/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/
#ifndef itkCyclicShiftImageFilter_hxx
#define itkCyclicShiftImageFilter_hxx

#include "itkNumericTraits.h"
#include "itkTotalProgressReporter.h"
#include "itkImageRegionIteratorWithIndex.h"

namespace itk
{

template <typename TInputImage, typename TOutputImage>
CyclicShiftImageFilter<TInputImage, TOutputImage>::CyclicShiftImageFilter()
{
  m_Shift.Fill(OffsetValueType{});
  this->DynamicMultiThreadingOn();
  this->ThreaderUpdateProgressOff();
}

template <typename TInputImage, typename TOutputImage>
void
CyclicShiftImageFilter<TInputImage, TOutputImage>::GenerateInputRequestedRegion()
{
  // Call the superclass' implementation of this method.
  Superclass::GenerateInputRequestedRegion();

  // We need all the input.
  InputImagePointer input = const_cast<InputImageType *>(this->GetInput());
  if (!input)
  {
    return;
  }
  input->SetRequestedRegionToLargestPossibleRegion();
}

template <typename TInputImage, typename TOutputImage>
void
CyclicShiftImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
  const OutputImageRegionType & outputRegionForThread)
{
  const InputImageType * inputImage = this->GetInput();

  // The index and size of the image needed to compute the shift
  const IndexType outIdx = this->GetOutput()->GetLargestPossibleRegion().GetIndex();
  const SizeType  outSize = this->GetOutput()->GetLargestPossibleRegion().GetSize();

  TotalProgressReporter progress(this, this->GetOutput()->GetRequestedRegion().GetNumberOfPixels());

  // Now iterate over the pixels of the output region for this thread.
  for (ImageRegionIteratorWithIndex<OutputImageType> outIt(this->GetOutput(), outputRegionForThread); !outIt.IsAtEnd();
       ++outIt)
  {
    IndexType index = outIt.GetIndex();

    for (unsigned int i = 0; i < ImageDimension; ++i)
    {
      IndexValueType shiftedIdx = (index[i] - outIdx[i] - m_Shift[i]) % static_cast<OffsetValueType>(outSize[i]);
      if (shiftedIdx < 0)
      {
        shiftedIdx += outSize[i];
      }
      index[i] = shiftedIdx + outIdx[i];
    }

    outIt.Set(static_cast<OutputImagePixelType>(inputImage->GetPixel(index)));
    progress.CompletedPixel();
  }
}

template <typename TInputImage, typename TOutputImage>
void
CyclicShiftImageFilter<TInputImage, TOutputImage>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);

  os << indent << "Shift: " << m_Shift << std::endl;
}

} // end namespace itk
#endif
