const MINUTE = 60000,
    HOUR = 3600000,
    DAY = 86400000,
    WEEK = 604800000,
    MONTH = 2592000000,
    YEAR = 31536000000;

$(function () {
    $(window).on("setup_post_events", function (event) {
        setup_events($(`#${event.id}`).find("time"));
    });

    setup_events($("time"));

    setInterval(() => {
        setup_events($("time"));
    }, 60000);

    function setup_events(elements) {
        elements.each(function () {
            let title = $(this).attr("title");

            if (!title) {
                $(this).attr("title", $(this).text());
            }

            let rel = reltime($(this).attr("datetime"));

            $(this).text(rel);
        });
    }

    function reltime(date) {
        let delta = Date.now() - Date.parse(date);
        let fut = false;

        if (delta < 0) {
            delta = Math.abs(delta);
            fut = true;
        }

        let minutes = Math.floor(delta / MINUTE);
        let hours = Math.floor(delta / HOUR);
        let days = Math.floor(delta / DAY);
        let weeks = Math.floor(delta / WEEK);
        let months = Math.floor(delta / MONTH);
        let years = Math.floor(delta / YEAR);

        let rt = "Teď";

        if (minutes > 0) {
            if (fut) {
                rt = `za ${minutes} ${plural("minutu|minuty|minut", minutes)}`;
            } else {
                rt = `před ${minutes} ${plural(
                    "minutou|minutami|minutami",
                    minutes
                )}`;
            }
        }

        if (hours > 0) {
            if (fut) {
                rt = `za ${hours} ${plural("hodinu|hodiny|hodin", hours)}`;
            } else {
                rt = `před ${hours} ${plural(
                    "hodinou|hodinami|hodinami",
                    hours
                )}`;
            }
        }

        if (days > 0) {
            if (fut) {
                rt = `za ${days} ${plural("den|dny|dnů", days)}`;
            } else {
                rt = `před ${days} ${plural("dnem|dny|dny", days)}`;
            }
        }

        if (weeks > 0) {
            if (fut) {
                rt = `za ${weeks} ${plural("týden|týdny", weeks)}`;
            } else {
                rt = `před ${weeks} ${plural("týdnem|týdny", weeks)}`;
            }
        }

        if (months > 0) {
            if (fut) {
                rt = `za ${months} ${plural("měsíc|měsíce|měsíců", months)}`;
            } else {
                rt = `před ${months} ${plural(
                    "měsícem|měsíci|měsíci",
                    months
                )}`;
            }
        }

        if (years > 0) {
            if (fut) {
                rt = `za ${years} ${plural("rok|roky|let", years)}`;
            } else {
                rt = `před ${years} ${plural("rokem|lety|lety", years)}`;
            }
        }

        return rt;
    }

    function plural(plurals, count) {
        let plurals_arr = plurals.split("|");
        let one = plurals_arr[0];
        let few = plurals_arr[1];
        let other = plurals_arr[2];

        if (count === 1) {
            return one;
        } else if (count < 5 && count !== 0) {
            return few;
        } else {
            return other;
        }
    }
});