#include <cmath>
#include <iostream>
#include <limits>
#include <string>

#include <itkImage.h>
#include <itkImageFileReader.h>
#include <itkImageToVTKImageFilter.h>
#include <itkMinimumMaximumImageCalculator.h>
#include <itkInvertIntensityImageFilter.h>
#include <itkDanielssonDistanceMapImageFilter.h>
#include <itkUnaryFunctorImageFilter.h>

#include <vtkImageActor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkPointHandleRepresentation3D.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSeedRepresentation.h>
#include <vtkSeedWidget.h>
#include <vtkSmartPointer.h>

#include <fpa/Image/Dijkstra.h>
#include <fpa/VTK/Image2DObserver.h>

// -------------------------------------------------------------------------
const unsigned int Dim = 2;
typedef unsigned char TPixel;
typedef double TScalar;
typedef itk::Image< TPixel, Dim >  TImage;
typedef itk::Image< TScalar, Dim >  TScalarImage;
typedef itk::ImageToVTKImageFilter< TImage > TVTKImage;

typedef itk::ImageFileReader< TImage > TImageReader;
typedef fpa::Image::Dijkstra< TScalarImage, TScalar > TFrontAlgorithm;

typedef
fpa::VTK::Image2DObserver< TFrontAlgorithm, vtkRenderWindow >
TObserver;

// -------------------------------------------------------------------------
class InvertPixelFunctor
{
public:
  InvertPixelFunctor( )
    { }
  virtual ~InvertPixelFunctor( )
    { }
  bool operator!=( const InvertPixelFunctor& other ) const
    { return( false ); }
  bool operator==( const InvertPixelFunctor& other ) const
    { return( !( *this != other ) ); }
  inline TScalar operator()( const TScalar& A ) const
    {
      return( TScalar( 1 ) / std::pow( TScalar( 1 ) + A, TScalar( 4 ) ) );
    }
};

// -------------------------------------------------------------------------
int main( int argc, char* argv[] )
{
  if( argc < 3 )
  {
    std::cerr
      << "Usage: " << argv[ 0 ]
      << " input_image neighborhood_order [stop_at_one_front]"
      << std::endl;
    return( 1 );

  } // fi
  std::string input_image_fn = argv[ 1 ];
  unsigned int neighborhood_order = std::atoi( argv[ 2 ] );
  bool stop_at_one_front = false;
  if( 3 < argc )
    stop_at_one_front = ( std::atoi( argv[ 3 ] ) == 1 );

  // Read image
  TImageReader::Pointer input_image_reader = TImageReader::New( );
  input_image_reader->SetFileName( input_image_fn );
  try
  {
    input_image_reader->Update( );
  }
  catch( itk::ExceptionObject& err )
  {
    std::cerr << "Error caught: " << err << std::endl;
    return( 1 );

  } // yrt
  TImage::ConstPointer input_image = input_image_reader->GetOutput( );

  TVTKImage::Pointer vtk_image = TVTKImage::New( );
  vtk_image->SetInput( input_image );
  vtk_image->Update( );

  // VTK visualization
  vtkSmartPointer< vtkImageActor > actor =
    vtkSmartPointer< vtkImageActor >::New( );
  actor->SetInputData( vtk_image->GetOutput( ) );

  vtkSmartPointer< vtkRenderer > renderer =
    vtkSmartPointer< vtkRenderer >::New( );
  renderer->SetBackground( 0.1, 0.2, 0.7 );
  renderer->AddActor( actor );
  vtkSmartPointer< vtkRenderWindow > window =
    vtkSmartPointer< vtkRenderWindow >::New( );
  window->SetSize( 800, 800 );
  window->AddRenderer( renderer );

  // VTK interaction
  vtkSmartPointer< vtkInteractorStyleImage > imageStyle =
    vtkSmartPointer< vtkInteractorStyleImage >::New( );
  vtkSmartPointer< vtkRenderWindowInteractor > interactor =
    vtkSmartPointer< vtkRenderWindowInteractor >::New( );
  interactor->SetInteractorStyle( imageStyle );
  window->SetInteractor( interactor );
  window->Render( );

  // Create the widget and its representation
  vtkSmartPointer< vtkPointHandleRepresentation3D > handle =
    vtkSmartPointer< vtkPointHandleRepresentation3D >::New( );
  handle->GetProperty( )->SetColor( 1, 0, 0 );
  vtkSmartPointer< vtkSeedRepresentation > rep =
    vtkSmartPointer< vtkSeedRepresentation >::New( );
  rep->SetHandleRepresentation( handle );

  vtkSmartPointer< vtkSeedWidget > widget =
    vtkSmartPointer< vtkSeedWidget >::New( );
  widget->SetInteractor( interactor );
  widget->SetRepresentation( rep );

  // Let some interaction
  interactor->Initialize( );
  window->Render( );
  widget->On( );
  interactor->Start( );

  // Compute cost map
  typedef itk::MinimumMaximumImageCalculator< TImage > TMinMax;
  typedef itk::InvertIntensityImageFilter< TImage > TInvert;
  typedef itk::DanielssonDistanceMapImageFilter< TImage, TScalarImage > TDanielsson;
  typedef itk::UnaryFunctorImageFilter< TScalarImage, TScalarImage, InvertPixelFunctor > TInvertFunctor;

  TMinMax::Pointer input_image_min_max = TMinMax::New( );
  input_image_min_max->SetImage( input_image );
  input_image_min_max->Compute( );

  TInvert::Pointer invert = TInvert::New( );
  invert->SetInput( input_image );
  invert->SetMaximum( input_image_min_max->GetMaximum( ) );

  TDanielsson::Pointer danielsson = TDanielsson::New( );
  danielsson->SetInput( invert->GetOutput( ) );
  danielsson->InputIsBinaryOn( );
  danielsson->SquaredDistanceOff( );
  danielsson->UseImageSpacingOn( );

  TInvertFunctor::Pointer invert_pixels = TInvertFunctor::New( );
  invert_pixels->SetInput( danielsson->GetOutput( ) );
  invert_pixels->Update( );

  // Configure observer
  TObserver::Pointer obs = TObserver::New( );
  obs->SetImage( invert_pixels->GetOutput( ), window );

  // Configure algorithm
  TFrontAlgorithm::Pointer algorithm = TFrontAlgorithm::New( );
  for( unsigned int s = 0; s < rep->GetNumberOfSeeds( ); s++ )
  {
    double pos[ 3 ];
    rep->GetSeedWorldPosition( s, pos );

    TImage::PointType pnt;
    pnt[ 0 ] = pos[ 0 ];
    pnt[ 1 ] = pos[ 1 ];

    TImage::IndexType idx;
    if( input_image->TransformPhysicalPointToIndex( pnt, idx ) )
    {
      algorithm->AddSeed( idx, 0 );
      std::cout << " Seed --> " << idx << std::endl;

    } // fi

  } // rof
  algorithm->AddObserver( itk::AnyEvent( ), obs );
  algorithm->ThrowEventsOn( );
  algorithm->SetInput( invert_pixels->GetOutput( ) );
  algorithm->SetNeighborhoodOrder( neighborhood_order );
  algorithm->SetStopAtOneFront( stop_at_one_front );
  algorithm->Update( );

  // One last interaction
  window->Render( );
  interactor->Start( );

  return( 0 );
}

// eof - $RCSfile$