#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <string.h>

#include "FSM_private.h"
#include "FSM_protected.h"
#include "FSM_public.h"

/* 
    protected 函数
 */

void resetBaseFSM(FSM *pFSM)
{
   
    if (pFSM->privateVars.fcns.exitActionTable[pFSM->privateVars.curState] != NULL)
        pFSM->privateVars.fcns.exitActionTable[pFSM->privateVars.curState](pFSM->data, pFSM->privateVars.childFSM);

    pFSM->privateVars.curState = 0;
}

static inline void setEvent(FSM* pFSM){
    assert(pFSM->vtbl.selectEvent);
    pFSM->privateVars.curEvent = pFSM->vtbl.selectEvent(pFSM->data);

    if(0 == pFSM->privateVars.numChild){
        return;
    }

    for (int i = 0; i < pFSM->privateVars.numChild; i++)
    {
        FSM *cFSM = pFSM->privateVars.childFSM[i];
        setEvent(cFSM);
    }
}

static inline void preload(FSM* pFSM){
    if(pFSM->privateVars.preloader.isReady){
        memcpy(pFSM->data, pFSM->privateVars.preloader.in, pFSM->privateVars.preloader.preloadSize);
        pFSM->privateVars.preloader.isReady = 0;
    }    
}

  
void stepBaseFSM(FSM *pFSM)
{
    preload(pFSM);
    setEvent(pFSM);

    FSMHandler *fcns = &pFSM->privateVars.fcns;
    int curState = pFSM->privateVars.curState;
    void *data = pFSM->data;
    FSM **childFSM = pFSM->privateVars.childFSM;
    int index = pFSM->privateVars.curState * pFSM->privateVars.numEvent + pFSM->privateVars.curEvent;
    int nextState;

    if(fcns->delayedEvent){
        fcns->transitionDelayTable[fcns->delayedEvent](data);
        fcns->delayedEvent = 0;
    }

    if (fcns->transitionTable[index] != NULL)
    {
        if (fcns->exitActionTable[curState] != NULL)
            fcns->exitActionTable[curState](data, childFSM);

        nextState = (*fcns->transitionTable[index])(data, curState, &fcns->delayedEvent);

        if (fcns->enterActionTable[nextState] != NULL)
            fcns->enterActionTable[nextState](data, childFSM);

        pFSM->privateVars.curState = nextState;
    }
    else if(curState == 0){
        nextState = pFSM->privateVars.defaultState;
        if (fcns->enterActionTable[nextState] != NULL)
            fcns->enterActionTable[nextState](data, childFSM);
        pFSM->privateVars.curState = nextState;
    }
    else
    {
        if (fcns->duringActionTable[curState] != NULL)
            fcns->duringActionTable[curState](data, childFSM);
    }
}

FSM*  newBaseFSM(int numState, int numEvent, int defaultState){
    typedef void (*StateFuncPtr)(void *data); 
    typedef void (*ChildFSMStepFuncPtr)(FSM **cFSM); 
    typedef int (*TransitionFuncPtr)(void *data, int currentState);

    FSM *pFSM = calloc(1, sizeof(FSM));
    pFSM->privateVars.curEvent = 0;
    pFSM->privateVars.curState = 0;
    pFSM->privateVars.numEvent = numEvent;
    pFSM->privateVars.defaultState = defaultState;
    pFSM->privateVars.numChild = 0;

    pFSM->privateVars.preloader.isReady = 0;

    pFSM->privateVars.fcns.duringActionTable = calloc(numState,  sizeof(StateFuncPtr));
    pFSM->privateVars.fcns.enterActionTable = calloc(numState, sizeof(StateFuncPtr));
    pFSM->privateVars.fcns.exitActionTable = calloc(numState, sizeof(StateFuncPtr));
    
    pFSM->privateVars.fcns.transitionTable = calloc(numState * numEvent, sizeof(TransitionFuncPtr));
    pFSM->privateVars.fcns.childFSMStepTable = calloc(numState * numEvent, sizeof(ChildFSMStepFuncPtr));
    pFSM->privateVars.fcns.transitionDelayTable = calloc(numEvent,  sizeof(StateFuncPtr));

    FSMVtbl vtbl = {
        .reset = resetBaseFSM,
        .step = stepBaseFSM,
        .selectEvent = NULL,
        .setupHandler = NULL,
        .initData = NULL,
        .initDataLoader = NULL,
    };

    pFSM->vtbl = vtbl;
    return pFSM;
}


void constructFSM(FSM* pFSM){
    assert(pFSM->vtbl.setupHandler);
    assert(pFSM->vtbl.initData);
    assert(pFSM->vtbl.initDataLoader);

    pFSM->vtbl.setupHandler(&pFSM->privateVars.fcns);
    pFSM->vtbl.initData(pFSM);
    pFSM->vtbl.initDataLoader(pFSM);
}


/* 
    public 函数
 */


int getFSMCurState(FSM *pFSM){
    return pFSM->privateVars.curState;
}
int getFSMCurEvent(FSM *pFSM){
    return pFSM->privateVars.curEvent;
}




void setChildNum(FSM *pFSM, int num){
    pFSM->privateVars.numChild = num;
    pFSM->privateVars.childFSM = (FSM **)calloc(num, sizeof(FSM *));
}

void registerChildFSM(FSM *parent, FSM *child, int index){
    parent->privateVars.childFSM[index] = child;
}

const void *getData(FSM* pFSM){
    return (const void *)pFSM->data;
}

void *_preloadIn(FSM *pFSM){
    return pFSM->privateVars.preloader.in;
}

void _setPreloaderReady(FSM *pFSM){
    pFSM->privateVars.preloader.isReady = 1;
}


FSMVtbl *_vptrFSM(FSM* pFSM){
    return &pFSM->vtbl;
}