// ==UserScript==
// @name         CF Rating Table
// @namespace    http://codeforces.com/
// @version      0.1
// @description  try to take over the world!
// @author       PikMike
// @match        http://codeforces.com/group/*/customrating/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    function comp(a, b) {
        if (a[0] < b[0]) {
            return -1;
        }
        if (a[0] > b[0]) {
            return 1;
        }
        return 0;
    }

    function calcRating(state){
        var cnt = 0;
        var sum = 0.0;
        for (var i = 4; i < state.children.length; i++){
            var text = state.children[i].innerHTML;
            if (text.indexOf('/') == -1){
                if (text.indexOf('-') != -1)
                    continue;
                cnt += 1;
                sum += parseFloat(text.replace(',', '.'));
            }
            else{
                text = text.split('/');
                if (text[0].indexOf('-') != -1)
                    continue;
                cnt += 1;
                sum += parseFloat(text[0].replace(',', '.'));
                text = state.children[i].children[0].innerHTML;
                sum += parseFloat(text.replace(',', '.'));
            }
        }
        state.children[2].innerHTML = cnt.toString();
        state.children[3].innerHTML = (cnt === 0 ? 0.0 : sum / cnt).toFixed(2).toString();
        return (cnt === 0 ? 0.0 : sum / cnt);
    }

    var panel = document.getElementsByClassName("datatable")[0];
    var panel2 = panel.children[panel.children.length - 1];
    var tableFull = panel2.children[panel2.children.length - 1];
    var table = tableFull.children[tableFull.children.length - 1];

    var ar = [];

    for (var i = 0; i < table.children.length; i++)
        ar.push([calcRating(table.children[i]), i]);

    ar.sort(comp);

    var newTable = document.createElement("tbody");
    for (var i = ar.length - 1; i >= 0; i--){
        var tmp = table.children[ar[i][1]].cloneNode(true);
        tmp.children[0].innerHTML = (ar.length - i).toString();
        newTable.appendChild(tmp);
    }

    tableFull.removeChild(table);
    tableFull.appendChild(newTable);
})();