/*=========================================================================
 *
 *  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 "itkEuclideanDistanceMetric.h"

int
itkEuclideanDistanceMetricTest(int, char *[])
{
  constexpr unsigned int MeasurementVectorSize = 3;

  using MeasurementVectorType = itk::Array<float>;

  using DistanceMetricType = itk::Statistics::EuclideanDistanceMetric<MeasurementVectorType>;

  auto distance = DistanceMetricType::New();

  std::cout << distance->GetNameOfClass() << std::endl;

  distance->Print(std::cout);

  MeasurementVectorType measurementNew;
  itk::NumericTraits<MeasurementVectorType>::SetLength(measurementNew, 3);
  measurementNew[0] = 2.5;
  measurementNew[1] = 3.3;
  measurementNew[2] = 4.0;

  // Attempting to compute distance before setting a measurement vector should
  // throw an exception

  try
  {
    distance->Evaluate(measurementNew);
    std::cerr << "Attempting to compute distance w/o setting measurement vector"
                 "size, Exception should have been thrown"
              << std::endl;
  }
  catch (const itk::ExceptionObject & excp)
  {
    std::cerr << "Exception: " << excp << std::endl;
  }

  distance->SetMeasurementVectorSize(MeasurementVectorSize);

  if (distance->GetMeasurementVectorSize() != MeasurementVectorSize)
  {
    std::cerr << "GetMeasurementVectorSize() Failed !" << std::endl;
    return EXIT_FAILURE;
  }

  // Test if the distance computed is correct
  DistanceMetricType::OriginType origin;
  itk::NumericTraits<DistanceMetricType::OriginType>::SetLength(origin, 3);
  origin[0] = 1.5;
  origin[1] = 2.3;
  origin[2] = 1.0;
  distance->SetOrigin(origin);

  MeasurementVectorType measurement;
  itk::NumericTraits<MeasurementVectorType>::SetLength(measurement, 3);
  measurement[0] = 2.5;
  measurement[1] = 3.3;
  measurement[2] = 4.0;

  double           trueValue = 3.31662;
  double           distanceComputed = distance->Evaluate(measurement);
  constexpr double tolerance = 0.001;

  if (itk::Math::abs(distanceComputed - trueValue) > tolerance)
  {
    std::cerr << "Distance computed not correct: "
              << "truevalue= " << trueValue << "ComputedValue=" << distanceComputed << std::endl;
    return EXIT_FAILURE;
  }

  // Compute distance between two measurement vectors
  MeasurementVectorType measurement2;
  itk::NumericTraits<MeasurementVectorType>::SetLength(measurement2, 3);
  measurement2[0] = 1.5;
  measurement2[1] = 3.5;
  measurement2[2] = 3.5;

  double trueValue2 = 1.136;
  double distanceComputed2 = distance->Evaluate(measurement, measurement2);

  if (itk::Math::abs(distanceComputed2 - trueValue2) > tolerance)
  {
    std::cerr << "Distance computed not correct: "
              << "truevalue= " << trueValue2 << "ComputedValue=" << distanceComputed2 << std::endl;
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}
