var mainchart;

var refresh_time = 3;

var prev_total = prev_idle = 0;
var chart_ram, chart_hdd, chart_cpu;

$(document).ready(function()
{
    $("#refresh_time").text(refresh_time);

    highChartsInit();

    chart_ram = createChart("doughnut-ram", ["Free RAM", "Used ram"]);
    chart_hdd = createChart("doughnut-hdd", ["Free space", "Used space"]);
    chart_cpu = createChart("doughnut-cpu", ["Unused load", "Cpu load"]);

    setInterval(refresh, refresh_time * 1000);
});

function highChartsInit()
{
    Highcharts.setOptions({ global: { useUTC: false } });
    mainchart = new Highcharts.stockChart({
        rangeSelector: {
            buttons: [{
            count: 1,
            type: 'minute',
            text: '1M'
        },{
            count: 5,
            type: 'minute',
            text: '5M'
        },{
            count: 10,
            type: 'minute',
            text: '10M'
        },{
            count: 15,
            type: 'minute',
            text: '15M'
        },{
            type: 'all',
            text: 'All'
        }],
            inputEnabled: false,
            selected: 0
        },

        tooltip: { pointFormat: '{series.name}: <b>{point.y}%</b>' },
        chart: { renderTo: 'mainchart' },
        title: { text: 'Hardware usage' },
        xAxis: { title: "Time", type: "datetime" },

        yAxis: {
            title: 'Percentage',
            max: 100,
            min: 0,
            tickInterval:10
        },

        series: [
            { name: 'RAM', data: getDummyData() },
            { name: 'HDD', data: getDummyData() },
            { name: 'CPU', data: getDummyData() }
        ]
    });
}

function createChart(forid, labelarray) {
    return new Chart(document.getElementById(forid).getContext('2d'), {
        type: 'doughnut',
        data: {
            labels: labelarray,
            datasets: [{
                data: [0, 0],
                backgroundColor: ["#c3e6cb", "#f5c6cb" ],
                hoverBackgroundColor: ["#155724", "#721c24"]
            }]
        },
        options: {
            responsive: true,
            legend: {
                display: false
            }
        }
    });
}

function getDummyData()
{
    var chartdata = new Array(), curtime = new Date().getTime();

    for (i = -399; i <= 0; i++) chartdata.push([curtime + i * 1000, 0]);
        chartdata.push([curtime, 0]);

    return chartdata;
}

function refresh()
{
    $.getJSON("getData.php", null, function(data) {
        var time = (new Date()).getTime();

        var cpuload = getCpuLoad(data.CPUDetail);
        var currentram = ((data.memory[1] / data.memory[0]) * 100).toFixed(2);
        var currenthdd = ((data.storage["used"] / data.storage["total"]) * 100).toFixed(2);
        var currentcpu = cpuload > 100 ? 100 : cpuload;

        mainchart.series[0].addPoint([time, parseFloat(currentram)], false, true);
        mainchart.series[1].addPoint([time, parseFloat(currenthdd)], false, true);
        mainchart.series[2].addPoint([time, parseFloat(currentcpu)], true, true);

        $("#ram .usage").html(formatNumber(data.memory[1]) + " kb<br/>Cache: " + formatNumber(data.memory[3]) + " kb");
        $("#ram .total").text(formatNumber(data.memory[0]));
        $("#ram .free").text(formatNumber(data.memory[2]));

        $("#hdd .usage").text(formatNumber(data.storage["used"]));
        $("#hdd .total").text(formatNumber(data.storage["total"]));
        $("#hdd .free").text(formatNumber(data.storage["free"]));

        $("#network .rec").html(formatNumber(data.network[0]) + " bytes <br/>Packets: " + formatNumber(data.network[1]));
        $("#network .sent").html(formatNumber(data.network[2]) + " bytes <br/>Packets: " + formatNumber(data.network[3]));

        var info = "Uptime: " + getTime(data.uptime) + "<br />Operating System: " + data.OS;
        $("#general_info").html(info);

        $("#cpu .list-group").empty();

        chart_ram.data.datasets[0].data = [data.memory[2], data.memory[1]];
        chart_hdd.data.datasets[0].data = [data.storage["free"], data.storage["used"]];
        chart_cpu.data.datasets[0].data = [100.0 - currentcpu, currentcpu];
        chart_ram.update();
        chart_hdd.update();
        chart_cpu.update();

        for (var i = 0; i < data.CPU.length; i++)
        {
            if(i % 3 === 0)
            {
                var listitem = $("<li>", {"class": "list-group-item"});
                listitem.html(data.CPU[i][1] + "<br />" + data.CPU[i + 1][0] + ": " + data.CPU[i + 1][1] + "<br />" + data.CPU[i + 2][0] + ": " + data.CPU[i + 2][1]);
                $("#cpu .list-group").append(listitem);
            }
        }
    });
}

//Calculation by https://github.com/Leo-G/DevopsWiki/wiki/How-Linux-CPU-Usage-Time-and-Percentage-is-calculated
function getCpuLoad(input)
{
    var cpuload = input.split(' ');
    var sum = 0;

    for (var i = 0; i < cpuload.length; i++) {
        sum += parseInt(cpuload[i]);
    }

    var idlecpuload = cpuload[3];
    var diff_idle = idlecpuload - prev_idle;
    var diff_total = sum - prev_total;
    var diff_usage = (1000 * (diff_total - diff_idle) / diff_total + 5) / 10;

    prev_total = sum;
    prev_idle = idlecpuload;

    return diff_usage.toFixed(2);
}

function formatNumber(number)
{
    return number.toLocaleString("nl").replace(/\./g, " ");
}

function getTime(seconds)
{
    var leftover = seconds;

    var days = Math.floor(leftover / 86400);
    leftover = leftover - (days * 86400);

    var hours = Math.floor(leftover / 3600);
    leftover = leftover - (hours * 3600);

    var minutes = Math.floor(leftover / 60);
    leftover = leftover - (minutes * 60);

    return days + " days, " + hours + " hours, " + minutes + " minutes, " + leftover + " seconds";
}