#if !defined(__GAMG_IMPL)
#define __GAMG_IMPL
#include <petsc-private/pcimpl.h>
#include <../src/ksp/pc/impls/mg/mgimpl.h>                    /*I "petscksp.h" I*/
#include <../src/mat/impls/aij/seq/aij.h>
#include <../src/mat/impls/aij/mpi/mpiaij.h>

struct _PCGAMGOps {
  PetscErrorCode (*graph)(PC, const Mat, Mat*);
  PetscErrorCode (*coarsen)(PC, Mat*, PetscCoarsenData**);
  PetscErrorCode (*prolongator)(PC, const Mat, const Mat, PetscCoarsenData*, Mat*);
  PetscErrorCode (*optprol)(PC, const Mat, Mat*);
  PetscErrorCode (*createdefaultdata)(PC, Mat); /* for data methods that have a default (SA) */
  PetscErrorCode (*setfromoptions)(PC);
  PetscErrorCode (*destroy)(PC);
};

/* Private context for the GAMG preconditioner */
typedef struct gamg_TAG {
  PetscInt  Nlevels;
  PetscInt  setup_count;
  PetscBool repart;
  PetscBool reuse_prol;
  PetscBool use_aggs_in_gasm;
  PetscInt  min_eq_proc;
  PetscInt  coarse_eq_limit;
  PetscReal threshold;      /* common quatity to many AMG methods so keep it up here */
  PetscInt  verbose;
  PetscInt  emax_id;      /* stashing places */

  /* these 4 are all related to the method data and should be in the subctx */
  PetscInt  data_sz;      /* nloc*data_rows*data_cols */
  PetscInt  data_cell_rows;
  PetscInt  data_cell_cols;
  PetscInt  orig_data_cell_rows;
  PetscInt  orig_data_cell_cols;
  PetscReal eigtarget[2];
  PetscReal *data;          /* [data_sz] blocked vector of vertex data on fine grid (coordinates/nullspace) */
  PetscReal *orig_data;          /* cache data */

  struct _PCGAMGOps *ops;
  char *gamg_type_name;

  void *subctx;
} PC_GAMG;

PetscErrorCode PCSetFromOptions_MG(PC);
PetscErrorCode PCReset_MG(PC);

/* hooks create derivied classes */
PetscErrorCode  PCCreateGAMG_GEO(PC pc);
PetscErrorCode  PCCreateGAMG_AGG(PC pc);
PetscErrorCode  PCCreateGAMG_Classical(PC pc);

PetscErrorCode PCSetFromOptions_GAMG(PC pc);
PetscErrorCode PCDestroy_GAMG(PC pc);

/* helper methods */
PetscErrorCode PCGAMGCreateGraph(const Mat, Mat*);
PetscErrorCode PCGAMGFilterGraph(Mat*, const PetscReal, const PetscBool, const PetscInt);
PetscErrorCode PCGAMGGetDataWithGhosts(const Mat a_Gmat, const PetscInt a_data_sz, const PetscReal a_data_in[],PetscInt *a_stride, PetscReal **a_data_out);

#if defined PETSC_USE_LOG
/* #define PETSC_GAMG_USE_LOG */
enum tag {SET1,SET2,GRAPH,GRAPH_MAT,GRAPH_FILTER,GRAPH_SQR,SET4,SET5,SET6,FIND_V,SET7,SET8,SET9,SET10,SET11,SET12,SET13,SET14,SET15,SET16,NUM_SET};
#if defined PETSC_GAMG_USE_LOG
PETSC_INTERN PetscLogEvent petsc_gamg_setup_events[NUM_SET];
#endif
PETSC_INTERN PetscLogEvent PC_GAMGGgraph_AGG;
PETSC_INTERN PetscLogEvent PC_GAMGGgraph_GEO;
PETSC_INTERN PetscLogEvent PC_GAMGCoarsen_AGG;
PETSC_INTERN PetscLogEvent PC_GAMGCoarsen_GEO;
PETSC_INTERN PetscLogEvent PC_GAMGProlongator_AGG;
PETSC_INTERN PetscLogEvent PC_GAMGProlongator_GEO;
PETSC_INTERN PetscLogEvent PC_GAMGOptprol_AGG;
#endif

typedef struct _GAMGHashTable {
  PetscInt *table;
  PetscInt *data;
  PetscInt size;
} GAMGHashTable;

PETSC_EXTERN PetscErrorCode GAMGTableCreate(PetscInt a_size, GAMGHashTable *a_tab);
PETSC_EXTERN PetscErrorCode GAMGTableDestroy(GAMGHashTable*);
PETSC_EXTERN PetscErrorCode GAMGTableAdd(GAMGHashTable *a_tab, PetscInt a_key, PetscInt a_data);
PETSC_EXTERN PetscErrorCode GAMGTableFind(GAMGHashTable *a_tab, PetscInt a_key, PetscInt *a_data);

#endif