/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/
// The example tests the class itk::Statistics::JointDomainImageToListSampleAdaptor.


#include "itkJointDomainImageToListSampleAdaptor.h"
#include "itkImageRegionIteratorWithIndex.h"
#include "itkMath.h"

int
itkJointDomainImageToListSampleAdaptorTest(int, char *[])
{
  constexpr unsigned int MeasurementVectorSize = 8;
  using MeasurementComponentType = unsigned long;
  using PixelType = itk::FixedArray<MeasurementComponentType, MeasurementVectorSize>;

  constexpr unsigned int ImageDimension = 3;
  using ImageType = itk::Image<PixelType, ImageDimension>;

  auto image = ImageType::New();

  ImageType::IndexType start;
  ImageType::SizeType  size;

  start.Fill(0);
  size.Fill(10);

  unsigned long         totalSize = size[0] * size[1] * size[2];
  ImageType::RegionType region(start, size);
  image->SetRegions(region);
  image->Allocate();

  using RegionIteratorType = itk::ImageRegionIteratorWithIndex<ImageType>;

  RegionIteratorType it(image, region);

  it.GoToBegin();

  while (!it.IsAtEnd())
  {
    PixelType value;
    for (unsigned int i = 0; i < MeasurementVectorSize; ++i)
    {
      value[i] = i + it.GetIndex()[0];
    }
    it.Set(value);
    ++it;
  }

  // define an adaptor type
  using JointDomainImageToListSampleAdaptorType = itk::Statistics::JointDomainImageToListSampleAdaptor<ImageType>;
  auto adaptor = JointDomainImageToListSampleAdaptorType::New();
  // Test if the methods throw exceptions if invoked before setting the image
  try
  {
    // calling Size() method prematurely in order to trigger an exception.
    adaptor->Size();
    std::cerr << "Exception should have been thrown since the input image is not set yet" << std::endl;
  }
  catch (const itk::ExceptionObject & excp)
  {
    std::cerr << "Caught expected exception: " << excp << std::endl;
  }
  try
  {
    // calling GetTotalFrequency() method prematurely in order to trigger an exception.
    adaptor->GetTotalFrequency();
    std::cerr << "Exception should have been thrown since the input image is not set yet" << std::endl;
  }
  catch (const itk::ExceptionObject & excp)
  {
    std::cerr << "Caught expected exception: " << excp << std::endl;
  }

  try
  {
    // calling GetMeasurementVector() method prematurely in order to trigger an exception.
    adaptor->GetMeasurementVector(0);
    std::cerr << "Exception should have been thrown since the input image is not set yet" << std::endl;
  }
  catch (const itk::ExceptionObject & excp)
  {
    std::cerr << "Caught expected exception: " << excp << std::endl;
  }

  try
  {
    // calling GetImage() method prematurely in order to trigger an exception.
    adaptor->GetImage();
    std::cerr << "Exception should have been thrown since the input image is not set yet" << std::endl;
  }
  catch (const itk::ExceptionObject & excp)
  {
    std::cerr << "Caught expected exception: " << excp << std::endl;
  }

  try
  {
    // calling GetFrequency() method prematurely in order to trigger an exception.
    adaptor->GetFrequency(0);
    std::cerr << "Exception should have been thrown since the input image is not set yet" << std::endl;
  }
  catch (const itk::ExceptionObject & excp)
  {
    std::cerr << "Caught expected exception: " << excp << std::endl;
  }


  adaptor->SetImage(image);

  // check size
  if (totalSize != adaptor->Size())
  {
    std::cerr << "Size() is not returning the correct size" << std::endl;
    return EXIT_FAILURE;
  }

  // check frequency
  if (totalSize != adaptor->GetTotalFrequency())
  {
    std::cerr << "GetTotalFrequency() is not returning the correct frequency" << std::endl;
    return EXIT_FAILURE;
  }


  adaptor->Print(std::cout);

