/*=========================================================================
 *
 *  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 "itkMeanImageFunction.h"
#include "itkMath.h"
#include "itkTestingMacros.h"

int
itkMeanImageFunctionTest(int, char *[])
{
  int testStatus = EXIT_SUCCESS;

  constexpr unsigned int Dimension = 3;
  using PixelType = unsigned char;

  using ImageType = itk::Image<PixelType, Dimension>;
  using FunctionType = itk::MeanImageFunction<ImageType>;

  // Create and allocate the image
  auto image = ImageType::New();

  ImageType::SizeType   size;
  ImageType::IndexType  start;
  ImageType::RegionType region;

  size[0] = 50;
  size[1] = 50;
  size[2] = 50;

  start.Fill(0);

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

  image->SetRegions(region);
  image->Allocate();

  ImageType::PixelType initialValue = 27;

  image->FillBuffer(initialValue);

  auto function = FunctionType::New();

  ITK_EXERCISE_BASIC_OBJECT_METHODS(function, MeanImageFunction, ImageFunction);

  function->SetInputImage(image);

  unsigned int neighborhoodRadius = 5;
  function->SetNeighborhoodRadius(neighborhoodRadius);
  ITK_TEST_SET_GET_VALUE(neighborhoodRadius, function->GetNeighborhoodRadius());

  ImageType::IndexType index;

  index[0] = 25;
  index[1] = 25;
  index[2] = 25;

  FunctionType::RealType mean;
  mean = function->EvaluateAtIndex(index);

  double epsilon = 1e-7;
  if (!itk::Math::FloatAlmostEqual(static_cast<FunctionType::RealType>(initialValue), mean, 10, epsilon))
  {
    std::cout.precision(static_cast<unsigned int>(itk::Math::abs(std::log10(epsilon))));
    std::cout << "Mean value (" << mean << ") does not equal initialValue (" << initialValue << ')' << std::endl;
    testStatus = EXIT_FAILURE;
  }

  // Test Evaluate
  FunctionType::PointType point;
  point[0] = 25;
  point[1] = 25;
  point[2] = 25;
  FunctionType::RealType mean2;
  mean2 = function->Evaluate(point);

  if (!itk::Math::FloatAlmostEqual(static_cast<FunctionType::RealType>(initialValue), mean2, 10, epsilon))
  {
    std::cout.precision(static_cast<unsigned int>(itk::Math::abs(std::log10(epsilon))));
    std::cout << "Mean value (" << mean2 << ") does not equal initialValue (" << initialValue << ')' << std::endl;
    testStatus = EXIT_FAILURE;
  }

  // Test EvaluateAtContinuousIndex
  FunctionType::ContinuousIndexType cindex;
  cindex[0] = 25;
  cindex[1] = 25;
  cindex[2] = 25;
  FunctionType::RealType mean3;
  mean3 = function->EvaluateAtContinuousIndex(cindex);

  if (!itk::Math::FloatAlmostEqual(static_cast<FunctionType::RealType>(initialValue), mean3, 10, epsilon))
  {
    std::cout.precision(static_cast<unsigned int>(itk::Math::abs(std::log10(epsilon))));
    std::cout << "Mean value (" << mean3 << ") does not equal initialValue (" << initialValue << ')' << std::endl;
    testStatus = EXIT_FAILURE;
  }

  return testStatus;
}
