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

  Program:   Visualization Toolkit
  Module:    vtkBoostBrandesCentrality.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.

=========================================================================*/
/*-------------------------------------------------------------------------
  Copyright 2008 Sandia Corporation.
  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
  the U.S. Government retains certain rights in this software.
-------------------------------------------------------------------------*/
#include "vtkBoostBrandesCentrality.h"

#include "vtkCellArray.h"
#include "vtkCellData.h"
#include "vtkMath.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkFloatArray.h"
#include "vtkDataArray.h"
#include "vtkSmartPointer.h"
#include "vtkStringArray.h"

#include "vtkBoostGraphAdapter.h"
#include "vtkDirectedGraph.h"
#include "vtkUndirectedGraph.h"

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/betweenness_centrality.hpp>
#include <boost/graph/properties.hpp>

using namespace boost;

vtkStandardNewMacro(vtkBoostBrandesCentrality);

//-----------------------------------------------------------------------------
vtkBoostBrandesCentrality::vtkBoostBrandesCentrality() :
  UseEdgeWeightArray    (false),
  InvertEdgeWeightArray (false),
  EdgeWeightArrayName   (nullptr)
{
}

//-----------------------------------------------------------------------------
vtkBoostBrandesCentrality::~vtkBoostBrandesCentrality()
{
  this->SetEdgeWeightArrayName(nullptr);
}

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

  os << indent << "UseEdgeWeightArray: " << this->UseEdgeWeightArray << endl;

  os << indent << "InvertEdgeWeightArray: " << this->InvertEdgeWeightArray
    << endl;

  os << indent << "this->EdgeWeightArrayName: " <<
    (this->EdgeWeightArrayName ?  this->EdgeWeightArrayName : "nullptr") << endl;
}

//-----------------------------------------------------------------------------
int vtkBoostBrandesCentrality::RequestData(
  vtkInformation *vtkNotUsed(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
  vtkGraph *input = vtkGraph::SafeDownCast(
    inInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkGraph *output = vtkGraph::SafeDownCast(
    outInfo->Get(vtkDataObject::DATA_OBJECT()));

  // Send the data to output.
  output->ShallowCopy(input);

  // Compute betweenness centrality

  // Property map for vertices
  vtkFloatArray* vertexCMap = vtkFloatArray::New();
  vertexCMap->SetName("centrality");
  identity_property_map imap;

  // Property map for edges
  vtkFloatArray* edgeCMap = vtkFloatArray::New();
  edgeCMap->SetName("centrality");
  vtkGraphEdgePropertyMapHelper<vtkFloatArray*> helper(edgeCMap);

  vtkSmartPointer<vtkDataArray> edgeWeight (0);
  if(this->UseEdgeWeightArray && this->EdgeWeightArrayName)
  {
    if(!this->InvertEdgeWeightArray)
    {
      edgeWeight = input->GetEdgeData()->GetArray(this->EdgeWeightArrayName);
    }
    else
    {
      vtkDataArray* weights =
          input->GetEdgeData()->GetArray(this->EdgeWeightArrayName);

      if(!weights)
      {
        vtkErrorMacro(<<"Error: Edge weight array " << this->EdgeWeightArrayName
                      << " is set but not found or not a data array.\n");
        return 0;
      }

      edgeWeight.TakeReference(
        vtkDataArray::CreateDataArray(weights->GetDataType()));

      double range[2];
      weights->GetRange(range);

      if(weights->GetNumberOfComponents() > 1)
      {
        return 0;
      }

      for(int i=0; i < weights->GetDataSize(); ++i)
      {
        edgeWeight->InsertNextTuple1(range[1] - weights->GetTuple1(i));
      }
    }

    if(!edgeWeight)
    {
      vtkErrorMacro(<<"Error: Edge weight array " << this->EdgeWeightArrayName
                    << " is set but not found or not a data array.\n");
      return 0;
    }
  }

  // Is the graph directed or undirected
  if (vtkDirectedGraph::SafeDownCast(output))
  {
    vtkDirectedGraph *g = vtkDirectedGraph::SafeDownCast(output);
    if(edgeWeight)
    {
      vtkGraphEdgePropertyMapHelper<vtkDataArray*> helper2(edgeWeight);
      brandes_betweenness_centrality(g,
        centrality_map(vertexCMap).edge_centrality_map(
          helper).vertex_index_map(imap).weight_map(helper2));
    }
    else
    {
      brandes_betweenness_centrality(g,
        centrality_map(vertexCMap).edge_centrality_map(
          helper).vertex_index_map(imap));
    }
  }
  else
  {
    vtkUndirectedGraph *g = vtkUndirectedGraph::SafeDownCast(output);
    if(edgeWeight)
    {
      vtkGraphEdgePropertyMapHelper<vtkDataArray*> helper2(edgeWeight);
      brandes_betweenness_centrality(g,
             centrality_map(vertexCMap).edge_centrality_map(
               helper).vertex_index_map(imap).weight_map(helper2));
    }
    else
    {
      brandes_betweenness_centrality(g,
             centrality_map(vertexCMap).edge_centrality_map(
               helper).vertex_index_map(imap));
    }
  }

  // Add the arrays to the output and dereference
  output->GetVertexData()->AddArray(vertexCMap);
  vertexCMap->Delete();
  output->GetEdgeData()->AddArray(edgeCMap);
  edgeCMap->Delete();

  return 1;
}