/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/

/**
 * Test program for itkGPUImageToImageFilter class
 *
 * This program creates a GPU Mean filter and a CPU threshold filter using
 * object factory framework and test pipelining of GPU and CPU filters.
 */
//#include "pathToOpenCLSourceCode.h"

#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkMeanImageFilter.h"
#include "itkBinaryThresholdImageFilter.h"

#include "itkGPUImage.h"
#include "itkGPUKernelManager.h"
#include "itkGPUContextManager.h"
#include "itkGPUImageToImageFilter.h"
#include "itkGPUMeanImageFilter.h"

#include <string>

template <unsigned int VImageDimension>
int
runGPUImageFilterTest(const std::string & inFile, const std::string & outFile)
{
  using InputPixelType = unsigned char;
  using OutputPixelType = unsigned char;

  using InputImageType = itk::Image<InputPixelType, VImageDimension>;
  using OutputImageType = itk::Image<OutputPixelType, VImageDimension>;

  using ReaderType = itk::ImageFileReader<InputImageType>;
  using WriterType = itk::ImageFileWriter<OutputImageType>;

  auto reader = ReaderType::New();
  auto writer = WriterType::New();

  reader->SetFileName(inFile);
  writer->SetFileName(outFile);

  //
  // Note: We use regular itk filter type here but factory will automatically create
  //       GPU filter for Median filter and CPU filter for threshold filter.
  //
  using MeanFilterType = itk::MeanImageFilter<InputImageType, OutputImageType>;
  using ThresholdFilterType = itk::BinaryThresholdImageFilter<InputImageType, OutputImageType>;

  auto filter1 = MeanFilterType::New();
  auto filter2 = MeanFilterType::New();
  auto filter3 = ThresholdFilterType::New();

  // Mean filter kernel radius
  typename InputImageType::SizeType indexRadius;
  indexRadius[0] = 2; // radius along x
  indexRadius[1] = 2; // radius along y
  if (VImageDimension > 2)
  {
    indexRadius[2] = 2; // radius along z
  }

  // threshold parameters
  constexpr InputPixelType  upperThreshold = 255;
  constexpr InputPixelType  lowerThreshold = 175;
  constexpr OutputPixelType outsideValue = 0;
  constexpr OutputPixelType insideValue = 255;

  filter1->SetRadius(indexRadius);
  filter2->SetRadius(indexRadius);
  filter3->SetOutsideValue(outsideValue);
  filter3->SetInsideValue(insideValue);
  filter3->SetUpperThreshold(upperThreshold);
  filter3->SetLowerThreshold(lowerThreshold);

  // build pipeline
  filter1->SetInput(reader->GetOutput()); // copy CPU->GPU implicilty
  filter2->SetInput(filter1->GetOutput());
  filter3->SetInput(filter2->GetOutput());
  writer->SetInput(filter3->GetOutput()); // copy GPU->CPU implicilty

  // execute pipeline filter and write output
  writer->Update();

  return EXIT_SUCCESS;
}

int
itkGPUImageFilterTest(int argc, char * argv[])
{

  if (argc < 3)
  {
    std::cerr << "Error: missing arguments" << std::endl;
    std::cerr << "inputfile outputfile [num_dimensions]" << std::endl;
    return EXIT_FAILURE;
  }

  std::string inFile(argv[1]);
  std::string outFile(argv[2]);

  unsigned int dim = 3;
  if (argc >= 4)
  {
    dim = std::stoi(argv[3]);
  }

  if (dim == 2)
  {
    return runGPUImageFilterTest<2>(inFile, outFile);
  }
  else if (dim == 3)
  {
    return runGPUImageFilterTest<3>(inFile, outFile);
  }
  else
  {
    std::cerr << "Error: only 2 or 3 dimensions allowed, " << dim << " selected." << std::endl;
    return EXIT_FAILURE;
  }
}
