/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/
/*
  This tests the classes ImageRandomNonRepeatingIteratorWithIndex and
  ImageRandomNonRepeatingConstIteratorWithIndex.  This was contributed
  by Rupert Brooks, McGill Centre for Intelligent
  Machines, Montreal, Canada.  It is heavily based on the
  ImageRandomIterator test program.
*/

#include <iostream>
#include "itkImageRegionIteratorWithIndex.h"
#include "itkImageRandomNonRepeatingIteratorWithIndex.h"
int
itkImageRandomNonRepeatingIteratorWithIndexTest(int, char *[])
{
  constexpr unsigned int ImageDimension = 3;
  using PixelType = itk::Index<ImageDimension>;
  using ImageType = itk::Image<PixelType, ImageDimension>;
  using PriorityPixelType = itk::SizeValueType;
  using PriorityImageType = itk::Image<PriorityPixelType, ImageDimension>;
  using IteratorType = itk::ImageRegionIteratorWithIndex<ImageType>;
  using PriorityIteratorType = itk::ImageRegionIteratorWithIndex<PriorityImageType>;
  using RandomIteratorType = itk::ImageRandomNonRepeatingIteratorWithIndex<ImageType>;
  using RandomConstIteratorType = itk::ImageRandomNonRepeatingConstIteratorWithIndex<ImageType>;
  std::cout << "Creating images" << std::endl;

  auto                    myImage = ImageType::New();
  ImageType::ConstPointer myConstImage = myImage;
  ImageType::SizeType     size0;
  size0[0] = 50;
  size0[1] = 50;
  size0[2] = 50;
  unsigned long        numberOfSamples = 10;
  ImageType::IndexType start0;
  start0.Fill(0);
  ImageType::RegionType region0{ start0, size0 };
  myImage->SetRegions(region0);
  myImage->Allocate();
  // Make the priority image
  auto                        priorityImage = PriorityImageType::New();
  PriorityImageType::SizeType prioritySize;
  prioritySize[0] = 50;
  prioritySize[1] = 50;
  prioritySize[2] = 50;
  PriorityImageType::IndexType priorityStart;
  priorityStart.Fill(0);
  PriorityImageType::RegionType priorityRegion{ priorityStart, prioritySize };
  priorityImage->SetRegions(priorityRegion);
  priorityImage->Allocate();
  // we will make most of this image ones, with a small region of
  // zeros.  Then pixels from the zero region should be selected
  // preferentially.
  std::cout << "Building Priority image" << std::endl;
  PriorityIteratorType pit(priorityImage, priorityRegion);
  pit.GoToBegin();
  while (!pit.IsAtEnd())
  {
    pit.Set(1);
    ++pit;
  }
  PriorityImageType::IndexType substart;
  substart[0] = 15;
  substart[1] = 16;
  substart[2] = 17;
  PriorityImageType::SizeType subsize;
  subsize[0] = 3;
  subsize[1] = 4;
  subsize[2] = 5;
  PriorityImageType::RegionType subregion{ substart, subsize };
  PriorityIteratorType          subit(priorityImage, subregion);
  subit.GoToBegin();
  while (!subit.IsAtEnd())
  {
    subit.Set(0);
    ++subit;
  }

  //********
  std::cout << "Filling image with indices" << std::endl;

  RandomIteratorType it(myImage, region0);
  it.SetNumberOfSamples(size0[0] * size0[1] * size0[2]);
  it.GoToBegin();
  ImageType::IndexType index0;
  // Because the random iterator does not repeat, this should
  // fill the image with indices
  while (!it.IsAtEnd())
  {
    index0 = it.GetIndex();
    it.Set(index0);
    ++it;
  }

  // Sample the image
  IteratorType ot(myImage, region0);
  ot.GoToBegin();
  // if it repeated its going to have missed a few.
  std::cout << "Verifying iterators... ";
  while (!ot.IsAtEnd())
  {
    index0 = ot.GetIndex();
    if (ot.Get() != index0)
    {
      std::cerr << "Values don't correspond to what was stored " << std::endl;
      std::cerr << "Test failed at index ";
      std::cerr << index0 << std::endl;
      return EXIT_FAILURE;
    }
    // std::cout <<".";
    // std::cout << index0 << std::endl;
    ++ot;
  }
  std::cout << std::endl << "   Done ! " << std::endl;

