/*=========================================================================
 *
 *  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 itkOpeningByReconstructionImageFilter_hxx
#define itkOpeningByReconstructionImageFilter_hxx

#include "itkImageRegionIterator.h"
#include "itkGrayscaleErodeImageFilter.h"
#include "itkReconstructionByDilationImageFilter.h"
#include "itkSubtractImageFilter.h"
#include "itkProgressAccumulator.h"

namespace itk
{
template <typename TInputImage, typename TOutputImage, typename TKernel>
OpeningByReconstructionImageFilter<TInputImage, TOutputImage, TKernel>::OpeningByReconstructionImageFilter()
  : m_Kernel()
{
  m_FullyConnected = false;
  m_PreserveIntensities = false;
}

template <typename TInputImage, typename TOutputImage, typename TKernel>
void
OpeningByReconstructionImageFilter<TInputImage, TOutputImage, TKernel>::GenerateInputRequestedRegion()
{
  // call the superclass' implementation of this method
  Superclass::GenerateInputRequestedRegion();

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

template <typename TInputImage, typename TOutputImage, typename TKernel>
void
OpeningByReconstructionImageFilter<TInputImage, TOutputImage, TKernel>::EnlargeOutputRequestedRegion(DataObject *)
{
  this->GetOutput()->SetRequestedRegion(this->GetOutput()->GetLargestPossibleRegion());
}

template <typename TInputImage, typename TOutputImage, typename TKernel>
void
OpeningByReconstructionImageFilter<TInputImage, TOutputImage, TKernel>::GenerateData()
{
  // Create a process accumulator for tracking the progress of this minipipeline
  auto progress = ProgressAccumulator::New();

  progress->SetMiniPipelineFilter(this);

  // Allocate the output
  this->AllocateOutputs();

  // Delegate to an erode filter.
  typename GrayscaleErodeImageFilter<TInputImage, TInputImage, TKernel>::Pointer erode =
    GrayscaleErodeImageFilter<TInputImage, TInputImage, TKernel>::New();

  erode->SetInput(this->GetInput());
  erode->SetKernel(this->m_Kernel);

  // Delegate to a dilate filter.
  typename ReconstructionByDilationImageFilter<TInputImage, TInputImage>::Pointer dilate =
    ReconstructionByDilationImageFilter<TInputImage, TInputImage>::New();

  dilate->SetMarkerImage(erode->GetOutput());
  dilate->SetMaskImage(this->GetInput());
  dilate->SetFullyConnected(m_FullyConnected);

  progress->RegisterInternalFilter(erode, 0.5f);
  progress->RegisterInternalFilter(dilate, 0.25f);

  if (m_PreserveIntensities)
  {
    dilate->Update();
    auto tempImage = TInputImage::New();
    tempImage->SetRegions(erode->GetOutput()->GetBufferedRegion());
    tempImage->CopyInformation(this->GetInput());

    tempImage->Allocate();

    ImageRegionConstIterator<TInputImage> inputIt(this->GetInput(), erode->GetOutput()->GetBufferedRegion());
    ImageRegionConstIterator<TInputImage> erodeIt(erode->GetOutput(), erode->GetOutput()->GetBufferedRegion());
    ImageRegionConstIterator<TInputImage> dilateIt(dilate->GetOutput(), erode->GetOutput()->GetBufferedRegion());
    ImageRegionIterator<TInputImage>      tempIt(tempImage, erode->GetOutput()->GetBufferedRegion());
    while (!erodeIt.IsAtEnd())
    {
      if (erodeIt.Get() == dilateIt.Get())
      {
        tempIt.Set(inputIt.Get());
      }
      else
      {
        tempIt.Set(NumericTraits<InputImagePixelType>::NonpositiveMin());
      }
      ++erodeIt;
      ++dilateIt;
      ++tempIt;
      ++inputIt;
    }

    typename ReconstructionByDilationImageFilter<TInputImage, TInputImage>::Pointer dilateAgain =
      ReconstructionByDilationImageFilter<TInputImage, TInputImage>::New();
    dilateAgain->SetMaskImage(this->GetInput());
    dilateAgain->SetMarkerImage(tempImage);
    dilateAgain->SetFullyConnected(m_FullyConnected);
    dilateAgain->GraftOutput(this->GetOutput());
    progress->RegisterInternalFilter(dilateAgain, 0.25f);
    dilateAgain->Update();
    this->GraftOutput(dilateAgain->GetOutput());
  }
  else
  {
    dilate->GraftOutput(this->GetOutput());
    dilate->Update();
    this->GraftOutput(dilate->GetOutput());
  }
}

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

  os << indent << "Kernel: " << m_Kernel << std::endl;
  os << indent << "FullyConnected: " << (m_FullyConnected ? "On" : "Off") << std::endl;
  os << indent << "PreserveIntensities: " << m_PreserveIntensities << std::endl;
}
} // end namespace itk
#endif
