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

/**
 * @class   vtkBSPCuts
 * @brief   This class represents an axis-aligned Binary Spatial
 *    Partitioning of a 3D space.
 *
 *
 *    This class converts between the vtkKdTree
 *    representation of a tree of vtkKdNodes (used by vtkDistributedDataFilter)
 *    and a compact array representation that might be provided by a
 *    graph partitioning library like Zoltan.  Such a representation
 *    could be used in message passing.
 *
 * @sa
 *      vtkKdTree vtkKdNode vtkDistributedDataFilter
 */

#ifndef vtkBSPCuts_h
#define vtkBSPCuts_h

#include "vtkCommonDataModelModule.h" // For export macro
#include "vtkDataObject.h"

VTK_ABI_NAMESPACE_BEGIN
class vtkKdNode;

class VTKCOMMONDATAMODEL_EXPORT vtkBSPCuts : public vtkDataObject
{
public:
  static vtkBSPCuts* New();
  vtkTypeMacro(vtkBSPCuts, vtkDataObject);
  void PrintSelf(ostream& os, vtkIndent indent) override;

  /**
   * Returns VTK_BSP_CUTS.
   */
  int GetDataObjectType() VTK_FUTURE_CONST override { return VTK_BSP_CUTS; }

  /**
   * Initialize the cuts with arrays of information.  This type of
   * information would be obtained from a graph partitioning software
   * package like Zoltan.

   * bounds - the bounds (xmin, xmax, ymin, ymax, zmin, zmax) of the
   * space being partitioned
   * ncuts - the number cuts, also the size of the following arrays
   * dim   - the dimension along which the cut is made (x/y/z - 0/1/2)
   * coord - the location of the cut along the axis
   * lower - array index for the lower region bounded by the cut
   * upper - array index for the upper region bounded by the cut
   * lowerDataCoord - optional upper bound of the data in the lower region
   * upperDataCoord - optional lower bound of the data in the upper region
   * npoints - optional number of points in the spatial region
   */

  void CreateCuts(double* bounds, int ncuts, int* dim, double* coord, int* lower, int* upper,
    double* lowerDataCoord, double* upperDataCoord, int* npoints);

  /**
   * Initialize the cuts from a tree of vtkKdNode's
   */

  void CreateCuts(vtkKdNode* kd);

  /**
   * Return a tree of vtkKdNode's representing the cuts specified
   * in this object.  This is our copy, don't delete it.
   */

  vtkKdNode* GetKdNodeTree() { return this->Top; }

  /**
   * Get the number of cuts in the partitioning, which also the size of
   * the arrays in the array representation of the partitioning.
   */

  vtkGetMacro(NumberOfCuts, int);

  /**
   * Get the arrays representing the cuts in the partitioning.
   */

  int GetArrays(int len, int* dim, double* coord, int* lower, int* upper, double* lowerDataCoord,
    double* upperDataCoord, int* npoints);

  /**
   * Compare these cuts with those of the other tree.  Returns true if
   * the two trees are the same.
   */
  int Equals(vtkBSPCuts* other, double tolerance = 0.0);

  void PrintTree();
  void PrintArrays();

  ///@{
  /**
   * Retrieve an instance of this class from an information object.
   */
  static vtkBSPCuts* GetData(vtkInformation* info);
  static vtkBSPCuts* GetData(vtkInformationVector* v, int i = 0);
  ///@}

  /**
   * Restore data object to initial state,
   */
  void Initialize() override;

  ///@{
  /**
   * Shallow copy.  These copy the data, but not any of the
   * pipeline connections.
   */
  void ShallowCopy(vtkDataObject* src) override;
  void DeepCopy(vtkDataObject* src) override;
  ///@}

protected:
  vtkBSPCuts();
  ~vtkBSPCuts() override;

  static void DeleteAllDescendants(vtkKdNode* kd);

  static int CountNodes(vtkKdNode* kd);
  static void SetMinMaxId(vtkKdNode* kd);
  static void PrintTree_(vtkKdNode* kd, int depth);

  void BuildTree(vtkKdNode* kd, int idx);
  int WriteArray(vtkKdNode* kd, int loc);

  void ResetArrays();
  void AllocateArrays(int size);

  vtkKdNode* Top;

  // required cut information

  int NumberOfCuts; // number of cuts, also length of each array
  int* Dim;         // dimension (x/y/z - 0/1/2) where cut occurs
  double* Coord;    // location of cut along axis
  int* Lower;       // location in arrays of left (lower) child info
  int* Upper;       // location in arrays of right (lower) child info

  // optional cut information

  double* LowerDataCoord; // coordinate of uppermost data in lower half
  double* UpperDataCoord; // coordinate of lowermost data in upper half
  int* Npoints;           // number of data values in partition

  double Bounds[6];

  vtkBSPCuts(const vtkBSPCuts&) = delete;
  void operator=(const vtkBSPCuts&) = delete;
};

VTK_ABI_NAMESPACE_END
#endif
