// ==UserScript==
// @name         记录上次查看时间
// @version      0.1.0
// @include      https://www.mcbbs.net/*
// @author       xmdhs
// @description 记录上次查看时间。
// @namespace https://xmdhs.top
// @downloadURL none
// ==/UserScript==

(function () {
    let tid;
    try {
        tid = document.querySelector("#pt > div > a:nth-child(9)").href.match(/thread-([0-9]{1,10})-1-1.html/)[1]
    } catch { }
    if (tid > 0) {
        let date = localStorage.getItem("lastview")
        if (date == null) {
            date = {}
        } else {
            date = JSON.parse(date)
        }
        date[tid] = new Date().getTime()
        let tempdate = {}
        if (date.length > 1000){
            let a = 0;
            for (let i in date) {
                a = a + 1
                if (a < 3) {
                    continue;
                }
                tempdate[i] = date[i]
            }
            date = tempdate
        }
        localStorage.setItem("lastview", JSON.stringify(date))
    } else {
        let date = localStorage.getItem("lastview")
        date = JSON.parse(date)
        jq(".s.xst").each(function () {
            let link = jq(this).attr("href")
            let tid = link.match(/thread-([0-9]{1,10})-1-[0-9]{1,10}.html/)
            let atime
            if (tid != null && tid.length >= 2){
                tid = tid[1]
                atime = date[tid]
            }else{
                let b = new URLSearchParams(link)
                let tidtemp = b.get("tid")            
                if (tidtemp != ""){
                    atime = date[tidtemp]
                }
            }
            if (atime > 0) {
                jq(this).prepend('<font color="#000000"><b>[' + diffTime(new Date(atime),new Date()) + '] </b></font>')
            }
        })
    }

})();

// https://www.jianshu.com/p/bdda96a1dcd8
function diffTime(startDate,endDate) {
    var diff=endDate.getTime() - startDate;//.getTime();//时间差的毫秒数

    //计算出相差天数
    var days=Math.floor(diff/(24*3600*1000));

    //计算出小时数
    var leave1=diff%(24*3600*1000);    //计算天数后剩余的毫秒数
    var hours=Math.floor(leave1/(3600*1000));
    //计算相差分钟数
    var leave2=leave1%(3600*1000);        //计算小时数后剩余的毫秒数
    var minutes=Math.floor(leave2/(60*1000));

    //计算相差秒数
    var leave3=leave2%(60*1000);      //计算分钟数后剩余的毫秒数
    var seconds=Math.round(leave3/1000);

    var returnStr = seconds + "秒前";
    if(minutes>0) {
        returnStr = minutes + "分钟前";//+ returnStr;
    }
    if(hours>0) {
        returnStr = hours + "小时前";// + returnStr;
    }
    if(days>0) {
        returnStr = days + "天前" ;//+ returnStr;
    }
    return returnStr;
}