/*=========================================================================
 *
 *  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 itkVectorExpandImageFilter_hxx
#define itkVectorExpandImageFilter_hxx

#include "itkImageRegionIteratorWithIndex.h"
#include "itkObjectFactory.h"
#include "itkNumericTraits.h"
#include "itkTotalProgressReporter.h"
#include "itkMath.h"

#if !defined(ITK_LEGACY_REMOVE)
namespace itk
{
template <typename TInputImage, typename TOutputImage>
VectorExpandImageFilter<TInputImage, TOutputImage>::VectorExpandImageFilter()
{
  // Set default factors to 1
  for (unsigned int j = 0; j < ImageDimension; ++j)
  {
    m_ExpandFactors[j] = 1;
  }

  // Setup the default interpolator
  auto interp = DefaultInterpolatorType::New();

  m_Interpolator = static_cast<InterpolatorType *>(interp.GetPointer());
  this->DynamicMultiThreadingOn();
  this->ThreaderUpdateProgressOff();
}


template <typename TInputImage, typename TOutputImage>
void
VectorExpandImageFilter<TInputImage, TOutputImage>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);

  unsigned int j;
  os << indent << "ExpandFactors: [";
  for (j = 0; j < ImageDimension - 1; ++j)
  {
    os << m_ExpandFactors[j] << ", ";
  }
  os << m_ExpandFactors[j] << ']' << std::endl;

  os << indent << "Interpolator: ";
  os << m_Interpolator.GetPointer() << std::endl;
}


template <typename TInputImage, typename TOutputImage>
void
VectorExpandImageFilter<TInputImage, TOutputImage>::SetExpandFactors(const float factor)
{
  unsigned int j;

  for (j = 0; j < ImageDimension; ++j)
  {
    if (Math::NotExactlyEquals(factor, m_ExpandFactors[j]))
    {
      break;
    }
  }
  if (j < ImageDimension)
  {
    this->Modified();
    for (j = 0; j < ImageDimension; ++j)
    {
      m_ExpandFactors[j] = factor;
      if (m_ExpandFactors[j] < 1)
      {
        m_ExpandFactors[j] = 1;
      }
    }
  }
}


template <typename TInputImage, typename TOutputImage>
void
VectorExpandImageFilter<TInputImage, TOutputImage>::BeforeThreadedGenerateData()
{
  if (!m_Interpolator || !this->GetInput())
  {
    itkExceptionMacro("Interpolator and/or Input not set");
  }

  // Connect input image to interpolator
  m_Interpolator->SetInputImage(this->GetInput());
}


template <typename TInputImage, typename TOutputImage>
void
VectorExpandImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerateData(
  const OutputImageRegionType & outputRegionForThread)
{
  OutputImagePointer outputPtr = this->GetOutput();
  using OutputIterator = ImageRegionIteratorWithIndex<TOutputImage>;

  TotalProgressReporter progress(this, outputPtr->GetRequestedRegion().GetNumberOfPixels());

  // Define a few indices that will be used to translate from an input
  // pixel to and output pixel
  typename TOutputImage::IndexType               outputIndex;
  typename InterpolatorType::ContinuousIndexType inputIndex;

  using InterpolatedType = typename InterpolatorType::OutputType;

  OutputPixelType  outputValue;
  InterpolatedType interpolatedValue;

  // Walk the output region, and interpolate the input image
  for (OutputIterator outIt(outputPtr, outputRegionForThread); !outIt.IsAtEnd(); ++outIt)
  {
    // Determine the index of the output pixel
    outputIndex = outIt.GetIndex();

    // Determine the input pixel location associated with this output pixel.
    // Don't need to check for division by zero because the factors are
    // clamped to be minimum for 1.
    for (unsigned int j = 0; j < ImageDimension; ++j)
    {
      inputIndex[j] = (static_cast<double>(outputIndex[j]) + 0.5) / static_cast<double>(m_ExpandFactors[j]) - 0.5;
    }

    // interpolate value and write to output
    if (m_Interpolator->IsInsideBuffer(inputIndex))
    {
      interpolatedValue = m_Interpolator->EvaluateAtContinuousIndex(inputIndex);

      for (unsigned int k = 0; k < VectorDimension; ++k)
      {
        outputValue[k] = static_cast<OutputValueType>(interpolatedValue[k]);
      }

      outIt.Set(outputValue);
    }
    else
    {
      itkExceptionMacro("Interpolator outside buffer should never occur ");
    }
    progress.CompletedPixel();
  }
}


template <typename TInputImage, typename TOutputImage>
void
VectorExpandImageFilter<TInputImage, TOutputImage>::GenerateInputRequestedRegion()
{
  Superclass::GenerateInputRequestedRegion();

