class Swiper {

    defaultOption = {
        TimeId: null,
        autoPlay: false,
        time: 1000,
        initialSlide: 0, // 实现了
        el: '.swiper',
        on: {},
        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`
        }
    }

    // 构造函数里面接受
    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()
        }

    }

    init() {
        this.defaultOption.initSlideLeft()
        if (this.$f(".button") != null) {
            this.next()
            this.prev()
        }

        this.defaultOption.autoPlay
            ? this.autoPlay()
            : ''

        this.$f(".dot") == null ? '' : this.renderDot()

    }

    next() {
        this.click(".right", (v) => this.sport(1))
    }

    prev() {
        this.click(".left", v => this.sport(-1))
    }


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

        if (this.$f(".dot") != null) {
            this._f(".dot li").forEach(val => val.classList.remove("active"))
            this._f(".dot li")[i].classList.add("active")
        }
        this.$f(".swiper_wrap").style.left = `${i * -this.defaultOption.width()}px`
    }

    renderDot() {
        for (var i = 0; i < this.defaultOption.length(); i++) {
            this.$f(".dot").innerHTML += `
             <li class="${i == this.defaultOption.initialSlide ? 'active' : ''}"></li>
            `
        }
        this.click(".dot li", (v, i) => this.changeDotActive(i))
    }

    autoPlay() {
        this.defaultOption.TimeId = setInterval(() => this.sport(1), this.defaultOption.time)
        this.$f("").onmouseover = () => clearInterval(this.defaultOption.TimeId)
        this.$f("").onmouseout = () => this.autoPlay()
    }

    sport(offset) {
        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.changeDotActive(this.defaultOption.initialSlide)
        }
    }

    slideTo(index) {
        this.changeDotActive(index)
    }

    click(className, callback) {
        this._f(className).forEach((v, i) => v.onclick = () => callback(v, 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)
    }

}