  // Verification
  RandomConstIteratorType cot(myConstImage, region0);
  cot.SetNumberOfSamples(numberOfSamples);
  cot.GoToBegin();

  std::cout << "Verifying const iterator... ";
  std::cout << "Random walk of the Iterator over the image " << std::endl;
  while (!cot.IsAtEnd())
  {
    index0 = cot.GetIndex();
    if (cot.Get() != index0)
    {
      std::cerr << "Values don't correspond to what was stored " << std::endl;
      std::cerr << "Test failed at index ";
      std::cerr << index0 << " value is " << cot.Get() << std::endl;
      return EXIT_FAILURE;
    }
    std::cout << index0 << std::endl;
    ++cot;
  }
  std::cout << "   Done ! " << std::endl;

  // Verification
  std::cout << "Verifying iterator in reverse direction... " << std::endl;
  std::cout << "Should be a random walk too (a different one)" << std::endl;
  RandomIteratorType ior(myImage, region0);
  ior.SetNumberOfSamples(numberOfSamples);
  ior.GoToEnd();
  --ior;

  while (!ior.IsAtBegin())
  {
    index0 = ior.GetIndex();
    if (ior.Get() != index0)
    {
      std::cerr << "Values don't correspond to what was stored " << std::endl;
      std::cerr << "Test failed at index ";
      std::cerr << index0 << " value is " << ior.Get() << std::endl;
      return EXIT_FAILURE;
    }
    std::cout << index0 << std::endl;
    --ior;
  }
  std::cout << index0 << std::endl; // print the value at the beginning index
  std::cout << "   Done ! " << std::endl;

  // Verification
  std::cout << "Verifying const iterator in reverse direction... ";
  RandomConstIteratorType cor(myImage, region0);
  cor.SetNumberOfSamples(numberOfSamples); // 0=x, 1=y, 2=z
  cor.GoToEnd();
  --cor; // start at the end position
  while (!cor.IsAtBegin())
  {
    index0 = cor.GetIndex();
    if (cor.Get() != index0)
    {
      std::cerr << "Values don't correspond to what was stored " << std::endl;
      std::cerr << "Test failed at index ";
      std::cerr << index0 << " value is " << cor.Get() << std::endl;
      return EXIT_FAILURE;
    }
    std::cout << index0 << std::endl;
    --cor;
  }
  std::cout << index0 << std::endl; // print the value at the beginning index
  std::cout << "   Done ! " << std::endl;
  // Verification
  std::cout << "Verifying const iterator in both directions... ";
  RandomConstIteratorType dor(myImage, region0);
  dor.SetNumberOfSamples(numberOfSamples); // 0=x, 1=y, 2=z
  dor.GoToEnd();
  --dor; // start at the last valid pixel position
  for (unsigned int counter = 0; !dor.IsAtEnd(); ++counter)
  {
    index0 = dor.GetIndex();
    if (dor.Get() != index0)
    {
      std::cerr << "Values don't correspond to what was stored " << std::endl;
      std::cerr << "Test failed at index ";
      std::cerr << index0 << " value is " << dor.Get() << std::endl;
      return EXIT_FAILURE;
    }
    std::cout << index0 << std::endl;
    if (counter < 6)
    {
      --dor;
    }
    else
    {
      ++dor;
    }
  }
  std::cout << index0 << std::endl; // print the value at the beginning index
  std::cout << "   Done ! " << std::endl;

  // Verification of the Iterator in a subregion of the image
  {
    std::cout << "Verifying Iterator in a Region smaller than the whole image... " << std::endl;
    ImageType::IndexType start;
    start[0] = 10;
    start[1] = 12;
    start[2] = 14;
    ImageType::SizeType size;
    size[0] = 11;
    size[1] = 12;
    size[2] = 13;
    ImageType::RegionType region{ start, size };
    RandomIteratorType    cbot(myImage, region);
    cbot.SetNumberOfSamples(numberOfSamples); // 0=x, 1=y, 2=z
    cbot.GoToBegin();
    while (!cbot.IsAtEnd())
    {
      ImageType::IndexType index = cbot.GetIndex();
      ImageType::PixelType pixel = cbot.Get();
      if (index != pixel)
      {
        std::cerr << "Iterator in region test failed" << std::endl;
        std::cerr << pixel << " should be" << index << std::endl;
        return EXIT_FAILURE;
      }
      if (!region.IsInside(index))
      {
        std::cerr << "Iterator in region test failed" << std::endl;
        std::cerr << index << " is outside the region " << region << std::endl;
        return EXIT_FAILURE;
      }
      std::cout << index << std::endl;
      ++cbot;
    }
    std::cout << "   Done ! " << std::endl;
  }

