/* -----------------------------------------------------------------
 * Programmer(s): Daniel R. Reynolds @ SMU
 * -----------------------------------------------------------------
 * SUNDIALS Copyright Start
 * Copyright (c) 2002-2020, Lawrence Livermore National Security
 * and Southern Methodist University.
 * All rights reserved.
 *
 * See the top-level LICENSE and NOTICE files for details.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 * SUNDIALS Copyright End
 * -----------------------------------------------------------------
 * This is the header file for the ARKode ARKStep module.
 * -----------------------------------------------------------------*/

#ifndef _ARKSTEP_H
#define _ARKSTEP_H

#include <sundials/sundials_nvector.h>
#include <sundials/sundials_linearsolver.h>
#include <sundials/sundials_nonlinearsolver.h>
#include <arkode/arkode.h>
#include <arkode/arkode_ls.h>
#include <arkode/arkode_butcher_erk.h>
#include <arkode/arkode_butcher_dirk.h>

#ifdef __cplusplus  /* wrapper to enable C++ usage */
extern "C" {
#endif

/* -----------------
 * ARKStep Constants
 * ----------------- */

/* Default Butcher tables for each method/order */

/*    explicit */
#define DEFAULT_ERK_2           HEUN_EULER_2_1_2
#define DEFAULT_ERK_3           BOGACKI_SHAMPINE_4_2_3
#define DEFAULT_ERK_4           ZONNEVELD_5_3_4
#define DEFAULT_ERK_5           CASH_KARP_6_4_5
#define DEFAULT_ERK_6           VERNER_8_5_6
#define DEFAULT_ERK_8           FEHLBERG_13_7_8

/*    implicit */
#define DEFAULT_DIRK_2          SDIRK_2_1_2
#define DEFAULT_DIRK_3          ARK324L2SA_DIRK_4_2_3
#define DEFAULT_DIRK_4          SDIRK_5_3_4
#define DEFAULT_DIRK_5          ARK548L2SA_DIRK_8_4_5

/*    ImEx */
#define DEFAULT_ARK_ETABLE_3    ARK324L2SA_ERK_4_2_3
#define DEFAULT_ARK_ETABLE_4    ARK436L2SA_ERK_6_3_4
#define DEFAULT_ARK_ETABLE_5    ARK548L2SA_ERK_8_4_5
#define DEFAULT_ARK_ITABLE_3    ARK324L2SA_DIRK_4_2_3
#define DEFAULT_ARK_ITABLE_4    ARK436L2SA_DIRK_6_3_4
#define DEFAULT_ARK_ITABLE_5    ARK548L2SA_DIRK_8_4_5


/* ------------------------------
 * User-Supplied Function Types
 * ------------------------------ */

typedef int (*ARKStepStagePredictFn)(realtype t, N_Vector zpred,
                                     void *user_data);
  
/* -------------------
 * Exported Functions
 * ------------------- */

/* Create, Resize, and Reinitialization functions */
SUNDIALS_EXPORT void* ARKStepCreate(ARKRhsFn fe, ARKRhsFn fi,
                                    realtype t0, N_Vector y0);

SUNDIALS_EXPORT int ARKStepResize(void *arkode_mem, N_Vector ynew,
                                  realtype hscale, realtype t0,
                                  ARKVecResizeFn resize,
                                  void *resize_data);

SUNDIALS_EXPORT int ARKStepReInit(void* arkode_mem, ARKRhsFn fe,
                                  ARKRhsFn fi, realtype t0, N_Vector y0);

/* Tolerance input functions */
SUNDIALS_EXPORT int ARKStepSStolerances(void *arkode_mem,
                                        realtype reltol,
                                        realtype abstol);
SUNDIALS_EXPORT int ARKStepSVtolerances(void *arkode_mem,
                                        realtype reltol,
                                        N_Vector abstol);
SUNDIALS_EXPORT int ARKStepWFtolerances(void *arkode_mem,
                                        ARKEwtFn efun);

/* Resudal tolerance input functions */
SUNDIALS_EXPORT int ARKStepResStolerance(void *arkode_mem,
                                         realtype rabstol);
SUNDIALS_EXPORT int ARKStepResVtolerance(void *arkode_mem,
                                         N_Vector rabstol);
SUNDIALS_EXPORT int ARKStepResFtolerance(void *arkode_mem,
                                         ARKRwtFn rfun);


