//============================================================================
//  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 (c) 2018, The Regents of the University of California, through
// Lawrence Berkeley National Laboratory (subject to receipt of any required approvals
// from the U.S. Dept. of Energy).  All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
// (1) Redistributions of source code must retain the above copyright notice, this
//     list of conditions and the following disclaimer.
//
// (2) Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//
// (3) Neither the name of the University of California, Lawrence Berkeley National
//     Laboratory, U.S. Dept. of Energy nor the names of its contributors may be
//     used to endorse or promote products derived from this software without
//     specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
// IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
// OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
// OF THE POSSIBILITY OF SUCH DAMAGE.
//
//=============================================================================
//
//  This code is an extension of the algorithm presented in the paper:
//  Parallel Peak Pruning for Scalable SMP Contour Tree Computation.
//  Hamish Carr, Gunther Weber, Christopher Sewell, and James Ahrens.
//  Proceedings of the IEEE Symposium on Large Data Analysis and Visualization
//  (LDAV), October 2016, Baltimore, Maryland.
//
//  The PPP2 algorithm and software were jointly developed by
//  Hamish Carr (University of Leeds), Gunther H. Weber (LBNL), and
//  Oliver Ruebel (LBNL)
//==============================================================================

#ifndef vtk_m_worklet_contourtree_augmented_contourtree_maker_inc_hypernodes_set_first_superchild_h
#define vtk_m_worklet_contourtree_augmented_contourtree_maker_inc_hypernodes_set_first_superchild_h

#include <vtkm/worklet/WorkletMapField.h>
#include <vtkm/worklet/contourtree_augmented/Types.h>

namespace vtkm
{
namespace worklet
{
namespace contourtree_augmented
{
namespace contourtree_maker_inc
{

// Worklet for loop through the hyperparents array, setting the first one for each
class ComputeHyperAndSuperStructure_HypernodesSetFirstSuperchild
  : public vtkm::worklet::WorkletMapField
{
public:
  typedef void ControlSignature(WholeArrayIn contourTreeHyperparents, // (input)
                                WholeArrayIn superSortIndex,          // (input)
                                WholeArrayOut contourTreeHypernodes   // (output)
  );
  typedef void ExecutionSignature(_1, InputIndex, _2, _3);
  using InputDomain = _1;

  // Default Constructor
  VTKM_EXEC_CONT
  ComputeHyperAndSuperStructure_HypernodesSetFirstSuperchild() {}

  template <typename InFieldPortalType, typename OutFieldPortalType>
  VTKM_EXEC void operator()(const InFieldPortalType& contourTreeHyperparentsPortal,
                            const vtkm::Id supernode,
                            const InFieldPortalType& superSortIndexPortal,
                            const OutFieldPortalType& contourTreeHypernodesPortal) const
  {
    bool isFirstSuperchild = false;
    vtkm::Id hyperparent = contourTreeHyperparentsPortal.Get(supernode);

    // first supernode is always a first superchild: otherwise, must have a different hyperparent
    if (supernode == 0)
      isFirstSuperchild = true;
    else if (hyperparent != contourTreeHyperparentsPortal.Get(supernode - 1))
      isFirstSuperchild = true;

    // set the hyperparent's first superchild
    if (isFirstSuperchild)
      contourTreeHypernodesPortal.Set(superSortIndexPortal.Get(MaskedIndex(hyperparent)),
                                      supernode);

    // In serial this worklet implements the following operation
    /*
      for (vtkm::Id supernode = 0; supernode < contourTree.Supernodes.size(); supernode++)
        { // per supernode
          bool isFirstSuperchild = false;
          vtkm::Id hyperparent = contourTree.hyperparents[supernode];

          // first supernode is always a first superchild: otherwise, must have a different hyperparent
          if (supernode == 0)
                  isFirstSuperchild = true;
          else if (hyperparent != contourTree.hyperparents[supernode-1])
                  isFirstSuperchild = true;

          // set the hyperparent's first superchild
          if (isFirstSuperchild)
                  contourTree.hypernodes[superSortIndex[MaskedIndex(hyperparent)]] = supernode;
        } // per supernode
      */
  }

}; // AugmentMergeTrees_InitNewJoinSplitIDAndSuperparents.h

} // namespace contourtree_maker_inc
} // namespace contourtree_augmented
} // namespace worklet
} // namespace vtkm

#endif