/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/
#ifndef itkFFTWInverseFFTImageFilter_hxx
#define itkFFTWInverseFFTImageFilter_hxx

#include "itkFullToHalfHermitianImageFilter.h"
#include "itkFFTWInverseFFTImageFilter.h"

#include "itkImageRegionIterator.h"
#include "itkProgressReporter.h"
#include "itkMultiThreaderBase.h"

namespace itk
{

template <typename TInputImage, typename TOutputImage>
FFTWInverseFFTImageFilter<TInputImage, TOutputImage>::FFTWInverseFFTImageFilter()
{
#ifndef ITK_USE_CUFFTW
  m_PlanRigor = FFTWGlobalConfiguration::GetPlanRigor();
#endif
  this->DynamicMultiThreadingOn();
}

template <typename TInputImage, typename TOutputImage>
void
FFTWInverseFFTImageFilter<TInputImage, TOutputImage>::BeforeThreadedGenerateData()
{
  // Get pointers to the input and output.
  typename InputImageType::ConstPointer inputPtr = this->GetInput();
  typename OutputImageType::Pointer     outputPtr = this->GetOutput();

  if (!inputPtr || !outputPtr)
  {
    return;
  }

  // We don't have a nice progress to report, but at least this simple line
  // reports the beginning and the end of the process.
  ProgressReporter progress(this, 0, 1);

  // Allocate output buffer memory.
  outputPtr->SetBufferedRegion(outputPtr->GetRequestedRegion());
  outputPtr->Allocate();

  const InputSizeType  inputSize = inputPtr->GetLargestPossibleRegion().GetSize();
  const OutputSizeType outputSize = outputPtr->GetLargestPossibleRegion().GetSize();

  // Figure out sizes.
  // Size of input and output aren't the same which is handled in the superclass,
  // sort of.
  // The input size and output size only differ in the fastest moving dimension.
  unsigned int totalOutputSize = 1;
  unsigned int totalInputSize = 1;

  for (unsigned i = 0; i < ImageDimension; i++)
  {
    totalOutputSize *= outputSize[i];
    totalInputSize *= inputSize[i];
  }

  // Cut the full complex image to just the portion needed by FFTW.
  using FullToHalfFilterType = FullToHalfHermitianImageFilter<InputImageType>;
  typename FullToHalfFilterType::Pointer fullToHalfFilter = FullToHalfFilterType::New();
  fullToHalfFilter->SetInput(this->GetInput());
  fullToHalfFilter->SetNumberOfWorkUnits(this->GetNumberOfWorkUnits());
  fullToHalfFilter->UpdateLargestPossibleRegion();

  auto * in = (typename FFTWProxyType::ComplexType *)fullToHalfFilter->GetOutput()->GetBufferPointer();

  OutputPixelType *                out = outputPtr->GetBufferPointer();
  typename FFTWProxyType::PlanType plan;

  int sizes[ImageDimension];
  for (unsigned int i = 0; i < ImageDimension; i++)
  {
    sizes[(ImageDimension - 1) - i] = outputSize[i];
  }

  plan = FFTWProxyType::Plan_dft_c2r(
    ImageDimension, sizes, in, out, m_PlanRigor, MultiThreaderBase::GetGlobalDefaultNumberOfThreads(), false);
  FFTWProxyType::Execute(plan);

  // Some cleanup.
  FFTWProxyType::DestroyPlan(plan);
}

template <typename TInputImage, typename TOutputImage>
void
FFTWInverseFFTImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
  const OutputImageRegionType & outputRegionForThread)
{
  using IteratorType = ImageRegionIterator<OutputImageType>;
  unsigned long totalOutputSize = this->GetOutput()->GetRequestedRegion().GetNumberOfPixels();
  IteratorType  it(this->GetOutput(), outputRegionForThread);
  while (!it.IsAtEnd())
  {
    it.Set(it.Value() / totalOutputSize);
    ++it;
  }
}

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

#ifndef ITK_USE_CUFFTW
  os << indent << "PlanRigor: " << FFTWGlobalConfiguration::GetPlanRigorName(m_PlanRigor) << " (" << m_PlanRigor << ")"
     << std::endl;
#endif
}

template <typename TInputImage, typename TOutputImage>
SizeValueType
FFTWInverseFFTImageFilter<TInputImage, TOutputImage>::GetSizeGreatestPrimeFactor() const
{
  return FFTWProxyType::GREATEST_PRIME_FACTOR;
}

} // namespace itk
#endif // _itkFFTWInverseFFTImageFilter_hxx
