/* Additional functions in the DMProduct API, which are not part of the general DM API. */
#include <petsc/private/dmproductimpl.h>

/*@C
  DMProductGetDM - Get sub-DM associated with a given slot of a DMProduct

  Not collective

  Input Parameters:
+ dm - the DMProduct
- slot - which dimension slot, in the range 0 to dim-1

  Output Parameter:
. subdm - the sub-DM

  Level: advanced

.seealso: DMPRODUCT, DMProductSetDM()
@*/
PETSC_EXTERN PetscErrorCode DMProductGetDM(DM dm,PetscInt slot,DM *subdm)
{
  PetscErrorCode ierr;
  DM_Product     *product = (DM_Product*)dm->data;
  PetscInt       dim;

  PetscFunctionBegin;
  PetscValidHeaderSpecificType(dm,DM_CLASSID,1,DMPRODUCT);
  ierr = DMGetDimension(dm,&dim);CHKERRQ(ierr);
  if (slot >= dim || slot < 0) SETERRQ1(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_OUTOFRANGE,"slot number must be in range 0-%D",dim-1);
  *subdm = product->dm[slot];
  PetscFunctionReturn(0);
}

/*@C
  DMProductSetDM - Set sub-DM associated with a given slot of DMProduct

  Not collective

  Input Parameters:
+ dm - the DMProduct
. slot - which dimension slot, in the range 0 to dim-1
- subdm - the sub-DM

  Notes:
  This function does not destroy the provided sub-DM. You may safely destroy it after calling this function.

  Level: advanced

.seealso: DMPRODUCT, DMProductGetDM(), DMProductSetDimensionIndex()
@*/
PETSC_EXTERN PetscErrorCode DMProductSetDM(DM dm,PetscInt slot,DM subdm)
{
  PetscErrorCode ierr;
  DM_Product     *product = (DM_Product*)dm->data;
  PetscInt       dim;

  PetscFunctionBegin;
  PetscValidHeaderSpecificType(dm,DM_CLASSID,1,DMPRODUCT);
  ierr = DMGetDimension(dm,&dim);CHKERRQ(ierr);
  if (slot >= dim || slot < 0) SETERRQ1(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_OUTOFRANGE,"slot number must be in range 0-%D",dim-1);
  ierr = PetscObjectReference((PetscObject)subdm);CHKERRQ(ierr);
  ierr = DMDestroy(&product->dm[slot]);CHKERRQ(ierr);
  product->dm[slot] = subdm;
  PetscFunctionReturn(0);
}

/*@C
  DMProductSetDimensionIndex - Set the dimension index associated with a given slot/sub-DM

  Not collective

  Input Parameters:
+ dm - the DMProduct
. slot - which dimension slot, in the range 0 to dim-1
- idx - the dimension index of the sub-DM

  Level: advanced

.seealso: DMPRODUCT
@*/
PETSC_EXTERN PetscErrorCode DMProductSetDimensionIndex(DM dm,PetscInt slot,PetscInt idx)
{
  PetscErrorCode ierr;
  DM_Product     *product = (DM_Product*)dm->data;
  PetscInt       dim;

  PetscFunctionBegin;
  PetscValidHeaderSpecificType(dm,DM_CLASSID,1,DMPRODUCT);
  ierr = DMGetDimension(dm,&dim);CHKERRQ(ierr);
  if (slot >= dim || slot < 0) SETERRQ1(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_OUTOFRANGE,"slot number must be in range 0-%D",dim-1);
  product->dim[slot] = idx;
  PetscFunctionReturn(0);
}