#include <cstdlib>
#include <iostream>
#include <limits>
#include <string>

#include <itkImage.h>
#include <itkImageToVTKImageFilter.h>
#include <itkRGBPixel.h>

#include <itkImageFileReader.h>

#include <vtkCamera.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/RegionGrow.h>
#include <fpa/VTK/Image2DObserver.h>
#include <fpa/Image/Functors/GaussianModelEstimatorFunction.h>

// -------------------------------------------------------------------------
const unsigned int Dim = 2;
typedef unsigned char TPixel;
typedef float         TScalar;

typedef itk::Image< itk::RGBPixel< TPixel >, Dim > TColorImage;
typedef itk::Image< TPixel, Dim >                  TImage;
typedef itk::ImageToVTKImageFilter< TColorImage >  TVTKImage;

// -------------------------------------------------------------------------
int main( int argc, char* argv[] )
{
  if( argc < 4 )
  {
    std::cerr
      << "Usage: " << argv[ 0 ]
      << " input_image neighborhood_order support [model_file]"
      << std::endl;
    return( 1 );

  } // fi
  std::string input_image_fn = argv[ 1 ];
  unsigned int neighborhood_order = std::atoi( argv[ 2 ] );
  unsigned long support = std::atoi( argv[ 3 ] );

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

  } // yrt
  TColorImage::ConstPointer input_image = input_image_reader->GetOutput( );
  TVTKImage::Pointer vtk_input_image = TVTKImage::New( );
  vtk_input_image->SetInput( input_image );
  vtk_input_image->Update( );

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

  // Correct camera due to the loaded image
  vtkCamera* camera = renderer->GetActiveCamera( );
  camera->SetViewUp( 0, -1, 0 );
  camera->SetPosition( 0, 0, -1 );
  camera->SetFocalPoint( 0, 0, 0 );

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

  // 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( );
  renderer->ResetCamera( );
  window->Render( );
  widget->On( );
  interactor->Start( );

  // Prepare region grow function
  typedef fpa::Image::Functors::GaussianModelEstimatorFunction< TColorImage, TScalar > TFunction;
  TFunction::Pointer function = TFunction::New( );
  function->SetModelSupport( support );
  if( argc > 4 )
    function->LoadModelFromFile( argv[ 4 ] );
  
  // Prepare region grow filter
  typedef fpa::Image::RegionGrow< TColorImage, TImage > TFilter;
  TFilter::Pointer filter = TFilter::New( );
  filter->SetInput( input_image );
  filter->SetMembershipFunction( function );
  filter->SetNeighborhoodOrder( neighborhood_order );
  filter->SetOutsideValue( TPixel( 0 ) );
  filter->SetInsideValue( std::numeric_limits< TPixel >::max( ) );
  filter->StopAtOneFrontOff( );

  // Get user-given seeds
  for( unsigned int s = 0; s < rep->GetNumberOfSeeds( ); s++ )
  {
    double pos[ 3 ];
    rep->GetSeedWorldPosition( s, pos );

    TImage::PointType pnt;
    pnt[ 0 ] = TImage::PointType::ValueType( pos[ 0 ] );
    pnt[ 1 ] = TImage::PointType::ValueType( pos[ 1 ] );

    TImage::IndexType idx;
    if( input_image->TransformPhysicalPointToIndex( pnt, idx ) )
      filter->AddSeed( idx, 0 );

  } // rof

  // Prepare graphical debugger
  typedef fpa::VTK::Image2DObserver< TFilter, vtkRenderWindow > TDebugger;
  TDebugger::Pointer debugger = TDebugger::New( );
  debugger->SetRenderWindow( window );
  debugger->SetRenderPercentage( 0.001 );
  filter->AddObserver( itk::AnyEvent( ), debugger );
  filter->ThrowEventsOn( );

  // Go!
  filter->Update( );

  window->Render( );
  widget->Off( );
  interactor->Start( );

  return( 0 );
}

// eof - $RCSfile$