/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/
#ifndef itkCSVNumericObjectFileWriter_hxx
#define itkCSVNumericObjectFileWriter_hxx

#include "itksys/SystemTools.hxx"

#include <fstream>
#include <iomanip>


namespace itk
{
template <typename TValue, unsigned int VRows, unsigned int VColumns>
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::CSVNumericObjectFileWriter()
{
  this->m_FieldDelimiterCharacter = ',';
  this->m_InputObject = nullptr;
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::SetInput(const vnlMatrixType * obj)
{
  this->m_InputObject = const_cast<TValue *>(obj->data_block());
  this->m_Rows = obj->rows();
  this->m_Columns = obj->cols();
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::SetInput(const vnlFixedMatrixType * obj)
{
  this->m_InputObject = const_cast<TValue *>(obj->data_block());
  this->m_Rows = obj->rows();
  this->m_Columns = obj->cols();
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::SetInput(const itkMatrixType * obj)
{
  this->m_InputObject = const_cast<TValue *>(obj->GetVnlMatrix().data_block());
  this->m_Rows = obj->RowDimensions;
  this->m_Columns = obj->ColumnDimensions;
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::ColumnHeadersPushBack(const std::string & header)
{
  this->m_ColumnHeaders.push_back(header);
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::RowHeadersPushBack(const std::string & header)
{
  this->m_RowHeaders.push_back(header);
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::SetColumnHeaders(const StringVectorType & columnheaders)
{
  this->m_ColumnHeaders = columnheaders;
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::SetRowHeaders(const StringVectorType & rowheaders)
{
  this->m_RowHeaders = rowheaders;
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::PrepareForWriting()
{
  // throw an exception if no filename is provided
  if (this->m_FileName.empty())
  {
    itkExceptionMacro("A filename for writing was not specified!");
  }

  // throw an exception if no input object is provided
  if (this->m_InputObject == nullptr)
  {
    itkExceptionMacro("An input object was not specified!");
  }

  // output a warning if the number of row headers and number of rows in the
  // object are not the same
  if (!this->m_RowHeaders.empty() && (this->m_RowHeaders.size() != this->m_Rows))
  {
    itkWarningMacro("Warning: The number of row headers and the number of rows in"
                    << " the input object is not consistent.");
  }

  // output a warning if the number of column headers and number of columns in
  // the object are not the same
  if (!this->m_ColumnHeaders.empty())
  {
    if (!this->m_RowHeaders.empty() && this->m_ColumnHeaders.size() != (this->m_Columns + 1))
    {
      itkWarningMacro("Warning: The number of column headers and the number of"
                      << " columns in the input object is not consistent.");
    }
    if (this->m_RowHeaders.empty() && this->m_ColumnHeaders.size() != this->m_Columns)
    {
      itkWarningMacro("Warning: The number of column headers and the number of"
                      << " columns in the input object is not consistent.");
    }
  }
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::Write()
{
  this->PrepareForWriting();

  std::ofstream outputStream(this->m_FileName.c_str());
  if (outputStream.fail())
  {
    itkExceptionMacro("The file " << this->m_FileName << " cannot be opened for writing!" << std::endl
                                  << "Reason: " << itksys::SystemTools::GetLastSystemError());
  }

  try
  {
    if (!this->m_ColumnHeaders.empty())
    {
      for (unsigned int i = 0; i < this->m_ColumnHeaders.size(); ++i)
      {
        outputStream << this->m_ColumnHeaders[i];
        if (i < this->m_ColumnHeaders.size() - 1)
        {
          outputStream << this->m_FieldDelimiterCharacter;
        }
      }
      outputStream << std::endl;
    }
    for (unsigned int i = 0; i < this->m_Rows; ++i)
    {
      if (!this->m_RowHeaders.empty())
      {
        if (i < this->m_RowHeaders.size())
        {
          outputStream << this->m_RowHeaders[i] << this->m_FieldDelimiterCharacter;
        }
      }

      for (unsigned int j = 0; j < this->m_Columns; ++j)
      {
        outputStream << std::setprecision(std::numeric_limits<TValue>::digits10) << *(this->m_InputObject++);

        if (j < this->m_Columns - 1)
        {
          outputStream << this->m_FieldDelimiterCharacter;
        }
      }
      outputStream << std::endl;
    }
  }
  catch (const itk::ExceptionObject & exp)
  {
    std::cerr << "Exception caught! " << std::endl << exp << std::endl;
    outputStream.close();
    throw;
  }
  catch (...)
  {
    outputStream.close();
    throw;
  }

  outputStream.close();
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::Update()
{
  this->Write();
}

template <typename TValue, unsigned int VRows, unsigned int VColumns>
void
CSVNumericObjectFileWriter<TValue, VRows, VColumns>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);
  os << indent << "File name: " << this->m_FileName << std::endl;
  os << indent << "Field Delimiter Character: " << this->m_FieldDelimiterCharacter << std::endl;
}


} // end namespace itk

#endif