/*=========================================================================
 *
 *  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 "itkLevelSetDenseImage.h"
#include "itkLevelSetDomainMapImageFilter.h"

int
itkMultiLevelSetDenseImageTest(int, char *[])
{
  constexpr unsigned int Dimension = 2;

  using PixelType = float;
  using ImageType = itk::Image<PixelType, Dimension>;
  using LevelSetType = itk::LevelSetDenseImage<ImageType>;
  using IteratorType = itk::ImageRegionIteratorWithIndex<ImageType>;
  using IdListType = std::list<itk::IdentifierType>;
  using IdListImageType = itk::Image<IdListType, Dimension>;
  using CacheImageType = itk::Image<short, Dimension>;
  using DomainMapImageFilterType = itk::LevelSetDomainMapImageFilter<IdListImageType, CacheImageType>;
  ImageType::IndexType index;
  index[0] = 0;
  index[1] = 0;

  ImageType::SizeType size;
  size[0] = 10;
  size[1] = 10;

  ImageType::RegionType region;
  region.SetIndex(index);
  region.SetSize(size);

  PixelType value = 0.;

  auto input1 = ImageType::New();
  input1->SetRegions(region);
  input1->Allocate();
  input1->FillBuffer(value);

  auto input2 = ImageType::New();
  input2->SetRegions(region);
  input2->Allocate();
  input2->FillBuffer(value);

  ImageType::IndexType idx;
  IdListType           list_ids;

  auto id_image = IdListImageType::New();
  id_image->SetRegions(region);
  id_image->Allocate();
  id_image->FillBuffer(list_ids);

  IteratorType it1(input1, input1->GetLargestPossibleRegion());
  IteratorType it2(input2, input2->GetLargestPossibleRegion());
  it1.GoToBegin();
  it2.GoToBegin();

  while (!it1.IsAtEnd())
  {
    idx = it1.GetIndex();
    list_ids.clear();

    if ((idx[0] < 5) && (idx[1] < 5))
    {
      list_ids.push_back(1);
    }

    if ((idx[0] > 1) && (idx[1] > 1) && (idx[0] < 8) && (idx[1] < 8))
    {
      list_ids.push_back(2);
    }

    id_image->SetPixel(idx, list_ids);

    it1.Set(std::sqrt(static_cast<float>((idx[0] - 2) * (idx[0] - 2) + (idx[1] - 2) * (idx[1] - 2))));

    it2.Set(std::sqrt(static_cast<float>((idx[0] - 5) * (idx[0] - 5) + (idx[1] - 5) * (idx[1] - 5))));
    ++it1;
    ++it2;
  }

  std::map<itk::IdentifierType, LevelSetType::Pointer> level_set;
  level_set[1] = LevelSetType::New();
  level_set[1]->SetImage(input1);

  level_set[2] = LevelSetType::New();
  level_set[2]->SetImage(input2);

  auto filter = DomainMapImageFilterType::New();
  filter->SetInput(id_image);
  filter->Update();
  CacheImageType::Pointer output = filter->GetOutput();

  itk::ImageRegionConstIteratorWithIndex<CacheImageType> it(output, output->GetLargestPossibleRegion());

  it.GoToBegin();

  CacheImageType::IndexType out_index;
  CacheImageType::PixelType out_id;

  using DomainMapType = DomainMapImageFilterType::DomainMapType;
  const DomainMapType                 domainMap = filter->GetDomainMap();
  DomainMapType::const_iterator       mapIt;
  const DomainMapType::const_iterator mapEnd = domainMap.end();
  while (!it.IsAtEnd())
  {
    out_index = it.GetIndex();
    out_id = it.Get();

    IdListType solution;
    if ((out_index[0] < 5) && (out_index[1] < 5))
    {
      solution.push_back(1);
    }

    if ((out_index[0] > 1) && (out_index[1] > 1) && (out_index[0] < 8) && (out_index[1] < 8))
    {
      solution.push_back(2);
    }
    solution.sort();

    std::cout << "***" << std::endl;
    std::cout << out_index << std::endl;

    if (out_id != 0)
    {
      mapIt = domainMap.find(out_id);
      if (mapIt != mapEnd)
      {
        const IdListType * lout = mapIt->second.GetIdList();
        std::cout << *(mapIt->second.GetRegion());
        if (lout->empty())
        {
          return EXIT_FAILURE;
        }
        else
        {
          for (const auto & lIt : *lout)
          {
            std::cout << lIt << ' ' << level_set[lIt]->Evaluate(out_index) << std::endl;
          }
          std::cout << std::endl;

          // lout->sort();
          if (*lout != solution)
          {
            std::cerr << "FAILURE!!!" << std::endl;
            return EXIT_FAILURE;
          }
        }
      }
    }
    ++it;
  }

  auto map_it = domainMap.begin();
  auto map_end = domainMap.end();
  while (map_it != map_end)
  {
    const IdListImageType::RegionType temp_region = *(map_it->second.GetRegion());

    itk::ImageRegionConstIteratorWithIndex<IdListImageType> temp_it(id_image, temp_region);
    temp_it.GoToBegin();

    // Iterate through image regions with same list pixels
    while (!temp_it.IsAtEnd())
    {
      std::cout << temp_it.GetIndex() << std::endl;
      const IdListType * lout = map_it->second.GetIdList();

      if (lout->empty())
      {
        return EXIT_FAILURE;
      }

      // Iterate through all the levelsets at a given pixel location
      for (const auto & lIt : *lout)
      {
        std::cout << lIt << ' ' << level_set[lIt]->Evaluate(temp_it.GetIndex()) << std::endl;
      }
      std::cout << std::endl;
      ++temp_it;
    }
    ++map_it;
  }

  return EXIT_SUCCESS;
}