vertex );
  push_needed     |= !( n.Value < this->_GetOutputValue( n.Parent ) );
  if( push_needed )
  {
    this->m_Queue.push_back( n );
    std::push_heap(
      this->m_Queue.begin( ), this->m_Queue.end( ), this->m_QueueOrder
      );

  } // fi
}

// -------------------------------------------------------------------------
template< class _TTraits >
unsigned long fpa::Filters::DijkstraBase< _TTraits >::
_QueueSize( ) const
{
  return( this->m_Queue.size( ) );
}

// -------------------------------------------------------------------------
template< class _TTraits >
void fpa::Filters::DijkstraBase< _TTraits >::
_ComputeOutputValue( TNode& n )
{
  if( this->m_VertexWeight.IsNotNull( ) )
  {
    TOutputValue c = this->m_VertexWeight->Evaluate( n.Vertex, n.Parent );
    if( this->m_ScalarWeight.IsNotNull( ) )
      c = this->m_ScalarWeight->Evaluate( c );
    n.Value = c + this->_GetOutputValue( n.Parent );
  }
  else
    n.Value = TOutputValue( -1 );
}

#endif // __fpa__Filters__DijkstraBase__hxx__
// eof - $RCSfile$