/* Linear solver set functions */
SUNDIALS_EXPORT int ARKStepSetLinearSolver(void *arkode_mem,
                                           SUNLinearSolver LS,
                                           SUNMatrix A);
SUNDIALS_EXPORT int ARKStepSetMassLinearSolver(void *arkode_mem,
                                               SUNLinearSolver LS,
                                               SUNMatrix M,
                                               booleantype time_dep);

/* Rootfinding initialization */
SUNDIALS_EXPORT int ARKStepRootInit(void *arkode_mem, int nrtfn,
                                    ARKRootFn g);

/* Optional input functions -- must be called AFTER ARKStepCreate */
SUNDIALS_EXPORT int ARKStepSetDefaults(void* arkode_mem);
SUNDIALS_EXPORT int ARKStepSetOptimalParams(void *arkode_mem);
SUNDIALS_EXPORT int ARKStepSetOrder(void *arkode_mem, int maxord);
SUNDIALS_EXPORT int ARKStepSetDenseOrder(void *arkode_mem, int dord);
SUNDIALS_EXPORT int ARKStepSetNonlinearSolver(void *arkode_mem,
                                              SUNNonlinearSolver NLS);
SUNDIALS_EXPORT int ARKStepSetLinear(void *arkode_mem, int timedepend);
SUNDIALS_EXPORT int ARKStepSetNonlinear(void *arkode_mem);
SUNDIALS_EXPORT int ARKStepSetExplicit(void *arkode_mem);
SUNDIALS_EXPORT int ARKStepSetImplicit(void *arkode_mem);
SUNDIALS_EXPORT int ARKStepSetImEx(void *arkode_mem);
SUNDIALS_EXPORT int ARKStepSetTables(void *arkode_mem, int q, int p,
                                     ARKodeButcherTable Bi,
                                     ARKodeButcherTable Be);
SUNDIALS_EXPORT int ARKStepSetTableNum(void *arkode_mem,
                                       int itable, int etable);
SUNDIALS_EXPORT int ARKStepSetCFLFraction(void *arkode_mem,
                                          realtype cfl_frac);
SUNDIALS_EXPORT int ARKStepSetSafetyFactor(void *arkode_mem,
                                           realtype safety);
SUNDIALS_EXPORT int ARKStepSetErrorBias(void *arkode_mem,
                                        realtype bias);
SUNDIALS_EXPORT int ARKStepSetMaxGrowth(void *arkode_mem,
                                        realtype mx_growth);
SUNDIALS_EXPORT int ARKStepSetFixedStepBounds(void *arkode_mem,
                                              realtype lb, realtype ub);
SUNDIALS_EXPORT int ARKStepSetAdaptivityMethod(void *arkode_mem,
                                               int imethod,
                                               int idefault, int pq,
                                               realtype adapt_params[3]);
SUNDIALS_EXPORT int ARKStepSetAdaptivityFn(void *arkode_mem,
                                           ARKAdaptFn hfun,
                                           void *h_data);
SUNDIALS_EXPORT int ARKStepSetMaxFirstGrowth(void *arkode_mem,
                                             realtype etamx1);
SUNDIALS_EXPORT int ARKStepSetMaxEFailGrowth(void *arkode_mem,
                                             realtype etamxf);
SUNDIALS_EXPORT int ARKStepSetSmallNumEFails(void *arkode_mem,
                                             int small_nef);
SUNDIALS_EXPORT int ARKStepSetMaxCFailGrowth(void *arkode_mem,
                                             realtype etacf);
SUNDIALS_EXPORT int ARKStepSetNonlinCRDown(void *arkode_mem,
                                           realtype crdown);
SUNDIALS_EXPORT int ARKStepSetNonlinRDiv(void *arkode_mem,
                                         realtype rdiv);
SUNDIALS_EXPORT int ARKStepSetDeltaGammaMax(void *arkode_mem,
                                            realtype dgmax);
SUNDIALS_EXPORT int ARKStepSetMaxStepsBetweenLSet(void *arkode_mem,
                                                  int msbp);
SUNDIALS_EXPORT int ARKStepSetPredictorMethod(void *arkode_mem,
                                              int method);
SUNDIALS_EXPORT int ARKStepSetStabilityFn(void *arkode_mem,
                                          ARKExpStabFn EStab,
                                          void *estab_data);
SUNDIALS_EXPORT int ARKStepSetMaxErrTestFails(void *arkode_mem,
                                              int maxnef);
SUNDIALS_EXPORT int ARKStepSetMaxNonlinIters(void *arkode_mem,
                                             int maxcor);
SUNDIALS_EXPORT int ARKStepSetMaxConvFails(void *arkode_mem,
                                           int maxncf);
SUNDIALS_EXPORT int ARKStepSetNonlinConvCoef(void *arkode_mem,
                                             realtype nlscoef);
SUNDIALS_EXPORT int ARKStepSetConstraints(void *arkode_mem,
                                          N_Vector constraints);
SUNDIALS_EXPORT int ARKStepSetMaxNumSteps(void *arkode_mem,
                                          long int mxsteps);
SUNDIALS_EXPORT int ARKStepSetMaxHnilWarns(void *arkode_mem,
                                           int mxhnil);
SUNDIALS_EXPORT int ARKStepSetInitStep(void *arkode_mem,
                                       realtype hin);
SUNDIALS_EXPORT int ARKStepSetMinStep(void *arkode_mem,
                                      realtype hmin);
SUNDIALS_EXPORT int ARKStepSetMaxStep(void *arkode_mem,
                                      realtype hmax);
SUNDIALS_EXPORT int ARKStepSetStopTime(void *arkode_mem,
                                       realtype tstop);
SUNDIALS_EXPORT int ARKStepSetFixedStep(void *arkode_mem,
                                        realtype hfixed);
SUNDIALS_EXPORT int ARKStepSetMaxNumConstrFails(void *arkode_mem,
                                                int maxfails);

