/*=========================================================================

  Program:   Advanced Normalization Tools

  Copyright (c) ConsortiumOfANTS. All rights reserved.
  See accompanying COPYING.txt or
 https://github.com/stnava/ANTs/blob/master/ANTSCopyright.txt for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/

#include "antsUtilities.h"
#include "antsAllocImage.h"
#include <algorithm>

#include "itkDiscreteGaussianImageFilter.h"

//  RecursiveAverageImages img1  img2 weightonimg2 outputname

// We divide the 2nd input image by its mean and add it to the first
// input image with weight 1/n.
// The output overwrites the 1st img with the sum.

#include "ReadWriteData.h"

namespace ants
{
template <unsigned int ImageDimension, unsigned int NVectorComponents>
int
MultiplyImages(int argc, char * argv[])
{
  using PixelType = itk::Vector<float, NVectorComponents>;
  using ImageType = itk::Image<PixelType, ImageDimension>;
  using Iterator = itk::ImageRegionIteratorWithIndex<ImageType>;
  using readertype = itk::ImageFileReader<ImageType>;
  using writertype = itk::ImageFileWriter<ImageType>;

  if (argc < 3)
  {
    std::cout << "missing 1st filename" << std::endl;
    throw;
  }
  if (argc < 4)
  {
    std::cout << "missing 2nd filename" << std::endl;
    throw;
  }
  if (argc < 5)
  {
    std::cout << "missing output filename" << std::endl;
    throw;
  }

  std::string fn1 = std::string(argv[2]);
  std::string fn2 = std::string(argv[3]);

  typename ImageType::Pointer image1 = nullptr;
  typename ImageType::Pointer image2 = nullptr;
  typename ImageType::Pointer varimage = nullptr;

  typename readertype::Pointer reader2 = readertype::New();
  typename readertype::Pointer reader1 = readertype::New();
  reader2->SetFileName(fn2.c_str());

  bool isfloat = false;
  try
  {
    reader2->UpdateLargestPossibleRegion();
  }
  catch (...)
  {
    //    std::cout << " Rather than opening " << fn2
    //             <<
    //      " as an image file, this program has decided, in its great wisdom, to consider it to be a floating point
    //      numerical value, and has acted accordingly -- i.e. read this as a number. "
    //             << std::endl;
    isfloat = true;
  }

  float floatval = 1.0;
  if (isfloat)
  {
    floatval = atof(argv[3]);
  }
  else
  {
    image2 = reader2->GetOutput();
  }

  reader1->SetFileName(fn1.c_str());
  try
  {
    reader1->UpdateLargestPossibleRegion();
    image1 = reader1->GetOutput();
  }
  catch (...)
  {
    std::cout << " read 1 error ";
  }

  varimage = AllocImage<ImageType>(image1);

  Iterator vfIter2(varimage, varimage->GetLargestPossibleRegion());
  for (vfIter2.GoToBegin(); !vfIter2.IsAtEnd(); ++vfIter2)
  {
    typename ImageType::IndexType ind = vfIter2.GetIndex();
    PixelType                     pix1 = image1->GetPixel(ind);
    if (isfloat)
    {
      vfIter2.Set(pix1 * floatval);
    }
    else
    {
      // element-wise multiplication
      PixelType result = image2->GetPixel(ind);
      for (unsigned d = 0; d < pix1.GetNumberOfComponents(); ++d)
      {
        result[d] *= pix1[d];
      }
      vfIter2.Set(result);
    }
  }
  typename writertype::Pointer writer = writertype::New();
  writer->SetFileName(argv[4]);
  writer->SetInput(varimage);
  writer->Write();

  return EXIT_SUCCESS;
}

// entry point for the library; parameter 'args' is equivalent to 'argv' in (argc,argv) of commandline parameters to
// 'main()'
int
MultiplyImages(std::vector<std::string> args, std::ostream * /*out_stream = nullptr */)
{
  // put the arguments coming in as 'args' into standard (argc,argv) format;
  // 'args' doesn't have the command name as first, argument, so add it manually;
  // 'args' may have adjacent arguments concatenated into one argument,
  // which the parser should handle
  args.insert(args.begin(), "MultiplyImages");

  int     argc = args.size();
  char ** argv = new char *[args.size() + 1];
  for (unsigned int i = 0; i < args.size(); ++i)
  {
    // allocate space for the string plus a null character
    argv[i] = new char[args[i].length() + 1];
    std::strncpy(argv[i], args[i].c_str(), args[i].length());
    // place the null character in the end
    argv[i][args[i].length()] = '\0';
  }
  argv[argc] = nullptr;
  // class to automatically cleanup argv upon destruction
  class Cleanup_argv
  {
  public:
    Cleanup_argv(char ** argv_, int argc_plus_one_)
      : argv(argv_)
      , argc_plus_one(argc_plus_one_)
    {}

