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

  Program:   ParaView
  Module:    $RCSfile: vtkPExtentTranslator.cxx,v $

  Copyright (c) Kitware, Inc.
  All rights reserved.
  See Copyright.txt or http://www.paraview.org/HTML/Copyright.html 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.

=========================================================================*/
#include "vtkPExtentTranslator.h"

#include "vtkImageData.h"
#include "vtkMultiProcessController.h"
#include "vtkObjectFactory.h"
#include "vtkRectilinearGrid.h"
#include "vtkStructuredGrid.h"

#include <cassert>
#include <vector>

class vtkPExtentTranslatorInternals
{
public:
  std::vector<int> AllProcessExtents;
};

vtkStandardNewMacro(vtkPExtentTranslator);
//----------------------------------------------------------------------------
vtkPExtentTranslator::vtkPExtentTranslator()
{
  this->Internals = new vtkPExtentTranslatorInternals;
}

//----------------------------------------------------------------------------
vtkPExtentTranslator::~vtkPExtentTranslator()
{
  delete this->Internals;
  this->Internals = NULL;
}

//----------------------------------------------------------------------------
int vtkPExtentTranslatorPieceToExtentThreadSafe(
  int *resultExtent, vtkDataSet* dataSet)
{
  // this is really only meant for topologically structured grids
  if (vtkImageData* id = vtkImageData::SafeDownCast(dataSet))
    {
    id->GetExtent(resultExtent);
    }
  else if (vtkStructuredGrid* sd = vtkStructuredGrid::SafeDownCast(dataSet))
    {
    sd->GetExtent(resultExtent);
    }
  else if (vtkRectilinearGrid* rd = vtkRectilinearGrid::SafeDownCast(dataSet))
    {
    rd->GetExtent(resultExtent);
    }
  else
    {
    return 0;
    }
  return 1;
}

//-----------------------------------------------------------------------------
int vtkPExtentTranslator::PieceToExtentThreadSafe(
  int piece, int vtkNotUsed(numPieces), int vtkNotUsed(ghostLevel),
  int *vtkNotUsed(wholeExtent), int *resultExtent, int vtkNotUsed(splitMode),
  int vtkNotUsed(byPoints))
{
  assert(piece >= 0);

  assert(
    static_cast<int>(this->Internals->AllProcessExtents.size()) % 6 == 0);

  if (this->Internals->AllProcessExtents.size() >= 6)
    {
    if (static_cast<size_t>(piece*6) >= this->Internals->AllProcessExtents.size())
      {
      vtkErrorMacro("Invalid piece.");
      return 0;
      }

    memcpy(resultExtent, &this->Internals->AllProcessExtents[piece*6], sizeof(int)*6);
    return 1;
    }

  vtkErrorMacro("GatherExtents must be called before this method");
  return 0;
}

//----------------------------------------------------------------------------
void vtkPExtentTranslator::GatherExtents(vtkDataSet* dataset)
{
  if (dataset == NULL)
    {
    this->Internals->AllProcessExtents.clear();
    return;
    }

  vtkMultiProcessController* controller = vtkMultiProcessController::GetGlobalController();

  int myExtent[6];
  vtkPExtentTranslatorPieceToExtentThreadSafe(myExtent, dataset);
  int myId = controller? controller->GetLocalProcessId() : 0;
  int numProcs = controller? controller->GetNumberOfProcesses() : 1;

  assert(numProcs >= 1);

  this->Internals->AllProcessExtents.resize(numProcs*6);
  if (numProcs > 1)
    {
    controller->AllGather(
      myExtent, &(this->Internals->AllProcessExtents[0]), 6);
    }
  else
    {
    assert(myId == 0);
    (void)myId; // "use" myId in non-assert'ing builds.
    memcpy(&this->Internals->AllProcessExtents[0], myExtent, sizeof(int)*6);
    }
}

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