/*
 * Obtiene los datos de la cuota de cgi-bin/limitator.json y los muestra.
 */

getCounters(parseCounters);
setInterval(() => getCounters(parseCounters), 5000);

var ctx = document.getElementById('speed_chart');
var chart = new Chart(ctx, {
    type: 'line',
    data: {
        labels: ['', '', '', '', '', '', '', '', '', ''],
        datasets: [{
            label: 'Velocidad (KB/s)',
            data: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
        }]
    },
    options: {
        responsive: false,
        elements: {
            point: {
                radius: 0
            }
        },
        scales: {
            xAxes: [{
                ticks: {
                    display: false
                }
            }],
            yAxes: [{
                ticks: {
                    min: 0
                }
            }]
        }
    }
});

function getCounters(funcToParse) {
    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function () {
        if (this.readyState == 4 && this.status == 200) {
            funcToParse(this.responseText);
        }
    };
    xhttp.open("GET", "cgi-bin/limitator.json", true);
    xhttp.send();
}

function parseCounters(data) {
    let counters = JSON.parse(data);
    document.getElementById("remaining").innerHTML = bytesToMegas(counters.remaining);
    document.getElementById("used_bytes").innerHTML = bytesToMegas(counters.used_bytes);
    document.getElementById("current_quota").innerHTML = bytesToMegas(counters.current_quota);
    document.getElementById("total_quota").innerHTML = bytesToMegas(counters.total_quota);

    updateSpeed(counters.used_bytes);
}

var used_bytes_array = new Array();
function updateSpeed(used_bytes) {
    used_bytes_array.push({ used_bytes: used_bytes, date: new Date() });

    if (used_bytes_array.length <= 1)
        return;
    else if (used_bytes_array.length > 10)
        used_bytes_array.shift();

    let previous_used_bytes = used_bytes_array[used_bytes_array.length - 2];
    let byte_transferred = used_bytes - previous_used_bytes.used_bytes;
    let time_elapsed = (new Date() - previous_used_bytes.date) / 1000;
    document.getElementById("speed").innerHTML = bytesToKbps(byte_transferred / time_elapsed);

    chart.data.datasets[0].data.shift();
    chart.data.datasets[0].data.push(byte_transferred / time_elapsed / 1024);
    chart.update();
}

function bytesToMegas(number) {
    return (number / 1024 / 1024).toFixed(1) + ' MB';
}

function bytesToKbps(number) {
    return (number / 1024).toFixed(1) + ' KB/s';
}