//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt 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.
//
//  Copyright 2014 Sandia Corporation.
//  Copyright 2014 UT-Battelle, LLC.
//  Copyright 2014 Los Alamos National Security.
//
//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
//  the U.S. Government retains certain rights in this software.
//
//  Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
//  Laboratory (LANL), the U.S. Government retains certain rights in
//  this software.
//============================================================================

#include <vtkm/worklet/DispatcherMapField.h>

namespace
{

template<typename DeviceAdapter>
class DeduceCellSet 
{
  mutable vtkm::worklet::Tetrahedralize Worklet;
  vtkm::cont::CellSetSingleType<> &OutCellSet;

public:
  DeduceCellSet(vtkm::worklet::Tetrahedralize worklet,
                vtkm::cont::CellSetSingleType<>& outCellSet) :
    Worklet(worklet),
    OutCellSet(outCellSet)
  {}

  template<typename CellSetType>
  void operator()(const CellSetType& cellset ) const
  {
     this->OutCellSet = Worklet.Run(cellset, DeviceAdapter());
  }
};

}

namespace vtkm {
namespace filter {

//-----------------------------------------------------------------------------
inline VTKM_CONT
Tetrahedralize::Tetrahedralize():
  vtkm::filter::FilterDataSet<Tetrahedralize>(),
  Worklet()
{
}

//-----------------------------------------------------------------------------
template<typename DerivedPolicy,
         typename DeviceAdapter>
inline VTKM_CONT
vtkm::filter::ResultDataSet Tetrahedralize::DoExecute(
                                                 const vtkm::cont::DataSet& input,
                                                 const vtkm::filter::PolicyBase<DerivedPolicy>& policy,
                                                 const DeviceAdapter&)
{
  const vtkm::cont::DynamicCellSet& cells =
                  input.GetCellSet(this->GetActiveCellSetIndex());

  vtkm::cont::CellSetSingleType<> outCellSet;
  DeduceCellSet<DeviceAdapter> tetrahedralize(this->Worklet, outCellSet);

  vtkm::cont::CastAndCall(vtkm::filter::ApplyPolicy(cells, policy),
                          tetrahedralize);

  // create the output dataset
  vtkm::cont::DataSet output;
  output.AddCellSet(outCellSet);
  output.AddCoordinateSystem(input.GetCoordinateSystem(this->GetActiveCoordinateSystemIndex()) );

  return vtkm::filter::ResultDataSet(output);
}

//-----------------------------------------------------------------------------
template<typename T,
         typename StorageType,
         typename DerivedPolicy,
         typename DeviceAdapter>
inline VTKM_CONT
bool Tetrahedralize::DoMapField(
                           vtkm::filter::ResultDataSet& result,
                           const vtkm::cont::ArrayHandle<T, StorageType>& input,
                           const vtkm::filter::FieldMetadata& fieldMeta,
                           const vtkm::filter::PolicyBase<DerivedPolicy>&,
                           const DeviceAdapter& device)
{
  // point data is copied as is because it was not collapsed
  if(fieldMeta.IsPointField())
  {
    result.GetDataSet().AddField(fieldMeta.AsField(input));
    return true;
  }
  
  // cell data must be scattered to the cells created per input cell
  if(fieldMeta.IsCellField())
  {
    vtkm::cont::ArrayHandle<T, StorageType> output =
        this->Worklet.ProcessField(input, device);

    result.GetDataSet().AddField(fieldMeta.AsField(output));
    return true;
  }

  return false;
}

}
}