export default class BadIntersectionObserver {
    constructor(options) {
        this.$options = {
            context: null,
            selector: null,
            onEach: res => res.dataset,
            onFinal: () => null,
            relativeTo: null,
            threshold: 0.5,
            delay: 200,
            observeAll: false,
            initialRatio: 0,
            ...options,
        }
        this.$observer = null
    }

    connect() {
        if (this.$observer) return this
        this.$observer = this._createObserver()
        return this
    }

    reconnect() {
        this.disconnect()
        this.connect()
    }

    disconnect() {
        if (!this.$observer) return
        const ob = this.$observer
        if (ob.$timer) clearTimeout(ob.$timer)
        ob.disconnect()
        this.$observer = null
    }

    _createObserver() {
        const opt = this.$options
        const observerOptions = {
            thresholds: [opt.threshold],
            observeAll: opt.observeAll,
            initialRatio: opt.initialRatio,
        }

        // 创建监听器
        const ob = uni.createIntersectionObserver(opt.context, observerOptions)

        // 相交区域设置
        if (opt.relativeTo) ob.relativeTo(opt.relativeTo)
        else ob.relativeToViewport()

        // 开始监听
        // let finalData = []
        // let isCollecting = false
        ob.observe(opt.selector, res => {
            const {
                intersectionRatio
            } = res
            const visible = intersectionRatio >= opt.threshold
            if (!visible) return

            const data = opt.onEach(res)
            // finalData.push(data)

            // if (isCollecting) return
            // isCollecting = true

            // setTimeout(() => {
            //     opt.onFinal.call(null, finalData)
            //     finalData = []
            //     isCollecting = false
            // }, opt.delay)
        })
        return ob
    }
}