/*
   A star forest (SF) describes a communication pattern
*/
#ifndef PETSCSF_H
#define PETSCSF_H

#include <petscsys.h>
#include <petscsftypes.h>
#include <petscvec.h> /* for Vec, VecScatter etc */

/* SUBMANSEC = PetscSF */

PETSC_EXTERN PetscClassId PETSCSF_CLASSID;

#define PETSCSFBASIC      "basic"
#define PETSCSFNEIGHBOR   "neighbor"
#define PETSCSFALLGATHERV "allgatherv"
#define PETSCSFALLGATHER  "allgather"
#define PETSCSFGATHERV    "gatherv"
#define PETSCSFGATHER     "gather"
#define PETSCSFALLTOALL   "alltoall"
#define PETSCSFWINDOW     "window"

/*E
   PetscSFPattern - Pattern of the PetscSF graph

$  `PETSCSF_PATTERN_GENERAL`   - A general graph. One sets the graph with PetscSFSetGraph() and usually does not use this enum directly.
$  `PETSCSF_PATTERN_ALLGATHER` - A graph that every rank gathers all roots from all ranks (like `MPI_Allgather()`). One sets the graph with `PetscSFSetGraphWithPattern()`.
$  `PETSCSF_PATTERN_GATHER`    - A graph that rank 0 gathers all roots from all ranks (like `MPI_Gatherv()` with root=0). One sets the graph with `PetscSFSetGraphWithPattern()`.
$  `PETSCSF_PATTERN_ALLTOALL`  - A graph that every rank gathers different roots from all ranks (like `MPI_Alltoall()`). One sets the graph with `PetscSFSetGraphWithPattern()`.
                               In an ALLTOALL graph, we assume each process has <size> leaves and <size> roots, with each leaf connecting to a remote root. Here <size> is
                               the size of the communicator. This does not mean one can not communicate multiple data items between a pair of processes. One just needs to
                               create a new MPI datatype for the multiple data items, e.g., by `MPI_Type_contiguous`.
   Level: beginner

.seealso: `PetscSFSetGraph()`, `PetscSFSetGraphWithPattern()`
E*/
typedef enum {
  PETSCSF_PATTERN_GENERAL = 0,
  PETSCSF_PATTERN_ALLGATHER,
  PETSCSF_PATTERN_GATHER,
  PETSCSF_PATTERN_ALLTOALL
} PetscSFPattern;

/*E
    PetscSFWindowSyncType - Type of synchronization for `PETSCSFWINDOW`

$  `PETSCSF_WINDOW_SYNC_FENCE` - simplest model, synchronizing across communicator
$  `PETSCSF_WINDOW_SYNC_LOCK` - passive model, less synchronous, requires less setup than PETSCSF_WINDOW_SYNC_ACTIVE, but may require more handshakes
$  `PETSCSF_WINDOW_SYNC_ACTIVE` - active model, provides most information to MPI implementation, needs to construct 2-way process groups (more setup than PETSCSF_WINDOW_SYNC_LOCK)

   Level: advanced

.seealso: `PetscSFWindowSetSyncType()`, `PetscSFWindowGetSyncType()`
E*/
typedef enum {
  PETSCSF_WINDOW_SYNC_FENCE,
  PETSCSF_WINDOW_SYNC_LOCK,
  PETSCSF_WINDOW_SYNC_ACTIVE
} PetscSFWindowSyncType;
PETSC_EXTERN const char *const PetscSFWindowSyncTypes[];

/*E
    PetscSFWindowFlavorType - Flavor for the creation of MPI windows for PETSCSFWINDOW

$  `PETSCSF_WINDOW_FLAVOR_CREATE` - Use `MPI_Win_create()`, no reuse
$  `PETSCSF_WINDOW_FLAVOR_DYNAMIC` - Use `MPI_Win_create_dynamic()` and dynamically attach pointers
$  `PETSCSF_WINDOW_FLAVOR_ALLOCATE` - Use `MPI_Win_allocate()`
$  `PETSCSF_WINDOW_FLAVOR_SHARED` - Use `MPI_Win_allocate_shared()`

