/*
 * Copyright (c) 2021 Bestechnic (Shanghai) Co., Ltd. All rights reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef HSM_H_
#define HSM_H_

#ifdef __cplusplus
extern "C" {
#endif

typedef enum
{
    USM_RET_NO_ERROR = 0,
    USM_RET_TIMEOUT,
    USM_RET_FAILED,
} USB_RET_CODE_E;

typedef int Event;
typedef struct {
    Event evt;
    unsigned char srcStmIdx;
    unsigned char dstStmIdx;
    unsigned int param0;
    unsigned int param1;
    unsigned int param2;
} Msg;

typedef struct Hsm Hsm;
typedef Msg const *(*EvtHndlr)(Hsm*, Msg const*);

typedef struct State State;
struct State {
    State *super;                                  /* pointer to superstate */
    EvtHndlr hndlr;                             /* state's handler function */
    char const *name;
};

void AddState(State *me, char const *name, State *super, EvtHndlr hndlr);
#define StateOnEvent(me_, ctx_, msg_) \
    (*(me_)->hndlr)((ctx_), (msg_))

struct Hsm {                       /* Hierarchical State Machine base class */
    char const *name;                             /* pointer to static name */
    State *curr;                                           /* current state */
    State *next;                  /* next state (non 0 if transition taken) */
    State *source;                   /* source state during last transition */
    State top;                                     /* top-most state object */
};

void HsmCtor(Hsm *me, char const *name, EvtHndlr topHndlr);
void HsmOnStart(Hsm *me);                  /* enter and start the top state */
void HsmOnEvent(Hsm *me, Msg const *msg);                   /* "HSM engine" */

/* protected: */
unsigned char HsmToLCA_(Hsm *me, State *target);
void HsmExit_(Hsm *me, unsigned char toLca);
/* get current state */
#define STATE_CURR(me_) (((Hsm *)me_)->curr)

/* take start transition (no states need to be exited) */
#define STATE_START(me_, target_) (((Hsm *)me_)->next = (target_))

 /* take a state transition (exit states up to the LCA) */
#define STATE_TRAN(me_, target_) if (1) { \
    static unsigned char toLca_ = 0xFF; \
    ASSERT(((Hsm *)me_)->next == 0,"%p",((Hsm *)me_)->next); \
    if (toLca_ == 0xFF) \
        toLca_ = HsmToLCA_((Hsm *)(me_), (target_)); \
    HsmExit_((Hsm *)(me_), toLca_); \
    ((Hsm *)(me_))->next = (target_); \
    TRACE(1, "target=%s",((Hsm *)(me_))->next->name);\
} else ((void)0)

#define START_EVT ((Event)(-1))
#define ENTRY_EVT ((Event)(-2))
#define EXIT_EVT    ((Event)(-3))

#ifdef __cplusplus
}
#endif

#endif /* hsm_h */