/*=========================================================================
 *
 *  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 "itkConstrainedValueDifferenceImageFilter.h"
#include "itkImageFileWriter.h"
#include "itkImageRegionIteratorWithIndex.h"
#include "itkTestingMacros.h"

int
itkConstrainedValueDifferenceImageFilterTest(int argc, char * argv[])
{
  if (argc < 2)
  {
    std::cout << "Usage: " << itkNameOfTestExecutableMacro(argv) << "outputImage " << std::endl;
    return EXIT_FAILURE;
  }

  // Define the dimension of the images
  constexpr unsigned int Dimension = 3;

  // Define the pixel types
  using InputImage1PixelType = float;
  using InputImage2PixelType = float;
  using OutputImagePixelType = unsigned short;

  // Declare the types of the images
  using InputImage1Type = itk::Image<InputImage1PixelType, Dimension>;
  using InputImage2Type = itk::Image<InputImage2PixelType, Dimension>;
  using OutputImageType = itk::Image<OutputImagePixelType, Dimension>;

  // Declare the type of the index to access images
  using IndexType = itk::Index<Dimension>;

  // Declare the type of the size
  using SizeType = itk::Size<Dimension>;

  // Declare the type of the Region
  using RegionType = itk::ImageRegion<Dimension>;

  // Create the two input images
  auto inputImageA = InputImage1Type::New();
  auto inputImageB = InputImage2Type::New();

  // Define their size and start index
  SizeType size;
  size[0] = 2;
  size[1] = 2;
  size[2] = 2;

  IndexType start;
  start[0] = 0;
  start[1] = 0;
  start[2] = 0;

  RegionType region;
  region.SetIndex(start);
  region.SetSize(size);

  // Initialize Image A
  inputImageA->SetRegions(region);
  inputImageA->Allocate();

  // Initialize Image B
  inputImageB->SetRegions(region);
  inputImageB->Allocate();

  // Declare Iterator types for each image
  using InputImage1IteratorType = itk::ImageRegionIteratorWithIndex<InputImage1Type>;
  using InputImage2IteratorType = itk::ImageRegionIteratorWithIndex<InputImage2Type>;

  // Create one iterator for Image A (this is a light object)
  InputImage1IteratorType it1(inputImageA, inputImageA->GetBufferedRegion());

  // Initialize the content of Image A
  constexpr InputImage1Type::PixelType valueA = 125;
  while (!it1.IsAtEnd())
  {
    it1.Set(valueA);
    ++it1;
  }

  // Create one iterator for Image B (this is a light object)
  InputImage2IteratorType it2(inputImageB, inputImageB->GetBufferedRegion());

  // Initialize the content of Image B: when subtracted from A, the filter will
  // saturate a char in some of the pixels
  InputImage2Type::PixelType valueB = 120;
  while (!it2.IsAtEnd())
  {
    it2.Set(valueB);
    ++it2;
    valueB += 1.0;
  }

  using ConstrainedValueDifferenceImageFilterType =
    itk::ConstrainedValueDifferenceImageFilter<InputImage1Type, InputImage2Type, OutputImageType>;

  // Create the filter
  auto filter = ConstrainedValueDifferenceImageFilterType::New();

  ITK_EXERCISE_BASIC_OBJECT_METHODS(filter, ConstrainedValueDifferenceImageFilter, BinaryGeneratorImageFilter);

  // Set the input images
  filter->SetInput1(inputImageA);
  filter->SetInput2(inputImageB);


  // Execute the filter
  filter->Update();

  // Get the the filter output
  OutputImageType::Pointer outputImage = filter->GetOutput();

  // Write the result image
  using WriterType = itk::ImageFileWriter<OutputImageType>;

  auto writer = WriterType::New();

  writer->SetFileName(argv[1]);

  writer->SetInput(outputImage);

  ITK_TRY_EXPECT_NO_EXCEPTION(writer->Update());

  // All objects should be automatically destroyed at this point
  return EXIT_SUCCESS;
}
