/*=========================================================================
 *
 *  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
 *
 *         http://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.
 *
 *=========================================================================*/

#ifndef itkFreeSurferBinaryMeshIO_h
#define itkFreeSurferBinaryMeshIO_h
#include "ITKIOMeshFreeSurferExport.h"

#include "itkByteSwapper.h"
#include "itkMeshIOBase.h"
#include "itkIntTypes.h"

#include <fstream>

namespace itk
{
/** \class FreeSurferBinaryMeshIO
 * \brief This class defines how to read Freesurfer binary surface file format.
 * To use IO factory, define the suffix as *.fsb.
 * \ingroup IOFilters
 * \ingroup ITKIOMeshFreeSurfer
 */

class ITKIOMeshFreeSurfer_EXPORT FreeSurferBinaryMeshIO : public MeshIOBase
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(FreeSurferBinaryMeshIO);

  /** Standard class type aliases. */
  using Self = FreeSurferBinaryMeshIO;
  using Superclass = MeshIOBase;
  using ConstPointer = SmartPointer<const Self>;
  using Pointer = SmartPointer<Self>;

  using SizeValueType = Superclass::SizeValueType;
  using StreamOffsetType = Superclass::StreamOffsetType;

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

  /** Run-time type information (and related methods). */
  itkTypeMacro(FreeSurferBinaryMeshIO, MeshIOBase);

  /*-------- This part of the interfaces deals with reading data. ----- */

  /** Determine if the file can be read with this MeshIO implementation.
   * \param FileNameToRead The name of the file to test for reading.
   * \post Sets classes MeshIOBase::m_FileName variable to be FileNameToWrite
   * \return Returns true if this MeshIO can read the file specified.
   */
  bool
  CanReadFile(const char * fileName) override;

  /** Set the spacing and dimension information for the set filename. */
  void
  ReadMeshInformation() override;

  /** Reads the data from disk into the memory buffer provided. */
  void
  ReadPoints(void * buffer) override;

  void
  ReadCells(void * buffer) override;

  void
  ReadPointData(void * buffer) override;

  void
  ReadCellData(void * buffer) override;

  /*-------- This part of the interfaces deals with writing data. ----- */

  /** Determine if the file can be written with this MeshIO implementation.
   * \param FileNameToWrite The name of the file to test for writing.
   * \post Sets classes MeshIOBase::m_FileName variable to be FileNameToWrite
   * \return Returns true if this MeshIO can write the file specified.
   */
  bool
  CanWriteFile(const char * fileName) override;

  /** Set the spacing and dimension information for the set filename. */
  void
  WriteMeshInformation() override;

  /** Writes the data to disk from the memory buffer provided. Make sure
   * that the IORegions has been set properly. */
  void
  WritePoints(void * buffer) override;

  void
  WriteCells(void * buffer) override;

  void
  WritePointData(void * buffer) override;

  void
  WriteCellData(void * buffer) override;

  void
  Write() override;

protected:
  /** Write points to output stream */
  template <typename T>
  void
  WritePoints(T * buffer, std::ofstream & outputFile)
  {
    auto * data = new float[this->m_NumberOfPoints * this->m_PointDimension];

    for (SizeValueType ii = 0; ii < this->m_NumberOfPoints; ii++)
    {
      for (unsigned int jj = 0; jj < this->m_PointDimension; jj++)
      {
        data[ii * this->m_PointDimension + jj] = static_cast<float>(buffer[ii * this->m_PointDimension + jj]);
      }
    }

    itk::ByteSwapper<float>::SwapWriteRangeFromSystemToBigEndian(
      data, this->m_NumberOfPoints * this->m_PointDimension, &outputFile);
    delete[] data;
  }

  /** Write cells to utput stream */
  template <typename T>
  void
  WriteCells(T * buffer, std::ofstream & outputFile)
  {
    constexpr itk::uint32_t numberOfCellPoints = 3;

    auto * data = new itk::uint32_t[this->m_NumberOfCells * numberOfCellPoints];

    ReadCellsBuffer(buffer, data);
    itk::ByteSwapper<itk::uint32_t>::SwapWriteRangeFromSystemToBigEndian(
      data, this->m_NumberOfCells * numberOfCellPoints, &outputFile);

    delete[] data;
  }

  /** Read cells from a data buffer, used when writting mesh */
  template <typename TInput, typename TOutput>
  void
  ReadCellsBuffer(TInput * input, TOutput * output)
  {
    if (input && output)
    {
      for (SizeValueType ii = 0; ii < this->m_NumberOfCells; ii++)
      {
        for (unsigned int jj = 0; jj < 3; jj++)
        {
          /** point identifiers start from the third elements, first element is
            cellType, the second is numberOfPoints. */
          output[ii * 3 + jj] = static_cast<TOutput>(input[5 * ii + jj + 2]);
        }
      }
    }
  }

  /** Write points to output stream */
  template <typename T>
  void
  WritePointData(T * buffer, std::ofstream & outputFile)
  {
    auto * data = new float[this->m_NumberOfPointPixels];

    for (SizeValueType ii = 0; ii < this->m_NumberOfPointPixels; ii++)
    {
      data[ii] = static_cast<float>(buffer[ii]);
    }

    itk::ByteSwapper<float>::SwapWriteRangeFromSystemToBigEndian(data, this->m_NumberOfPointPixels, &outputFile);
    delete[] data;
  }

protected:
  FreeSurferBinaryMeshIO();
  ~FreeSurferBinaryMeshIO() override;

  void
  PrintSelf(std::ostream & os, Indent indent) const override;

  void
  OpenFile();

  void
  CloseFile();

private:
  StreamOffsetType m_FilePosition{ 0 };
  itk::uint32_t    m_FileTypeIdentifier{ 0 };
  std::ifstream    m_InputFile;
};
} // end namespace itk

#endif