  ImageType::IndexType index;
  ImageType::PixelType pixel;

  JointDomainImageToListSampleAdaptorType::InstanceIdentifier iid;
  using MeasurementVectorType = JointDomainImageToListSampleAdaptorType::MeasurementVectorType;
  JointDomainImageToListSampleAdaptorType::PointType tempPoint;


  MeasurementVectorType measurementVector;

  for (unsigned int i = 0; i < size[2]; ++i)
  {
    for (unsigned int j = 0; j < size[1]; ++j)
    {
      for (unsigned int k = 0; k < size[0]; ++k)
      {
        index[0] = k;
        index[1] = j;
        index[2] = i;

        adaptor->GetImage()->TransformIndexToPhysicalPoint(index, tempPoint);

        pixel = adaptor->GetImage()->GetPixel(index);

        measurementVector[0] = tempPoint[0];
        measurementVector[1] = tempPoint[1];
        measurementVector[2] = tempPoint[2];
        measurementVector[3] = pixel[0];
        measurementVector[4] = pixel[1];
        measurementVector[5] = pixel[2];

        iid = adaptor->GetImage()->ComputeOffset(index);

        MeasurementVectorType measurementVectorFromAdaptor = adaptor->GetMeasurementVector(iid);
        for (unsigned int m = 0; m < 5; ++m)
        {
          if (!itk::Math::FloatAlmostEqual(measurementVectorFromAdaptor[m], measurementVector[m], 4, 1.0E-6))
          {
            std::cerr << "Error in measurement vector value accessed using the adaptor "
                      << (measurementVectorFromAdaptor[m] - measurementVector[m]) << std::endl;
            return EXIT_FAILURE;
          }
        }
      }
    }
  }

  // Test the Use_PixelContainer boolean

  adaptor->SetUsePixelContainer(false);
  if (adaptor->GetUsePixelContainer() != false)
  {
    std::cerr << "Error in Set/Get UsePixelContainer methods" << std::endl;
    return EXIT_FAILURE;
  }

  adaptor->UsePixelContainerOn();
  if (adaptor->GetUsePixelContainer() != true)
  {
    std::cerr << "Error in Set/Get UsePixelContainerOn method" << std::endl;
    return EXIT_FAILURE;
  }

  // Get measurement vector from the pixel container and using ComputeIndex and compare
  // the result
  JointDomainImageToListSampleAdaptorType::MeasurementVectorType v1 = adaptor->GetMeasurementVector(4);
  adaptor->UsePixelContainerOff();
  JointDomainImageToListSampleAdaptorType::MeasurementVectorType v2 = adaptor->GetMeasurementVector(4);

  const double epsilon = 1e-3;

  for (unsigned int m = 0; m < 5; ++m)
  {
    if (!itk::Math::FloatAlmostEqual(v1[m], v2[m], 4, epsilon))
    {
      std::cerr << "Accessing the measurement vector using the two method produced different result " << std::endl;
      return EXIT_FAILURE;
    }
  }

  // Exercise GetFrequency method on the first and last element
  if (adaptor->GetFrequency(0) != 1 || adaptor->GetFrequency(adaptor->Size()) != 1)
  {
    std::cerr << "GetFrequency is not returning the expected value: " << std::endl;
    return EXIT_FAILURE;
  }

  // iterator tests
  //
  std::cerr << "Iterators..." << std::endl;
  {
    // forward iterator
    using IteratorType = JointDomainImageToListSampleAdaptorType::Iterator;

    IteratorType s_iter = adaptor->Begin();

    // copy constructor
    IteratorType bs_iter(s_iter);
    if (bs_iter != s_iter)
    {
      std::cerr << "Iterator::Copy Constructor failed" << std::endl;
      return EXIT_FAILURE;
    }

