/*=========================================================================
 *
 *  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 "itkImage.h"
#include "itkFixedArray.h"
#include "itkImageAlgorithm.h"
#include "itkTransform.h"

template <unsigned int InputDimension>
class TestTransform
{
public:
  using InputPointType = itk::Point<double, InputDimension>;
  using OutputPointType = itk::Point<double, 2>;
  OutputPointType
  TransformPoint(const InputPointType & inputPoint) const
  {
    OutputPointType outputPoint;
    outputPoint.Fill(0.0);
    // if InputPoint Dimension < 2 then embed point in 2D space
    // else project the point to 2D space.
    for (unsigned int d = 0; d < std::min(inputPoint.GetPointDimension(), outputPoint.GetPointDimension()); ++d)
    {
      outputPoint[d] = inputPoint[d];
    }
    return outputPoint;
  }
};


int
itkImageTest(int, char *[])
{

  using Image = itk::Image<float, 2>;
  auto                image = Image::New();
  Image::ConstPointer myconstptr = image;
  image->DebugOn();
  const char * const knownStringName = "My First Image For Testing.";
  image->SetObjectName(knownStringName);
  if (std::string(knownStringName) != image->GetObjectName())
  {
    std::cerr << "ERROR:  Object name not set and recovered correctly.\n"
              << std::string(knownStringName) << " != " << image->GetObjectName() << std::endl;
    return EXIT_FAILURE;
  }
  image->GetSource();
  image->DisconnectPipeline();

  Image::SpacingType spacing;
  spacing.Fill(1.0);
  Image::PointType origin;
  origin.Fill(1.0);
  Image::DirectionType direction;
  direction[0][0] = .5;
  direction[0][1] = .7;
  direction[1][0] = .7;
  direction[1][1] = .5;
  image->SetSpacing(spacing);
  image->SetOrigin(origin);
  image->SetDirection(direction);

  double dspacing[Image::ImageDimension] = { 2.0, 2.0 };
  double dorigin[Image::ImageDimension] = { 2.0, 2.0 };
  image->SetSpacing(dspacing);
  image->SetOrigin(dorigin);

  float fspacing[Image::ImageDimension] = { 3.0, 3.0 };
  float forigin[Image::ImageDimension] = { 3.0, 3.0 };
  image->SetSpacing(fspacing);
  image->SetOrigin(forigin);

  // test inverse direction
  std::cout << "Test inverse direction." << std::endl;
  Image::DirectionType product;
  product = direction * image->GetInverseDirection();
  double eps = 1e-06;
  if (itk::Math::abs(product[0][0] - 1.0) > eps || itk::Math::abs(product[1][1] - 1.0) > eps ||
      itk::Math::abs(product[0][1]) > eps || itk::Math::abs(product[1][0]) > eps)
  {
    std::cerr << "Inverse direction test failed: "
              << "direction * inverse: " << product << std::endl;
    return EXIT_FAILURE;
  }

  std::cout << "Test transform to/from physical vector." << std::endl;
  using GradientType = itk::FixedArray<float, 2>;
  GradientType truthGradient, outputGradient, testGradient;
  truthGradient[0] = 1.0;
  truthGradient[1] = 1.0;
  image->TransformLocalVectorToPhysicalVector(truthGradient, outputGradient);
  image->TransformPhysicalVectorToLocalVector(outputGradient, testGradient);
  if (itk::Math::abs(truthGradient[0] - testGradient[0]) > eps ||
      itk::Math::abs(truthGradient[1] - testGradient[1]) > eps)
  {
    std::cerr << "Transform to/from PhysicalVector test failed: "
              << "truthGradient: " << truthGradient << std::endl
              << "testGradient:  " << testGradient << std::endl;
    return EXIT_FAILURE;
  }

  std::cout << "Test GetSmallestRegionContainingRegion." << std::endl;
  image->SetSpacing(spacing);
  origin.Fill(1.2);
  image->SetOrigin(origin);
  direction.SetIdentity();
  image->SetDirection(direction);
  Image::RegionType region;
  Image::IndexType  index;
  index.Fill(0);
  Image::SizeType size;
  size.Fill(4);
  region.SetIndex(index);
  region.SetSize(size);
  image->SetRegions(region);

