/*
 * Copyright (C) 2005-2020 Centre National d'Etudes Spatiales (CNES)
 *
 * This file is part of Orfeo Toolbox
 *
 *     https://www.orfeo-toolbox.org/
 *
 * 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
 *
 * 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 otbBinaryImageToDensityImageFilter_hxx
#define otbBinaryImageToDensityImageFilter_hxx

#include "otbBinaryImageToDensityImageFilter.h"
#include "itkImageRegionIterator.h"
#include "itkProgressReporter.h"
#include "itkZeroFluxNeumannBoundaryCondition.h"
#include "itkNeighborhoodAlgorithm.h"

#include "otbMacro.h"

namespace otb
{
/** Constructor */
template <class TInputImage, class TOutputImage, class TCountFunction>
BinaryImageToDensityImageFilter<TInputImage, TOutputImage, TCountFunction>::BinaryImageToDensityImageFilter()
{
  m_NeighborhoodRadius.Fill(1);
  m_CountFunction = CountFunctionType::New();
}

/** Destructor */
template <class TInputImage, class TOutputImage, class TCountFunction>
BinaryImageToDensityImageFilter<TInputImage, TOutputImage, TCountFunction>::~BinaryImageToDensityImageFilter()
{
}

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

  // get pointers to the input and output
  InputImagePointerType  inputPtr  = const_cast<TInputImage*>(this->GetInput());
  OutputImagePointerType outputPtr = this->GetOutput();

  if (!inputPtr || !outputPtr)
  {
    return;
  }
  // get a copy of the input requested region (should equal the output
  // requested region)
  InputImageRegionType inputRequestedRegion = inputPtr->GetRequestedRegion();

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

  // 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
    itk::InvalidRequestedRegionError e(__FILE__, __LINE__);
    std::ostringstream               msg;
    msg << this->GetNameOfClass() << "::GenerateInputRequestedRegion()";
    e.SetLocation(msg.str());
    e.SetDescription("Requested region is (at least partially) outside the largest possible region.");
    e.SetDataObject(inputPtr);
    throw e;
  }
}

template <class TInputImage, class TOutputImage, class TCountFunction>
void BinaryImageToDensityImageFilter<TInputImage, TOutputImage, TCountFunction>::BeforeThreadedGenerateData()
{
  Superclass::BeforeThreadedGenerateData();

  m_CountFunction->SetInputImage(this->GetInput());
  m_CountFunction->SetNeighborhoodRadius(m_NeighborhoodRadius);
}

/** Main computation method */
template <class TInputImage, class TOutputImage, class TCountFunction>
void BinaryImageToDensityImageFilter<TInputImage, TOutputImage, TCountFunction>::ThreadedGenerateData(const InputImageRegionType& outputRegionForThread,
                                                                                                      itk::ThreadIdType threadId)
{
  InputImagePointerType  inputPtr  = const_cast<InputImageType*>(this->GetInput());
  OutputImagePointerType outputPtr = this->GetOutput();

  itk::ZeroFluxNeumannBoundaryCondition<TInputImage> nbc;
  RadiusType                                         r;
  r[0] = m_NeighborhoodRadius[0];
  r[1] = m_NeighborhoodRadius[1];

  NeighborhoodIteratorType                                                                     it;
  typename itk::NeighborhoodAlgorithm::ImageBoundaryFacesCalculator<TInputImage>::FaceListType faceList;
  typename itk::NeighborhoodAlgorithm::ImageBoundaryFacesCalculator<TInputImage>               bC;
  faceList = bC(inputPtr, outputRegionForThread, r);
  typename itk::NeighborhoodAlgorithm::ImageBoundaryFacesCalculator<TInputImage>::FaceListType::iterator fit;

  itk::ImageRegionIterator<OutputImageType> itOut(outputPtr, outputRegionForThread);

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

  typename InputImageType::IndexType index;

  for (fit = faceList.begin(); fit != faceList.end(); ++fit)
  {
    it = itk::ConstNeighborhoodIterator<TInputImage>(r, inputPtr, *fit);

    itOut = itk::ImageRegionIterator<TOutputImage>(outputPtr, *fit);
    it.OverrideBoundaryCondition(&nbc);
    it.GoToBegin();

    while (!itOut.IsAtEnd())
    {
      index = it.GetIndex();

      if (outputRegionForThread.IsInside(index))
      {
        itOut.Set(m_CountFunction->EvaluateAtIndex(index));
      }

      ++itOut;
      ++it;
      progress.CompletedPixel(); // potential exception thrown here
    }
  }
}

/** PrintSelf method */
template <class TInputImage, class TOutputImage, class TCountFunction>
void BinaryImageToDensityImageFilter<TInputImage, TOutputImage, TCountFunction>::PrintSelf(std::ostream& os, itk::Indent indent) const
{
  Superclass::PrintSelf(os, indent);
  os << indent << "Neighborhood Radius : " << m_NeighborhoodRadius << std::endl;
}
} // End namespace otb
#endif
