/*=========================================================================
 *
 *  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 itkVotingBinaryImageFilter_hxx
#define itkVotingBinaryImageFilter_hxx

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

#include <vector>
#include <algorithm>

namespace itk
{
template <typename TInputImage, typename TOutputImage>
VotingBinaryImageFilter<TInputImage, TOutputImage>::VotingBinaryImageFilter()
{
  m_Radius.Fill(1);
  m_ForegroundValue = NumericTraits<InputPixelType>::max();
  m_BackgroundValue = InputPixelType{};
  m_BirthThreshold = 1;
  m_SurvivalThreshold = 1;
  this->ThreaderUpdateProgressOff();
}

template <typename TInputImage, typename TOutputImage>
void
VotingBinaryImageFilter<TInputImage, TOutputImage>::GenerateInputRequestedRegion()
{
  // call the superclass' implementation of this method
  Superclass::GenerateInputRequestedRegion();

  // get pointers to the input and output
  typename Superclass::InputImagePointer  inputPtr = const_cast<TInputImage *>(this->GetInput());
  typename Superclass::OutputImagePointer outputPtr = this->GetOutput();

  if (!inputPtr || !outputPtr)
  {
    return;
  }

  // get a copy of the input requested region (should equal the output
  // requested region)
  typename TInputImage::RegionType inputRequestedRegion;
  inputRequestedRegion = inputPtr->GetRequestedRegion();

  // pad the input requested region by the operator radius
  inputRequestedRegion.PadByRadius(m_Radius);

  // crop the input requested region at the input's largest possible region
  if (inputRequestedRegion.Crop(inputPtr->GetLargestPossibleRegion()))
  {
    inputPtr->SetRequestedRegion(inputRequestedRegion);
    return;
  }
  else
  {
    // Couldn't crop the region (requested region is outside the largest
    // possible region).  Throw an exception.

    // store what we tried to request (prior to trying to crop)
    inputPtr->SetRequestedRegion(inputRequestedRegion);

    // build an exception
    InvalidRequestedRegionError e(__FILE__, __LINE__);
    e.SetLocation(ITK_LOCATION);
    e.SetDescription("Requested region is (at least partially) outside the largest possible region.");
    e.SetDataObject(inputPtr);
    throw e;
  }
}

template <typename TInputImage, typename TOutputImage>
void
VotingBinaryImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
  const OutputImageRegionType & outputRegionForThread)
{
  ZeroFluxNeumannBoundaryCondition<InputImageType> nbc;

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

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

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

  TotalProgressReporter progress(this, output->GetRequestedRegion().GetNumberOfPixels());
  // Process each of the boundary faces.  These are N-d regions which border
  // the edge of the buffer.
  for (const auto & face : faceList)
  {
    bit = ConstNeighborhoodIterator<InputImageType>(m_Radius, input, face);
    it = ImageRegionIterator<OutputImageType>(output, face);
    bit.OverrideBoundaryCondition(&nbc);
    bit.GoToBegin();

    unsigned int neighborhoodSize = bit.Size();

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

      // 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 == m_ForegroundValue)
        {
          ++count;
        }
      }

      // Unless the birth or survival rate is meet the pixel will be
      // the same value
      it.Set(static_cast<OutputPixelType>(inpixel));

      if (inpixel == m_BackgroundValue && count >= m_BirthThreshold)
      {
        it.Set(static_cast<OutputPixelType>(m_ForegroundValue));
      }
      else if (inpixel == m_ForegroundValue && count < m_SurvivalThreshold)
      {
        it.Set(static_cast<OutputPixelType>(m_BackgroundValue));
      }

      ++bit;
      ++it;
      progress.CompletedPixel();
    }
  }
}

/**
 * Standard "PrintSelf" method
 */
template <typename TInputImage, typename TOutput>
void
VotingBinaryImageFilter<TInputImage, TOutput>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);
  os << indent << "Radius: " << m_Radius << std::endl;
  os << indent
     << "Foreground value : " << static_cast<typename NumericTraits<InputPixelType>::PrintType>(m_ForegroundValue)
     << std::endl;
  os << indent
     << "Background value : " << static_cast<typename NumericTraits<InputPixelType>::PrintType>(m_BackgroundValue)
     << std::endl;
  os << indent << "Birth Threshold   : " << m_BirthThreshold << std::endl;
  os << indent << "Survival Threshold   : " << m_SurvivalThreshold << std::endl;
}
} // end namespace itk

#endif
