live-model-bing/model/Countdown.js

console.log("Hello world")
const COUNT_IN_MILLIS = 10
const SECOND_IN_MILLIS = 100 * COUNT_IN_MILLIS
const MINUTE_IN_MILLIS = 60 * SECOND_IN_MILLIS
const HOUR_IN_MILLIS = 60 * MINUTE_IN_MILLIS
const DAY_IN_MILLIS = 24 * HOUR_IN_MILLIS

// 只有一位的数字前面补0
export function toFixed(num) {
    return `0${num}`.slice(-2)
}


class Countdown {
    constructor(ontick, endTimes, step = 200) {
        this.ontick = ontick
        this.endTimes = endTimes
        this.step = step
        this.status = Countdown.CountdownStatus.paused
        // 当前计数
        this.remainTime = {
            days: 0,
            hours: 0,
            minutes: 0,
            seconds: 0,
            count: 0
        }
    }

    /**
     * 开始计时
     */
    start() {
        this.status = Countdown.CountdownStatus.running
        this.ontick && this.ontick()
        this.countdown()
    }

    /**
     * 停止计时
     */
    pause() {
        this.status = Countdown.CountdownStatus.paused
        this.ontick && this.ontick()
    }

    /**
     * 停止计时
     */
    stop() {
        this.status = Countdown.CountdownStatus.stoped
        this.ontick && this.ontick()
    }

    /**
     * 计时数数逻辑
     */
    countdown() {
        if(this.status !== Countdown.CountdownStatus.running) {
            return
        }
        let count = this.endTimes - Date.now()
        count = count > 0 ? count : 0
        this.remainTime = this.formatRemainTime(count)
        if(count > 0) {
            setTimeout(this.countdown.bind(this), this.step)
        }else{
            this.stop()
        }
        // 重复调用可能导致多次diff
        this.ontick && this.ontick()
    }

    formatRemainTime(count) {
        const days = parseInt(count / DAY_IN_MILLIS)
        count = count % DAY_IN_MILLIS

        const hours = parseInt(count / HOUR_IN_MILLIS)
        count = count % HOUR_IN_MILLIS

        const minutes = parseInt(count / MINUTE_IN_MILLIS)
        count = count % MINUTE_IN_MILLIS

        const seconds = parseInt(count / SECOND_IN_MILLIS)
        count = count % SECOND_IN_MILLIS

        count = count / parseInt(COUNT_IN_MILLIS)
        count = count % COUNT_IN_MILLIS

        return {
            days,
            hours,
            minutes,
            seconds,
            count
        }

    }

}

Countdown.CountdownStatus = {
    running: "running",
    paused: "paused",
    stoped: "stoped"
}

export default Countdown