Cambridge application statistics analyser

cambridge_stats.user.js

// ==UserScript==
// @name         Cambridge application statistics analyser
// @namespace    https://gist.github.com/daniilS/
// @description  Go to the application statistics page, select courses or colleges, and press the button!
// @author       daniilS
// @version      2
// @updateURL    https://gist.github.com/daniilS/0eb8ea9130822b1ff7c4eef64b53f2f5/raw/cambridge_stats.user.js
// @match        http://www.undergraduate.study.cam.ac.uk/apply/statistics
// @require      https://code.highcharts.com/highcharts.js
// @require      https://code.highcharts.com/modules/exporting.js
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_deleteValue
// @run-at       document-idle
// ==/UserScript==

var count = GM_getValue("CambridgeStatCounter", 0);
var data = GM_getValue("CambridgeStatData", []);
var firstYear = GM_getValue("CambridgeStatFirstYear", parseInt(document.getElementById("edit-year")[document.getElementById("edit-year").length - 1].value));

var lastYear = parseInt(document.getElementById("edit-year")[0].value);

function addButton(){
    var button = document.getElementById("edit-submit").cloneNode();
    button.value = "Collect statistics";
    button.style.margin = "0px 5px";
    button.addEventListener("click", function(e){
        e.preventDefault();

        firstYear = parseInt(document.getElementById("yearInput").value);
        GM_setValue("CambridgeStatFirstYear", firstYear);

        document.getElementById("edit-period-year").click();
        document.getElementById("edit-year").value = firstYear.toString();
        document.getElementById("edit-app-applications").checked = true;
        document.getElementById("edit-open-open").checked = false;
        document.getElementById("edit-off-offers").checked = true;
        document.getElementById("edit-winter-winter").checked = true;
        document.getElementById("edit-acc-acceptances").checked = false;

        count++;
        GM_setValue("CambridgeStatCounter", count);
        document.getElementById("edit-submit").click();

        return false;
    });

    var yearInput = document.getElementById("edit-year").cloneNode(true);
    yearInput.id = "yearInput";
    yearInput.value = firstYear.toString();

    var yearLabel = document.createElement("label");
    yearLabel.setAttribute("for", yearInput);
    yearLabel.innerHTML = "Collect statistics starting from:";

    document.getElementById("edit-submit").parentNode.appendChild(button);
    document.getElementById("edit-submit").parentNode.appendChild(yearLabel);
    document.getElementById("edit-submit").parentNode.appendChild(yearInput);
}

function processData(data){
    var offersSummed = [];
    data.forEach(function(yearData){ //sum direct and pool offers
        var processedYearData = [];
        processedYearData.push(yearData[0]);
        processedYearData.push(yearData[1]);
        var accepted = [];
        for(var x = 0; x < yearData[2].length; x++){
            accepted.push(yearData[2][x]+yearData[3][x]);
        }
        processedYearData.push(accepted);
        offersSummed.push(processedYearData);
    });

    var average = [];
    for(var college = 0; college < offersSummed[offersSummed.length - 1][0].length; college++){ //calculate average applications and offers, then divide
        var name = offersSummed[offersSummed.length - 1][0][college];
        var applicationsSum = 0;
        var offersSum = 0;
        offersSummed.forEach(function(year){
            var index = year[0].findIndex(function(e){ //to ensure only colleges that offered the course last year are taken into account
                return e == name;
            });
            if(index != -1){
                applicationsSum += year[1][index];
                offersSum += year[2][index];
            }
        });
        if(applicationsSum !== 0 && offersSum !== 0){
            average.push([name, applicationsSum/offersSum]);
        }
    }
    average.sort(function(collegeA, collegeB){
        return collegeA[1] - collegeB[1];
    });
    average.forEach(function(college, index, array){
        array[index][0] = college[0].replace(" College", "");
    });
    return average;
}

function drawChart(chartData){
    var options;
    if(document.getElementById("edit-group-college").checked === true){ //grouped by college
        options = document.getElementsByClassName("chosen-choices")[1];
    }
    else{ //grouped by course
        options = document.getElementsByClassName("chosen-choices")[0];
    }

    var title = "Applicants per offered place";
    if(options.children.length == 2){ //only one college/course selected, so add it to the graph title
        title += " (" + options.children[0].innerText + ")";
        if(document.getElementById("edit-group-course").checked === true){
            alert("Warning: this data does not include offers made by other colleges. Consider grouping by college instead, or not selecting any specific college.");
        }
    }
    if(firstYear != lastYear){
        title += "—average of " + firstYear + "–" + lastYear;
    }

    Highcharts.chart("highcharts-0", {
        chart: {
            height: 600,
            spacingLeft: 50,
            type: "column"
        },
        title: {
            text: title
        },
        xAxis: {
            type: "category",
            labels: {
                rotation: -45,
                style: {
                    fontSize: "13px",
                    fontFamily: "Verdana, sans-serif"
                }
            }
        },
        yAxis: {
            min: 0,
            title: {
                text: null
            }
        },
        legend: {
            enabled: false
        },
        tooltip: {
            pointFormat: "Applicants per offered place: <b>{point.y:.1f}</b>"
        },
        series: [{
            data: chartData
        }]
    });
}

if(!count){
    addButton();
}
else{
    var thisData = [];
    var colleges = [];
    for(var college of unsafeWindow.Highcharts.charts[0].series[0].data){
        colleges.push(college.category);
    }
    thisData.push(colleges);
    if(unsafeWindow.Highcharts.charts[0].series.length == 4){ //grouped by college
        [0, 1, 3].forEach(function(x){ //total applications, direct offers, pool offers from other colleges
            thisData.push(unsafeWindow.Highcharts.charts[0].series[x].processedYData);
        });
    }
    else{ //grouped by course
        [0, 1, 2].forEach(function(x){ //total applications, direct offers, pool offers
            thisData.push(unsafeWindow.Highcharts.charts[0].series[x].processedYData);
        });
    }
    data.push(thisData);
    var nextYear = firstYear + count;
    if(nextYear > lastYear){
        chartData = processData(data);

        drawChart(chartData);

        count = 0;
        GM_deleteValue("CambridgeStatCounter");
        GM_deleteValue("CambridgeStatData");
        GM_deleteValue("CambridgeStatFirstYear");

        firstYear = parseInt(document.getElementById("edit-year")[document.getElementById("edit-year").length - 1].value);
        addButton();
    }
    else{
        document.getElementById("edit-year").value = nextYear.toString();
        count++;
        GM_setValue("CambridgeStatData", data);
        GM_setValue("CambridgeStatCounter", count);
        document.getElementById("edit-submit").click();
    }
}