   Level: advanced

.seealso: `PetscSFWindowSetFlavorType()`, `PetscSFWindowGetFlavorType()`
E*/
typedef enum {
  PETSCSF_WINDOW_FLAVOR_CREATE,
  PETSCSF_WINDOW_FLAVOR_DYNAMIC,
  PETSCSF_WINDOW_FLAVOR_ALLOCATE,
  PETSCSF_WINDOW_FLAVOR_SHARED
} PetscSFWindowFlavorType;
PETSC_EXTERN const char *const PetscSFWindowFlavorTypes[];

/*E
    PetscSFDuplicateOption - Aspects to preserve when duplicating a `PetscSF`

$  `PETSCSF_DUPLICATE_CONFONLY` - configuration only, user must call `PetscSFSetGraph()`
$  `PETSCSF_DUPLICATE_RANKS` - communication ranks preserved, but different graph (allows simpler setup after calling `PetscSFSetGraph()`)
$  `PETSCSF_DUPLICATE_GRAPH` - entire graph duplicated

   Level: beginner

.seealso: `PetscSFDuplicate()`
E*/
typedef enum {
  PETSCSF_DUPLICATE_CONFONLY,
  PETSCSF_DUPLICATE_RANKS,
  PETSCSF_DUPLICATE_GRAPH
} PetscSFDuplicateOption;
PETSC_EXTERN const char *const PetscSFDuplicateOptions[];

/*E
    PetscSFConcatenateRootMode - Modes of root concatenation when concatenating SFs

$  `PETSCSF_CONCATENATE_ROOTMODE_LOCAL`  - concatenate root spaces locally (separately on each rank)
$  `PETSCSF_CONCATENATE_ROOTMODE_SHARED` - do not concatenate roots; root space is considered the same for each input SF (checked in debug mode)
$  `PETSCSF_CONCATENATE_ROOTMODE_GLOBAL` - concatenate root spaces globally

   Level: advanced

.seealso: `PetscSFConcatenate()`
E*/
typedef enum {
  PETSCSF_CONCATENATE_ROOTMODE_LOCAL,
  PETSCSF_CONCATENATE_ROOTMODE_SHARED,
  PETSCSF_CONCATENATE_ROOTMODE_GLOBAL,
} PetscSFConcatenateRootMode;
PETSC_EXTERN const char *const PetscSFConcatenateRootModes[];

PETSC_EXTERN PetscFunctionList PetscSFList;
PETSC_EXTERN PetscErrorCode    PetscSFRegister(const char[], PetscErrorCode (*)(PetscSF));

PETSC_EXTERN PetscErrorCode PetscSFInitializePackage(void);
PETSC_EXTERN PetscErrorCode PetscSFFinalizePackage(void);
PETSC_EXTERN PetscErrorCode PetscSFCreate(MPI_Comm, PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFDestroy(PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFSetType(PetscSF, PetscSFType);
PETSC_EXTERN PetscErrorCode PetscSFGetType(PetscSF, PetscSFType *);
PETSC_EXTERN PetscErrorCode PetscSFView(PetscSF, PetscViewer);
PETSC_EXTERN PetscErrorCode PetscSFViewFromOptions(PetscSF, PetscObject, const char[]);
PETSC_EXTERN PetscErrorCode PetscSFSetUp(PetscSF);
PETSC_EXTERN PetscErrorCode PetscSFSetFromOptions(PetscSF);
PETSC_EXTERN PetscErrorCode PetscSFDuplicate(PetscSF, PetscSFDuplicateOption, PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFWindowSetSyncType(PetscSF, PetscSFWindowSyncType);
PETSC_EXTERN PetscErrorCode PetscSFWindowGetSyncType(PetscSF, PetscSFWindowSyncType *);
PETSC_EXTERN PetscErrorCode PetscSFWindowSetFlavorType(PetscSF, PetscSFWindowFlavorType);
PETSC_EXTERN PetscErrorCode PetscSFWindowGetFlavorType(PetscSF, PetscSFWindowFlavorType *);
PETSC_EXTERN PetscErrorCode PetscSFWindowSetInfo(PetscSF, MPI_Info);
PETSC_EXTERN PetscErrorCode PetscSFWindowGetInfo(PetscSF, MPI_Info *);
PETSC_EXTERN PetscErrorCode PetscSFSetRankOrder(PetscSF, PetscBool);
PETSC_EXTERN PetscErrorCode PetscSFSetGraph(PetscSF, PetscInt, PetscInt, PetscInt *, PetscCopyMode, PetscSFNode *, PetscCopyMode);
PETSC_EXTERN PetscErrorCode PetscSFSetGraphWithPattern(PetscSF, PetscLayout, PetscSFPattern);
PETSC_EXTERN PetscErrorCode PetscSFGetGraph(PetscSF, PetscInt *, PetscInt *, const PetscInt **, const PetscSFNode **);
PETSC_EXTERN PetscErrorCode PetscSFGetLeafRange(PetscSF, PetscInt *, PetscInt *);
PETSC_EXTERN PetscErrorCode PetscSFCreateEmbeddedRootSF(PetscSF, PetscInt, const PetscInt *, PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFCreateEmbeddedLeafSF(PetscSF, PetscInt, const PetscInt *, PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFReset(PetscSF);
PETSC_EXTERN PetscErrorCode PetscSFSetUpRanks(PetscSF, MPI_Group);
PETSC_EXTERN PetscErrorCode PetscSFGetRootRanks(PetscSF, PetscInt *, const PetscMPIInt **, const PetscInt **, const PetscInt **, const PetscInt **);
PETSC_EXTERN PetscErrorCode PetscSFGetLeafRanks(PetscSF, PetscInt *, const PetscMPIInt **, const PetscInt **, const PetscInt **);
PETSC_EXTERN PetscErrorCode PetscSFGetGroups(PetscSF, MPI_Group *, MPI_Group *);
PETSC_EXTERN PetscErrorCode PetscSFGetMultiSF(PetscSF, PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFCreateInverseSF(PetscSF, PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFConcatenate(MPI_Comm, PetscInt, PetscSF[], PetscSFConcatenateRootMode, PetscInt[], PetscSF *);

