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

  Program:   Visualization Toolkit
  Module:    vtkmPolyDataNormals.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 "vtkmPolyDataNormals.h"

#include "vtkCellData.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkPointData.h"
#include "vtkPolyData.h"
#include "vtkSmartPointer.h"

#include "vtkmlib/ArrayConverters.h"
#include "vtkmlib/PolyDataConverter.h"
#include "vtkmlib/Storage.h"

#include "vtkmCellSetExplicit.h"
#include "vtkmCellSetSingleType.h"
#include "vtkmFilterPolicy.h"

#include "vtkm/filter/SurfaceNormals.h"


vtkStandardNewMacro(vtkmPolyDataNormals)

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

//------------------------------------------------------------------------------
vtkmPolyDataNormals::vtkmPolyDataNormals()
{
  // change defaults from parent
  this->Splitting = 0;
  this->Consistency = 0;
  this->FlipNormals = 0;
  this->ComputePointNormals = 1;
  this->ComputeCellNormals = 0;
  this->AutoOrientNormals = 0;
}

//------------------------------------------------------------------------------
vtkmPolyDataNormals::~vtkmPolyDataNormals() = default;

//------------------------------------------------------------------------------
int vtkmPolyDataNormals::RequestData(
  vtkInformation *request,
  vtkInformationVector **inputVector,
  vtkInformationVector *outputVector)
{
  // get the info objects
  vtkInformation *inInfo = inputVector[0]->GetInformationObject(0);
  vtkInformation *outInfo = outputVector->GetInformationObject(0);

  // get the input and output
  vtkPolyData *input = vtkPolyData::SafeDownCast(
    inInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkPolyData *output = vtkPolyData::SafeDownCast(
    outInfo->Get(vtkDataObject::DATA_OBJECT()));

  // convert the input dataset to a vtkm::cont::DataSet
  vtkm::cont::DataSet in = tovtkm::Convert(input);
  if (in.GetNumberOfCoordinateSystems() <= 0 || in.GetNumberOfCellSets() <= 0)
  {
    vtkErrorMacro(<< "Could not convert vtk dataset to vtkm dataset");
    return 0;
  }

  vtkmInputFilterPolicy policy;
  vtkm::cont::DataSet out;

  // check for flags that vtkm filter cannot handle
  bool unsupported = this->Splitting || this->Consistency || this->FlipNormals;
  bool vtkmSuccess = false;
  if (!unsupported)
  {
    vtkm::filter::SurfaceNormals filter;
    filter.SetGenerateCellNormals(this->ComputeCellNormals);
    filter.SetCellNormalsName("Normals");
    filter.SetGeneratePointNormals(this->ComputePointNormals);
    filter.SetPointNormalsName("Normals");
    auto result = filter.Execute(in, policy);

    if (result.IsFieldValid())
    {
      out = result.GetDataSet();
      vtkmSuccess = true;
    }
  }

  if (!vtkmSuccess)
  {
    vtkWarningMacro(<< "VTKm SurfaceNormals algorithm failed to run"
                    << (unsupported ? ": unsupported settings." : ".")
                    << "Falling back to vtkPolyDataNormals.");
    return this->Superclass::RequestData(request, inputVector, outputVector);
  }

  if (!fromvtkm::Convert(out, output, input))
  {
    vtkErrorMacro(<< "Unable to convert VTKm DataSet back to VTK");
    return 0;
  }
  vtkSmartPointer<vtkDataArray> pointNormals = output->GetPointData()->GetArray("Normals");
  vtkSmartPointer<vtkDataArray> cellNormals = output->GetCellData()->GetArray("Normals");

  output->GetPointData()->CopyNormalsOff();
  output->GetPointData()->PassData(input->GetPointData());
  output->GetCellData()->CopyNormalsOff();
  output->GetCellData()->PassData(input->GetPointData());

  if (pointNormals)
  {
    output->GetPointData()->SetNormals(pointNormals.GetPointer());
  }
  if (cellNormals)
  {
    output->GetCellData()->SetNormals(cellNormals.GetPointer());
  }

  return 1;
}
