/*
     Provides utility routines for manulating any type of PETSc object.
*/
#include <petsc/private/petscimpl.h> /*I   "petscsys.h"    I*/

/*@C
   PetscObjectComm - Gets the MPI communicator for any `PetscObject` regardless of the type.

   Not Collective

   Input Parameter:
.  obj - any PETSc object, for example a `Vec`, `Mat` or `KSP`. Thus must be
         cast with a (`PetscObject`), for example,
         `PetscObjectComm`((`PetscObject`)mat,...);

   Output Parameter:
.  comm - the MPI communicator or `MPI_COMM_NULL` if `obj` is not valid

   Level: advanced

   Note:
   This is one of the rare PETSc routines that does not return an error code. Use `PetscObjectGetComm()`
   when appropriate for error handling.

.seealso: `PetscObject`, `PetscObjectGetComm()`
@*/
MPI_Comm PetscObjectComm(PetscObject obj)
{
  return obj ? obj->comm : MPI_COMM_NULL;
}

/*@C
   PetscObjectGetComm - Gets the MPI communicator for any `PetscObject`,
   regardless of the type.

   Not Collective

   Input Parameter:
.  obj - any PETSc object, for example a `Vec`, `Mat` or `KSP`. Thus must be
         cast with a (`PetscObject`), for example,
         `PetscObjectGetComm`((`PetscObject`)mat,&comm);

   Output Parameter:
.  comm - the MPI communicator

   Level: advanced

.seealso: `PetscObject`, `PetscObjectComm()`
@*/
PetscErrorCode PetscObjectGetComm(PetscObject obj, MPI_Comm *comm)
{
  PetscFunctionBegin;
  PetscValidHeader(obj, 1);
  PetscValidPointer(comm, 2);
  *comm = obj->comm;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
   PetscObjectGetTabLevel - Gets the number of tabs that `PETSCVIEWERASCII` output for that object uses

   Not Collective

   Input Parameter:
.  obj - any PETSc object, for example a `Vec`, `Mat` or `KSP`. Thus must be
         cast with a (`PetscObject`), for example,
         `PetscObjectGetTabLevel`((`PetscObject`)mat,&tab);

   Output Parameter:
.   tab - the number of tabs

   Level: developer

    Note:
    This is used to manage the output from options that are embedded in other objects. For example
      the `KSP` object inside a `SNES` object. By indenting each lower level further the hierarchy of objects
      is very clear.

.seealso: `PetscObjectIncrementTabLevel()`, `PetscObjectSetTabLevel()`, `PETSCVIEWERASCII`, `PetscObject`
@*/
PetscErrorCode PetscObjectGetTabLevel(PetscObject obj, PetscInt *tab)
{
  PetscFunctionBegin;
  PetscValidHeader(obj, 1);
  PetscValidIntPointer(tab, 2);
  *tab = obj->tablevel;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
   PetscObjectSetTabLevel - Sets the number of tabs that `PETSCVIEWERASCII` output for that object uses

   Not Collective

   Input Parameters:
+  obj - any PETSc object, for example a `Vec`, `Mat` or `KSP`. Thus must be
         cast with a (`PetscObject`), for example,
         `PetscObjectSetTabLevel`((`PetscObject`)mat,tab;
-   tab - the number of tabs

   Level: developer

    Notes:
    this is used to manage the output from options that are embedded in other objects. For example
      the `KSP` object inside a `SNES` object. By indenting each lower level further the hierarchy of objects
      is very clear.

    `PetscObjectIncrementTabLevel()` is the preferred API

.seealso: `PetscObjectIncrementTabLevel()`, `PetscObjectGetTabLevel()`
@*/
PetscErrorCode PetscObjectSetTabLevel(PetscObject obj, PetscInt tab)
{
  PetscFunctionBegin;
  PetscValidHeader(obj, 1);
  obj->tablevel = tab;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
   PetscObjectIncrementTabLevel - Increments the number of tabs that `PETSCVIEWERASCII` output for that object use based on
         the tablevel of another object. This should be called immediately after the object is created.

   Not Collective

   Input Parameters:
+  obj - any PETSc object where we are changing the tab
.  oldobj - the object providing the tab, optional pass `NULL` to use 0 as the previous tablevel for `obj`
-  tab - the increment that is added to the old objects tab

   Level: developer

    Note:
    this is used to manage the output from options that are embedded in other objects. For example
      the `KSP` object inside a `SNES` object. By indenting each lower level further the hierarchy of objects
      is very clear.

.seealso: `PETSCVIEWERASCII`, `PetscObjectSetTabLevel()`, `PetscObjectGetTabLevel()`
@*/
PetscErrorCode PetscObjectIncrementTabLevel(PetscObject obj, PetscObject oldobj, PetscInt tab)
{
  PetscFunctionBegin;
  PetscValidHeader(obj, 1);
  if (oldobj) PetscValidHeader(oldobj, 2);
  obj->tablevel = (oldobj ? oldobj->tablevel : 0) + tab;
  PetscFunctionReturn(PETSC_SUCCESS);
}