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

#include <iostream>
#include "itkRGBPixel.h"
#include "itkComposeImageFilter.h"
#include "itkTestingMacros.h"

int
itkComposeRGBImageFilterTest(int, char *[])
{
  using PixelType = unsigned char;
  using InputImageType = itk::Image<PixelType, 3>;

  using RGBPixelType = itk::RGBPixel<unsigned char>;
  using OutputImageType = itk::Image<RGBPixelType, 3>;


  using FilterType = itk::ComposeImageFilter<InputImageType, OutputImageType>;

  using RegionType = InputImageType::RegionType;
  using SizeType = InputImageType::SizeType;

  auto filter = FilterType::New();

  auto redImage = InputImageType::New();
  auto greenImage = InputImageType::New();
  auto blueImage = InputImageType::New();

  constexpr SizeType size{ 2, 2, 2 };
  RegionType         region{ size };

  redImage->SetRegions(region);
  greenImage->SetRegions(region);
  blueImage->SetRegions(region);

  redImage->Allocate();
  greenImage->Allocate();
  blueImage->Allocate();

  redImage->FillBuffer(29);
  greenImage->FillBuffer(51);
  blueImage->FillBuffer(83);

  filter->SetInput1(redImage);
  filter->SetInput2(greenImage);
  filter->SetInput3(blueImage);

  ITK_TRY_EXPECT_NO_EXCEPTION(filter->Update());

  const OutputImageType::Pointer rgbImage = filter->GetOutput();

  using OutputIterator = itk::ImageRegionIterator<OutputImageType>;
  using InputIterator = itk::ImageRegionIterator<InputImageType>;

  InputIterator ir(redImage, region);
  InputIterator ig(greenImage, region);
  InputIterator ib(blueImage, region);

  OutputIterator ot(rgbImage, region);

  ir.GoToBegin();
  ig.GoToBegin();
  ib.GoToBegin();

  ot.GoToBegin();

  using OutputPixelType = OutputImageType::PixelType;

  while (!ot.IsAtEnd())
  {
    const OutputPixelType outp = ot.Get();
    if (ir.Get() != outp.GetRed())
    {
      std::cerr << "Error in red component" << std::endl;
      return EXIT_FAILURE;
    }
    if (ig.Get() != outp.GetGreen())
    {
      std::cerr << "Error in green component" << std::endl;
      return EXIT_FAILURE;
    }
    if (ib.Get() != outp.GetBlue())
    {
      std::cerr << "Error in blue component" << std::endl;
      return EXIT_FAILURE;
    }
    ++ot;
    ++ir;
    ++ig;
    ++ib;
  }

  std::cout << "Test finished." << std::endl;
  return EXIT_SUCCESS;
}