    ~Cleanup_argv()
    {
      for (unsigned int i = 0; i < argc_plus_one; ++i)
      {
        delete[] argv[i];
      }
      delete[] argv;
    }

  private:
    char **      argv;
    unsigned int argc_plus_one;
  };
  Cleanup_argv cleanup_argv(argv, argc + 1);

  // antscout->set_stream( out_stream );

  if (argc < 4)
  {
    std::cout << "Usage:  " << std::endl;
    std::cout << argv[0] << " ImageDimension img1.nii img2.nii product.nii {smoothing}" << std::endl;
    std::cout << " 2nd image file may also be floating point numerical value, and program will act accordingly -- i.e. "
                 "read as a number. "
              << std::endl;
    std::cout << " Program handles vector and tensor images as well " << std::endl;
    if (argc >= 2 && (std::string(argv[1]) == std::string("--help") || std::string(argv[1]) == std::string("-h")))
    {
      return EXIT_SUCCESS;
    }
    return EXIT_FAILURE;
  }

  int                       dim = std::stoi(argv[1]);
  itk::ImageIOBase::Pointer imageIO = itk::ImageIOFactory::CreateImageIO(argv[2], itk::IOFileModeEnum::ReadMode);
  imageIO->SetFileName(argv[2]);
  imageIO->ReadImageInformation();
  unsigned int ncomponents = imageIO->GetNumberOfComponents();

  int returnValue = EXIT_FAILURE;

  // Get the image dimension
  switch (std::stoi(argv[1]))
  {
    case 1:
    {
      switch (ncomponents)
      {
        case 3:
        {
          returnValue = MultiplyImages<1, 3>(argc, argv);
        }
        break;
        case 2:
        {
          returnValue = MultiplyImages<1, 2>(argc, argv);
        }
        break;
        default:
        {
          returnValue = MultiplyImages<1, 1>(argc, argv);
        }
        break;
      }
    }
    break;
    case 2:
    {
      switch (ncomponents)
      {
        case 3:
        {
          returnValue = MultiplyImages<2, 3>(argc, argv);
        }
        break;
        case 2:
        {
          returnValue = MultiplyImages<2, 2>(argc, argv);
        }
        break;
        default:
        {
          returnValue = MultiplyImages<2, 1>(argc, argv);
        }
        break;
      }
    }
    break;
    case 3:
    {
      switch (ncomponents)
      {
        case 7:
        {
          returnValue = MultiplyImages<3, 7>(argc, argv);
        }
        break;
        case 6:
        {
          returnValue = MultiplyImages<3, 6>(argc, argv);
        }
        break;
        case 3:
        {
          returnValue = MultiplyImages<3, 3>(argc, argv);
        }
        break;
        default:
        {
          returnValue = MultiplyImages<3, 1>(argc, argv);
        }
        break;
      }
    }
    break;
    case 4:
    {
      switch (ncomponents)
      {
        case 7:
        {
          returnValue = MultiplyImages<4, 7>(argc, argv);
        }
        break;
        case 6:
        {
          returnValue = MultiplyImages<4, 6>(argc, argv);
        }
        break;
        case 4:
        {
          returnValue = MultiplyImages<4, 4>(argc, argv);
        }
        break;
        case 3:
        {
          returnValue = MultiplyImages<4, 3>(argc, argv);
        }
        break;
        case 2:
        {
          returnValue = MultiplyImages<4, 2>(argc, argv);
        }
        break;
        default:
        {
          returnValue = MultiplyImages<4, 1>(argc, argv);
        }
        break;
      }
    }
    break;
    default:
      std::cout << " not supported " << dim << std::endl;
      return EXIT_FAILURE;
  }

  return returnValue;
}
} // namespace ants