SUNDIALS_EXPORT int ARKStepSetRootDirection(void *arkode_mem,
                                            int *rootdir);
SUNDIALS_EXPORT int ARKStepSetNoInactiveRootWarn(void *arkode_mem);

SUNDIALS_EXPORT int ARKStepSetErrHandlerFn(void *arkode_mem,
                                           ARKErrHandlerFn ehfun,
                                           void *eh_data);
SUNDIALS_EXPORT int ARKStepSetErrFile(void *arkode_mem,
                                      FILE *errfp);
SUNDIALS_EXPORT int ARKStepSetUserData(void *arkode_mem,
                                       void *user_data);
SUNDIALS_EXPORT int ARKStepSetDiagnostics(void *arkode_mem,
                                          FILE *diagfp);

SUNDIALS_EXPORT int ARKStepSetPostprocessStepFn(void *arkode_mem,
                                                ARKPostProcessStepFn ProcessStep);
SUNDIALS_EXPORT int ARKStepSetStagePredictFn(void *arkode_mem,
                                             ARKStepStagePredictFn PredictStage);

/* Linear solver interface optional input functions -- must be called
   AFTER ARKStepSetLinearSolver and/or ARKStepSetMassLinearSolver */
SUNDIALS_EXPORT int ARKStepSetJacFn(void *arkode_mem, ARKLsJacFn jac);
SUNDIALS_EXPORT int ARKStepSetMassFn(void *arkode_mem, ARKLsMassFn mass);
SUNDIALS_EXPORT int ARKStepSetMaxStepsBetweenJac(void *arkode_mem,
                                                 long int msbj);
SUNDIALS_EXPORT int ARKStepSetEpsLin(void *arkode_mem, realtype eplifac);
SUNDIALS_EXPORT int ARKStepSetMassEpsLin(void *arkode_mem, realtype eplifac);
SUNDIALS_EXPORT int ARKStepSetPreconditioner(void *arkode_mem,
                                             ARKLsPrecSetupFn psetup,
                                             ARKLsPrecSolveFn psolve);
SUNDIALS_EXPORT int ARKStepSetMassPreconditioner(void *arkode_mem,
                                                 ARKLsMassPrecSetupFn psetup,
                                                 ARKLsMassPrecSolveFn psolve);
SUNDIALS_EXPORT int ARKStepSetJacTimes(void *arkode_mem,
                                       ARKLsJacTimesSetupFn jtsetup,
                                       ARKLsJacTimesVecFn jtimes);
SUNDIALS_EXPORT int ARKStepSetMassTimes(void *arkode_mem,
                                        ARKLsMassTimesSetupFn msetup,
                                        ARKLsMassTimesVecFn mtimes,
                                        void *mtimes_data);
SUNDIALS_EXPORT int ARKStepSetLinSysFn(void *arkode_mem, ARKLsLinSysFn linsys);

