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

/**
 *
 *  This program illustrates the AdaptImageFilter
 *
 *  The example shows how an Accessor can be used to
 *  convert an RGBPixel image to an image that has
 *  just the red component.
 *
 *  That will allow to pass the red component of this
 *  image as input any filter that expects
 *  a float image
 *
 */


#include "itkAdaptImageFilter.h"
#include "itkRedPixelAccessor.h"
#include "itkGreenPixelAccessor.h"
#include "itkBluePixelAccessor.h"
#include "itkSimpleFilterWatcher.h"

#include "vnl/vnl_sample.h"
#include "itkMath.h"


//-------------------------------------
//     Typedefs for convenience
//-------------------------------------
using myRGBImageType = itk::Image<itk::RGBPixel<float>, 2>;
using myRGBIteratorType = itk::ImageRegionIteratorWithIndex<myRGBImageType>;

using myRedAccessorType = itk::RedPixelAccessor<float>;
using myGreenAccessorType = itk::GreenPixelAccessor<float>;
using myBlueAccessorType = itk::BluePixelAccessor<float>;

using myImageType = itk::Image<float, 2>;
using myIteratorType = itk::ImageRegionIteratorWithIndex<myImageType>;

//-------------------------
//
//   Main code
//
//-------------------------
int
itkAdaptImageFilterTest(int, char *[])
{


  myRGBImageType::SizeType size;
  size[0] = 2;
  size[1] = 2;

  myRGBImageType::IndexType index;
  index[0] = 0;
  index[1] = 0;

  myRGBImageType::RegionType region;
  region.SetIndex(index);
  region.SetSize(size);

  auto myImage = myRGBImageType::New();


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

  myRGBIteratorType it1(myImage, myImage->GetRequestedRegion());

  // Value to initialize the pixels
  myRGBImageType::PixelType color;

  // Initializing all the pixel in the image
  it1.GoToBegin();
  while (!it1.IsAtEnd())
  {
    color.Set(static_cast<float>(vnl_sample_uniform(0.0, 1.0)),
              static_cast<float>(vnl_sample_uniform(0.0, 1.0)),
              static_cast<float>(vnl_sample_uniform(0.0, 1.0)));
    it1.Set(color);
    ++it1;
  }

  // Reading the values to verify the image content
  std::cout << "--- Initial image --- " << std::endl;
  it1.GoToBegin();
  while (!it1.IsAtEnd())
  {
    const myRGBImageType::PixelType c(it1.Get());
    std::cout << c.GetRed() << "  ";
    std::cout << c.GetGreen() << "  ";
    std::cout << c.GetBlue() << std::endl;
    ++it1;
  }


  bool passed = true;

  // Convert to a red image
  itk::AdaptImageFilter<myRGBImageType, myImageType, myRedAccessorType>::Pointer adaptImageToRed =
    itk::AdaptImageFilter<myRGBImageType, myImageType, myRedAccessorType>::New();
  itk::SimpleFilterWatcher redWatcher(adaptImageToRed, "Red");
  adaptImageToRed->SetInput(myImage);
  adaptImageToRed->UpdateLargestPossibleRegion();

  myIteratorType it(adaptImageToRed->GetOutput(), adaptImageToRed->GetOutput()->GetRequestedRegion());

  std::cout << "--- Red values --- " << std::endl;

  it.GoToBegin();
  it1.GoToBegin();
  while (!it.IsAtEnd())
  {
    std::cout << it.Get() << std::endl;
    if (itk::Math::NotExactlyEquals(it.Get(), it1.Get().GetRed()))
    {
      passed = false;
    }

    ++it;
    ++it1;
  }

  // Convert to a green image
  itk::AdaptImageFilter<myRGBImageType, myImageType, myGreenAccessorType>::Pointer adaptImageToGreen =
    itk::AdaptImageFilter<myRGBImageType, myImageType, myGreenAccessorType>::New();
  itk::SimpleFilterWatcher greenWatcher(adaptImageToGreen, "Green");

  adaptImageToGreen->SetInput(myImage);
  adaptImageToGreen->UpdateLargestPossibleRegion();

  it = myIteratorType(adaptImageToGreen->GetOutput(), adaptImageToGreen->GetOutput()->GetRequestedRegion());

  std::cout << "--- Green values --- " << std::endl;

  it.GoToBegin();
  it1.GoToBegin();
  while (!it.IsAtEnd())
  {
    std::cout << it.Get() << std::endl;
    if (itk::Math::NotExactlyEquals(it.Get(), it1.Get().GetGreen()))
    {
      passed = false;
    }

    ++it;
    ++it1;
  }

  // Convert to a blue image
  itk::AdaptImageFilter<myRGBImageType, myImageType, myBlueAccessorType>::Pointer adaptImageToBlue =
    itk::AdaptImageFilter<myRGBImageType, myImageType, myBlueAccessorType>::New();
  itk::SimpleFilterWatcher blueWatcher(adaptImageToBlue, "Blue");

  adaptImageToBlue->SetInput(myImage);
  adaptImageToBlue->UpdateLargestPossibleRegion();

  it = myIteratorType(adaptImageToBlue->GetOutput(), adaptImageToBlue->GetOutput()->GetRequestedRegion());

  std::cout << "--- Blue values --- " << std::endl;

  it.GoToBegin();
  it1.GoToBegin();
  while (!it.IsAtEnd())
  {
    std::cout << it.Get() << std::endl;
    if (itk::Math::NotExactlyEquals(it.Get(), it1.Get().GetBlue()))
    {
      passed = false;
    }

    ++it;
    ++it1;
  }

  std::cout << std::endl;
  if (passed)
  {
    std::cout << "AdaptImageFilterTest passed." << std::endl;
    return EXIT_SUCCESS;
  }
  else
  {
    std::cerr << "AdaptImageFilterTest failed." << std::endl;
    return EXIT_FAILURE;
  }
}
