#pragma once

#include <petsc/private/pcisimpl.h>

/*
   Private context (data structure) for the NN preconditioner.
*/
typedef struct {
  /* First MUST come the following line, for the stuff that is common to FETI and Neumann-Neumann. */
  PC_IS pcis;

  /* Then, everything else. */
  Mat           coarse_mat;
  Vec           coarse_x;
  Vec           coarse_b;
  KSP           ksp_coarse;
  PetscScalar **DZ_IN; /* proc[k].DZ_IN[i][] = bit of vector to be received from processor i by proc. k  */
  PetscScalar   factor_coarse_rhs;
} PC_NN;

PETSC_EXTERN PetscErrorCode PCNNCreateCoarseMatrix(PC);
PETSC_EXTERN PetscErrorCode PCNNApplySchurToChunk(PC pc, PetscInt n, PetscInt *idx, PetscScalar *chunk, PetscScalar *array_N, Vec vec1_B, Vec vec2_B, Vec vec1_D, Vec vec2_D);
PETSC_EXTERN PetscErrorCode PCNNApplyInterfacePreconditioner(PC pc, Vec r, Vec z, PetscScalar *work_N, Vec vec1_B, Vec vec2_B, Vec vec3_B, Vec vec1_D, Vec vec2_D, Vec vec1_N, Vec vec2_N);
PETSC_EXTERN PetscErrorCode PCNNBalancing(PC pc, Vec r, Vec u, Vec z, Vec vec1_B, Vec vec2_B, Vec vec3_B, Vec vec1_D, Vec vec2_D, PetscScalar *work_N);