/* Integrate the ODE over an interval in t */
SUNDIALS_EXPORT int ARKStepEvolve(void *arkode_mem, realtype tout,
                                  N_Vector yout, realtype *tret,
                                  int itask);

/* Computes the kth derivative of the y function at time t */
SUNDIALS_EXPORT int ARKStepGetDky(void *arkode_mem, realtype t,
                                  int k, N_Vector dky);

/* Optional output functions */
SUNDIALS_EXPORT int ARKStepGetNumExpSteps(void *arkode_mem,
                                          long int *expsteps);
SUNDIALS_EXPORT int ARKStepGetNumAccSteps(void *arkode_mem,
                                          long int *accsteps);
SUNDIALS_EXPORT int ARKStepGetNumStepAttempts(void *arkode_mem,
                                              long int *step_attempts);
SUNDIALS_EXPORT int ARKStepGetNumRhsEvals(void *arkode_mem,
                                          long int *nfe_evals,
                                          long int *nfi_evals);
SUNDIALS_EXPORT int ARKStepGetNumLinSolvSetups(void *arkode_mem,
                                               long int *nlinsetups);
SUNDIALS_EXPORT int ARKStepGetNumErrTestFails(void *arkode_mem,
                                              long int *netfails);
SUNDIALS_EXPORT int ARKStepGetCurrentButcherTables(void *arkode_mem,
                                                   ARKodeButcherTable *Bi,
                                                   ARKodeButcherTable *Be);
SUNDIALS_EXPORT int ARKStepGetEstLocalErrors(void *arkode_mem,
                                             N_Vector ele);
SUNDIALS_EXPORT int ARKStepGetWorkSpace(void *arkode_mem,
                                        long int *lenrw,
                                        long int *leniw);
SUNDIALS_EXPORT int ARKStepGetNumSteps(void *arkode_mem,
                                       long int *nsteps);
SUNDIALS_EXPORT int ARKStepGetActualInitStep(void *arkode_mem,
                                             realtype *hinused);
SUNDIALS_EXPORT int ARKStepGetLastStep(void *arkode_mem,
                                       realtype *hlast);
SUNDIALS_EXPORT int ARKStepGetCurrentStep(void *arkode_mem,
                                          realtype *hcur);
SUNDIALS_EXPORT int ARKStepGetCurrentTime(void *arkode_mem,
                                          realtype *tcur);
SUNDIALS_EXPORT int ARKStepGetCurrentState(void *arkode_mem,
                                           N_Vector *ycur);
SUNDIALS_EXPORT int ARKStepGetCurrentGamma(void *arkode_mem,
                                           realtype *gamma);
SUNDIALS_EXPORT int ARKStepGetTolScaleFactor(void *arkode_mem,
                                             realtype *tolsfac);
SUNDIALS_EXPORT int ARKStepGetErrWeights(void *arkode_mem,
                                         N_Vector eweight);
SUNDIALS_EXPORT int ARKStepGetResWeights(void *arkode_mem,
                                         N_Vector rweight);
SUNDIALS_EXPORT int ARKStepGetNumGEvals(void *arkode_mem,
                                        long int *ngevals);
SUNDIALS_EXPORT int ARKStepGetRootInfo(void *arkode_mem,
                                       int *rootsfound);
SUNDIALS_EXPORT int ARKStepGetNumConstrFails(void *arkode_mem,
                                             long int *nconstrfails);
SUNDIALS_EXPORT char *ARKStepGetReturnFlagName(long int flag);

SUNDIALS_EXPORT int ARKStepWriteParameters(void *arkode_mem, FILE *fp);

SUNDIALS_EXPORT int ARKStepWriteButcher(void *arkode_mem, FILE *fp);


