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

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

#include <itkImageFileReader.h>
#include <itkImageFileWriter.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/Dijkstra.h>
#include <fpa/Image/Functors/ImageAbsoluteDifferenceCostFunction.h>
#include <fpa/VTK/ImageMPR.h>
#include <fpa/VTK/Image3DObserver.h>

// -------------------------------------------------------------------------
const unsigned int Dim = 3;
typedef float TInputPixel;
typedef float TOutputPixel;

typedef itk::Image< TInputPixel, Dim >            TInputImage;
typedef itk::Image< TOutputPixel, Dim >           TOutputImage;
typedef itk::ImageToVTKImageFilter< TInputImage > TVTKInputImage;

// -------------------------------------------------------------------------
int main( int argc, char* argv[] )
{
  if( argc < 8 )
  {
    std::cerr
      << "Usage: " << argv[ 0 ]
      << " input_image input_seeds output_image"
      << " neighborhood_order stop_at_one_front"
      << " init_seed end_seed"
      << std::endl;
    return( 1 );

  } // fi
  std::string input_image_fn = argv[ 1 ];
  std::string input_seeds_fn = argv[ 2 ];
  std::string output_image_fn = argv[ 3 ];
  unsigned int neighborhood_order = std::atoi( argv[ 4 ] );
  bool stop_at_one_front = ( std::atoi( argv[ 5 ] ) != 0 );
  unsigned int init_seed = std::atoi( argv[ 6 ] );
  unsigned int end_seed = std::atoi( argv[ 7 ] );

  // Read image
  itk::ImageFileReader< TInputImage >::Pointer input_image_reader =
    itk::ImageFileReader< TInputImage >::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
  TInputImage::ConstPointer input_image = input_image_reader->GetOutput( );
  TVTKInputImage::Pointer vtk_input_image = TVTKInputImage::New( );
  vtk_input_image->SetInput( input_image );
  vtk_input_image->Update( );

  // Show input image and let some interaction
  fpa::VTK::ImageMPR view;
  view.SetBackground( 0.3, 0.2, 0.8 );
  view.SetSize( 600, 600 );
  view.SetImage( vtk_input_image->GetOutput( ) );

  // Allow some interaction
  view.Render( );
  view.Start( );

  // Prepare region grow filter and cost function
  typedef fpa::Image::Dijkstra< TInputImage, TOutputImage > TFilter;
  typedef fpa::Image::Functors::
    ImageAbsoluteDifferenceCostFunction< TFilter::TInputImage, TFilter::TResult >
    TCost;

  TCost::Pointer cost = TCost::New( );

  TFilter::Pointer filter = TFilter::New( );
  filter->SetInput( input_image );
  filter->SetCostFunction( cost );
  filter->SetConversionFunction( NULL );
  filter->SetNeighborhoodOrder( neighborhood_order );
  filter->SetStopAtOneFront( stop_at_one_front );

  // Get user-given seeds
  std::ifstream input_seeds_str( input_seeds_fn.c_str( ) );
  if( !input_seeds_str )
  {
    std::cerr << "Error opening \"" << input_seeds_fn << "\"" << std::endl;
    return( 1 );

  } // fi

  unsigned int nSeeds;
  input_seeds_str >> nSeeds;
  std::vector< TInputImage::IndexType > input_seeds;
  for( unsigned int s = 0; s < nSeeds; s++ )
  {
    TInputImage::IndexType idx;
    input_seeds_str >> idx[ 0 ] >> idx[ 1 ] >> idx[ 2 ];
    input_seeds.push_back( idx );

  } // rof
  input_seeds_str.close( );

  filter->AddSeed( input_seeds[ init_seed ], 0 );
  filter->AddSeed( input_seeds[ end_seed ], 0 );

  // Prepare graphical debugger
  typedef fpa::VTK::Image3DObserver< TFilter, vtkRenderWindow > TDebugger;
  TDebugger::Pointer debugger = TDebugger::New( );
  debugger->SetRenderWindow( view.GetWindow( ) );
  debugger->SetRenderPercentage( 0.0001 );
  filter->AddObserver( itk::AnyEvent( ), debugger );
  filter->ThrowEventsOn( );

  // Go!
  filter->Update( );

  // Save final total cost map
  itk::ImageFileWriter< TOutputImage >::Pointer output_image_writer =
    itk::ImageFileWriter< TOutputImage >::New( );
  output_image_writer->SetFileName( output_image_fn );
  output_image_writer->SetInput( filter->GetOutput( ) );
  try
  {
    output_image_writer->Update( );
  }
  catch( itk::ExceptionObject& err )
  {
    std::cerr
      << "Error while writing image to " << output_image_fn << ": "
      << err << std::endl;
    return( 1 );

  } // yrt

  return( 0 );
}

// eof - $RCSfile$