    // assignment operator
    IteratorType assignment_iter(bs_iter);
    assignment_iter = s_iter;
    if (assignment_iter != s_iter)
    {
      std::cerr << "Iterator::assignment operator failed" << std::endl;
      return EXIT_FAILURE;
    }

    JointDomainImageToListSampleAdaptorType::InstanceIdentifier iid2 = 0;
    while (s_iter != adaptor->End())
    {
      if (adaptor->GetMeasurementVector(iid2) != s_iter.GetMeasurementVector())
      {
        std::cerr << "Iterator::GetMeasurementVector (forward) failed" << std::endl;
        return EXIT_FAILURE;
      }
      if (iid2 != s_iter.GetInstanceIdentifier())
      {
        std::cerr << "Iterator::GetInstanceIdentifier (forward) failed" << std::endl;
        return EXIT_FAILURE;
      }
      if (s_iter.GetFrequency() != 1)
      {
        std::cerr << "Iterator::GetFrequency (forward) failed" << std::endl;
        return EXIT_FAILURE;
      }
      if (adaptor->GetFrequency(iid2) != 1)
      {
        std::cerr << "GetFrequency (forward) failed" << std::endl;
        return EXIT_FAILURE;
      }
      ++iid2;
      ++s_iter;
    }

    if (s_iter != adaptor->End())
    {
      std::cerr << "Iterator::End (forward) failed" << std::endl;
      return EXIT_FAILURE;
    }
  }


  // Test the iterators
  std::cerr << "Const Iterators..." << std::endl;
  {
    // forward iterator
    using ConstIteratorType = JointDomainImageToListSampleAdaptorType::ConstIterator;

    ConstIteratorType s_iter = adaptor->Begin();

    // copy constructor
    ConstIteratorType bs_iter(s_iter);
    if (bs_iter != s_iter)
    {
      std::cerr << "Iterator::Copy Constructor (from const) failed" << std::endl;
      return EXIT_FAILURE;
    }

    // assignment operator
    ConstIteratorType assignment_iter(bs_iter);
    assignment_iter = s_iter;
    if (assignment_iter != s_iter)
    {
      std::cerr << "Const Iterator::operator= () failed" << std::endl;
      return EXIT_FAILURE;
    }

    // copy from non-const iterator
    JointDomainImageToListSampleAdaptorType::Iterator      nonconst_iter = adaptor->Begin();
    JointDomainImageToListSampleAdaptorType::ConstIterator s2_iter(nonconst_iter);
    if (s2_iter != s_iter)
    {
      std::cerr << "Iterator::Copy Constructor (from non-const) failed" << std::endl;
      return EXIT_FAILURE;
    }
    // assignment from non-const iterator
    s2_iter = nonconst_iter;
    if (s2_iter != s_iter)
    {
      std::cerr << "Iterator::assignment (from non-const) failed" << std::endl;
      return EXIT_FAILURE;
    }

    JointDomainImageToListSampleAdaptorType::InstanceIdentifier iid3 = 0;
    while (s_iter != adaptor->End())
    {
      if (adaptor->GetMeasurementVector(iid3) != s_iter.GetMeasurementVector())
      {
        std::cerr << "Iterator::GetMeasurementVector (forward) failed" << std::endl;
        return EXIT_FAILURE;
      }
      if (iid3 != s_iter.GetInstanceIdentifier())
      {
        std::cerr << "Iterator::GetInstanceIdentifier (forward) failed" << std::endl;
        return EXIT_FAILURE;
      }
      if (s_iter.GetFrequency() != 1)
      {
        std::cerr << "Iterator::GetFrequency (forward) failed" << std::endl;
        return EXIT_FAILURE;
      }
      ++iid3;
      ++s_iter;
    }

    if (s_iter != adaptor->End())
    {
      std::cerr << "Iterator::End (forward) failed" << std::endl;
      return EXIT_FAILURE;
    }
  }


  std::cerr << "[PASSED]" << std::endl;
  return EXIT_SUCCESS;
}
