path: root/js/gradings.js

const API_ENDPOINT = "https://gimb.tk/test.php";
// const API_ENDPOINT = "http://localhost:5000/test.php";

var calendar_obj = null;

async function checkLogin() {
    localforage.getItem("logged_in").then((value) => {
        // This code runs once the value has been loaded
        // from the offline store.
        if (value !== true) {
            window.location.replace("/index.html");
        }
    }).catch((err) => {
        // This code runs if there were any errors
        console.log(err);
    });
}

// Set loading bar visibility
function setLoading(state) {
    if (state) {
        $("#loading-bar").removeClass("hidden");
    } else {
        $("#loading-bar").addClass("hidden");
    }
}

// GET COLOR FROM STRING
function hashCode(str) { // java String#hashCode
    var hash = 0;
    for (var i = 0; i < str.length; i++) {
        hash = str.charCodeAt(i) + ((hash << 5) - hash);
    }
    return hash;
}

function intToRGB(i) {
    var c = (i & 0x00FFFFFF)
        .toString(16)
        .toUpperCase();

    return "00000".substring(0, 6 - c.length) + c;
}

// http://www.w3.org/TR/AERT#color-contrast
function getForegroundFromBackground(background_color) {
    let color_hex = background_color.replace("#", "");
    let rgb = [
        parseInt(color_hex.substring(0, 2), 16),
        parseInt(color_hex.substring(2, 4), 16),
        parseInt(color_hex.substring(4, 6), 16)
    ];
    let o = Math.round(((parseInt(rgb[0]) * 299) + (parseInt(rgb[1]) * 587) + (parseInt(rgb[2]) * 114)) / 1000);
    if (o > 180) {
        return "#000000";
    } else {
        return "#ffffff";
    }
}

function getHexColorFromString(str) {
    return "#" + intToRGB(hashCode(str));
}
// --------------------------------------------------

function getDateString() {
    let date = new Date();

    let year_str = date.getFullYear();
    let month_str = date.getMonth() + 1
    month_str = month_str.toString().padStart(2, "0");
    let day_str = date.getDate();
    day_str = day_str.toString().padStart(2, "0");

    let date_string = year_str + "-" + month_str + "-" + day_str;
    return date_string;
}

async function loadGradings(force_refresh = false) {
    setLoading(true);

    let promises_to_run = [
        localforage.getItem("username").then((value) => {
            username = value;
        }),
        localforage.getItem("password").then((value) => {
            password = value;
        }),
        localforage.getItem("gradings").then((value) => {
            gradings = value;
        })
    ];

    await Promise.all(promises_to_run);

    if (gradings === null || force_refresh) {
        $.ajax({
            url: API_ENDPOINT,
            crossDomain: true,

            data: {
                "u": username,
                "p": password,
                "m": "fetchocenjevanja"
            },
            dataType: "json",

            cache: false,
            type: "GET",

            success: (data) => {

                // If data is null, the credentials were incorrect
                if (data === null) {
                    M.toast({ html: "Request failed!" });
                    setLoading(false);
                } else {
                    // Save gradings & populate calendar
                    localforage.setItem("gradings", data).then((value) => {
                        gradings = value;
                        displayData();
                        setLoading(false);
                    });
                }

            },

            error: () => {
                M.toast({ html: "No internet connection!" });
                setLoading(false);
            }

        })

    } else {
        displayData();
        setLoading(false);
    }

}

function displayData() {
    let transformed_gradings = [];
    gradings.forEach((element, index) => {

        let bg_color = getHexColorFromString(element["kratica"]);
        let fg_color = getForegroundFromBackground(bg_color);

        let grading_object = {
            // Convert from dd.mm.yyyy to yyyy-mm-dd
            start: element["datum"].split(".").reverse().join("-"),
            title: element["kratica"],
            id: index.toString(),
            backgroundColor: bg_color,
            textColor: fg_color
        };

        transformed_gradings.push(grading_object);
    });

    calendar_obj.removeAllEvents();
    calendar_obj.addEventSource(transformed_gradings);
}

function gradingClickHandler(eventClickInfo) {
    let grading_id = parseInt(eventClickInfo.event.id);
    let grading_subject = gradings[grading_id]["predmet"];
    let grading_date = gradings[grading_id]["datum"];
    let grading_description = gradings[grading_id]["opis"];

    document.getElementById("grading-subject").innerText = grading_subject;
    document.getElementById("grading-date").innerText = grading_date;
    document.getElementById("grading-description").innerText = grading_description;

    const modal = document.querySelectorAll('.side-modal')[0];
    M.Sidenav.getInstance(modal).open();
}

document.addEventListener("DOMContentLoaded", () => {
    checkLogin();

    // Calendar setup
    var calendarEl = document.getElementById("calendar");
    calendar_obj = new FullCalendar.Calendar(calendarEl, {
        plugins: ["dayGrid"],
        defaultDate: getDateString(),
        navLinks: false,
        editable: false,
        events: [],
        eventClick: gradingClickHandler,
        height: "parent"
    });
    calendar_obj.render();

    loadGradings();

    // Setup refresh handler
    $("#refresh-icon").click(() => {
        loadGradings(true);
    });

    // Setup side menu
    const menus = document.querySelectorAll(".side-menu");
    M.Sidenav.init(menus, { edge: "right", draggable: true });

    // Setup side modal
    const modals = document.querySelectorAll('.side-modal');
    M.Sidenav.init(modals, { edge: 'left', draggable: false });
});