/*=========================================================================
 *
 *  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 itkVectorNeighborhoodInnerProduct_h
#define itkVectorNeighborhoodInnerProduct_h

#include "itkNeighborhoodIterator.h"
#include "itkVector.h"
#include "itkConstSliceIterator.h"
#include "itkImageBoundaryCondition.h"

namespace itk
{
/** \class VectorNeighborhoodInnerProduct
 *  \brief Defines the inner product operation between an itk::Neighborhood
 *         and an itk::NeighborhoodOperator.
 *
 * This is an explicit implementation of what should really be a partial
 * template specialization of NeighborhoodInnerProduct for itkVector.
 *
 * This class defines the inner product operation between an itk::Neighborhood
 * and and itk::NeighborhoodOperator.  The operator() method is overloaded
 * to support various types of neighborhoods as well as inner products with
 * slices of neighborhoods.
 *
 * \ingroup Operators
 *
 * \ingroup ITKCommon
 */
template <typename TImage>
class ITK_TEMPLATE_EXPORT VectorNeighborhoodInnerProduct
{
public:
  /** Standard type alias */
  using Self = VectorNeighborhoodInnerProduct;

  static constexpr unsigned int ImageDimension = TImage::ImageDimension;

  /** Extract the pixel type and scalar type from the image template parameter.
   */
  using PixelType = typename TImage::PixelType;
  using ScalarValueType = typename PixelType::ValueType;
  using NeighborhoodType = Neighborhood<PixelType, Self::ImageDimension>;

  /** Extract the image and vector dimension from the image template parameter.
   */
  static constexpr unsigned int VectorDimension = PixelType::Dimension;

  /** Operator type alias */
  using OperatorType = Neighborhood<ScalarValueType, Self::ImageDimension>;

  /** Conversion operator. */
  PixelType
  operator()(const std::slice & s, const ConstNeighborhoodIterator<TImage> & it, const OperatorType & op) const;

  /** Conversion operator. */
  PixelType
  operator()(const ConstNeighborhoodIterator<TImage> & it, const OperatorType & op) const
  {
    return this->operator()(std::slice(0, it.Size(), 1), it, op);
  }

  PixelType
  operator()(const std::slice & s, const NeighborhoodType & it, const OperatorType & op) const;
};
} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkVectorNeighborhoodInnerProduct.hxx"
#endif

#endif
