/*=========================================================================
 *
 *  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 <iostream>

#include "itkConstNeighborhoodIterator.h"
#include "itkVectorImage.h"

typedef itk::Image< int, 2 >                        ImageType;
typedef ImageType::RegionType                       RegionType;
typedef ImageType::IndexType                        IndexType;
typedef ImageType::SizeType                         SizeType;
typedef itk::ConstNeighborhoodIterator< ImageType > IteratorType;
typedef IteratorType::RadiusType                    RadiusType;

typedef itk::VectorImage< int, 2 >                        VectorImageType;
typedef itk::ConstNeighborhoodIterator< VectorImageType > VectorIteratorType;

static bool TestPrintNeighborhood( IteratorType & p, VectorIteratorType & v )
{
  bool success = true;

  std::cout
    << "Output from operator()(const OffsetType &, const OffsetType &, const NeighborhoodType *) const"
    << std::endl;
  unsigned x, y, i=0;
  for (y = 0; y < p.GetSize()[1]; ++y)
    {
      for (x = 0; x < p.GetSize()[0]; ++x, ++i)
        {
          std::cout << p.GetPixel(i) << " ";
        }
      std::cout << std::endl;
    }

  std::cout
    << "Output from operator()(const OffsetType &, const OffsetType &, const NeighborhoodType *, "
    << "const NeighborhoodAccessorFunctorType &) const"
    << std::endl;

  i = 0;
  for (y = 0; y < v.GetSize()[1]; ++y)
    {
      for (x = 0; x < v.GetSize()[0]; ++x, ++i)
        {
          std::cout << v.GetPixel(i)[0] << " ";
        }
      std::cout << std::endl;
    }

  std::cout
    << "Ouptut from GetPixel( const IndexType & index, const TImage * image ) const"
    << std::endl;

  i = 0;
  for (y = 0; y < p.GetSize()[1]; ++y)
    {
    itk::Index< 2 > index;
    index[1] = p.GetIndex()[1] - p.GetRadius()[1] + y;
    for (x = 0; x < p.GetSize()[0]; ++x, ++i)
      {
      index[0] = p.GetIndex()[0] - p.GetRadius()[0] + x;

      // Access the pixel value through three different methods in the
      // boundary condition.
      int pixel1 = p.GetBoundaryCondition()->GetPixel( index, p.GetImagePointer() );
      int pixel2 = p.GetPixel( i );
      int pixel3 = v.GetPixel( i )[0];

      std::cout << pixel1 << " ";

      // Check agreement of output from three three methods of accessing pixel values.
      if ( pixel1 != pixel2 || pixel2 != pixel3 )
        {
        success = false;
        }

      }
    std::cout << std::endl;
    }

  std::cout << "----" << std::endl;
  if ( !success )
    {
    std::cerr << "Unexpected neighborhood value encountered in neighborhoods printed above."
              << std::endl;
    }

  return success;
}

static bool CheckInputRequestedRegion( const RegionType & imageRegion,
                                       const RegionType & requestedRegion,
                                       const RegionType & expectedRegion )
{
  if ( requestedRegion != expectedRegion )
    {
    std::cerr << "Unexpected input region for request region: " << std::endl;
    std::cerr << imageRegion << std::endl;
    std::cerr << "Got:" << std::endl;
    std::cerr << requestedRegion << std::endl;
    std::cerr << "Expected: " << std::endl;
    std::cerr << expectedRegion << std::endl;

    return false;
    }

  return true;
}

int itkZeroFluxBoundaryConditionTest(int, char* [] )
{
  // Test an image to cover one operator() method.
  ImageType::Pointer image = ImageType::New();
  RegionType imageRegion;
  SizeType imageSize = {{ 5, 5 }};
  IndexType imageIndex = {{ 0, 0 }};
  imageRegion.SetSize( imageSize );
  imageRegion.SetIndex( imageIndex );
  image->SetRegions( imageRegion );
  image->Allocate();

  // Test a vector image to cover the other operator() method.
  VectorImageType::Pointer vectorImage = VectorImageType::New();
  vectorImage->SetRegions( imageRegion );
  vectorImage->SetNumberOfComponentsPerPixel( 1 );
  vectorImage->Allocate();

  ImageType::IndexType pos;
  for ( pos[1] = 0; pos[1] < 5; ++pos[1] )
    {
    for ( pos[0] = 0; pos[0] < 5; ++pos[0] )
      {
      image->SetPixel( pos, pos[0] * 10 + pos[1] );
      VectorImageType::PixelType vectorPixel( 1 );
      vectorPixel[0] = image->GetPixel( pos );
      vectorImage->SetPixel( pos, vectorPixel );
      std::cout << image->GetPixel(pos) << " ";
      }
      std::cout << std::endl;
    }

