/*=========================================================================
 *
 *  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 itkVotingBinaryHoleFillingImageFilter_hxx
#define itkVotingBinaryHoleFillingImageFilter_hxx
#include "itkVotingBinaryHoleFillingImageFilter.h"

#include "itkConstNeighborhoodIterator.h"
#include "itkNeighborhoodInnerProduct.h"
#include "itkImageRegionIterator.h"
#include "itkNeighborhoodAlgorithm.h"
#include "itkProgressReporter.h"

#include <vector>
#include <algorithm>

namespace itk
{
template< typename TInputImage, typename TOutputImage >
VotingBinaryHoleFillingImageFilter< TInputImage, TOutputImage >
::VotingBinaryHoleFillingImageFilter()
{
  this->SetSurvivalThreshold(0);
  this->m_MajorityThreshold = 1;
  this->m_NumberOfPixelsChanged = 0;
  this->DynamicMultiThreadingOff();
}

template< typename TInputImage, typename TOutputImage >
void
VotingBinaryHoleFillingImageFilter< TInputImage, TOutputImage >
::BeforeThreadedGenerateData()
{
  unsigned int threshold = 1;

  InputSizeType radius = this->GetRadius();

  for ( unsigned int i = 0; i < InputImageDimension; i++ )
    {
    threshold *= ( 2 * radius[i] + 1 );
    }

  // remove central pixel and take 50%
  threshold = static_cast< unsigned int >( ( threshold - 1 ) / 2.0 );

  // add the majority threshold.
  threshold += this->GetMajorityThreshold();

  this->SetBirthThreshold(threshold);
  this->SetSurvivalThreshold(0);

  this->m_NumberOfPixelsChanged = 0;

  unsigned int numberOfThreads = this->GetNumberOfWorkUnits();
  this->m_Count.SetSize(numberOfThreads);
  for ( unsigned int i = 0; i < numberOfThreads; i++ )
    {
    this->m_Count[i] = 0;
    }
}

template< typename TInputImage, typename TOutputImage >
void
VotingBinaryHoleFillingImageFilter< TInputImage, TOutputImage >
::ThreadedGenerateData(const OutputImageRegionType & outputRegionForThread,
                       ThreadIdType threadId)
{
  ZeroFluxNeumannBoundaryCondition< InputImageType > nbc;

  ConstNeighborhoodIterator< InputImageType > bit;
  ImageRegionIterator< OutputImageType >      it;

  // Allocate output
  typename OutputImageType::Pointer output = this->GetOutput();
  typename InputImageType::ConstPointer input  = this->GetInput();

  // Find the data-set boundary "faces"
  typename NeighborhoodAlgorithm::ImageBoundaryFacesCalculator< InputImageType >::FaceListType faceList;
  NeighborhoodAlgorithm::ImageBoundaryFacesCalculator< InputImageType > bC;
  faceList = bC( input, outputRegionForThread, this->GetRadius() );

  typename NeighborhoodAlgorithm::ImageBoundaryFacesCalculator< InputImageType >::FaceListType::iterator fit;

  ProgressReporter progress( this, threadId, outputRegionForThread.GetNumberOfPixels() );

  const InputPixelType backgroundValue = this->GetBackgroundValue();
  const InputPixelType foregroundValue = this->GetForegroundValue();
  const auto birthThreshold = (unsigned int)( this->GetBirthThreshold() );

  unsigned int numberOfPixelsChanged = 0;

  // Process each of the boundary faces.  These are N-d regions which border
  // the edge of the buffer.
  for ( fit = faceList.begin(); fit != faceList.end(); ++fit )
    {
    bit = ConstNeighborhoodIterator< InputImageType >(this->GetRadius(), input, *fit);
    it  = ImageRegionIterator< OutputImageType >(output, *fit);
    bit.OverrideBoundaryCondition(&nbc);
    bit.GoToBegin();

    unsigned int neighborhoodSize = bit.Size();

    while ( !bit.IsAtEnd() )
      {
      const InputPixelType inpixel = bit.GetCenterPixel();

      if ( inpixel == backgroundValue )
        {
        // count the pixels ON in the neighborhood
        unsigned int count = 0;
        for ( unsigned int i = 0; i < neighborhoodSize; ++i )
          {
          InputPixelType value = bit.GetPixel(i);
          if ( value == foregroundValue )
            {
            count++;
            }
          }

        if ( count >= birthThreshold )
          {
          it.Set( static_cast< OutputPixelType >( foregroundValue ) );
          numberOfPixelsChanged++;
          }
        else
          {
          it.Set( static_cast< OutputPixelType >( backgroundValue ) );
          }
        }
      else
        {
        it.Set( static_cast< OutputPixelType >( foregroundValue ) );
        }
      ++bit;
      ++it;
      progress.CompletedPixel();
      }
    }
  this->m_Count[threadId] = numberOfPixelsChanged;
}

template< typename TInputImage, typename TOutputImage >
void
VotingBinaryHoleFillingImageFilter< TInputImage, TOutputImage >
::AfterThreadedGenerateData()
{
  this->m_NumberOfPixelsChanged = NumericTraits< SizeValueType >::ZeroValue();

  unsigned int numberOfThreads = this->GetNumberOfWorkUnits();
  this->m_Count.SetSize(numberOfThreads);
  for ( unsigned int t = 0; t < numberOfThreads; t++ )
    {
    this->m_NumberOfPixelsChanged += this->m_Count[t];
    }
}


template< typename TInputImage, typename TOutput >
void
VotingBinaryHoleFillingImageFilter< TInputImage, TOutput >
::PrintSelf(
  std::ostream & os,
  Indent indent) const
{
  Superclass::PrintSelf(os, indent);
  os << indent << "Majority Threshold           : " << m_MajorityThreshold << std::endl;
  os << indent << "Number of Pixels Changed     : " << m_NumberOfPixelsChanged << std::endl;
}
} // end namespace itk

#endif
