// 哪些功能需要自定义？
//  是否需要自动播放
//  设置自动播放的时间间隔
//  可以设置默认显示第几张
//  如果不写html，就不需要对应的功能
//  可以js编程控制轮播图滚动到第几张
//   当轮播图滚动的时候要抛出当前下标

class Swiper {
    //设置默认选项
    defaultOption = {
        TimeId: null,
        autoPlay: false,
        time: 100,
        initialSlide: 0,
        el: '.swiper',
        on: {},
        // length: () => {
        //     //获取li标签的长度 
        //     console.log(this._f(".banner_ul li").length);
        //     return this._f(".banner_ul li").length

        // }

        length: () => this._f(`.swiper_wrap li`).length,
        width: () => this.$f(``).offsetWidth,
        initSlideLeft: () => {
            this.$f(".swiper_wrap").style.left = `${this.defaultOption.initialSlide * -this.defaultOption.width()
                }px`
        }
    }
    constructor(el, option) {

        if (el.length == 0 || this.$(el) == null) {
            console.error(`类名:${el}不存在，请检查`);
        } else {
            this.defaultOption.el = el || this.defaultOption.el;
            this.defaultOption.autoPlay = option.autoPlay || this.defaultOption.autoPlay;
            this.defaultOption.time = option.time || this.defaultOption.time;
            this.defaultOption.initialSlide = option.initialSlide || this.defaultOption.initialSlide;
            if (option.hasOwnProperty("on")) {
                this.defaultOption.on = option.on
            }
            this.init()
        }

    }
    //构造函数里面调用类里面的方法
    //程序调用
    init() {
        this.next()
        this.prev()
        this.sport()
        this.click()
    }
    next() {
        //var xxx = this; 保存this指向

        //当前this属于next()
        this.click(".button_right", (v, i) => {
            //console.log(this);
            //console.log(v,i);
            this.sport(1)
        })
    }
    prev() {
        this.click(".button_left", (v, i) => {
            //console.log(v,i);
            this.sport(-1)
        })
    }


    click(className, callback) {
        //this._f(className).forEach((v,i) => v.onclick = () => callback(v,i))
        //批量绑定点击事件
        this._f(className).forEach((v, i) => {
            v.onclick = () => {
                //  console.log("s");
                //把数据回传出去 v,i
                callback(v, i)
            }
        })
    }
    slideTo(index) {
        this.changeActive(index)
    }
    //移动
    sport(offset) {

        //利用下标判断是第几张图
        this.defaultOption.initialSlide += offset

        if (this.defaultOption.initialSlide < 0) {
            this.defaultOption.initialSlide = 0
        }
        if (this.defaultOption.initialSlide > this.defaultOption.length() - 1) {
            this.defaultOption.initialSlide = this.defaultOption.length() - 1
        }
        if (this.defaultOption.initialSlide >= 0 && this.defaultOption.initialSlide <= this.defaultOption.length() - 1) {
            this.changeActive(this.defaultOption.initialSlide)
        }
    }
    //todo 图片添加了active 但是没有删掉上一次的active

    changeActive(i) {
        this.defaultOption.on.slideChange && this.defaultOption.on.slideChange(i)

        if(this.$f(".banner_dot") != null){
            this._f(".banner_dot i").forEach(val => {
                val.classList.remove("active")
            })
            this._f(".banner_dot i")[i].classList.add("active")
        }

      //  this.$f(".banner_dot").style.left = `${i * -this.defaultOption.width()}px`

        // this._f(".banner_dot i").forEach(val => {
        //     console.log(this._f(".banner_dot i"));
        //     val.classList.remove("avtive")
        // })
        // this._f(".banner_dot i")[i].classList.add("active");
        // console.log( this._(".banner_dot i")[i]);
    }

    renderOot(){
        for (var i = 0; i<this.defaultOption.length(); i++ ){
            this.$f(".banner_dot").innerHTML +=`
                <li class="${i == this.defaultOption.initialSlide ? 'active' : ''}"></li>

            `
        }
        this.click(".banner_dot i",(v,i) => this.changeActive(i))
    }

    $f(className) {
        return this.$(`${this.defaultOption.el} ${className}`)
    }
    _f(className) {
        return this._(`${this.defaultOption.el} ${className}`)
    }

    $(className) {
        return document.querySelector(className);
    }
    _(className) {
        return document.querySelectorAll(className);
    }
}