#ifndef __FPA__VTK__IMAGE3DOBSERVER__HXX__
#define __FPA__VTK__IMAGE3DOBSERVER__HXX__

#include <vtkCellArray.h>
#include <vtkPolyDataMapper.h>
#include <vtkPoints.h>
#include <vtkPointData.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRendererCollection.h>

// -------------------------------------------------------------------------
template< class F, class R >
void fpa::VTK::Image3DObserver< F, R >::
SetRenderWindow( R* rw )
{
  this->m_RenderWindow = rw;
}

// -------------------------------------------------------------------------
template< class F, class R >
void fpa::VTK::Image3DObserver< F, R >::
Render( )
{
  if( this->m_RenderWindow != NULL )
    this->m_RenderWindow->Render( );
}

// -------------------------------------------------------------------------
template< class F, class R >
void fpa::VTK::Image3DObserver< F, R >::
Execute( const itk::Object* c, const itk::EventObject& e )
{
  typedef typename F::TStartEvent     _TStartEvent;
  typedef typename F::TStartLoopEvent _TStartLoopEvent;
  typedef typename F::TEndEvent       _TEndEvent;
  typedef typename F::TEndLoopEvent   _TEndLoopEvent;
  typedef typename F::TAliveEvent     _TAliveEvent;
  typedef typename F::TFrontEvent     _TFrontEvent;
  typedef typename F::TFreezeEvent    _TFreezeEvent;

  typedef typename F::TStartBacktrackingEvent _TStartBacktrackingEvent;
  typedef typename F::TEndBacktrackingEvent   _TEndBacktrackingEvent;
  typedef typename F::TBacktrackingEvent      _TBacktrackingEvent;

  static unsigned char Colors[][4] =
    {
      {   0,   0, 127, 127 },
      {   0, 127, 127, 127 },
      { 127,   0, 127, 127 },
      { 127, 127,   0, 127 },
      {   0,   0,  63, 127 },
      {   0,  63,  63, 127 },
      {  63,   0,  63, 127 },
      {  63,  63,   0, 127 },
      {  63,  63, 127, 127 },
      {  63, 127, 127, 127 },
      { 127,  63, 127, 127 },
      { 127, 127,  63, 127 },
      { 127, 127,  63, 127 },
      { 127,  63,  63, 127 },
      {  63, 127,  63, 127 },
      {  63,  63, 127, 127 }
    };

  const F* filter = dynamic_cast< const F* >( c );
  if( this->m_RenderWindow == NULL || filter == NULL )
    return;
  auto image = filter->GetInput( );
  if( image == NULL )
    return;

  const _TStartEvent* startEvt = dynamic_cast< const _TStartEvent* >( &e );
  const _TStartBacktrackingEvent* startBackEvt =
    dynamic_cast< const _TStartBacktrackingEvent* >( &e );
  if( startEvt != NULL || startBackEvt != NULL )
  {
    this->m_Count = 0;
    this->m_RenderCount =
      image->GetLargestPossibleRegion( ).GetNumberOfPixels( );
    this->m_PointsToReplace.clear( );
    this->m_PointsInFront.clear( );

    vtkRenderer* ren =
      this->m_RenderWindow->GetRenderers( )->GetFirstRenderer( );
    ren->AddActor( this->m_PolyDataActor );
    return;

  } // fi

  const _TFrontEvent* frontEvt = dynamic_cast< const _TFrontEvent* >( &e );
  if( frontEvt != NULL )
  {
    typename F::TInputImage::PointType pnt;
    image->TransformIndexToPhysicalPoint( frontEvt->Vertex, pnt );
    if( this->m_PointsToReplace.empty( ) )
    {
      unsigned long nPoints = this->m_PolyData->GetNumberOfPoints( );
      this->m_PolyData->GetPoints( )->
        InsertNextPoint( pnt[ 0 ], pnt[ 1 ], pnt[ 2 ] );
      this->m_PolyData->GetVerts( )->InsertNextCell( 1 );
      this->m_PolyData->GetVerts( )->InsertCellPoint( nPoints );
      this->m_PointsInFront[ frontEvt->Vertex ] = nPoints;
    }
    else
    {
      auto pIt = this->m_PointsToReplace.begin( );
      this->m_PolyData->GetPoints( )->
        SetPoint( pIt->second, pnt[ 0 ], pnt[ 1 ], pnt[ 2 ] );
      this->m_PointsToReplace.erase( pIt );

    } // fi
    this->m_PolyData->Modified( );
    this->m_PolyDataMapper->Modified( );
    this->m_PolyDataActor->Modified( );

    // Render visual debug
    this->m_Count++;
    double per = double( this->m_RenderCount ) * this->m_RenderPercentage;
    if( double( this->m_Count ) >= per )
      this->Render( );
    if( double( this->m_Count ) >= per )
      this->m_Count = 0;

    return;

  } // fi

  const _TAliveEvent* aliveEvt = dynamic_cast< const _TAliveEvent* >( &e );
  if( aliveEvt != NULL )
  {
    auto pIt = this->m_PointsInFront.find( aliveEvt->Vertex );
    if( pIt != this->m_PointsInFront.end( ) )
    {
      this->m_PointsToReplace[ pIt->first ] = pIt->second;
      this->m_PointsInFront.erase( pIt );

    } // fi
    return;

  } // fi

  const _TEndEvent* endEvt = dynamic_cast< const _TEndEvent* >( &e );
  if( endEvt != NULL )
  {
    vtkRenderer* ren =
      this->m_RenderWindow->GetRenderers( )->GetFirstRenderer( );
    ren->RemoveActor( this->m_PolyDataActor );
    this->Render( );
    return;

  } // fi

  const _TBacktrackingEvent* backEvt =
    dynamic_cast< const _TBacktrackingEvent* >( &e );
  const _TEndBacktrackingEvent* endBackEvt =
    dynamic_cast< const _TEndBacktrackingEvent* >( &e );
  if( backEvt != NULL )
  {
    // TODO: 
    return;

  } // fi

  if( endBackEvt != NULL )
  {
    this->m_RenderWindow->Render( );

    /* TODO: DEBUG
       std::cout << "Press enter: " << std::ends;
       int aux;
       std::cin >> aux;
    */
    return;

  } // fi
}

// -------------------------------------------------------------------------
template< class F, class R >
fpa::VTK::Image3DObserver< F, R >::
Image3DObserver( )
  : Superclass( ),
    m_RenderWindow( NULL ),
    m_RenderPercentage( double( 0.001 ) )
{
  this->m_PolyData = vtkSmartPointer< vtkPolyData >::New( );
  this->m_PolyDataMapper = vtkSmartPointer< vtkPolyDataMapper >::New( );
  this->m_PolyDataActor =vtkSmartPointer< vtkActor >::New( );

  vtkSmartPointer< vtkPoints > points =
    vtkSmartPointer< vtkPoints >::New( );
  vtkSmartPointer< vtkCellArray > verts =
    vtkSmartPointer< vtkCellArray >::New( );
  this->m_PolyData->SetPoints( points );
  this->m_PolyData->SetVerts( verts );
  this->m_PolyDataMapper->SetInputData( this->m_PolyData );
  this->m_PolyDataActor->SetMapper( this->m_PolyDataMapper );
  this->m_PolyDataActor->GetProperty( )->SetColor( 0, 1, 0 );
}

// -------------------------------------------------------------------------
template< class F, class R >
fpa::VTK::Image3DObserver< F, R >::
~Image3DObserver( )
{
}

#endif // __FPA__VTK__IMAGE3DOBSERVER__HXX__

// eof - $RCSfile$