/*=========================================================================
 *
 *  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 itkHConcaveImageFilter_hxx
#define itkHConcaveImageFilter_hxx

#include "itkImageRegionIterator.h"
#include "itkHMinimaImageFilter.h"
#include "itkSubtractImageFilter.h"

namespace itk
{
template <typename TInputImage, typename TOutputImage>
HConcaveImageFilter<TInputImage, TOutputImage>::HConcaveImageFilter()
  : m_Height(2)

{}

template <typename TInputImage, typename TOutputImage>
void
HConcaveImageFilter<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)
  {
    input->SetRequestedRegion(input->GetLargestPossibleRegion());
  }
}

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

template <typename TInputImage, typename TOutputImage>
void
HConcaveImageFilter<TInputImage, TOutputImage>::GenerateData()
{
  // Allocate the output
  this->AllocateOutputs();

  // Create a process accumulator for tracking the progress of this minipipeline
  auto progress = ProgressAccumulator::New();
  progress->SetMiniPipelineFilter(this);

  // Delegate to a H-Minima filter.
  //
  //
  typename HMinimaImageFilter<TInputImage, TInputImage>::Pointer hmin =
    HMinimaImageFilter<TInputImage, TInputImage>::New();

  hmin->SetInput(this->GetInput());
  hmin->SetHeight(m_Height);
  hmin->SetFullyConnected(m_FullyConnected);

  // Need to subtract the input from the H-Minima image
  typename SubtractImageFilter<TInputImage, TInputImage, TOutputImage>::Pointer subtract =
    SubtractImageFilter<TInputImage, TInputImage, TOutputImage>::New();

  subtract->SetInput1(hmin->GetOutput());
  subtract->SetInput2(this->GetInput());

  // Graft our output to the subtract filter to force the proper regions
  // to be generated
  subtract->GraftOutput(this->GetOutput());

  // run the algorithm
  progress->RegisterInternalFilter(hmin, .9f);
  progress->RegisterInternalFilter(subtract, .1f);

  subtract->Update();

  // Graft the output of the subtract filter back onto this filter's
  // output. this is needed to get the appropriate regions passed
  // back.
  this->GraftOutput(subtract->GetOutput());
}

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

  os << indent << "Depth of local minima (contrast): "
     << static_cast<typename NumericTraits<InputImagePixelType>::PrintType>(m_Height) << std::endl;
  os << indent << "Number of iterations used to produce current output: " << m_NumberOfIterationsUsed << std::endl;
  os << indent << "FullyConnected: " << (m_FullyConnected ? "On" : "Off") << std::endl;
}
} // end namespace itk
#endif
