/*=========================================================================
 *
 *  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_h
#define itkMorphologicalWatershedImageFilter_h

#include "itkImageToImageFilter.h"

namespace itk
{
/** \class MorphologicalWatershedImageFilter
 * \brief Watershed segmentation implementation with morphological operators
 *
 * Watershed pixel are labeled 0.
 * TOutputImage should be an integer type.
 * Labels of output image are in no particular order. You can reorder the
 * labels such that object labels are consecutive and sorted based on object
 * size by passing the output of this filter to a RelabelComponentImageFilter.
 *
 * The morphological watershed transform algorithm is described in
 * Chapter 9.2 of Pierre Soille's book "Morphological Image Analysis:
 * Principles and Applications", Second Edition, Springer, 2003.
 *
 *
 * This code was contributed in the Insight Journal paper:
 * "The watershed transform in ITK - discussion and new developments"
 * by Beare R., Lehmann G.
 * https://www.insight-journal.org/browse/publication/92
 *
 * \author Gaetan Lehmann. Biologie du Developpement et de la Reproduction, INRA de Jouy-en-Josas, France.
 *
 * \sa WatershedImageFilter, MorphologicalWatershedFromMarkersImageFilter
 * \ingroup ImageEnhancement  MathematicalMorphologyImageFilters
 * \ingroup ITKWatersheds
 *
 * \sphinx
 * \sphinxexample{Segmentation/Watersheds/MorphologicalWatershedSegmentation,Morphological Watershed Segmentation}
 * \endsphinx
 */
template <typename TInputImage, typename TOutputImage>
class ITK_TEMPLATE_EXPORT MorphologicalWatershedImageFilter : public ImageToImageFilter<TInputImage, TOutputImage>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(MorphologicalWatershedImageFilter);

  /** Standard class type aliases. */
  using Self = MorphologicalWatershedImageFilter;
  using Superclass = ImageToImageFilter<TInputImage, TOutputImage>;
  using Pointer = SmartPointer<Self>;
  using ConstPointer = SmartPointer<const Self>;

  /** Some convenient type alias. */
  using InputImageType = TInputImage;
  using OutputImageType = TOutputImage;
  using InputImagePointer = typename InputImageType::Pointer;
  using InputImageConstPointer = typename InputImageType::ConstPointer;
  using InputImageRegionType = typename InputImageType::RegionType;
  using InputImagePixelType = typename InputImageType::PixelType;
  using OutputImagePointer = typename OutputImageType::Pointer;
  using OutputImageConstPointer = typename OutputImageType::ConstPointer;
  using OutputImageRegionType = typename OutputImageType::RegionType;
  using OutputImagePixelType = typename OutputImageType::PixelType;

  /** ImageDimension constants */
  static constexpr unsigned int InputImageDimension = TInputImage::ImageDimension;
  static constexpr unsigned int OutputImageDimension = TOutputImage::ImageDimension;

  /** Standard New method. */
  itkNewMacro(Self);

  /** \see LightObject::GetNameOfClass() */
  itkOverrideGetNameOfClassMacro(MorphologicalWatershedImageFilter);

  /**
   * Set/Get whether the connected components are defined strictly by
   * face connectivity or by face+edge+vertex connectivity.  Default is
   * FullyConnectedOff.  For objects that are 1 pixel wide, use
   * FullyConnectedOn.
   */
  itkSetMacro(FullyConnected, bool);
  itkGetConstReferenceMacro(FullyConnected, bool);
  itkBooleanMacro(FullyConnected);

  /**
   * Set/Get whether the watershed pixel must be marked or not. Default
   * is true. Set it to false do not only avoid writing watershed pixels,
   * it also decrease algorithm complexity.
   */
  itkSetMacro(MarkWatershedLine, bool);
  itkGetConstReferenceMacro(MarkWatershedLine, bool);
  itkBooleanMacro(MarkWatershedLine);

  /**
   */
  itkSetMacro(Level, InputImagePixelType);
  itkGetConstMacro(Level, InputImagePixelType);

protected:
  MorphologicalWatershedImageFilter();
  ~MorphologicalWatershedImageFilter() override = default;
  void
  PrintSelf(std::ostream & os, Indent indent) const override;

  /** MorphologicalWatershedImageFilter needs the entire input be
   * available. Thus, it needs to provide an implementation of
   * GenerateInputRequestedRegion(). */
  void
  GenerateInputRequestedRegion() override;

  /** MorphologicalWatershedImageFilter will produce the entire output. */
  void
  EnlargeOutputRequestedRegion(DataObject * itkNotUsed(output)) override;

  /** Single-threaded version of GenerateData.  This filter delegates
   * to GrayscaleGeodesicErodeImageFilter. */
  void
  GenerateData() override;

private:
  bool m_FullyConnected{ false };

  bool m_MarkWatershedLine{ true };

  InputImagePixelType m_Level{};
}; // end of class
} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkMorphologicalWatershedImageFilter.hxx"
#endif

#endif
