// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause

/**
 * @class vtkDistributedPointCloudFilter
 * @brief Distributes points among MPI processors.
 *
 * This filter distributes points among processors into spatially
 * contiguous point set, containing an equivalent number of points.
 * Algorithm: point set is recursively split in two, among MPI groups.
 * Note: input cells are ignored. Output is a vtkPolyData.
 *
 * @par Thanks:
 * This class has been written by Kitware SAS from an initial work made by
 * Aymeric Pelle from Universite de Technologie de Compiegne, France,
 * and Laurent Colombet and Thierry Carrard from Commissariat a l'Energie
 * Atomique (CEA/DIF).
 */

#ifndef vtkDistributedPointCloudFilter_h
#define vtkDistributedPointCloudFilter_h

#include "vtkFiltersParallelMPIModule.h" // For export macro
#include "vtkPointSetAlgorithm.h"

#include <vector> // for vector

VTK_ABI_NAMESPACE_BEGIN
class vtkMPIController;
class vtkMultiProcessController;

class VTKFILTERSPARALLELMPI_EXPORT vtkDistributedPointCloudFilter : public vtkPointSetAlgorithm
{
public:
  static vtkDistributedPointCloudFilter* New();
  vtkTypeMacro(vtkDistributedPointCloudFilter, vtkPointSetAlgorithm);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  ///@{
  /**
   * Set/Get the communicator object
   */
  void SetController(vtkMultiProcessController*);
  vtkGetObjectMacro(Controller, vtkMultiProcessController);
  ///@}

  /**
   * Get the points that are inside innerBounds and put them in output DataSet.
   * Ask other MPI ranks for their corresponding points.
   */
  static void GetPointsInsideBounds(
    vtkMPIController*, vtkPointSet* input, vtkPointSet* output, const double innerBounds[6]);

protected:
  vtkDistributedPointCloudFilter();
  ~vtkDistributedPointCloudFilter() override;

  int FillOutputPortInformation(int port, vtkInformation* info) override;

  int RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;

  /**
   * Optimize bounding box following this rules:
   * - no intersection of bounding box of different MPI nodes
   * - same amount of point inside bounding box of each MPI nodes.
   *
   * Return false if input pointSet is nullptr or if no communicator was found.
   * Return true otherwise.
   */
  bool OptimizeBoundingBox(std::vector<vtkMPIController*>&, vtkPointSet*, double bounds[6]);

  /**
   * Initialize KdTreeRound: creates subControllers from Controller.
   * Delete old values if any.
   * Return false if KdTree cannot be initialized.
   */
  bool InitializeKdTree(std::vector<vtkMPIController*>&);

private:
  vtkDistributedPointCloudFilter(const vtkDistributedPointCloudFilter&) = delete;
  void operator=(const vtkDistributedPointCloudFilter&) = delete;

  vtkMultiProcessController* Controller;
};

VTK_ABI_NAMESPACE_END
#endif