/*=========================================================================
 *
 *  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 "itkLevelSetContainer.h"
#include "itkLevelSetEquationChanAndVeseExternalTerm.h"
#include "itkLevelSetEquationTermContainer.h"
#include "itkLevelSetEquationContainer.h"
#include "itkAtanRegularizedHeavisideStepFunction.h"
#include "itkLevelSetEvolution.h"
#include "itkLevelSetEvolutionNumberOfIterationsStoppingCriterion.h"
#include "itkTestingMacros.h"

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

  using InputPixelType = unsigned char;
  using InputImageType = itk::Image<InputPixelType, Dimension>;

  using PixelType = float;
  using ImageType = itk::Image<PixelType, Dimension>;
  using LevelSetType = itk::LevelSetDenseImage<ImageType>;
  using LevelSetOutputRealType = LevelSetType::OutputRealType;
  using IteratorType = itk::ImageRegionIteratorWithIndex<ImageType>;
  using IdentifierType = itk::IdentifierType;
  using IdListType = std::list<IdentifierType>;
  using IdListImageType = itk::Image<IdListType, Dimension>;
  using CacheImageType = itk::Image<short, Dimension>;
  using DomainMapImageFilterType = itk::LevelSetDomainMapImageFilter<IdListImageType, CacheImageType>;

  using LevelSetContainerType = itk::LevelSetContainer<IdentifierType, LevelSetType>;
  using ChanAndVeseInternalTermType =
    itk::LevelSetEquationChanAndVeseInternalTerm<InputImageType, LevelSetContainerType>;
  using ChanAndVeseExternalTermType =
    itk::LevelSetEquationChanAndVeseExternalTerm<InputImageType, LevelSetContainerType>;
  using TermContainerType = itk::LevelSetEquationTermContainer<InputImageType, LevelSetContainerType>;

  using EquationContainerType = itk::LevelSetEquationContainer<TermContainerType>;

  using LevelSetEvolutionType = itk::LevelSetEvolution<EquationContainerType, LevelSetType>;

  using HeavisideFunctionBaseType =
    itk::AtanRegularizedHeavisideStepFunction<LevelSetOutputRealType, LevelSetOutputRealType>;

  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 input = InputImageType::New();
  input->SetRegions(region);
  input->Allocate();
  input->FillBuffer(1);

  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);
    input->SetPixel(idx, idx[0]);

    it1.Set(std::sqrt(static_cast<float>((idx[0] - 2) * (idx[0] - 2) + (idx[1] - 2) * (idx[1] - 2))) - 1.5);

    it2.Set(std::sqrt(static_cast<float>((idx[0] - 5) * (idx[0] - 5) + (idx[1] - 5) * (idx[1] - 5))) - 2.5);
    ++it1;
    ++it2;
  }

  auto domainMapFilter = DomainMapImageFilterType::New();
  domainMapFilter->SetInput(id_image);
  domainMapFilter->Update();

  // Define the Heaviside function
  auto heaviside = HeavisideFunctionBaseType::New();
  heaviside->SetEpsilon(1.0);

  // Map of levelset bases
  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);

  // Insert the levelsets in a levelset container
  auto lscontainer = LevelSetContainerType::New();
  lscontainer->SetHeaviside(heaviside);
  lscontainer->SetDomainMapFilter(domainMapFilter);

  bool LevelSetNotYetAdded = lscontainer->AddLevelSet(0, level_set[1], false);
  if (!LevelSetNotYetAdded)
  {
    return EXIT_FAILURE;
  }

  LevelSetNotYetAdded = lscontainer->AddLevelSet(1, level_set[2], false);
  if (!LevelSetNotYetAdded)
  {
    return EXIT_FAILURE;
  }
  std::cout << "Level set container created" << std::endl;

  // **************** CREATE ALL TERMS ****************

  // -----------------------------
  // *** 1st Level Set phi_{1} ***

  // Create ChanAndVese internal term for phi_{1}
  auto cvInternalTerm0 = ChanAndVeseInternalTermType::New();
  cvInternalTerm0->SetInput(input);
  cvInternalTerm0->SetCoefficient(1.0);
  std::cout << "LevelSet 1: CV internal term created" << std::endl;

  // Create ChanAndVese external term for phi_{1}
  auto cvExternalTerm0 = ChanAndVeseExternalTermType::New();
  cvExternalTerm0->SetInput(input);
  cvExternalTerm0->SetCoefficient(1.0);
  std::cout << "LevelSet 1: CV external term created" << std::endl;

  // -----------------------------
  // *** 2nd Level Set phi_{2} ***

  // Create ChanAndVese internal term for phi_{1}
  auto cvInternalTerm1 = ChanAndVeseInternalTermType::New();
  cvInternalTerm1->SetInput(input);
  cvInternalTerm1->SetCoefficient(1.0);
  std::cout << "LevelSet 2: CV internal term created" << std::endl;

  // Create ChanAndVese external term for phi_{2}
  auto cvExternalTerm1 = ChanAndVeseExternalTermType::New();
  cvExternalTerm1->SetInput(input);
  cvExternalTerm1->SetCoefficient(1.0);
  std::cout << "LevelSet 2: CV external term created" << std::endl;

  // **************** CREATE ALL EQUATIONS ****************

  // Create Term Container
  auto termContainer0 = TermContainerType::New();
  termContainer0->SetInput(input);
  termContainer0->SetCurrentLevelSetId(0);
  termContainer0->SetLevelSetContainer(lscontainer);

  termContainer0->AddTerm(0, cvInternalTerm0);
  termContainer0->AddTerm(1, cvExternalTerm0);
  std::cout << "Term container 0 created" << std::endl;

  auto termContainer1 = TermContainerType::New();
  termContainer1->SetInput(input);
  termContainer1->SetCurrentLevelSetId(1);
  termContainer1->SetLevelSetContainer(lscontainer);

  termContainer1->AddTerm(0, cvInternalTerm1);
  termContainer1->AddTerm(1, cvExternalTerm1);
  std::cout << "Term container 1 created" << std::endl;

  using StoppingCriterionType = itk::LevelSetEvolutionNumberOfIterationsStoppingCriterion<LevelSetContainerType>;
  auto criterion = StoppingCriterionType::New();
  criterion->SetNumberOfIterations(2);

  auto equationContainer = EquationContainerType::New();
  equationContainer->AddEquation(0, termContainer0);
  equationContainer->AddEquation(1, termContainer1);
  equationContainer->SetLevelSetContainer(lscontainer);

  auto evolution = LevelSetEvolutionType::New();

  ITK_EXERCISE_BASIC_OBJECT_METHODS(evolution, LevelSetEvolution, LevelSetEvolutionBase);


  evolution->SetEquationContainer(equationContainer);
  ITK_TEST_SET_GET_VALUE(equationContainer, evolution->GetEquationContainer());

  evolution->SetStoppingCriterion(criterion);
  ITK_TEST_SET_GET_VALUE(criterion, evolution->GetStoppingCriterion());

  evolution->SetLevelSetContainer(lscontainer);
  ITK_TEST_SET_GET_VALUE(lscontainer, evolution->GetLevelSetContainer());

  try
  {
    evolution->Update();
  }
  catch (const itk::ExceptionObject & err)
  {
    std::cout << err << std::endl;
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}