/*=========================================================================
 *
 *  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 itkCSVArray2DFileReader_hxx
#define itkCSVArray2DFileReader_hxx


#include "itksys/SystemTools.hxx"
#include <limits>

namespace itk
{

template <typename TData>
CSVArray2DFileReader<TData>::CSVArray2DFileReader()
{
  this->m_Array2DDataObject = Array2DDataObjectType::New();
}

template <typename TData>
void
CSVArray2DFileReader<TData>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);
  os << this->m_Array2DDataObject << std::endl;
}

template <typename TData>
void
CSVArray2DFileReader<TData>::Parse()
{
  SizeValueType rows = 0;
  SizeValueType columns = 0;

  this->PrepareForParsing();

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

  // Get the data dimension and set the matrix size
  this->GetDataDimension(rows, columns);

  this->m_Array2DDataObject->SetMatrixSize(rows, columns);

  /** initialize the matrix to NaN so that missing data will automatically be
   *  set to this value. */
  this->m_Array2DDataObject->FillMatrix(std::numeric_limits<TData>::quiet_NaN());

  std::string entry;

  // Get the Column Headers if there are any.
  if (this->m_HasColumnHeaders)
  {
    this->m_Array2DDataObject->HasColumnHeadersOn();

    // push the entries into the column headers vector.
    for (unsigned int i = 0; i < columns + 1; ++i)
    {
      this->GetNextField(entry);
      this->m_Array2DDataObject->ColumnHeadersPushBack(entry);
      if (this->m_Line.empty())
      {
        break;
      }
    }

    /** if there are row headers, get rid of the first entry in the column
     *  headers as it will just be the name of the table. */
    if (this->m_HasRowHeaders)
    {
      this->m_Array2DDataObject->EraseFirstColumnHeader();
    }
  }

  // Get the rest of the data
  for (unsigned int i = 0; i < rows; ++i)
  {
    // if there are row headers, push them into the vector for row headers
    if (this->m_HasRowHeaders)
    {
      this->m_Array2DDataObject->HasRowHeadersOn();
      this->GetNextField(entry);
      this->m_Array2DDataObject->RowHeadersPushBack(entry);
    }

    // parse the numeric data into the Array2D object
    for (unsigned int j = 0; j < columns; ++j)
    {
      this->GetNextField(entry);
      this->m_Array2DDataObject->SetMatrixData(i, j, this->ConvertStringToValueType<TData>(entry));

      /** if the file contains missing data, m_Line will contain less data
       * fields. So we check if m_Line is empty and if it is, we break out of
       * this loop and move to the next line. */
      if (this->m_Line.empty())
      {
        break;
      }
    }
  }

  this->m_InputStream.close();
}

/** Update method */
template <typename TData>
void
CSVArray2DFileReader<TData>::Update()
{
  this->Parse();
}

/** Get the output */
template <typename TData>
auto
CSVArray2DFileReader<TData>::GetOutput() -> Array2DDataObjectPointer
{
  return this->GetModifiableArray2DDataObject();
}


} // end namespace itk

#endif
