/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  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
 *
 *         http://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 "itkGaussianSmoothingOnUpdateDisplacementFieldTransform.h"
#include "itkGaussianSmoothingOnUpdateDisplacementFieldTransformParametersAdaptor.h"
#include "itkMath.h"

int itkGaussianSmoothingOnUpdateDisplacementFieldTransformParametersAdaptorTest(int, char * [] )
{
  const unsigned int SpaceDimension = 3;
  typedef double CoordinateRepType;
  typedef itk::GaussianSmoothingOnUpdateDisplacementFieldTransform<CoordinateRepType, SpaceDimension> TransformType;

  /**
   * Define the transformation domain
   */
  typedef TransformType::PointType PointType;
  PointType origin;
  origin.Fill( -5.0 );

  typedef TransformType::SizeType SizeType;
  SizeType size;
  size.Fill( 65 );

  typedef TransformType::SpacingType SpacingType;
  SpacingType spacing;
  spacing.Fill( 1.2 );

  typedef TransformType::DirectionType DirectionType;
  DirectionType direction;
  direction.SetIdentity();

  typedef TransformType::DisplacementFieldType DisplacementFieldType;
  DisplacementFieldType::Pointer displacementField = DisplacementFieldType::New();
  displacementField->SetOrigin( origin );
  displacementField->SetSpacing( spacing );
  displacementField->SetRegions( size );
  displacementField->SetDirection( direction );
  displacementField->Allocate();

  TransformType::OutputVectorType zeroVector;
  zeroVector.Fill( 0 );
  displacementField->FillBuffer( zeroVector );


  TransformType::OutputVectorType nonzeroVector;
  nonzeroVector.Fill( 10.3 );

  DisplacementFieldType::IndexType index;
  index.Fill( 40 );
  displacementField->SetPixel( index, nonzeroVector );

  /**
   * Instantiate a transform
   */
  std::cout << "Initialize transform." << std::endl;

  TransformType::Pointer transform = TransformType::New();
  transform->SetDisplacementField( displacementField );

  TransformType::InputPointType point;
  point.Fill( 50.0 );
  TransformType::OutputPointType outputPointBeforeAdapt = transform->TransformPoint( point );

  SpacingType spacingBefore = transform->GetDisplacementField()->GetSpacing();
  SizeType sizeBefore = transform->GetDisplacementField()->GetLargestPossibleRegion().GetSize();

  /**
   * Instantiate the adaptor
   *   we keep the transform domain definition the same except we increase
   *   the size and decrease the spacing.
   */

  std::cout << "Instantiate adaptor." << std::endl;

  SpacingType requiredSpacing;
  requiredSpacing.Fill( 0.6 );
  SizeType requiredSize;
  for( unsigned int d = 0; d < SpaceDimension; d++ )
    {
    requiredSize[d] = static_cast<SizeType::SizeValueType>
      ( ( spacing[d] * ( size[d] - 1 ) / requiredSpacing[d] ) + 1 );
    }

  typedef itk::GaussianSmoothingOnUpdateDisplacementFieldTransformParametersAdaptor<TransformType> AdaptorType;
  AdaptorType::Pointer adaptor = AdaptorType::New();
  adaptor->SetTransform( transform );
  adaptor->SetRequiredSize( requiredSize );
  adaptor->SetRequiredSpacing( requiredSpacing );
  adaptor->SetRequiredOrigin( displacementField->GetOrigin() );
  adaptor->SetRequiredDirection( displacementField->GetDirection() );
  adaptor->SetGaussianSmoothingVarianceForTheUpdateField( 1.0 );
  adaptor->SetGaussianSmoothingVarianceForTheTotalField( 0.2 );
  try
    {
    adaptor->AdaptTransformParameters();
    }
  catch(...)
    {
    std::cerr << "Error in adapting transform." << std::endl;
    return EXIT_FAILURE;
    }


  SpacingType spacingAfter = transform->GetDisplacementField()->GetSpacing();
  SizeType sizeAfter = transform->GetDisplacementField()->GetLargestPossibleRegion().GetSize();

  std::cout << "Spacing: " << spacingBefore << "(before), " << spacingAfter << "(after)." << std::endl;
  std::cout << "Size: " << sizeBefore << "(before), " << sizeAfter << "(after)." << std::endl;

  TransformType::ParametersType fixedParameters = adaptor->GetRequiredFixedParameters();
  std::cout << "Fixed parameters: " << fixedParameters << std::endl;
  adaptor->SetRequiredFixedParameters( fixedParameters );

  if( adaptor->GetRequiredSize() != transform->GetDisplacementField()->GetLargestPossibleRegion().GetSize() )
    {
    std::cerr << "required size conversion is incorrect." << std::endl;
    return EXIT_FAILURE;
    }
  if( adaptor->GetRequiredSpacing() != transform->GetDisplacementField()->GetSpacing() )
    {
    std::cerr << "required spacing conversion is incorrect." << std::endl;
    return EXIT_FAILURE;
    }
  if( adaptor->GetRequiredOrigin() != transform->GetDisplacementField()->GetOrigin() )
    {
    std::cerr << "required origin conversion is incorrect." << std::endl;
    return EXIT_FAILURE;
    }
  if( adaptor->GetRequiredDirection() != transform->GetDisplacementField()->GetDirection() )
    {
    std::cerr << "required direction conversion is incorrect." << std::endl;
    return EXIT_FAILURE;
    }
  if( itk::Math::NotAlmostEquals( adaptor->GetGaussianSmoothingVarianceForTheUpdateField(),
                                      transform->GetGaussianSmoothingVarianceForTheUpdateField() ) )
    {
    std::cerr << "update field variance conversion is incorrect." << std::endl;
    return EXIT_FAILURE;
    }
  if( itk::Math::NotAlmostEquals( adaptor->GetGaussianSmoothingVarianceForTheTotalField(),
                                      transform->GetGaussianSmoothingVarianceForTheTotalField() ) )
    {
    std::cerr << "total field variance conversion is incorrect." << std::endl;
    return EXIT_FAILURE;
    }

  TransformType::OutputPointType outputPointAfterAdapt = transform->TransformPoint( point );
  std::cout << point << " to (before) " << outputPointBeforeAdapt << std::endl;
  std::cout << point << " to (after) " << outputPointAfterAdapt << std::endl;

  if( outputPointBeforeAdapt.EuclideanDistanceTo( outputPointAfterAdapt ) > 1e-6 )
    {
    std::cerr << "output points don't match up before and after adapt call." << std::endl;
    return EXIT_FAILURE;
    }

  adaptor->Print( std::cout, 5 );

  return EXIT_SUCCESS;
}
