/*=========================================================================
 *
 *  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 itkIsolatedWatershedImageFilter_h
#define itkIsolatedWatershedImageFilter_h

#include "itkWatershedImageFilter.h"
#include "itkGradientMagnitudeImageFilter.h"

namespace itk
{
/**
 * \class IsolatedWatershedImageFilter
 * \brief Isolate watershed basins using two seeds
 *
 * IsolatedWatershedImageFilter labels pixels with ReplaceValue1 that
 * are in the same watershed basin as Seed1 AND NOT the same as
 * Seed2. The filter adjusts the waterlevel until the two seeds are
 * not in different basins. The user supplies a Watershed
 * threshold. The algorithm uses a binary search to adjust the upper
 * waterlevel, starting at UpperValueLimit. UpperValueLimit defaults
 * to the 1.0.
 * \ingroup WatershedSegmentation
 * \ingroup ITKWatersheds
 */

template <typename TInputImage, typename TOutputImage>
class ITK_TEMPLATE_EXPORT IsolatedWatershedImageFilter : public ImageToImageFilter<TInputImage, TOutputImage>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(IsolatedWatershedImageFilter);

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

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

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

  using InputImageType = TInputImage;
  using InputImagePointer = typename InputImageType::Pointer;
  using InputImageConstPointer = typename InputImageType::ConstPointer;
  using InputImageRegionType = typename InputImageType::RegionType;
  using InputImagePixelType = typename InputImageType::PixelType;
  using IndexType = typename InputImageType::IndexType;
  using SizeType = typename InputImageType::SizeType;

  using OutputImageType = TOutputImage;
  using OutputImagePointer = typename OutputImageType::Pointer;
  using OutputImageRegionType = typename OutputImageType::RegionType;
  using OutputImagePixelType = typename OutputImageType::PixelType;

  using RealPixelType = typename NumericTraits<InputImagePixelType>::RealType;
  using RealImageType = Image<RealPixelType, TInputImage::ImageDimension>;

  using WatershedType = WatershedImageFilter<RealImageType>;
  using GradientMagnitudeType = GradientMagnitudeImageFilter<InputImageType, RealImageType>;
  void
  PrintSelf(std::ostream & os, Indent indent) const override;

  /** Set seed point 1. This seed will be isolated from Seed2 (if
   *  possible). All pixels connected to this seed will be replaced
   *  with ReplaceValue1. */
  itkSetMacro(Seed1, IndexType);
  itkGetConstMacro(Seed1, IndexType);

  /** Set seed point 2. This seed will be isolated from Seed1 (if
   *  possible). All pixels connected to this seed will be replaced
   *  with ReplaceValue2. */
  itkSetMacro(Seed2, IndexType);
  itkGetConstMacro(Seed2, IndexType);

  /** Set/Get the Watershed threshold. The default is 0. */
  itkSetMacro(Threshold, double);
  itkGetConstMacro(Threshold, double);

  /** Set/Get the precision required for the intensity threshold
   *  value. The default is .001. */
  itkSetMacro(IsolatedValueTolerance, double);
  itkGetConstMacro(IsolatedValueTolerance, double);

  /** Set/Get the limit on the upper waterlevel value. The default is
   *  1.0. */
  itkSetMacro(UpperValueLimit, double);
  itkGetConstMacro(UpperValueLimit, double);

  /** Set/Get value to replace Seed1(Seed2) pixels, pixels that are
   *  within the basin that contains Seed1(Seed2) this  value. The
   *  default is 1(0). */
  itkSetMacro(ReplaceValue1, OutputImagePixelType);
  itkGetConstMacro(ReplaceValue1, OutputImagePixelType);
  itkSetMacro(ReplaceValue2, OutputImagePixelType);
  itkGetConstMacro(ReplaceValue2, OutputImagePixelType);

  /** Get value that isolates the two seeds. */
  itkGetConstMacro(IsolatedValue, double);

protected:
  IsolatedWatershedImageFilter();
  ~IsolatedWatershedImageFilter() override = default;
  IndexType m_Seed1{};
  IndexType m_Seed2{};

  OutputImagePixelType m_ReplaceValue1{};
  OutputImagePixelType m_ReplaceValue2{};

  typename GradientMagnitudeType::Pointer m_GradientMagnitude{};

  typename WatershedType::Pointer m_Watershed{};

  double m_Threshold{};
  double m_IsolatedValue{};
  double m_IsolatedValueTolerance{};
  double m_UpperValueLimit{};

  // Override since the filter needs all the data for the algorithm
  void
  GenerateInputRequestedRegion() override;

  // Override since the filter produces the entire dataset
  void
  EnlargeOutputRequestedRegion(DataObject * output) override;

  void
  VerifyInputInformation() ITKv5_CONST override;
  void
  GenerateData() override;
};
} // end namespace itk

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

#endif
