// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
// .SECTION Thanks
// This file is part of the generalized Youngs material interface reconstruction algorithm
// contributed by CEA/DIF - Commissariat a l'Energie Atomique, Centre DAM Ile-De-France <br> BP12,
// F-91297 Arpajon, France. <br> Implementation by Thierry Carrard and Philippe Pebay

#include "vtkPYoungsMaterialInterface.h"

#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkMultiBlockDataSet.h"
#include "vtkMultiProcessController.h"
#include "vtkObjectFactory.h"

VTK_ABI_NAMESPACE_BEGIN
vtkStandardNewMacro(vtkPYoungsMaterialInterface);
vtkCxxSetObjectMacro(vtkPYoungsMaterialInterface, Controller, vtkMultiProcessController);
//------------------------------------------------------------------------------
vtkPYoungsMaterialInterface::vtkPYoungsMaterialInterface()
{
  this->Controller = nullptr;
  this->SetController(vtkMultiProcessController::GetGlobalController());

  vtkDebugMacro(<< "vtkPYoungsMaterialInterface::vtkPYoungsMaterialInterface() ok\n");
}

//------------------------------------------------------------------------------
vtkPYoungsMaterialInterface::~vtkPYoungsMaterialInterface()
{
  this->SetController(nullptr);
}

//------------------------------------------------------------------------------
void vtkPYoungsMaterialInterface::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  os << indent << "Controller: " << this->Controller << endl;
}

//------------------------------------------------------------------------------
void vtkPYoungsMaterialInterface::Aggregate(int nmat, int* inputsPerMaterial)
{
  vtkIdType nprocs = this->Controller->GetNumberOfProcesses();
  if (nprocs < 2)
  {
    return;
  }

  // Now get ready for parallel calculations
  vtkCommunicator* com = this->Controller->GetCommunicator();
  if (!com)
  {
    vtkErrorMacro(<< "No parallel communicator.");
  }

  // Gather inputs per material from all processes
  vtkIdType myid = this->Controller->GetLocalProcessId();
  int* tmp = new int[nmat * nprocs];
  com->AllGather(inputsPerMaterial, tmp, nmat);

  // Scan sum : done by all processes, not optimal but easy
  for (vtkIdType m = 0; m < nmat; ++m)
  {
    for (vtkIdType p = 1; p < nprocs; ++p)
    {
      vtkIdType pnmat = p * nmat + m;
      tmp[pnmat] += tmp[pnmat - nmat];
    }
  }

  vtkIdType offset = (nprocs - 1) * nmat;
  this->NumberOfDomains = 0;
  for (int m = 0; m < nmat; ++m)
  {
    // Sum all counts from all processes
    int inputsPerMaterialSum = tmp[offset + m];
    this->NumberOfDomains = std::max(inputsPerMaterialSum, this->NumberOfDomains);

    // Calculate partial sum of all preceding processors
    inputsPerMaterial[m] = (myid ? tmp[(myid - 1) * nmat + m] : 0);
  }
  delete[] tmp;
}
VTK_ABI_NAMESPACE_END