  InputImagePointer  inputPtr = const_cast<TInputImage *>(this->GetInput());
  OutputImagePointer outputPtr = this->GetOutput();

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

  // We need to compute the input requested region (size and start index)
  unsigned int                             i;
  const typename TOutputImage::SizeType &  outputRequestedRegionSize = outputPtr->GetRequestedRegion().GetSize();
  const typename TOutputImage::IndexType & outputRequestedRegionStartIndex = outputPtr->GetRequestedRegion().GetIndex();

  typename TInputImage::SizeType  inputRequestedRegionSize;
  typename TInputImage::IndexType inputRequestedRegionStartIndex;

  // inputRequestedSize = (outputRequestedSize / ExpandFactor) + 1)
  // The extra 1 above is to take care of edge effects when streaming.
  for (i = 0; i < TInputImage::ImageDimension; ++i)
  {
    inputRequestedRegionSize[i] = (SizeValueType)std::ceil(static_cast<double>(outputRequestedRegionSize[i]) /
                                                           static_cast<double>(m_ExpandFactors[i])) +
                                  1;

    inputRequestedRegionStartIndex[i] = (IndexValueType)std::floor(
      static_cast<double>(outputRequestedRegionStartIndex[i]) / static_cast<double>(m_ExpandFactors[i]));
  }

  typename TInputImage::RegionType inputRequestedRegion;
  inputRequestedRegion.SetSize(inputRequestedRegionSize);
  inputRequestedRegion.SetIndex(inputRequestedRegionStartIndex);

  // 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
VectorExpandImageFilter<TInputImage, TOutputImage>::GenerateOutputInformation()
{
  Superclass::GenerateOutputInformation();

  InputImagePointer  inputPtr = const_cast<TInputImage *>(this->GetInput());
  OutputImagePointer outputPtr = this->GetOutput();

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

  // We need to compute the output spacing, the output image size, and the
  // output image start index
  const typename InputImageType::SpacingType & inputSpacing = inputPtr->GetSpacing();
  const typename TInputImage::SizeType &       inputSize = inputPtr->GetLargestPossibleRegion().GetSize();
  const typename TInputImage::IndexType &      inputStartIndex = inputPtr->GetLargestPossibleRegion().GetIndex();
  const typename TInputImage::PointType &      inputOrigin = inputPtr->GetOrigin();

  typename OutputImageType::SpacingType outputSpacing;
  typename TOutputImage::SizeType       outputSize;
  typename TOutputImage::IndexType      outputStartIndex;
  typename TOutputImage::PointType      outputOrigin;

  typename TInputImage::SpacingType inputOriginShift;

  for (unsigned int i = 0; i < TOutputImage::ImageDimension; ++i)
  {
    outputSpacing[i] = inputSpacing[i] / static_cast<float>(m_ExpandFactors[i]);
    outputSize[i] = (SizeValueType)(static_cast<float>(inputSize[i]) * m_ExpandFactors[i] + 0.5f);
    outputStartIndex[i] = (IndexValueType)(static_cast<float>(inputStartIndex[i]) * m_ExpandFactors[i] + 0.5f);
    const double fraction = static_cast<double>(m_ExpandFactors[i] - 1) / static_cast<double>(m_ExpandFactors[i]);
    inputOriginShift[i] = -(inputSpacing[i] / 2.0) * fraction;
  }
  const typename TInputImage::DirectionType inputDirection = inputPtr->GetDirection();
  const typename TOutputImage::SpacingType  outputOriginShift = inputDirection * inputOriginShift;

  outputOrigin = inputOrigin + outputOriginShift;

  outputPtr->SetSpacing(outputSpacing);
  outputPtr->SetOrigin(outputOrigin);

  const typename TOutputImage::RegionType outputLargestPossibleRegion(outputStartIndex, outputSize);

  outputPtr->SetLargestPossibleRegion(outputLargestPossibleRegion);
}
} // end namespace itk
#endif // ITK_LEGACY_REMOVE

#endif