  // Verification of the Const Iterator in a subregion of the image
  {
    std::cout << "Verifying Const Iterator in a Region smaller than the whole image... " << std::endl;
    ImageType::IndexType start;
    start[0] = 10;
    start[1] = 12;
    start[2] = 14;
    ImageType::SizeType size;
    size[0] = 11;
    size[1] = 12;
    size[2] = 13;
    ImageType::RegionType   region{ start, size };
    RandomConstIteratorType cbot(myImage, region);
    cbot.SetNumberOfSamples(numberOfSamples);
    cbot.GoToBegin();
    while (!cbot.IsAtEnd())
    {
      ImageType::IndexType index = cbot.GetIndex();
      ImageType::PixelType pixel = cbot.Get();
      if (index != pixel)
      {
        std::cerr << "Iterator in region test failed" << std::endl;
        std::cerr << pixel << " should be" << index << std::endl;
        return EXIT_FAILURE;
      }
      if (!region.IsInside(index))
      {
        std::cerr << "Iterator in region test failed" << std::endl;
        std::cerr << index << " is outside the region " << region << std::endl;
        return EXIT_FAILURE;
      }
      std::cout << index << std::endl;
      ++cbot;
    }
    std::cout << "   Done ! " << std::endl;
  }


  // Verifying iterator works with  the priority image

  {
    std::cout << "Verifying Iterator with respect to priority image... " << std::endl;

    RandomIteratorType cbot(myImage, region0);
    cbot.SetPriorityImage(priorityImage);
    cbot.SetNumberOfSamples(numberOfSamples); // 0=x, 1=y, 2=z
    cbot.GoToBegin();
    unsigned int count = 0;
    while (!cbot.IsAtEnd() && count < (subsize[0] * subsize[1] * subsize[2]))
    {
      ImageType::IndexType index = cbot.GetIndex();
      if (!subregion.IsInside(index))
      {
        std::cerr << "Iterator in priority region test failed" << std::endl;
        std::cerr << index << " is outside the region " << region0 << std::endl;
        return EXIT_FAILURE;
      }
      std::cout << index << std::endl;
      ++cbot;
      ++count;
    }
    // Now we have walked through all the pixels of low priority, next
    // one should be outside the region.
    if (subregion.IsInside(index0))
    {
      std::cerr << "Iterator in priority region test failed" << std::endl;
      std::cerr << index0 << " is outside the region (should be in)" << region0 << std::endl;
      return EXIT_FAILURE;
    }
    std::cout << "   Done ! " << std::endl;
  }
  {
    std::cout << "Verifying const Iterator with respect to priority image... " << std::endl;

    RandomConstIteratorType cbot(myImage, region0);
    cbot.SetPriorityImage(priorityImage);
    cbot.SetNumberOfSamples(numberOfSamples); // 0=x, 1=y, 2=z
    cbot.GoToBegin();
    unsigned int count = 0;
    while (!cbot.IsAtEnd() && count < (subsize[0] * subsize[1] * subsize[2]))
    {
      ImageType::IndexType index = cbot.GetIndex();
      if (!subregion.IsInside(index))
      {
        std::cerr << "Iterator in priority region test failed" << std::endl;
        std::cerr << index << " is outside the region " << region0 << std::endl;
        return EXIT_FAILURE;
      }
      std::cout << index << std::endl;
      ++cbot;
      ++count;
    }
    // Now we have walked through all the pixels of low priority, next
    // one should be outside the region.
    if (subregion.IsInside(index0))
    {
      std::cerr << "Iterator in priority region test failed" << std::endl;
      std::cerr << index0 << " is outside the region (should be in)" << region0 << std::endl;
      return EXIT_FAILURE;
    }
    std::cout << "   Done ! " << std::endl;
  }
  {
    // Exercise assignment operator
    std::cout << "Exercising assignment operator... " << std::endl;
    RandomConstIteratorType iteratorAssignment;
    iteratorAssignment = RandomConstIteratorType(myImage, myImage->GetLargestPossibleRegion());
    iteratorAssignment.SetNumberOfSamples(myImage->GetLargestPossibleRegion().GetNumberOfPixels());
    iteratorAssignment.GoToBegin();
    std::cout << "Finished exercising assignment operator!" << std::endl;
  }
  std::cout << "Test passed" << std::endl;
  return EXIT_SUCCESS;
}