// =========================================================================
// @author Leonardo Florez Valencia
// @email florez-l@javeriana.edu.co
// =========================================================================

#ifndef __fpa__Base__Dijkstra__hxx__
#define __fpa__Base__Dijkstra__hxx__

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
typename
fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
TMST* fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
GetMinimumSpanningTree( )
{
  return(
    dynamic_cast< TMST* >(
      this->itk::ProcessObject::GetOutput( this->m_MSTIndex )
      )
    );
}

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
const typename
fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
TMST* fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
GetMinimumSpanningTree( ) const
{
  return(
    dynamic_cast< const TMST* >(
      this->itk::ProcessObject::GetOutput( this->m_MSTIndex )
      )
    );
}

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
const typename
fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
TIntensityFunctor*
fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
GetIntensityFunctor( ) const
{
  return( this->m_IntensityFunctor );
}

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
const typename
fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
TVertexFunctor*
fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
GetVertexFunctor( ) const
{
  return( this->m_VertexFunctor );
}

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
void fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
SetFunctor( TIntensityFunctor* functor )
{
  if( this->m_IntensityFunctor.GetPointer( ) != functor )
  {
    this->m_IntensityFunctor = functor;
    this->Modified( );

  } // fi
}

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
void fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
SetFunctor( TVertexFunctor* functor )
{
  if( this->m_VertexFunctor.GetPointer( ) != functor )
  {
    this->m_VertexFunctor = functor;
    this->Modified( );

  } // fi
}

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
Dijkstra( )
  : Superclass( ),
    _TMarksInterface( this ),
    _TSeedsInterface( this )
{
  this->m_MSTIndex = this->GetNumberOfRequiredOutputs( );
  this->SetNumberOfRequiredOutputs( this->m_MSTIndex + 1 );
  this->itk::ProcessObject::SetNthOutput( this->m_MSTIndex, TMST::New( ) );
}

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
~Dijkstra( )
{
}

// -------------------------------------------------------------------------
template< class _TFilter, class _TMarksInterface, class _TSeedsInterface, class _TMST >
void fpa::Base::Dijkstra< _TFilter, _TMarksInterface, _TSeedsInterface, _TMST >::
GenerateData( )
{
  // Init objects
  this->_ConfigureOutputs( TOutputValue( 0 ) );
  this->_InitMarks( this->GetNumberOfSeeds( ) );
  TMST* mst = this->GetMinimumSpanningTree( );

  // Init queue
  std::vector< _TNode > q;
  unsigned long frontId = 1;
  for( TVertex seed: this->GetSeeds( ) )
    q.push_back( _TNode( seed, seed, frontId++ ) );

  // Main loop
  while( q.size( ) > 0 )
  {
    // Get next candidate
    std::pop_heap( q.begin( ), q.end( ) );
    _TNode node = q.back( );
    q.pop_back( );
    if( this->_IsMarked( node.Vertex ) )
      continue;
    this->_Mark( node.Vertex, node.FrontId );

    // Ok, pixel lays inside region
    this->_SetOutputValue( node.Vertex, node.Cost );
    mst->SetParent( node.Vertex, node.Parent );

    // Add neighborhood
    TVertices neighbors = this->_GetNeighbors( node.Vertex );
    for( TVertex neigh: neighbors )
    {
      if( this->_IsMarked( neigh ) )
      {
        // Invoke stop at collisions
        unsigned long nColl = this->_Collisions( node.Vertex, neigh );
        if(
          this->StopAtOneFront( ) &&
          this->GetNumberOfSeeds( ) > 1 &&
          nColl == 1
          )
          q.clear( );
      }
      else
      {
        // Compute new cost
        TOutputValue ncost =
          this->m_VertexFunctor->Evaluate( neigh, node.Vertex );
        if( this->m_IntensityFunctor.IsNotNull( ) )
          ncost = this->m_IntensityFunctor->Evaluate( ncost );

        // This algorithm only supports positive values
        if( ncost >= TOutputValue( 0 ) )
        {
          // Insert new node
          _TNode nn( neigh, node.Vertex, node.FrontId );
          nn.Cost = node.Cost + ncost;
          q.push_back( nn );
          std::push_heap( q.begin( ), q.end( ) );

        } // fi

      } // fi

    } // rof

  } // elihw
  this->_FreeMarks( );
}

#endif // __fpa__Base__Dijkstra__hxx__

// eof - $RCSfile$