/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/
#ifndef itkSignedDanielssonDistanceMapImageFilter_hxx
#define itkSignedDanielssonDistanceMapImageFilter_hxx

#include "itkSignedDanielssonDistanceMapImageFilter.h"
#include "itkProgressAccumulator.h"
#include "itkBinaryBallStructuringElement.h"
#include "itkBinaryDilateImageFilter.h"
#include "itkUnaryFunctorImageFilter.h"

namespace itk
{
/**
 *    Constructor
 */
template< typename TInputImage, typename TOutputImage, typename TVoronoiImage >
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >
::SignedDanielssonDistanceMapImageFilter()
{
  this->SetNumberOfRequiredOutputs(3);

  // distance map
  this->SetNthOutput( 0,
    static_cast< OutputImageType* >( this->MakeOutput( 0 ).GetPointer() ) );

  // voronoi map
  this->SetNthOutput( 1,
    static_cast< VoronoiImageType* >( this->MakeOutput( 1 ).GetPointer() ) );

  // distance vectors
  this->SetNthOutput( 2,
    static_cast< VectorImageType* >( this->MakeOutput( 2 ).GetPointer() ) );

  //Default values
  this->m_SquaredDistance     = false;  //Should we remove this ?
                                        //doesn't make sense in a SignedDaniel
  this->m_UseImageSpacing     = true;
  this->m_InsideIsPositive    = false;
}

/** This is overloaded to create the VectorDistanceMap output image */
template< typename TInputImage, typename TOutputImage, typename TVoronoiImage >
typename
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >::DataObjectPointer
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >
::MakeOutput(DataObjectPointerArraySizeType idx)
{
  if ( idx == 1 )
    {
    return VoronoiImageType::New().GetPointer();
    }
  if ( idx == 2 )
    {
    return VectorImageType::New().GetPointer();
    }
  return Superclass::MakeOutput(idx);
}

/**
 *  Return the distance map Image pointer
 */
template< typename TInputImage, typename TOutputImage, typename TVoronoiImage >
typename
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >::OutputImageType *
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >
::GetDistanceMap()
{
  return dynamic_cast< OutputImageType * >(
           this->ProcessObject::GetOutput(0) );
}

/**
 *  Return Closest Points Map
 */
template< typename TInputImage, typename TOutputImage, typename TVoronoiImage >
typename
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >::VoronoiImageType *
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >
::GetVoronoiMap()
{
  return dynamic_cast< VoronoiImageType * >(
           this->ProcessObject::GetOutput(1) );
}

/**
 *  Return the distance vectors
 */
template< typename TInputImage, typename TOutputImage, typename TVoronoiImage >
typename
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >::VectorImageType *
SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >
::GetVectorDistanceMap()
{
  return dynamic_cast< VectorImageType * >(
           this->ProcessObject::GetOutput(2) );
}

/**
 *  Compute Distance and Voronoi maps by calling
 * DanielssonDistanceMapImageFilter twice.
 */
template< typename TInputImage, typename TOutputImage, typename TVoronoiImage >
void SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >
::GenerateData()
{
  //Set up mini pipeline filter
  typename ProgressAccumulator::Pointer progress = ProgressAccumulator::New();
  progress->SetMiniPipelineFilter(this);

  using FilterType = DanielssonDistanceMapImageFilter<
    InputImageType, OutputImageType, VoronoiImageType >;
  typename FilterType::Pointer filter1 = FilterType::New();
  typename FilterType::Pointer filter2 = FilterType::New();

  filter1->SetUseImageSpacing(m_UseImageSpacing);
  filter2->SetUseImageSpacing(m_UseImageSpacing);
  filter1->SetSquaredDistance(m_SquaredDistance);
  filter2->SetSquaredDistance(m_SquaredDistance);

  //Invert input image for second Danielsson filter
  using InputPixelType = typename InputImageType::PixelType;
  using FunctorType = Functor::InvertIntensityFunctor< InputPixelType >;
  using InverterType = UnaryFunctorImageFilter< InputImageType,
                                   InputImageType,
                                   FunctorType >;

  typename InverterType::Pointer inverter = InverterType::New();

  inverter->SetInput( this->GetInput() );

  //Dilate the inverted image by 1 pixel to give it the same boundary
  //as the uninverted input.

  using StructuringElementType = BinaryBallStructuringElement<
    InputPixelType,
    InputImageDimension  >;

  using DilatorType = BinaryDilateImageFilter<
    InputImageType,
    InputImageType,
    StructuringElementType >;

  typename DilatorType::Pointer dilator = DilatorType::New();

  StructuringElementType structuringElement;
  structuringElement.SetRadius(1);    // 3x3 structuring element
  structuringElement.CreateStructuringElement();
  dilator->SetKernel(structuringElement);
  dilator->SetDilateValue(1);

  filter1->SetInput( this->GetInput() );
  dilator->SetInput( inverter->GetOutput() );
  filter2->SetInput( dilator->GetOutput() );

  //Subtract Distance maps results of the two Danielsson filters
  using SubtracterType = SubtractImageFilter< OutputImageType, OutputImageType,
                               OutputImageType >;

  typename SubtracterType::Pointer subtracter = SubtracterType::New();

  if ( m_InsideIsPositive )
    {
    subtracter->SetInput1( filter2->GetDistanceMap() );
    subtracter->SetInput2( filter1->GetDistanceMap() );
    }
  else
    {
    subtracter->SetInput2( filter2->GetDistanceMap() );
    subtracter->SetInput1( filter1->GetDistanceMap() );
    }

  subtracter->Update();
  filter1->Update();
  filter2->Update();

  // Register progress
  progress->RegisterInternalFilter(filter1, .5f);

  // Graft outputs
  this->GraftNthOutput( 0, subtracter->GetOutput() );

  // we must use not use this->GetOutput method because the
  // output's are of different types then ImageSource
  this->GraftNthOutput( 1, filter1->GetVoronoiMap() );
  this->GraftNthOutput( 2, filter1->GetVectorDistanceMap() );
}

// end GenerateData()

/**
 *  Print Self
 */
template< typename TInputImage, typename TOutputImage, typename TVoronoiImage >
void SignedDanielssonDistanceMapImageFilter< TInputImage, TOutputImage, TVoronoiImage >
::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);
  os << indent << "Signed Danielson Distance: " << std::endl;
  os << indent << "Use Image Spacing : " << m_UseImageSpacing << std::endl;
  os << indent << "Squared Distance  : " << m_SquaredDistance << std::endl;
  os << indent << "Inside is positive  : " << m_InsideIsPositive << std::endl;
}
} // end namespace itk

#endif
