/*
 * Copyright (C) 2005-2022 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 otbUnaryFunctorNeighborhoodWithOffsetImageFilter_hxx
#define otbUnaryFunctorNeighborhoodWithOffsetImageFilter_hxx

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

namespace otb
{
/**
 * Constructor
 */
template <class TInputImage, class TOutputImage, class TFunction>
UnaryFunctorNeighborhoodWithOffsetImageFilter<TInputImage, TOutputImage, TFunction>::UnaryFunctorNeighborhoodWithOffsetImageFilter()
{
  this->SetNumberOfRequiredInputs(1);
  m_Radius.Fill(1);
  m_Offset.Fill(1);
  m_FunctorList.clear();
}

template <class TInputImage, class TOutputImage, class TFunction>
void UnaryFunctorNeighborhoodWithOffsetImageFilter<TInputImage, TOutputImage, TFunction>::BeforeThreadedGenerateData()
{
  Superclass::BeforeThreadedGenerateData();

  for (itk::ThreadIdType i = 0; i < this->GetNumberOfThreads(); ++i)
  {
    m_FunctorList.push_back(m_Functor);
  }
}

template <class TInputImage, class TOutputImage, class TFunction>
void UnaryFunctorNeighborhoodWithOffsetImageFilter<TInputImage, TOutputImage, TFunction>::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
  InputImageSizeType maxRad;
  maxRad[0] = m_Radius[0] + std::abs(m_Offset[0]);
  maxRad[1] = m_Radius[1] + std::abs(m_Offset[1]);
  inputRequestedRegion.PadByRadius(maxRad);

  // 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;
  }
}

/**
 * ThreadedGenerateData Performs the neighborhood-wise operation
 */
template <class TInputImage, class TOutputImage, class TFunction>
void UnaryFunctorNeighborhoodWithOffsetImageFilter<TInputImage, TOutputImage, TFunction>::ThreadedGenerateData(
    const OutputImageRegionType& outputRegionForThread, itk::ThreadIdType threadId)
{
  itk::ZeroFluxNeumannBoundaryCondition<TInputImage> nbc;
  itk::ZeroFluxNeumannBoundaryCondition<TInputImage> nbcOff;
  // We use dynamic_cast since inputs are stored as DataObjects.  The
  // ImageToImageFilter::GetInput(int) always returns a pointer to a
  // TInputImage so it cannot be used for the second input.
  InputImagePointer  inputPtr  = dynamic_cast<const TInputImage*>(ProcessObjectType::GetInput(0));
  OutputImagePointer outputPtr = this->GetOutput(0);

  itk::ImageRegionIterator<TOutputImage> outputIt;

  // Neighborhood+offset iterator
  RadiusType rOff;
  rOff[0] = m_Radius[0] + std::abs(m_Offset[0]);
  rOff[1] = m_Radius[1] + std::abs(m_Offset[1]);
  NeighborhoodIteratorType neighInputOffIt;
  // Find the data-set boundary "faces"
  typename itk::NeighborhoodAlgorithm::ImageBoundaryFacesCalculator<TInputImage>::FaceListType faceListOff;
  typename itk::NeighborhoodAlgorithm::ImageBoundaryFacesCalculator<TInputImage>               bCOff;
  faceListOff = bCOff(inputPtr, outputRegionForThread, rOff);
  typename itk::NeighborhoodAlgorithm::ImageBoundaryFacesCalculator<TInputImage>::FaceListType::iterator fitOff;

  // support progress methods/callbacks
  itk::ProgressReporter progress(this, threadId, outputRegionForThread.GetNumberOfPixels());

  // Process each of the boundary faces.  These are N-d regions which border
  // the edge of the buffer.
  fitOff = faceListOff.begin();

  while (fitOff != faceListOff.end())
  {
    // Neighborhood+offset iterator
    neighInputOffIt = itk::ConstNeighborhoodIterator<TInputImage>(rOff, inputPtr, *fitOff);
    neighInputOffIt.OverrideBoundaryCondition(&nbcOff);
    neighInputOffIt.GoToBegin();

    outputIt = itk::ImageRegionIterator<TOutputImage>(outputPtr, *fitOff);

    while (!outputIt.IsAtEnd())
    {

      outputIt.Set(m_FunctorList[threadId](neighInputOffIt.GetNeighborhood()));

      ++neighInputOffIt;
      ++outputIt;
      progress.CompletedPixel();
    }
    ++fitOff;
  }
}

} // end namespace otb

#endif
