//============================================================================
//  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 National Technology & Engineering Solutions of Sandia, LLC (NTESS).
//  Copyright 2014 UT-Battelle, LLC.
//  Copyright 2014 Los Alamos National Security.
//
//  Under the terms of Contract DE-NA0003525 with NTESS,
//  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.
//============================================================================
// 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 vtkm_worklet_contourtree_augmented_active_graph_initialize_edge_far_from_active_indices_h
#define vtkm_worklet_contourtree_augmented_active_graph_initialize_edge_far_from_active_indices_h

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


namespace vtkm
{
namespace worklet
{
namespace contourtree_augmented
{
namespace active_graph_inc
{


// Worklet for computing the sort indices from the sort order
class InitializeEdgeFarFromActiveIndices : public vtkm::worklet::WorkletMapField
{
public:
  typedef void ControlSignature(WholeArrayInOut<IdType> edgeFar,     // (input/output) edge far
                                WholeArrayIn<IdType> extrema,        // (input) extremum
                                WholeArrayIn<IdType> activeIndices); // (input) activeIndices
  typedef void ExecutionSignature(_1, InputIndex, _2, _3);
  typedef _1 InputDomain;

  // Default Constructor
  VTKM_EXEC_CONT
  InitializeEdgeFarFromActiveIndices() {}

  template <typename InOutFieldPortalType, typename InFieldPortalType>
  VTKM_EXEC void operator()(const InOutFieldPortalType& edgeFarPortal,
                            const vtkm::Id edge,
                            const InFieldPortalType& extremaPortal,
                            const InFieldPortalType& activeIndicesPortal) const
  {
    // first we retrieve the ID of the far end
    vtkm::Id currEdgeFar = edgeFarPortal.Get(edge);
    // next we follow up to an extremum
    currEdgeFar = vtkm::worklet::contourtree_augmented::maskedIndex(extremaPortal.Get(currEdgeFar));
    // now we reverse lookup to get the new ID
    edgeFarPortal.Set(edge, activeIndicesPortal.Get(currEdgeFar));

    // In serial this worklet implements the following operation
    // for (indexType edge = 0; edge < edgeNear.size(); edge++)
    // { // per edge
    //   // first we retrieve the ID of the far end
    //   indexType currEdgeFar = edgeFar[edge];
    //   // next we follow up to an extremum
    //   currEdgeFar = maskedIndex(extrema[currEdgeFar]);
    //   // now we reverse lookup to get the new ID
    //   edgeFar[edge] = activeIndices[currEdgeFar];
    // } per edge
  }


}; //  InitializeEdgeFarFromActiveIndices


} // namespace active_graph_inc
} // namespace contourtree_augmented
} // namespace worklet
} // namespace vtkm

#endif