/* Grouped optional output functions */
SUNDIALS_EXPORT int ARKStepGetTimestepperStats(void *arkode_mem,
                                               long int *expsteps,
                                               long int *accsteps,
                                               long int *step_attempts,
                                               long int *nfe_evals,
                                               long int *nfi_evals,
                                               long int *nlinsetups,
                                               long int *netfails);
SUNDIALS_EXPORT int ARKStepGetStepStats(void *arkode_mem,
                                        long int *nsteps,
                                        realtype *hinused,
                                        realtype *hlast,
                                        realtype *hcur,
                                        realtype *tcur);

/* Nonlinear solver optional output functions */
SUNDIALS_EXPORT int ARKStepGetNumNonlinSolvIters(void *arkode_mem,
                                                long int *nniters);
SUNDIALS_EXPORT int ARKStepGetNumNonlinSolvConvFails(void *arkode_mem,
                                                    long int *nncfails);
SUNDIALS_EXPORT int ARKStepGetNonlinSolvStats(void *arkode_mem,
                                             long int *nniters,
                                             long int *nncfails);

/* Linear solver optional output functions */
SUNDIALS_EXPORT int ARKStepGetLinWorkSpace(void *arkode_mem,
                                           long int *lenrwLS,
                                           long int *leniwLS);
SUNDIALS_EXPORT int ARKStepGetNumJacEvals(void *arkode_mem,
                                          long int *njevals);
SUNDIALS_EXPORT int ARKStepGetNumPrecEvals(void *arkode_mem,
                                           long int *npevals);
SUNDIALS_EXPORT int ARKStepGetNumPrecSolves(void *arkode_mem,
                                            long int *npsolves);
SUNDIALS_EXPORT int ARKStepGetNumLinIters(void *arkode_mem,
                                          long int *nliters);
SUNDIALS_EXPORT int ARKStepGetNumLinConvFails(void *arkode_mem,
                                              long int *nlcfails);
SUNDIALS_EXPORT int ARKStepGetNumJTSetupEvals(void *arkode_mem,
                                              long int *njtsetups);
SUNDIALS_EXPORT int ARKStepGetNumJtimesEvals(void *arkode_mem,
                                             long int *njvevals);
SUNDIALS_EXPORT int ARKStepGetNumLinRhsEvals(void *arkode_mem,
                                             long int *nfevalsLS);
SUNDIALS_EXPORT int ARKStepGetLastLinFlag(void *arkode_mem,
                                          long int *flag);

SUNDIALS_EXPORT int ARKStepGetMassWorkSpace(void *arkode_mem,
                                            long int *lenrwMLS,
                                            long int *leniwMLS);
SUNDIALS_EXPORT int ARKStepGetNumMassSetups(void *arkode_mem,
                                            long int *nmsetups);
SUNDIALS_EXPORT int ARKStepGetNumMassMultSetups(void *arkode_mem,
                                                long int *nmvsetups);
SUNDIALS_EXPORT int ARKStepGetNumMassMult(void *arkode_mem,
                                          long int *nmvevals);
SUNDIALS_EXPORT int ARKStepGetNumMassSolves(void *arkode_mem,
                                            long int *nmsolves);
SUNDIALS_EXPORT int ARKStepGetNumMassPrecEvals(void *arkode_mem,
                                               long int *nmpevals);
SUNDIALS_EXPORT int ARKStepGetNumMassPrecSolves(void *arkode_mem,
                                                long int *nmpsolves);
SUNDIALS_EXPORT int ARKStepGetNumMassIters(void *arkode_mem,
                                           long int *nmiters);
SUNDIALS_EXPORT int ARKStepGetNumMassConvFails(void *arkode_mem,
                                               long int *nmcfails);
SUNDIALS_EXPORT int ARKStepGetNumMTSetups(void *arkode_mem,
                                          long int *nmtsetups);
SUNDIALS_EXPORT int ARKStepGetLastMassFlag(void *arkode_mem,
                                           long int *flag);

SUNDIALS_EXPORT char *ARKStepGetLinReturnFlagName(long int flag);


/* Free function */
SUNDIALS_EXPORT void ARKStepFree(void **arkode_mem);

/* Output the ARKStep memory structure (useful when debugging) */
SUNDIALS_EXPORT void ARKStepPrintMem(void* arkode_mem, FILE* outfile);


#ifdef __cplusplus
}
#endif

#endif