  auto               imageRef = Image::New();
  Image::SpacingType spacingRef;
  spacingRef.Fill(2);
  Image::PointType originRef;
  originRef.Fill(0);
  Image::DirectionType directionRef;
  directionRef.SetIdentity();
  imageRef->SetSpacing(spacingRef);
  imageRef->SetOrigin(originRef);
  imageRef->SetDirection(directionRef);
  Image::RegionType regionRef;
  Image::IndexType  indexRef;
  Image::SizeType   sizeRef;
  indexRef.Fill(0);
  sizeRef.Fill(5);
  regionRef.SetIndex(indexRef);
  regionRef.SetSize(sizeRef);
  imageRef->SetRegions(regionRef);

  using TransformType = itk::Transform<double, Image::ImageDimension, Image::ImageDimension>;

  Image::RegionType boxRegion = itk::ImageAlgorithm::EnlargeRegionOverBox(image->GetLargestPossibleRegion(),
                                                                          image.GetPointer(),
                                                                          imageRef.GetPointer(),
                                                                          static_cast<TransformType *>(nullptr));
  Image::IndexType  correctIndex;
  correctIndex.Fill(0);
  Image::SizeType correctSize;
  correctSize.Fill(3);
  if (!(boxRegion.GetIndex() == correctIndex) || !(boxRegion.GetSize() == correctSize))
  {
    std::cerr << "EnlargeRegionOverBox test failed: "
              << "boxRegion: " << boxRegion << std::endl;
    return EXIT_FAILURE;
  }

  using Image3D = itk::Image<float, 3>;
  auto                 volume = Image3D::New();
  Image3D::SpacingType spacingVol;
  spacingVol.Fill(1);
  Image3D::PointType originVol;
  originVol.Fill(0);
  Image3D::DirectionType directionVol;
  directionVol.SetIdentity();
  volume->SetSpacing(spacingVol);
  volume->SetOrigin(originVol);
  volume->SetDirection(directionVol);

  Image3D::RegionType cuboid;
  Image3D::IndexType  indexCuboid;
  indexCuboid.Fill(0);
  Image3D::SizeType sizeCuboid;
  sizeCuboid[0] = 1;
  sizeCuboid[1] = 2;
  sizeCuboid[2] = 3;
  cuboid.SetIndex(indexCuboid);
  cuboid.SetSize(sizeCuboid);
  volume->SetRegions(cuboid);

  using ProjectionTransformType = TestTransform<Image3D::ImageDimension>;
  ProjectionTransformType * projectionTransform = new ProjectionTransformType;

  Image::RegionType rectangleRegion = itk::ImageAlgorithm::EnlargeRegionOverBox(
    volume->GetLargestPossibleRegion(), volume.GetPointer(), imageRef.GetPointer(), projectionTransform);

  delete projectionTransform;
  Image::IndexType correctRectangleIndex;
  correctRectangleIndex.Fill(0);
  Image::SizeType correctRectangleSize;
  correctRectangleSize[0] = 1;
  correctRectangleSize[1] = 2;
  if (!(rectangleRegion.GetIndex() == correctRectangleIndex) || !(rectangleRegion.GetSize() == correctRectangleSize))
  {
    std::cerr << "EnlargeRegionOverBox test for projecting transform failed: "
              << "rectangle Region: " << rectangleRegion << std::endl;
    return EXIT_FAILURE;
  }

  using TestIdentityTransformType = TestTransform<Image::ImageDimension>;
  TestIdentityTransformType * testIdentityTransform = new TestIdentityTransformType;

  Image::RegionType tesBoxRegion = itk::ImageAlgorithm::EnlargeRegionOverBox(
    image->GetLargestPossibleRegion(), image.GetPointer(), imageRef.GetPointer(), testIdentityTransform);

  delete testIdentityTransform;

  if (!(tesBoxRegion.GetIndex() == correctIndex) || !(tesBoxRegion.GetSize() == correctSize))
  {
    std::cerr << "EnlargeRegionOverBox test for test Identity failed: "
              << "rectangle Region: " << tesBoxRegion << std::endl;
    return EXIT_FAILURE;
  }

  std::cout << "Print: " << std::endl;
  image->Print(std::cout);

  std::cout << "Test Graft." << std::endl;
  image->Graft(imageRef);
  if (image->GetPixelContainer() != imageRef->GetPixelContainer())
  {
    std::cerr << "Graft test failed." << std::endl;
    return EXIT_FAILURE;
  }

  return (EXIT_SUCCESS);
}