import { effect, reactive } from './reactivity';
let state = reactive({ name: 'zf', age: 11 })
effect(() => {
    console.log(state.name);
})
state.name = 'zf';
state.name = 'jw';
state.name = 'jg';

import { effect } from "./reactivity";
export function watchEffect(effect, options) {
    return doWatch(effect, null, options);
}
let postFlushCbs = [];
function queuePostFlushCb(cb){
    postFlushCbs(cb); // 将effect放到数组中进行刷新
    queueFlush();
}
function doWatch(source, cb, options) { // 做watch
    let getter;
    if (isFunction(source)) {
        getter = () => source();
    }
    let scheduler = (job) => queuePostFlushCb(job);
    const runner = effect(getter,{ // 创建一个effect
        lazy:true, 
        computed: true,
        scheduler // 自定义scheduler
    })
    runner();
}

let isFlushPending = false; // 是否正在等待刷新
let isFlushing = false; // 是否正在刷新
const p = Promise.resolve();
function nextTick(fn) {
    return fn ? p.then(fn) : p
}
function flushPostFlushCbs(){
    if(postFlushCbs.length){ // 队列有值进行队列刷新
        const cbs = [...new Set(postFlushCbs)];
        postFlushCbs.length = 0;
        for(let i = 0; i < cbs.length;i++){
            cbs[i]();
        }
    }
}
function flushJobs() {
    isFlushPending = false; // 开始执行任务
    isFlushing = true; // 正在刷新
    flushPostFlushCbs(); // 刷新队列
    isFlushing = false; // 刷新完毕
}
function queueFlush() {
    if (!isFlushPending && !isFlushing) {
        isFlushPending = true;
        nextTick(flushJobs); // 稍后刷新任务队列
    }
}