#include <petsc/private/tsimpl.h> /*I "petscts.h"  I*/

PetscFunctionList TSList              = NULL;
PetscBool         TSRegisterAllCalled = PETSC_FALSE;

/*@C
  TSSetType - Sets the method to be used as the timestepping solver.

  Collective

  Input Parameters:
+ ts   - The `TS` context
- type - A known method

  Options Database Key:
. -ts_type <type> - Sets the method; use -help for a list of available methods (for instance, euler)

   Level: intermediate

   Notes:
   See "petsc/include/petscts.h" for available methods (for instance)
+  TSEULER - Euler
.  TSSUNDIALS - SUNDIALS interface
.  TSBEULER - Backward Euler
-  TSPSEUDO - Pseudo-timestepping

   Normally, it is best to use the `TSSetFromOptions()` command and
   then set the `TS` type from the options database rather than by using
   this routine.  Using the options database provides the user with
   maximum flexibility in evaluating the many different solvers.
   The TSSetType() routine is provided for those situations where it
   is necessary to set the timestepping solver independently of the
   command line or options database.  This might be the case, for example,
   when the choice of solver changes during the execution of the
   program, and the user's application is taking responsibility for
   choosing the appropriate method.  In other words, this routine is
   not for beginners.

.seealso: [](ch_ts), `TS`, `TSSolve()`, `TSCreate()`, `TSSetFromOptions()`, `TSDestroy()`, `TSType`
@*/
PetscErrorCode TSSetType(TS ts, TSType type)
{
  PetscErrorCode (*r)(TS);
  PetscBool match;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(ts, TS_CLASSID, 1);
  PetscValidCharPointer(type, 2);
  PetscCall(PetscObjectTypeCompare((PetscObject)ts, type, &match));
  if (match) PetscFunctionReturn(PETSC_SUCCESS);

  PetscCall(PetscFunctionListFind(TSList, type, &r));
  PetscCheck(r, PetscObjectComm((PetscObject)ts), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown TS type: %s", type);
  PetscTryTypeMethod(ts, destroy);
  PetscCall(PetscMemzero(ts->ops, sizeof(*ts->ops)));
  ts->usessnes           = PETSC_FALSE;
  ts->default_adapt_type = TSADAPTNONE;

  ts->setupcalled = PETSC_FALSE;

  PetscCall(PetscObjectChangeTypeName((PetscObject)ts, type));
  PetscCall((*r)(ts));
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  TSGetType - Gets the `TS` method type (as a string).

  Not Collective

  Input Parameter:
. ts - The `TS`

  Output Parameter:
. type - The name of `TS` method

  Level: intermediate

.seealso: [](ch_ts), `TS`, `TSType`, `TSSetType()`
@*/
PetscErrorCode TSGetType(TS ts, TSType *type)
{
  PetscFunctionBegin;
  PetscValidHeaderSpecific(ts, TS_CLASSID, 1);
  PetscValidPointer(type, 2);
  *type = ((PetscObject)ts)->type_name;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*--------------------------------------------------------------------------------------------------------------------*/

/*@C
  TSRegister - Adds a creation method to the `TS` package.

  Not Collective

  Input Parameters:
+ sname        - The name of a new user-defined creation routine
- function - The creation routine itself

  Level: advanced

  Notes:
  `TSRegister()` may be called multiple times to add several user-defined tses.

  Sample usage:
.vb
  TSRegister("my_ts",  MyTSCreate);
.ve

  Then, your ts type can be chosen with the procedural interface via
.vb
    TS ts;
    TSCreate(MPI_Comm, &ts);
    TSSetType(ts, "my_ts")
.ve
  or at runtime via the option
.vb
    -ts_type my_ts
.ve

.seealso: [](ch_ts), `TSSetType()`, `TSType`, `TSRegisterAll()`, `TSRegisterDestroy()`
@*/
PetscErrorCode TSRegister(const char sname[], PetscErrorCode (*function)(TS))
{
  PetscFunctionBegin;
  PetscCall(TSInitializePackage());
  PetscCall(PetscFunctionListAdd(&TSList, sname, function));
  PetscFunctionReturn(PETSC_SUCCESS);
}