/* Build PetscSF from PetscLayout */
PETSC_EXTERN PetscErrorCode PetscSFSetGraphLayout(PetscSF, PetscLayout, PetscInt, PetscInt *, PetscCopyMode, const PetscInt *);
PETSC_EXTERN PetscErrorCode PetscSFGetGraphLayout(PetscSF, PetscLayout *, PetscInt *, const PetscInt *[], PetscInt *[]);
PETSC_EXTERN PetscErrorCode PetscSFCreateFromLayouts(PetscLayout, PetscLayout, PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFCreateByMatchingIndices(PetscLayout, PetscInt, const PetscInt *, const PetscInt *, PetscInt, PetscInt, const PetscInt *, const PetscInt *, PetscInt, PetscSF *, PetscSF *);

/* PetscSection interoperability */
PETSC_EXTERN PetscErrorCode PetscSFSetGraphSection(PetscSF, PetscSection, PetscSection);
PETSC_EXTERN PetscErrorCode PetscSFCreateRemoteOffsets(PetscSF, PetscSection, PetscSection, PetscInt **);
PETSC_EXTERN PetscErrorCode PetscSFDistributeSection(PetscSF, PetscSection, PetscInt **, PetscSection);
PETSC_EXTERN PetscErrorCode PetscSFCreateSectionSF(PetscSF, PetscSection, PetscInt[], PetscSection, PetscSF *);

/* Reduce rootdata to leafdata using provided operation */
PETSC_EXTERN PetscErrorCode PetscSFBcastBegin(PetscSF, MPI_Datatype, const void *, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2);
PETSC_EXTERN PetscErrorCode PetscSFBcastEnd(PetscSF, MPI_Datatype, const void *, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2);
PETSC_EXTERN PetscErrorCode PetscSFBcastWithMemTypeBegin(PetscSF, MPI_Datatype, PetscMemType, const void *, PetscMemType, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(6, 2);

/* Reduce leafdata into rootdata using provided operation */
PETSC_EXTERN PetscErrorCode PetscSFReduceBegin(PetscSF, MPI_Datatype, const void *, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2);
PETSC_EXTERN PetscErrorCode PetscSFReduceEnd(PetscSF, MPI_Datatype, const void *, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2);
PETSC_EXTERN PetscErrorCode PetscSFReduceWithMemTypeBegin(PetscSF, MPI_Datatype, PetscMemType, const void *, PetscMemType, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(6, 2);

