/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/

#define ITK_TEMPLATE_EXPLICIT_MatlabTransformIO
#include "itkMatlabTransformIO.h"
#include "itksys/SystemTools.hxx"
#include "vnl/vnl_matlab_read.h"
#include "vnl/vnl_matlab_write.h"

namespace itk
{
template <typename ParametersValueType>
MatlabTransformIOTemplate<ParametersValueType>::MatlabTransformIOTemplate() = default;

template <typename ParametersValueType>
MatlabTransformIOTemplate<ParametersValueType>::~MatlabTransformIOTemplate() = default;

template <typename ParametersValueType>
bool
MatlabTransformIOTemplate<ParametersValueType>::CanReadFile(const char * fileName)
{
  return itksys::SystemTools::GetFilenameLastExtension(fileName) == ".mat";
}

template <typename ParametersValueType>
bool
MatlabTransformIOTemplate<ParametersValueType>::CanWriteFile(const char * fileName)
{
  return itksys::SystemTools::GetFilenameLastExtension(fileName) == ".mat";
}

//
// ReadMat -- we always want double precision,
// but handle single precision as well.
template <typename ParametersValueType>
inline void
ReadMat(vnl_matlab_readhdr &                                                                     mathdr,
        typename MatlabTransformIOTemplate<ParametersValueType>::TransformType::ParametersType & array)
{
  if (mathdr.is_single())
  {
    vnl_vector<float> fv(mathdr.rows());
    mathdr.read_data(fv.begin());
    for (int i = 0; i < mathdr.rows(); ++i)
    {
      array[i] = (ParametersValueType)(fv[i]);
    }
  }
  else
  {
    vnl_vector<double> dv(mathdr.rows());
    mathdr.read_data(dv.begin());
    for (int i = 0; i < mathdr.rows(); ++i)
    {
      array[i] = (ParametersValueType)(dv[i]);
    }
  }
}

template <typename ParametersValueType>
void
MatlabTransformIOTemplate<ParametersValueType>::Read()
{
  std::ifstream matfile(this->GetFileName(), std::ios::in | std::ios::binary);

  if (matfile.fail())
  {
    matfile.close();
    itkExceptionMacro("The file could not be opened for read access " << std::endl
                                                                      << "Filename: \"" << this->GetFileName() << '"');
  }
  while (!matfile.eof())
  {
    vnl_matlab_readhdr mathdr(matfile);
    if (!mathdr)
    {
      break;
    }
    if (mathdr.cols() != 1)
    {
      matfile.close();
      itkExceptionMacro("Only vector parameters supported");
    }
    typename TransformType::ParametersType TmpParameterArray(mathdr.rows());
    ReadMat<ParametersValueType>(mathdr, TmpParameterArray);
    std::string classname(mathdr.name());
    // Transform name should be modified to have the output precision type.
    Superclass::CorrectTransformPrecisionType(classname);

    // create transform based on name of first vector
    TransformPointer transform;
    this->CreateTransform(transform, classname);
    this->GetReadTransformList().push_back(transform);
    vnl_matlab_readhdr mathdr2(matfile);
    if (mathdr2.cols() != 1)
    {
      matfile.close();
      itkExceptionMacro("Only vector parameters supported");
    }
    typename TransformType::FixedParametersType TmpFixedParameterArray(mathdr2.rows());
    ReadMat<typename TransformType::FixedParametersValueType>(mathdr2, TmpFixedParameterArray);
    transform->SetFixedParameters(TmpFixedParameterArray);
    transform->SetParametersByValue(TmpParameterArray);
  }
  matfile.close();
}

template <typename ParametersValueType>
void
MatlabTransformIOTemplate<ParametersValueType>::Write()
{
  auto it = this->GetWriteTransformList().begin();

  typename MatlabTransformIOTemplate<ParametersValueType>::TransformType::ParametersType TempArray;
  std::ofstream                                                                          out;
  this->OpenStream(out, true);
  while (it != this->GetWriteTransformList().end())
  {
    std::string xfrmType((*it)->GetTransformTypeAsString());
    TempArray = (*it)->GetParameters();
    vnl_matlab_write(out, TempArray.begin(), TempArray.size(), xfrmType.c_str());
    TempArray = (*it)->GetFixedParameters();
    vnl_matlab_write(out, TempArray.begin(), TempArray.size(), "fixed");
    ++it;
  }
  out.close();
}

ITK_GCC_PRAGMA_DIAG_PUSH()
ITK_GCC_PRAGMA_DIAG(ignored "-Wattributes")

template class ITKIOTransformMatlab_EXPORT MatlabTransformIOTemplate<double>;
template class ITKIOTransformMatlab_EXPORT MatlabTransformIOTemplate<float>;

ITK_GCC_PRAGMA_DIAG_POP()

} // end namespace itk