/*=========================================================================
 *
 *  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 itkNeighborhoodOperatorImageFilter_hxx
#define itkNeighborhoodOperatorImageFilter_hxx

#include "itkNeighborhoodOperatorImageFilter.h"

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

namespace itk
{
template< typename TInputImage, typename TOutputImage, typename TOperatorValueType >
void
NeighborhoodOperatorImageFilter< TInputImage, TOutputImage, TOperatorValueType >
::GenerateInputRequestedRegion()
{
  // call the superclass' implementation of this method. this should
  // copy the output requested region to the input requested region
  Superclass::GenerateInputRequestedRegion();

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

  if ( !inputPtr )
    {
    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_Operator.GetRadius() );

  // 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, typename TOperatorValueType >
void
NeighborhoodOperatorImageFilter< TInputImage, TOutputImage, TOperatorValueType >
::DynamicThreadedGenerateData(const OutputImageRegionType & outputRegionForThread)
{
  using BFC = NeighborhoodAlgorithm::ImageBoundaryFacesCalculator<InputImageType>;
  using FaceListType = typename BFC::FaceListType;

  NeighborhoodInnerProduct< InputImageType, OperatorValueType, ComputingPixelType > smartInnerProduct;
  BFC faceCalculator;
  FaceListType faceList;

  OutputImageType *output = this->GetOutput();
  const InputImageType *input   = this->GetInput();

  // Break the input into a series of regions.  The first region is free
  // of boundary conditions, the rest with boundary conditions. Note,
  // we pass in the input image and the OUTPUT requested region. We are
  // only concerned with centering the neighborhood operator at the
  // pixels that correspond to output pixels.
  faceList = faceCalculator( input, outputRegionForThread, m_Operator.GetRadius() );

  typename FaceListType::iterator fit;
  ImageRegionIterator< OutputImageType > it;

  // Process non-boundary region and each of the boundary faces.
  // These are N-d regions which border the edge of the buffer.
  ConstNeighborhoodIterator< InputImageType > bit;
  for ( fit = faceList.begin(); fit != faceList.end(); ++fit )
    {
    bit = ConstNeighborhoodIterator< InputImageType >(m_Operator.GetRadius(), input, *fit);
    bit.OverrideBoundaryCondition(m_BoundsCondition);
    it = ImageRegionIterator< OutputImageType >(output, *fit);
    bit.GoToBegin();
    while ( !bit.IsAtEnd() )
      {
      it.Value() = static_cast< typename OutputImageType::PixelType >( smartInnerProduct(bit, m_Operator) );
      ++bit;
      ++it;
      }
    }
}
} // end namespace itk

#endif
