/*=========================================================================
 *
 *  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 <iostream>

#include "itkAffineTransform.h"
#include "itkResampleImageFilter.h"
#include "itkImageFileWriter.h"
#include "itkMath.h"
#include "itkTestingMacros.h"

int
itkResampleImageTest(int, char *[])
{

  constexpr unsigned int VDimension = 2;

  using PixelType = float;
  using ImageType = itk::Image<PixelType, VDimension>;
  using ImageIndexType = ImageType::IndexType;
  using ImagePointerType = ImageType::Pointer;
  using ImageRegionType = ImageType::RegionType;
  using ImageSizeType = ImageType::SizeType;
  using CoordRepType = double;

  using AffineTransformType = itk::AffineTransform<CoordRepType, VDimension>;
  using InterpolatorType = itk::LinearInterpolateImageFunction<ImageType, CoordRepType>;


  // Create and configure an image
  ImagePointerType image = ImageType::New();
  ImageIndexType   index = { { 0, 0 } };
  ImageSizeType    size = { { 18, 12 } };
  ImageRegionType  region;
  region.SetSize(size);
  region.SetIndex(index);
  image->SetLargestPossibleRegion(region);
  image->SetBufferedRegion(region);
  image->Allocate();

  // Fill image with a ramp
  itk::ImageRegionIteratorWithIndex<ImageType> iter(image, region);
  PixelType                                    value;
  for (iter.GoToBegin(); !iter.IsAtEnd(); ++iter)
  {
    index = iter.GetIndex();
    value = index[0] + index[1];
    iter.Set(value);
  }

  // Create an affine transformation
  auto aff = AffineTransformType::New();
  aff->Scale(0.5);

  // Create a linear interpolation image function
  auto interp = InterpolatorType::New();
  interp->SetInputImage(image);

  // Create and configure a resampling filter
  itk::ResampleImageFilter<ImageType, ImageType>::Pointer resample =
    itk::ResampleImageFilter<ImageType, ImageType>::New();

  ITK_EXERCISE_BASIC_OBJECT_METHODS(resample, ResampleImageFilter, ImageToImageFilter);

  resample->SetInput(image);
  ITK_TEST_SET_GET_VALUE(image, resample->GetInput());

  resample->SetSize(size);
  ITK_TEST_SET_GET_VALUE(size, resample->GetSize());

  resample->SetTransform(aff);
  ITK_TEST_SET_GET_VALUE(aff, resample->GetTransform());

  resample->SetInterpolator(interp);
  ITK_TEST_SET_GET_VALUE(interp, resample->GetInterpolator());

  index.Fill(0);
  resample->SetOutputStartIndex(index);
  ITK_TEST_SET_GET_VALUE(index, resample->GetOutputStartIndex());

  ImageType::PointType origin;
  origin.Fill(0.0);
  resample->SetOutputOrigin(origin);
  ITK_TEST_SET_GET_VALUE(origin, resample->GetOutputOrigin());

  ImageType::SpacingType spacing;
  spacing.Fill(1.0);
  resample->SetOutputSpacing(spacing);
  ITK_TEST_SET_GET_VALUE(spacing, resample->GetOutputSpacing());


  // Run the resampling filter
  resample->Update();

  // Check if desired results were obtained
  bool                  passed = true;
  ImageType::RegionType region2;
  region2 = resample->GetOutput()->GetRequestedRegion();
  itk::ImageRegionIteratorWithIndex<ImageType> iter2(resample->GetOutput(), region2);
  PixelType                                    pixval;
  const double                                 tolerance = 1e-30;
  for (iter2.GoToBegin(); !iter2.IsAtEnd(); ++iter2)
  {
    index = iter2.GetIndex();
    value = iter2.Get();
    pixval = value;
    auto expectedValue = static_cast<PixelType>((index[0] + index[1]) / 2.0);
    if (!itk::Math::FloatAlmostEqual(expectedValue, pixval, 10, tolerance))
    {
      std::cout << "Error in resampled image: Pixel " << index << "value    = " << value << "  "
                << "pixval   = " << pixval << "  "
                << "expected = " << expectedValue << std::endl;
      passed = false;
    }
  }

  // Report success or failure
  if (!passed)
  {
    std::cout << "Resampling test failed" << std::endl;
    return EXIT_FAILURE;
  }

  // Exercise error handling

  try
  {
    std::cout << "Setting interpolator to nullptr" << std::endl;
    passed = false;
    resample->SetInterpolator(nullptr);
    resample->Update();
  }
  catch (const itk::ExceptionObject & err)
  {
    std::cout << err << std::endl;
    passed = true;
    resample->ResetPipeline();
    resample->SetInterpolator(interp);
  }

  if (!passed)
  {
    std::cout << "Resampling test failed" << std::endl;
    return EXIT_FAILURE;
  }

  std::cout << "Test passed." << std::endl;
  return EXIT_SUCCESS;
}
