#ifndef __SFBASIC_H
#define __SFBASIC_H

#include <petsc/private/sfimpl.h> /*I "petscsf.h" I*/

typedef struct _n_PetscSFLink *PetscSFLink;

#define SFBASICHEADER \
  PetscMPIInt    niranks;          /* Number of incoming ranks (ranks accessing my roots) */ \
  PetscMPIInt    ndiranks;         /* Number of incoming ranks (ranks accessing my roots) in distinguished set */ \
  PetscMPIInt   *iranks;           /* Array of ranks that reference my roots */ \
  PetscInt       itotal;           /* Total number of graph edges referencing my roots */ \
  PetscInt      *ioffset;          /* Array of length niranks+1 holding offset in irootloc[] for each rank */ \
  PetscInt      *irootloc;         /* Incoming roots referenced by ranks starting at ioffset[rank] */ \
  PetscInt      *irootloc_d[2];    /* A copy of irootloc[local/remote] in device memory if needed */ \
  PetscInt       rootbuflen[2];    /* Length (in unit) of root buffers, in layout of [PETSCSF_LOCAL/REMOTE] */ \
  PetscBool      rootcontig[2];    /* True means the local/remote segments of indices in irootloc[] are contiguous ... */ \
  PetscInt       rootstart[2];     /* ... and start from rootstart[0] and rootstart[1] respectively */ \
  PetscSFPackOpt rootpackopt[2];   /* Pack optimization plans based on patterns in irootloc[]. NULL for no optimizations */ \
  PetscSFPackOpt rootpackopt_d[2]; /* Copy of rootpackopt[] on device if needed */ \
  PetscBool      rootdups[2];      /* Indices of roots in irootloc[local/remote] have dups. Used for data-race test */ \
  PetscInt       nrootreqs;        /* Number of MPI requests */ \
  PetscSFLink    avail;            /* One or more entries per MPI Datatype, lazily constructed */ \
  PetscSFLink    inuse             /* Buffers being used for transactions that have not yet completed */

typedef struct {
  SFBASICHEADER;
#if defined(PETSC_HAVE_NVSHMEM)
  PetscInt rootbuflen_rmax;     /* max rootbuflen[REMOTE] over comm */
  PetscInt nRemoteLeafRanks;    /* niranks - ndiranks */
  PetscInt nRemoteLeafRanksMax; /* max nRemoteLeafRanks over comm */

  PetscInt *leafbufdisp; /* [nRemoteLeafRanks]. For my i-th remote leaf rank, I will put to its leafbuf_shmem[] at offset leafbufdisp[i], in <unit> to be set */
  PetscInt *leafsigdisp; /* [nRemoteLeafRanks]. For my i-th remote leaf rank, I am its leafsigdisp[i]-th root rank */

  PetscInt    *leafbufdisp_d;
  PetscInt    *leafsigdisp_d; /* Copy of leafsigdisp[] on device */
  PetscMPIInt *iranks_d;      /* Copy of the remote part of (leaf) iranks[] on device */
  PetscInt    *ioffset_d;     /* Copy of the remote part of ioffset[] on device */
#endif
} PetscSF_Basic;

static inline PetscErrorCode PetscSFGetRootInfo_Basic(PetscSF sf, PetscInt *nrootranks, PetscInt *ndrootranks, const PetscMPIInt **rootranks, const PetscInt **rootoffset, const PetscInt **rootloc)
{
  PetscSF_Basic *bas = (PetscSF_Basic *)sf->data;

  PetscFunctionBegin;
  if (nrootranks) *nrootranks = bas->niranks;
  if (ndrootranks) *ndrootranks = bas->ndiranks;
  if (rootranks) *rootranks = bas->iranks;
  if (rootoffset) *rootoffset = bas->ioffset;
  if (rootloc) *rootloc = bas->irootloc;
  PetscFunctionReturn(PETSC_SUCCESS);
}

static inline PetscErrorCode PetscSFGetLeafInfo_Basic(PetscSF sf, PetscInt *nleafranks, PetscInt *ndleafranks, const PetscMPIInt **leafranks, const PetscInt **leafoffset, const PetscInt **leafloc, const PetscInt **leafrremote)
{
  PetscFunctionBegin;
  if (nleafranks) *nleafranks = sf->nranks;
  if (ndleafranks) *ndleafranks = sf->ndranks;
  if (leafranks) *leafranks = sf->ranks;
  if (leafoffset) *leafoffset = sf->roffset;
  if (leafloc) *leafloc = sf->rmine;
  if (leafrremote) *leafrremote = sf->rremote;
  PetscFunctionReturn(PETSC_SUCCESS);
}

PETSC_INTERN PetscErrorCode PetscSFSetUp_Basic(PetscSF);
PETSC_INTERN PetscErrorCode PetscSFView_Basic(PetscSF, PetscViewer);
PETSC_INTERN PetscErrorCode PetscSFReset_Basic(PetscSF);
PETSC_INTERN PetscErrorCode PetscSFDestroy_Basic(PetscSF);
PETSC_INTERN PetscErrorCode PetscSFBcastEnd_Basic(PetscSF, MPI_Datatype, const void *, void *, MPI_Op);
PETSC_INTERN PetscErrorCode PetscSFReduceEnd_Basic(PetscSF, MPI_Datatype, const void *, void *, MPI_Op);
PETSC_INTERN PetscErrorCode PetscSFFetchAndOpBegin_Basic(PetscSF, MPI_Datatype, PetscMemType, void *, PetscMemType, const void *, void *, MPI_Op);
PETSC_INTERN PetscErrorCode PetscSFCreateEmbeddedRootSF_Basic(PetscSF, PetscInt, const PetscInt *, PetscSF *);
PETSC_INTERN PetscErrorCode PetscSFGetLeafRanks_Basic(PetscSF, PetscInt *, const PetscMPIInt **, const PetscInt **, const PetscInt **);

#if defined(PETSC_HAVE_NVSHMEM)
PETSC_INTERN PetscErrorCode PetscSFReset_Basic_NVSHMEM(PetscSF);
#endif

#endif