/*=========================================================================
 *
 *  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 itkMorphologicalWatershedImageFilter_hxx
#define itkMorphologicalWatershedImageFilter_hxx

#include "itkRegionalMinimaImageFilter.h"
#include "itkHMinimaImageFilter.h"
#include "itkConnectedComponentImageFilter.h"
#include "itkMorphologicalWatershedFromMarkersImageFilter.h"
#include "itkNumericTraits.h"

namespace itk
{

template <typename TInputImage, typename TOutputImage>
MorphologicalWatershedImageFilter<TInputImage, TOutputImage>::MorphologicalWatershedImageFilter()
  : m_Level(InputImagePixelType{})
{}


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

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


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


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

  progress->SetMiniPipelineFilter(this);

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

  const InputImageType * input = this->GetInput();

  // h-minima filter to remove the smallest minima
  using HMinimaType = HMinimaImageFilter<TInputImage, TInputImage>;
  typename HMinimaType::Pointer hmin;

  // Delegate to a R-Min filter to find the regional minima
  using RMinType = RegionalMinimaImageFilter<TInputImage, TOutputImage>;
  auto rmin = RMinType::New();
  rmin->SetInput(input);
  rmin->SetFullyConnected(m_FullyConnected);
  rmin->SetBackgroundValue(OutputImagePixelType{});
  rmin->SetForegroundValue(NumericTraits<OutputImagePixelType>::max());

  // label the components
  using ConnectedCompType = ConnectedComponentImageFilter<TOutputImage, TOutputImage>;
  auto label = ConnectedCompType::New();
  label->SetFullyConnected(m_FullyConnected);
  label->SetInput(rmin->GetOutput());

  // the watershed
  using WatershedType = MorphologicalWatershedFromMarkersImageFilter<TInputImage, TOutputImage>;
  auto wshed = WatershedType::New();
  wshed->SetInput(input);
  wshed->SetMarkerImage(label->GetOutput());
  wshed->SetFullyConnected(m_FullyConnected);
  wshed->SetMarkWatershedLine(m_MarkWatershedLine);

  if (m_Level != InputImagePixelType{})
  {
    // insert a h-minima filter to remove the smallest minima
    //
    hmin = HMinimaType::New();
    hmin->SetInput(input);
    hmin->SetHeight(m_Level);
    hmin->SetFullyConnected(m_FullyConnected);
    // replace the input of the r-min filter
    rmin->SetInput(hmin->GetOutput());

    progress->RegisterInternalFilter(hmin, 0.4f);
    progress->RegisterInternalFilter(rmin, 0.1f);
    progress->RegisterInternalFilter(label, .2f);
    progress->RegisterInternalFilter(wshed, .3f);
  }
  else
  {
    // don't insert the h-minima to save some resources
    progress->RegisterInternalFilter(rmin, 0.167f);
    progress->RegisterInternalFilter(label, .333f);
    progress->RegisterInternalFilter(wshed, .5f);
  }

  // run the algorithm
  // graft our output to the watershed filter to force the proper regions
  // to be generated
  wshed->GraftOutput(this->GetOutput());

  wshed->Update();

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


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

  os << indent << "FullyConnected: " << (m_FullyConnected ? "On" : "Off") << std::endl;
  os << indent << "MarkWatershedLine: " << m_MarkWatershedLine << std::endl;
  os << indent << "Level: " << static_cast<typename NumericTraits<InputImagePixelType>::PrintType>(m_Level)
     << std::endl;
}

} // end namespace itk
#endif