  RadiusType radius;
  RadiusType radiusTwo;
  radius[0] = radius[1] = 1;
  IteratorType it( radius, image, image->GetRequestedRegion() );
  VectorIteratorType vit( radius, vectorImage, vectorImage->GetRequestedRegion() );

  itk::ZeroFluxNeumannBoundaryCondition< ImageType > bc;
  itk::ZeroFluxNeumannBoundaryCondition< VectorImageType > vbc;

  it.OverrideBoundaryCondition( &bc );
  vit.OverrideBoundaryCondition( &vbc );

  pos[0] = pos[1] = 0;
  it.SetLocation( pos );
  vit.SetLocation( pos );

  for ( it.GoToBegin(), vit.GoToBegin(); !it.IsAtEnd(); ++it, ++vit )
    {
    std::cout << "Index: " << it.GetIndex() << std::endl;
    bool success = TestPrintNeighborhood( it, vit );
    if ( !success )
      {
      return EXIT_FAILURE;
      }
    }

  radiusTwo[0] = radiusTwo[1] = 2;
  IteratorType it2( radiusTwo, image, image->GetRequestedRegion() );
  VectorIteratorType vit2( radiusTwo, vectorImage, vectorImage->GetRequestedRegion() );

  it2.OverrideBoundaryCondition( &bc );
  vit2.OverrideBoundaryCondition( &vbc );

  pos[0] = pos[1] = 0;
  it2.SetLocation( pos );
  vit2.SetLocation( pos );

  for ( it2.GoToBegin(), vit2.GoToBegin(); !it2.IsAtEnd(); ++it2, ++vit2 )
    {
    std::cout << "Index: " << it2.GetIndex() << std::endl;
    bool success = TestPrintNeighborhood(it2, vit2);
    if ( !success )
      {
      return EXIT_FAILURE;
      }
    }

  // Now test the input region calculation
  IndexType  requestIndex;
  SizeType   requestSize;
  RegionType requestRegion;

  IndexType  expectedIndex;
  SizeType   expectedSize;
  RegionType expectedRegion;

  RegionType inputRegion;

  // Test 1
  std::cout << "GetInputRequestedRegion() Test 1" << std::endl;
  requestIndex.Fill( 0 );
  requestSize.Fill( 2 );
  requestRegion.SetIndex( requestIndex );
  requestRegion.SetSize( requestSize );

  expectedRegion = requestRegion;

  inputRegion = bc.GetInputRequestedRegion( imageRegion, requestRegion );
  if ( !CheckInputRequestedRegion( imageRegion, inputRegion, expectedRegion ) )
    {
    std::cerr << "[FAILED]" << std::endl;
    return EXIT_FAILURE;
    }
  std::cout << "[PASSED]" << std::endl;

  // Test 2
  std::cout << "GetInputRequestedRegion() Test 2" << std::endl;
  requestIndex[0] = -2;
  requestIndex[1] =  0;
  requestSize[0]  =  3;
  requestSize[1]  =  2;
  requestRegion.SetIndex( requestIndex );
  requestRegion.SetSize( requestSize );

  expectedIndex[0] = 0;
  expectedIndex[1] = 0;
  expectedSize[0]  = 1;
  expectedSize[1]  = 2;
  expectedRegion.SetIndex( expectedIndex );
  expectedRegion.SetSize( expectedSize );

  inputRegion = bc.GetInputRequestedRegion( imageRegion, requestRegion );
  if ( !CheckInputRequestedRegion( imageRegion, inputRegion, expectedRegion ) )
    {
    std::cerr << "[FAILED]" << std::endl;
    return EXIT_FAILURE;
    }
  std::cout << "[PASSED]" << std::endl;

  // Test 3
  std::cout << "GetInputRequestedRegion() Test 3" << std::endl;
  requestIndex[0] = -2;
  requestIndex[1] =  8;
  requestSize[0]  =  3;
  requestSize[1]  =  3;
  requestRegion.SetIndex( requestIndex );
  requestRegion.SetSize( requestSize );

  expectedIndex[0] = 0;
  expectedIndex[1] = 4;
  expectedSize[0]  = 1;
  expectedSize[1]  = 1;
  expectedRegion.SetIndex( expectedIndex );
  expectedRegion.SetSize( expectedSize );

  inputRegion = bc.GetInputRequestedRegion( imageRegion, requestRegion );
  if ( !CheckInputRequestedRegion( imageRegion, inputRegion, expectedRegion ) )
    {
    std::cerr << "[FAILED]" << std::endl;
    return EXIT_FAILURE;
    }
  std::cout << "[PASSED]" << std::endl;

  // Other boundary condition tests
  if ( bc.RequiresCompleteNeighborhood() != true )
    {
    std::cerr << "RequiresCompleteNeighborhood() expected to return true, got false instead."
              << std::endl;
    return EXIT_FAILURE;
    }

  // Print boundary conditions
  bc.Print( std::cout );
  vbc.Print( std::cout );

  return EXIT_SUCCESS;
}
