/*=========================================================================
 *
 *  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
 *
 *         http://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 "itkImageFileReader.h"
#include "itkDCMTKImageIO.h"
#include "itkImageRegionConstIterator.h"
#include "itkMultiplyImageFilter.h"
#include "itkAddImageFilter.h"
#include "itkSubtractImageFilter.h"
#include "itkStatisticsImageFilter.h"
#include "itkMath.h"

using PixelType = short;
using ImageType = itk::Image<PixelType, 3>;
using DirectionType = ImageType::DirectionType;
using SpacingType = ImageType::SpacingType;
using PointType = ImageType::PointType;
using ReaderType = itk::ImageFileReader<ImageType>;
using ImageIOType = itk::DCMTKImageIO;

namespace
{
//
// if the difference is < average/10000, close enough
bool
CloseEnough(double a, double b)
{
  double diff = itk::Math::abs(a - b);
  double avg = (itk::Math::abs(a) + itk::Math::abs(b)) / 2.0;
  if (diff == 0.0 || diff < avg / 10000.00)
  {
    return true;
  }
  return false;
}

bool
Equal(DirectionType dir1, DirectionType dir2)
{
  for (unsigned i = 0; i < 3; ++i)
  {
    for (unsigned j = 0; j < 3; ++j)
    {
      if (!CloseEnough(dir1(i, j), dir2(i, j)))
      {
        return false;
      }
    }
  }
  return true;
}

bool
Equal(SpacingType spacing1, SpacingType spacing2)
{
  for (unsigned i = 0; i < 3; ++i)
  {
    if (!CloseEnough(spacing1[i], spacing2[i]))
    {
      return false;
    }
  }
  return true;
}
} // namespace
//
// This tests a Philips Multiframe image orieintation/spacing
// known to exist in the test file in order to ensure that
// they're properly read out of the functional group.
int
itkDCMTKImageIOMultiFrameImageTest(int ac, char * av[])
{
  if (ac < 2)
  {
    std::cerr << "Usage: " << av[0] << " <multiframe image>" << std::endl;
    return EXIT_FAILURE;
  }

  ImageIOType::Pointer dcmImageIO = ImageIOType::New();

  ReaderType::Pointer reader = ReaderType::New();
  reader->SetFileName(av[1]);
  reader->SetImageIO(dcmImageIO);

  try
  {
    reader->Update();
  }
  catch (const itk::ExceptionObject & e)
  {
    std::cerr << "exception in file reader " << std::endl;
    std::cerr << e << std::endl;
    return EXIT_FAILURE;
  }
  ImageType::Pointer im = reader->GetOutput();
  DirectionType      dir = im->GetDirection();
  SpacingType        spacing = im->GetSpacing();
  PointType          origin = im->GetOrigin();

  std::cerr << "Direction " << dir << std::endl
            << "Spacing " << spacing << std::endl
            << "Origin " << origin << std::endl;
  DirectionType expectedDirection;
  expectedDirection(0, 0) = 0.0;
  expectedDirection(0, 1) = 0.0;
  expectedDirection(0, 2) = -1.0;
  expectedDirection(1, 0) = 1.0;
  expectedDirection(1, 1) = 0.0;
  expectedDirection(1, 2) = 0.0;
  expectedDirection(2, 0) = 0.0;
  expectedDirection(2, 1) = -1.0;
  expectedDirection(2, 2) = 0.0;
  if (!Equal(dir, expectedDirection))
  {
    std::cerr << "Expected directions" << std::endl
              << expectedDirection << std::endl
              << "Actual directions" << std::endl
              << dir << std::endl;
    return EXIT_FAILURE;
  }
  SpacingType expectedSpacing;
  expectedSpacing[0] = expectedSpacing[1] = expectedSpacing[2] = 0.75;
  if (!Equal(spacing, expectedSpacing))
  {
    std::cerr << "Expected spacing" << std::endl
              << expectedSpacing << std::endl
              << "Actual spacing" << std::endl
              << spacing << std::endl;
    return EXIT_FAILURE;
  }
  return EXIT_SUCCESS;
}