// ==UserScript==
// @name         Colorful Course
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Try and see
// @author       Ajax
// @match        http://zhjwxk.cic.tsinghua.edu.cn/xkBks.vxkBksXkbBs.do*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=tsinghua.edu.cn
// @grant        none
// @license      MIT
// @downloadURL none
// ==/UserScript==

function colorOne(td, sum, available) {
    var l = td.text.split(",");
    var html = "";
    for (var i=0; i<l.length; ++i) {
        l[i] = Number(l[i]);

        if (sum > available) {
            html += `<span style="color:red">${l[i]}</span>,`;
        }
        else if ((sum += l[i]) > available) {
            html += `<span style="color:orange">${l[i]}</span>,`;
        }
        else {
            html += `<span style="color:green">${l[i]}</span>,`;
        }
    }

    td.innerHTML = html.substr(0, html.length - 1);
    return sum;
}

(function() {
    'use strict';

    var frame = document.getElementsByName("top")[0];

    setInterval(function() {
        var doc = frame.contentDocument;

        if (doc.colored === true) {
            return;
        }

        doc.getElementsByClassName("trr2").forEach((tr) => {
            var available = Number(tr.children[4].text);
            var total = Number(tr.children[5].text);
            var sum = 0;

            sum = colorOne(tr.children[6], sum, available);
            sum = colorOne(tr.children[7], sum, available);
            sum = colorOne(tr.children[8], sum, available);
        });

        doc.colored = true;
    }, 1000);
})();