//=============================================================================
//
//  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 2012 Sandia Corporation.
//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
//  the U.S. Government retains certain rights in this software.
//
//=============================================================================
#include "vtkmLevelOfDetail.h"
#include "vtkmConfig.h"

#include "vtkDataSet.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkNew.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkPolyData.h"

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

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

#include <vtkm/filter/VertexClustering.h>
// To handle computing custom coordinate sets bounds we need to include
// the following
#include <vtkm/cont/ArrayRangeCompute.hxx>


vtkStandardNewMacro(vtkmLevelOfDetail)

//------------------------------------------------------------------------------
vtkmLevelOfDetail::vtkmLevelOfDetail()
{
  this->NumberOfDivisions[0] = 512;
  this->NumberOfDivisions[1] = 512;
  this->NumberOfDivisions[2] = 512;
}

//------------------------------------------------------------------------------
vtkmLevelOfDetail::~vtkmLevelOfDetail()
{
}

//------------------------------------------------------------------------------
void vtkmLevelOfDetail::SetNumberOfXDivisions(int num)
{
  this->Modified();
  this->NumberOfDivisions[0] = num;
}

//------------------------------------------------------------------------------
void vtkmLevelOfDetail::SetNumberOfYDivisions(int num)
{
  this->Modified();
  this->NumberOfDivisions[1] = num;
}

//------------------------------------------------------------------------------
void vtkmLevelOfDetail::SetNumberOfZDivisions(int num)
{
  this->Modified();
  this->NumberOfDivisions[2] = num;
}

//------------------------------------------------------------------------------
int vtkmLevelOfDetail::GetNumberOfXDivisions()
{
  return this->NumberOfDivisions[0];
}

//------------------------------------------------------------------------------
int vtkmLevelOfDetail::GetNumberOfYDivisions()
{
  return this->NumberOfDivisions[1];
}

//------------------------------------------------------------------------------
int vtkmLevelOfDetail::GetNumberOfZDivisions()
{
  return this->NumberOfDivisions[2];
}

//------------------------------------------------------------------------------
void vtkmLevelOfDetail::SetNumberOfDivisions(int div0, int div1, int div2)
{
  this->Modified();
  this->NumberOfDivisions[0] = div0;
  this->NumberOfDivisions[1] = div1;
  this->NumberOfDivisions[2] = div2;
}

//------------------------------------------------------------------------------
const int* vtkmLevelOfDetail::GetNumberOfDivisions()
{
  return this->NumberOfDivisions;
}

//------------------------------------------------------------------------------
void vtkmLevelOfDetail::GetNumberOfDivisions(int div[3])
{
  div[0] = this->NumberOfDivisions[0];
  div[1] = this->NumberOfDivisions[1];
  div[2] = this->NumberOfDivisions[1];
}

//------------------------------------------------------------------------------
int vtkmLevelOfDetail::RequestData(vtkInformation* vtkNotUsed(request),
                                   vtkInformationVector** inputVector,
                                   vtkInformationVector* outputVector)
{
  vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);
  vtkInformation* outInfo = outputVector->GetInformationObject(0);
  vtkDataSet* input =
      vtkDataSet::SafeDownCast(inInfo->Get(vtkDataObject::DATA_OBJECT()));

  vtkPolyData* output =
      vtkPolyData::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));

  if (!input || input->GetNumberOfPoints() == 0)
  {
    // Fail gracefully on empty inputs
    return 1;
  }

  // convert the input dataset to a vtkm::cont::DataSet
  vtkm::cont::DataSet in = tovtkm::Convert(input,
                                           tovtkm::FieldsFlag::PointsAndCells);
  const bool dataSetValid =
      in.GetNumberOfCoordinateSystems() > 0 && in.GetNumberOfCellSets() > 0;
  if (!dataSetValid)
  {
    vtkErrorMacro(<< "Unable convert dataset over to VTK-m for input.");
    return 0;
  }

  vtkm::filter::VertexClustering filter;

  filter.SetNumberOfDivisions(vtkm::make_Vec(this->NumberOfDivisions[0],
                                             this->NumberOfDivisions[1],
                                             this->NumberOfDivisions[2]));

  vtkmInputFilterPolicy policy;
  vtkm::filter::Result result = filter.Execute(in, policy);

  // currently we can't convert point based scalar arrays over to the new output
  // as the algorithm doesn't cache any of the interpolation data
  //
  // This shouldn't be hard, the question that we need answered is should
  // we average the point field like we average the coordinates, or should
  // we just take a random value. See VTKM issue #161. The mapping below is a
  // no-op until this is resolved.
  bool convertedDataSet = false;
  if (result.IsDataSetValid())
  {
    // Map fields:
    vtkm::Id numFields = static_cast<vtkm::Id>(in.GetNumberOfFields());
    for (vtkm::Id fieldIdx = 0; fieldIdx < numFields; ++fieldIdx)
    {
      const vtkm::cont::Field &field = in.GetField(fieldIdx);
      try
      {
        filter.MapFieldOntoOutput(result, field, policy);
      }
      catch (vtkm::cont::Error &e)
      {
        vtkWarningMacro(<< "Unable to use VTKm to convert field( "
                        << field.GetName() << " ) to the LevelOfDetail"
                        << " output: " << e.what());
      }
    }

    // convert back the dataset to VTK
    convertedDataSet = fromvtkm::Convert(result.GetDataSet(), output, input);
  }

  return static_cast<int>(convertedDataSet);
}

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

  os << indent << "Number of X Divisions: " << this->NumberOfDivisions[0]
     << "\n";
  os << indent << "Number of Y Divisions: " << this->NumberOfDivisions[1]
     << "\n";
  os << indent << "Number of Z Divisions: " << this->NumberOfDivisions[2]
     << "\n";
}