/* Atomically modifies (using provided operation) rootdata using leafdata from each leaf, value at root at time of modification is returned in leafupdate. */
PETSC_EXTERN PetscErrorCode PetscSFFetchAndOpBegin(PetscSF, MPI_Datatype, void *, const void *, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(5, 2);
PETSC_EXTERN PetscErrorCode PetscSFFetchAndOpEnd(PetscSF, MPI_Datatype, void *, const void *, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(5, 2);

PETSC_EXTERN PetscErrorCode PetscSFFetchAndOpWithMemTypeBegin(PetscSF, MPI_Datatype, PetscMemType, void *, PetscMemType, const void *, PetscMemType, void *, MPI_Op) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(6, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(8, 2);

/* Compute the degree of every root vertex (number of leaves in its star) */
PETSC_EXTERN PetscErrorCode PetscSFComputeDegreeBegin(PetscSF, const PetscInt **);
PETSC_EXTERN PetscErrorCode PetscSFComputeDegreeEnd(PetscSF, const PetscInt **);
PETSC_EXTERN PetscErrorCode PetscSFComputeMultiRootOriginalNumbering(PetscSF, const PetscInt[], PetscInt *, PetscInt *[]);
/* Concatenate data from all leaves into roots */
PETSC_EXTERN PetscErrorCode PetscSFGatherBegin(PetscSF, MPI_Datatype, const void *, void *) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2);
PETSC_EXTERN PetscErrorCode PetscSFGatherEnd(PetscSF, MPI_Datatype, const void *, void *) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2);
/* Distribute distinct values to each leaf from roots */
PETSC_EXTERN PetscErrorCode PetscSFScatterBegin(PetscSF, MPI_Datatype, const void *, void *) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2);
PETSC_EXTERN PetscErrorCode PetscSFScatterEnd(PetscSF, MPI_Datatype, const void *, void *) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(3, 2) PETSC_ATTRIBUTE_MPI_POINTER_WITH_TYPE(4, 2);

PETSC_EXTERN PetscErrorCode PetscSFCompose(PetscSF, PetscSF, PetscSF *);
PETSC_EXTERN PetscErrorCode PetscSFComposeInverse(PetscSF, PetscSF, PetscSF *);

#define MPIU_REPLACE MPI_REPLACE PETSC_DEPRECATED_MACRO("GCC warning \"MPIU_REPLACE macro is deprecated use MPI_REPLACE (since version 3.15)\"")

PETSC_DEPRECATED_FUNCTION("Use PetscSFGetRootRanks (since v3.12)")
static inline PetscErrorCode PetscSFGetRanks(PetscSF sf, PetscInt *nranks, const PetscMPIInt **ranks, const PetscInt **roffset, const PetscInt **rmine, const PetscInt **rremote)
{
  return PetscSFGetRootRanks(sf, nranks, ranks, roffset, rmine, rremote);
}

PETSC_DEPRECATED_FUNCTION("Use PetscSFCreateEmbeddedRootSF (since v3.15)")
static inline PetscErrorCode PetscSFCreateEmbeddedSF(PetscSF sf, PetscInt nselected, const PetscInt *selected, PetscSF *esf)
{
  return PetscSFCreateEmbeddedRootSF(sf, nselected, selected, esf);
}

PETSC_DEPRECATED_FUNCTION("Use PetscSFBcastBegin (since v3.15)")
static inline PetscErrorCode PetscSFBcastAndOpBegin(PetscSF sf, MPI_Datatype unit, const void *rootdata, void *leafdata, MPI_Op op)
{
  return PetscSFBcastBegin(sf, unit, rootdata, leafdata, op);
}

PETSC_DEPRECATED_FUNCTION("Use PetscSFBcastEnd (since v3.15)")
static inline PetscErrorCode PetscSFBcastAndOpEnd(PetscSF sf, MPI_Datatype unit, const void *rootdata, void *leafdata, MPI_Op op)
{
  return PetscSFBcastEnd(sf, unit, rootdata, leafdata, op);
}

PETSC_DEPRECATED_FUNCTION("Use PetscSFBcastWithMemTypeBegin (since v3.15)")
static inline PetscErrorCode PetscSFBcastAndOpWithMemtypeBegin(PetscSF sf, MPI_Datatype unit, PetscMemType rootmtype, const void *rootdata, PetscMemType leafmtype, void *leafdata, MPI_Op op)
{
  return PetscSFBcastWithMemTypeBegin(sf, unit, rootmtype, rootdata, leafmtype, leafdata, op);
}

#endif