/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  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
 *
 *         http://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 itkLabelMapToAttributeImageFilter_h
#define itkLabelMapToAttributeImageFilter_h

#include "itkImageToImageFilter.h"
#include "itkAttributeLabelObject.h"

namespace itk {

/** \class LabelMapToAttributeImageFilter
 * \brief Convert a LabelMap to a labeled image
 *
 * LabelMapToAttributeImageFilter converts a LabelMap to an
 * Image where all the pixels get the attribute value of the label object they belong.
 *
 * \author Gaetan Lehmann. Biologie du Developpement et de la Reproduction, INRA de Jouy-en-Josas, France.
 *
 * This implementation was taken from the Insight Journal paper:
 * https://hdl.handle.net/1926/584  or
 * http://www.insight-journal.org/browse/publication/176
 *
 * \sa LabelMapToBinaryImageFilter, LabelMapMaskImageFilter
 * \ingroup ImageEnhancement  MathematicalMorphologyImageFilters
 * \ingroup ITKLabelMap
 */
template<typename TInputImage, typename TOutputImage, typename TAttributeAccessor=
    typename Functor::AttributeLabelObjectAccessor< typename TInputImage::LabelObjectType > >
class ITK_TEMPLATE_EXPORT LabelMapToAttributeImageFilter :
    public ImageToImageFilter<TInputImage, TOutputImage>
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(LabelMapToAttributeImageFilter);

  /** Standard class type aliases. */
  using Self = LabelMapToAttributeImageFilter;
  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;
  using IndexType = typename OutputImageType::IndexType;

  using AttributeAccessorType = TAttributeAccessor;
  using AttributeValueType = typename AttributeAccessorType::AttributeValueType;

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

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

  /** Runtime information support. */
  itkTypeMacro(LabelMapToAttributeImageFilter,
               ImageToImageFilter);

  /**
   * Set/Get the value used as "background" in the output image, if the input
   * LabelMap use a background.
   * Defaults to NumericTraits<PixelType>::NonpositiveMin().
   */
  itkSetMacro(BackgroundValue, OutputImagePixelType);
  itkGetConstMacro(BackgroundValue, OutputImagePixelType);

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

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

  /** LabelMapToAttributeImageFilter 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:
  OutputImagePixelType m_BackgroundValue;

}; // end of class

} // end namespace itk

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

#endif
