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

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

/* -------------------------------------------------------------------------- */
/*                                private函数                                 */
/* -------------------------------------------------------------------------- */
static inline void setNextState(FSM* pFSM){
    int curState = pFSM->privateVars.curState;
    if(curState != 0){
        pFSM->signals.lastTriggeredSignal = Idle_Signal;
        pFSM->privateVars.nextState = pFSM->privateVars.fcns.selectNextState[curState](pFSM->data, &pFSM->signals);
        pFSM->privateVars.index = pFSM->privateVars.curState * pFSM->privateVars.numState + pFSM->privateVars.nextState;
    }

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


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

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




/* -------------------------------------------------------------------------- */
/*                                  protected                                 */
/* -------------------------------------------------------------------------- */
void stepBaseFSM(FSM *pFSM)
{
    pFSM->pureVtbl.loadExternalData(pFSM->data);
    // preload(pFSM);
    setNextState(pFSM);
    pFSM->pureVtbl.resetSignals(&pFSM->signals, pFSM->data);
    
    FSMHandler *fcns = &pFSM->privateVars.fcns;
    int curState = pFSM->privateVars.curState;
    void *data = pFSM->data;
    FSM **childFSM = pFSM->privateVars.childFSM;
    int index = pFSM->privateVars.index;
    int nextState = pFSM->privateVars.nextState;


    if(nextState && curState != nextState){  // 状态切换
        if (fcns->transitionTable[index] != NULL) // 有特定的状态转移函数
        {
            if (fcns->exitActionTable[curState] != NULL)
                fcns->exitActionTable[curState](data, childFSM);

            (*fcns->transitionTable[index])(data);
            
            if (fcns->enterActionTable[nextState] != NULL)
                fcns->enterActionTable[nextState](data, childFSM);
        }
        if(fcns->transitionGeneralAction != NULL)
            fcns->transitionGeneralAction(data);    // 通用状态转移函数
        pFSM->privateVars.curState = nextState;
    }
    else if(curState == 0){ // 处理刚运行进入的默认状态
        nextState = pFSM->privateVars.defaultState;
        if (fcns->enterActionTable[nextState] != NULL)
            fcns->enterActionTable[nextState](data, childFSM);
        pFSM->privateVars.curState = nextState;
    }
    else    // 状态机没动
    {
        if (fcns->duringActionTable[curState] != NULL)
            fcns->duringActionTable[curState](data, childFSM);
    }
}


/* -------------------------------------------------------------------------- */
/*                                public 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;
}

void _stepFSM(FSM *pFSM){
    pFSM->step(pFSM);
}


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


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 _setSignal(FSM *pFSM, Uint16 signalFlag){
    pFSM->signals.external |= (1 << signalFlag);
}

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

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

int _getPreloaderOverFlag(FSM *pFSM){
    return pFSM->privateVars.preloader.isOverflow;
}

void _clearPreloaderOverFlag(FSM *pFSM){
    pFSM->privateVars.preloader.isOverflow = 0;
}




/* -------------------------------------------------------------------------- */
/*                   构造函数，分两段，先新建再赋值                            */
/* -------------------------------------------------------------------------- */
FSM*  newBaseFSM(int numState, int defaultState){
    typedef void (*StateFuncPtr)(void *); 
    typedef void (*ChildFSMStepFuncPtr)(FSM **); 
    typedef int (*TransitionFuncPtr)(void *, int *);
    typedef int (*SelectNextStateFcnPtr)(void *, FSMSignals *);

    FSM *pFSM = calloc(1, sizeof(FSM));
    pFSM->privateVars.numState = numState;
    pFSM->privateVars.defaultState = defaultState;
    pFSM->privateVars.curState = 0;
    pFSM->privateVars.nextState = 0;
    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.selectNextState = calloc(numState, sizeof(SelectNextStateFcnPtr));
    pFSM->privateVars.fcns.transitionTable = calloc(numState * numState, sizeof(TransitionFuncPtr));
    pFSM->privateVars.fcns.transitionGeneralAction = calloc(1, sizeof(StateFuncPtr));

    pFSM->privateVars.fcns.childFSMStepTable = calloc(numState * numState, sizeof(ChildFSMStepFuncPtr));
    
    FSMPureVtbl pureVtbl = {
        .setupHandler = NULL,
        .initData = NULL,
        .loadExternalData = NULL,
        .initDataLoader = NULL,
        .initSignals = NULL,
        .resetSignals = NULL,
    };
    pFSM->pureVtbl = pureVtbl;

    pFSM->step = stepBaseFSM;
    pFSM->reset = resetBaseFSM;

    return pFSM;
}


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

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

    /* ---------------------------------- 检查状态表 --------------------------------- */
    for (int i = 1; i < pFSM->privateVars.numState; i++) // 跳过Idle状态，Idle状态只能跳转到默认状态
    {
        if(!pFSM->privateVars.fcns.selectNextState[i]){
            FSM_LOG("每个状态都要有一个状态选择函数!\n");
            assert(0); // 强制退出
        }
    }
}