/*=========================================================================
 *
 *  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 itkGPUNeighborhoodOperatorImageFilter_hxx
#define itkGPUNeighborhoodOperatorImageFilter_hxx

#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
GPUNeighborhoodOperatorImageFilter< 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, typename TParentImageFilter>
GPUNeighborhoodOperatorImageFilter<TInputImage, TOutputImage, TOperatorValueType, TParentImageFilter>::
  GPUNeighborhoodOperatorImageFilter()
{
  // Create GPU buffer to store neighborhood coefficient.
  // This will be used as __constant memory in the GPU kernel.
  m_NeighborhoodGPUBuffer = NeighborhoodGPUBufferType::New();

  std::ostringstream defines;

  if (TInputImage::ImageDimension > 3 || TInputImage::ImageDimension < 1)
  {
    itkExceptionMacro("GPUneighborhoodOperatorImageFilter supports 1/2/3D image.");
  }

  defines << "#define DIM_" << TInputImage::ImageDimension << '\n';

  defines << "#define INTYPE ";
  GetTypenameInString(typeid(typename TInputImage::PixelType), defines);

  defines << "#define OUTTYPE ";
  GetTypenameInString(typeid(typename TOutputImage::PixelType), defines);

  defines << "#define OPTYPE ";
  GetTypenameInString(typeid(TOperatorValueType), defines);

  const char * GPUSource = GPUNeighborhoodOperatorImageFilter::GetOpenCLSource();

  // load and build program
  this->m_GPUKernelManager->LoadProgramFromString(GPUSource, defines.str().c_str());

  // create kernel
  m_NeighborhoodOperatorFilterGPUKernelHandle = this->m_GPUKernelManager->CreateKernel("NeighborOperatorFilter");
}

template <typename TInputImage, typename TOutputImage, typename TOperatorValueType, typename TParentImageFilter>
void
GPUNeighborhoodOperatorImageFilter<TInputImage, TOutputImage, TOperatorValueType, TParentImageFilter>::SetOperator(
  const OutputNeighborhoodType & p)
{
  /** Call CPU SetOperator */
  CPUSuperclass::SetOperator(p);

  /** Create GPU memory for operator coefficients */
  m_NeighborhoodGPUBuffer->Initialize();

  typename NeighborhoodGPUBufferType::IndexType index;
  typename NeighborhoodGPUBufferType::SizeType  size;

  for (unsigned int i = 0; i < ImageDimension; ++i)
  {
    index[i] = 0;
    size[i] = static_cast<unsigned int>(p.GetSize(i));
  }
  const typename NeighborhoodGPUBufferType::RegionType region(index, size);

  m_NeighborhoodGPUBuffer->SetRegions(region);
  m_NeighborhoodGPUBuffer->Allocate();

  /** Copy coefficients */
  ImageRegionIterator<NeighborhoodGPUBufferType> iit(m_NeighborhoodGPUBuffer,
                                                     m_NeighborhoodGPUBuffer->GetLargestPossibleRegion());

  typename OutputNeighborhoodType::ConstIterator nit = p.Begin();

  for (iit.GoToBegin(); !iit.IsAtEnd(); ++iit, ++nit)
  {
    iit.Set(static_cast<typename NeighborhoodGPUBufferType::PixelType>(*nit));
  }

  /** Mark GPU dirty */
  m_NeighborhoodGPUBuffer->GetGPUDataManager()->SetGPUBufferDirty();
}

template <typename TInputImage, typename TOutputImage, typename TOperatorValueType, typename TParentImageFilter>
void
GPUNeighborhoodOperatorImageFilter<TInputImage, TOutputImage, TOperatorValueType, TParentImageFilter>::GPUGenerateData()
{
  int kHd = m_NeighborhoodOperatorFilterGPUKernelHandle;

  using GPUInputImage = typename itk::GPUTraits<TInputImage>::Type;
  using GPUOutputImage = typename itk::GPUTraits<TOutputImage>::Type;
  using GPUInputManagerType = GPUImageDataManager<GPUInputImage>;
  using GPUOutputManagerType = GPUImageDataManager<GPUOutputImage>;

  typename GPUInputImage::Pointer  inPtr = dynamic_cast<GPUInputImage *>(this->ProcessObject::GetInput(0));
  typename GPUOutputImage::Pointer otPtr = dynamic_cast<GPUOutputImage *>(this->ProcessObject::GetOutput(0));

  // typename GPUOutputImage::SizeType outSize = otPtr->GetLargestPossibleRegion().GetSize();
  typename GPUOutputImage::SizeType outSize = otPtr->GetBufferedRegion().GetSize();

  int radius[3];
  int imgSize[3];

  radius[0] = radius[1] = radius[2] = 0;
  imgSize[0] = imgSize[1] = imgSize[2] = 1;

  int ImageDim = static_cast<int>(TInputImage::ImageDimension);

  for (int i = 0; i < ImageDim; ++i)
  {
    radius[i] = (this->GetOperator()).GetRadius(i);
    imgSize[i] = outSize[i];
  }

  size_t localSize[3], globalSize[3];
  localSize[0] = localSize[1] = localSize[2] = OpenCLGetLocalBlockSize(ImageDim);
  for (int i = 0; i < ImageDim; ++i)
  {
    // total # of threads
    globalSize[i] =
      localSize[i] * static_cast<unsigned int>(ceil(static_cast<float>(outSize[i]) / static_cast<float>(localSize[i])));
  }

  // arguments set up
  cl_uint argidx = 0;
  this->m_GPUKernelManager->template SetKernelArgWithImageAndBufferedRegion<GPUInputManagerType>(
    kHd, argidx, inPtr->GetModifiableDataManager());
  this->m_GPUKernelManager->template SetKernelArgWithImageAndBufferedRegion<GPUOutputManagerType>(
    kHd, argidx, otPtr->GetModifiableDataManager());
  this->m_GPUKernelManager->SetKernelArgWithImage(kHd, argidx++, m_NeighborhoodGPUBuffer->GetGPUDataManager());

  for (int i = 0; i < static_cast<int>(TInputImage::ImageDimension); ++i)
  {
    this->m_GPUKernelManager->SetKernelArg(kHd, argidx++, sizeof(int), &(radius[i]));
  }

  // for(int i=0; i<static_cast<int>(TInputImage::ImageDimension); i++)
  //  {
  //  this->m_GPUKernelManager->SetKernelArg(kHd, argidx++, sizeof(int), &(imgSize[i]) );
  //  }

  // launch kernel
  this->m_GPUKernelManager->LaunchKernel(kHd, ImageDim, globalSize, localSize);

  /*
  using BFC =
      NeighborhoodAlgorithm::ImageBoundaryFacesCalculator< InputImageType >;

  using FaceListType = typename BFC::FaceListType;

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

  // This filter can only operate on data types that are signed.
   if ( !NumericTraits< typename NumericTraits< OutputPixelType  >::ValueType >::is_signed )
    {
    itkExceptionMacro("This filter can only create images of signed data type.");
    }

  // Allocate output
  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;

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

  // 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;
      progress.CompletedPixel();
      }
    }
    */
}

} // end namespace itk

#endif
