/*=========================================================================
 *
 *  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 itkLabelImageToLabelMapFilter_h
#define itkLabelImageToLabelMapFilter_h

#include "itkImageToImageFilter.h"
#include "itkLabelMap.h"
#include "itkLabelObject.h"

namespace itk
{
/** \class LabelImageToLabelMapFilter
 * \brief convert a labeled image to a label collection image
 *
 * LabelImageToLabelMapFilter converts a label image to a label collection image.
 * The labels are the same in the input and the output image.
 *
 * \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 BinaryImageToLabelMapFilter, LabelMapToLabelImageFilter
 * \ingroup ImageEnhancement  MathematicalMorphologyImageFilters
 * \ingroup ITKLabelMap
 *
 * \wiki
 * \wikiexample{ImageSegmentation/LabelImageToLabelMapFilter,Convert an itk::Image consisting of labeled regions to a LabelMap}
 * \endwiki
 */
template< typename TInputImage, typename TOutputImage =
            LabelMap< LabelObject< typename TInputImage::PixelType,
                                   TInputImage::ImageDimension > > >
class ITK_TEMPLATE_EXPORT LabelImageToLabelMapFilter:
  public ImageToImageFilter< TInputImage, TOutputImage >
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(LabelImageToLabelMapFilter);

  /** Standard class type aliases. */
  using Self = LabelImageToLabelMapFilter;
  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 IndexType = typename InputImageType::IndexType;

  using OutputImagePointer = typename OutputImageType::Pointer;
  using OutputImageConstPointer = typename OutputImageType::ConstPointer;
  using OutputImageRegionType = typename OutputImageType::RegionType;
  using OutputImagePixelType = typename OutputImageType::PixelType;
  using LabelObjectType = typename OutputImageType::LabelObjectType;
  using LengthType = typename LabelObjectType::LengthType;

  /** 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(LabelImageToLabelMapFilter,
               ImageToImageFilter);

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

#ifdef ITK_USE_CONCEPT_CHECKING
  itkConceptMacro( SameDimensionCheck,
                   ( Concept::SameDimension< InputImageDimension, OutputImageDimension > ) );
#endif

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

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

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

  void BeforeThreadedGenerateData() override;

  void ThreadedGenerateData(const OutputImageRegionType & outputRegionForThread, ThreadIdType threadId) override;

  void DynamicThreadedGenerateData( const OutputImageRegionType & ) override
  {
    itkExceptionMacro("This class requires threadId so it must use classic multi-threading model");
  }

  void AfterThreadedGenerateData() override;

private:
  OutputImagePixelType m_BackgroundValue;

  typename std::vector< OutputImagePointer > m_TemporaryImages;
}; // end of class
} // end namespace itk

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

#endif
