/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/

#include "itkUnsharpMaskLevelSetImageFilter.h"
#include <iostream>

constexpr unsigned int HEIGHT = (128);
constexpr unsigned int WIDTH = (128);

#define RADIUS (std::min(HEIGHT, WIDTH) / 4)

// Distance transform function for square
float
square(unsigned int x, unsigned int y)
{
  const float X = itk::Math::Absolute(x - float{ WIDTH } / 2.0);
  const float Y = itk::Math::Absolute(y - float{ HEIGHT } / 2.0);
  float       dis = -std::sqrt((X - RADIUS) * (X - RADIUS) + (Y - RADIUS) * (Y - RADIUS));
  if (!((X > RADIUS) && (Y > RADIUS)))
  {
    dis = RADIUS - std::max(X, Y);
  }
  return dis;
}

// Evaluates a function at each pixel in the itk image
void
evaluate_function(itk::Image<float, 2> * im, float (*f)(unsigned int, unsigned int))

{
  itk::Image<float, 2>::IndexType idx;
  for (unsigned int x = 0; x < WIDTH; ++x)
  {
    idx[0] = x;
    for (unsigned int y = 0; y < HEIGHT; ++y)
    {
      idx[1] = y;
      im->SetPixel(idx, f(x, y));
    }
  }
}

int
itkUnsharpMaskLevelSetImageFilterTest(int, char *[])
{
  using ImageType = itk::Image<float, 2>;

  auto im_init = ImageType::New();

  constexpr ImageType::SizeType sz{ HEIGHT, WIDTH };
  ImageType::RegionType         r{ sz };

  im_init->SetRegions(r);
  im_init->Allocate();

  evaluate_function(im_init, square);
  using FilterType = itk::UnsharpMaskLevelSetImageFilter<ImageType, ImageType>;
  auto filter = FilterType::New();
  filter->SetMaxFilterIteration(99);
  filter->SetNormalProcessUnsharpWeight(1);

  filter->SetInput(im_init);
  std::cout << "max iteration = " << (filter->GetMaxFilterIteration()) << '\n';
  std::cout << "Starting processing.\n";
  filter->Update();
  filter->Print(std::cout);
  std::cout << "Passed.\n";
  return EXIT_SUCCESS;
}
