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

  Program:   Visualization Toolkit
  Module:    vtkUnstructuredGridWriter.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm 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 notice for more information.

=========================================================================*/
#include "vtkUnstructuredGridWriter.h"

#include "vtkByteSwap.h"
#include "vtkCellArray.h"
#include "vtkCellIterator.h"
#include "vtkErrorCode.h"
#include "vtkInformation.h"
#include "vtkObjectFactory.h"
#include "vtkSmartPointer.h"
#include "vtkUnstructuredGrid.h"

#include <algorithm>
#include <iterator>
#include <vector>

#if !defined(_WIN32) || defined(__CYGWIN__)
# include <unistd.h> /* unlink */
#else
# include <io.h> /* unlink */
#endif

vtkStandardNewMacro(vtkUnstructuredGridWriter);

void vtkUnstructuredGridWriter::WriteData()
{
  ostream *fp;
  vtkUnstructuredGrid *input= vtkUnstructuredGrid::SafeDownCast(
    this->GetInput());
  int *types, ncells, cellId;

  vtkDebugMacro(<<"Writing vtk unstructured grid data...");

  if ( !(fp=this->OpenVTKFile()) || !this->WriteHeader(fp) )
  {
    if (fp)
    {
      vtkErrorMacro("Ran out of disk space; deleting file: "
                    << this->FileName);
      this->CloseVTKFile(fp);
      unlink(this->FileName);
    }
    return;
  }
  //
  // Write unstructured grid specific stuff
  //
  *fp << "DATASET UNSTRUCTURED_GRID\n";

  // Write data owned by the dataset
  if (!this->WriteDataSetData(fp, input))
  {
    vtkErrorMacro("Ran out of disk space; deleting file: " << this->FileName);
    this->CloseVTKFile(fp);
    unlink(this->FileName);
    return;
  }

  if (!this->WritePoints(fp, input->GetPoints()))
  {
    vtkErrorMacro("Ran out of disk space; deleting file: " << this->FileName);
    this->CloseVTKFile(fp);
    unlink(this->FileName);
    return;
  }

  // Write cells. Check for faces so that we can handle them if present:
  if (input->GetFaces() != nullptr)
  {
    // Handle face data:
    if (!this->WriteCellsAndFaces(fp, input, "CELLS"))
    {
      vtkErrorMacro("Ran out of disk space; deleting file: " << this->FileName);
      this->CloseVTKFile(fp);
      unlink(this->FileName);
      return;
    }
  }
  else
  {
    // Fall back to superclass:
    if (!this->WriteCells(fp, input->GetCells(),"CELLS"))
    {
      vtkErrorMacro("Ran out of disk space; deleting file: " << this->FileName);
      this->CloseVTKFile(fp);
      unlink(this->FileName);
      return;
    }
  }

  //
  // Cell types are a little more work
  //
  if ( input->GetCells() )
  {
    ncells = input->GetCells()->GetNumberOfCells();
    types = new int[ncells];
    for (cellId=0; cellId < ncells; cellId++)
    {
      types[cellId] = input->GetCellType(cellId);
    }

    *fp << "CELL_TYPES " << ncells << "\n";
    if ( this->FileType == VTK_ASCII )
    {
      for (cellId=0; cellId<ncells; cellId++)
      {
        *fp << types[cellId] << "\n";
      }
    }
    else
    {
      // swap the bytes if necessary
      vtkByteSwap::SwapWrite4BERange(types,ncells,fp);
    }
    *fp << "\n";
    delete [] types;
  }

  if (!this->WriteCellData(fp, input))
  {
    vtkErrorMacro("Ran out of disk space; deleting file: " << this->FileName);
    this->CloseVTKFile(fp);
    unlink(this->FileName);
    return;
  }
  if (!this->WritePointData(fp, input))
  {
    vtkErrorMacro("Ran out of disk space; deleting file: " << this->FileName);
    this->CloseVTKFile(fp);
    unlink(this->FileName);
    return;
  }

  this->CloseVTKFile(fp);
}

int vtkUnstructuredGridWriter::WriteCellsAndFaces(
    ostream *fp, vtkUnstructuredGrid *grid, const char *label)
{
  if (!grid->GetCells())
  {
    return 1;
  }

  // Create a copy of the cell data with the face streams expanded.
  // Do this before writing anything so that we know the size.
  // Use ints to represent vtkIdTypes, since that's what the superclass does.
  std::vector<int> cells;
  cells.reserve(grid->GetNumberOfCells() * grid->GetMaxCellSize());

  vtkSmartPointer<vtkCellIterator> it =
      vtkSmartPointer<vtkCellIterator>::Take(grid->NewCellIterator());

  for (it->InitTraversal(); !it->IsDoneWithTraversal(); it->GoToNextCell())
  {
    if (it->GetCellType() != VTK_POLYHEDRON)
    {
      vtkIdType cellSize = it->GetNumberOfPoints();
      cells.push_back(static_cast<int>(cellSize));
      std::copy(it->GetPointIds()->GetPointer(0),
                it->GetPointIds()->GetPointer(cellSize),
                std::back_inserter(cells));
    }
    else
    {
      vtkIdType cellSize = it->GetFaces()->GetNumberOfIds();
      cells.push_back(static_cast<int>(cellSize));
      std::copy(it->GetFaces()->GetPointer(0),
                it->GetFaces()->GetPointer(cellSize),
                std::back_inserter(cells));
    }
  }

  if (cells.empty())
  { // Nothing to do.
    return 1;
  }

  *fp << label << " " << grid->GetNumberOfCells() << " "
      << cells.size() << "\n";

  if ( this->FileType == VTK_ASCII )
  { // Write each cell out to a separate line, must traverse:
    std::vector<int>::const_iterator cellStart = cells.begin();
    std::vector<int>::const_iterator cellEnd;
    vtkIdType nCells = grid->GetNumberOfCells();
    while (nCells-- > 0)
    {
      cellEnd = cellStart + (*cellStart + 1);
      while (cellStart != cellEnd)
        *fp << static_cast<int>(*cellStart++) << " ";
      *fp << "\n";
    }
  }
  else
  {
    // Just dump the cell data
    vtkByteSwap::SwapWrite4BERange(&cells[0], cells.size(), fp);
    *fp << "\n";
  }

  fp->flush();
  if (fp->fail())
  {
    this->SetErrorCode(vtkErrorCode::OutOfDiskSpaceError);
    return 0;
  }

  return 1;
}

int vtkUnstructuredGridWriter::FillInputPortInformation(int,
                                                        vtkInformation *info)
{
  info->Set(vtkAlgorithm::INPUT_REQUIRED_DATA_TYPE(), "vtkUnstructuredGrid");
  return 1;
}

vtkUnstructuredGrid* vtkUnstructuredGridWriter::GetInput()
{
  return vtkUnstructuredGrid::SafeDownCast(this->Superclass::GetInput());
}

vtkUnstructuredGrid* vtkUnstructuredGridWriter::GetInput(int port)
{
  return vtkUnstructuredGrid::SafeDownCast(this->Superclass::GetInput(port));
}

void vtkUnstructuredGridWriter::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os,indent);
}
