const DEFAULT_OPTIONS = {showSeconds: true}
const HOUR_NAMES = [
    "Candle", "Ice", "Comet", "Owl", "Yarn", "Mist",
    "Sprout", "Rainbow", "Worm", "Rabbit", "Blossom", "Nest",
    "Coral", "Cherry", "Bee", "Melon", "Seashell", "Dragon",
    "Chestnut", "Kite", "Mushroom", "Lightning", "Mountain", "Lantern",
];
const HOUR_WIDTH = 70;
const HOUR_ICONS = [
    "🕯️️", "❄️️", "☄️️", "🦉️", "🧶️", "🌫️️",
    "🌱️", "🌈️", "🪱️", "🐇️", "🌸️", "🪺️",
    "🪸️", "🍒️", "🐝️", "🍉️", "🐚️", "🐉️",
    "🌰️", "🪁️", "🍄️", "⚡️️", "⛰️️", "🏮️",
];

const loadSettings = () => {
    var loadedOpts;

    try {
        var data = localStorage.getItem("options");
        console.debug("Loaded", data);
        loadedOpts = JSON.parse(data);
    } catch (e) {
        loadedOpts = null;
    }

    console.debug("Parsed as", loadedOpts);

    return loadedOpts || DEFAULT_OPTIONS;
};

const saveSettings = () => {
    console.debug("Saving", options)
    localStorage.setItem("options", JSON.stringify(options));
};

const zeroPad = (num, numZeros) => {
    if (num == 0) {
        return "".padStart(numZeros, "0")
    }

    var an = Math.abs (num);
    var digitCount = 1 + Math.floor (Math.log (an) / Math.LN10);

    if (digitCount >= numZeros) {
        return String(num);
    }

    var zeroString = Math.pow (10, numZeros - digitCount).toString ().substr (1);

    return num < 0 ? "-" + zeroString + an : zeroString + an;
};

const updateClock = () => {
    var docCenter = document.body.offsetWidth / 2;
    var momentNow = moment();

    var momentUTC = momentNow.utc();
    var utcHour = momentUTC.hours();
    var utcMinute = momentUTC.minutes();

    var momentLocal = momentNow.tz(options.timezone);
    var localHour = momentLocal.hours();
    var localMinute = momentLocal.minutes();

    currentTimeContainer.innerHTML = (
        HOUR_ICONS[utcHour]
        + "<br>"
        + momentLocal.locale(options.locale).format(options.showSeconds ? "LTS" : "LT")
        + "<br>"
        + HOUR_NAMES[utcHour]
    );

    var utcOffset = (
        24 * HOUR_WIDTH
        + utcHour * HOUR_WIDTH
        + utcMinute * HOUR_WIDTH / 60
    );
    var localOffset = (
        24 * HOUR_WIDTH
        + localHour * HOUR_WIDTH
        + localMinute * HOUR_WIDTH / 60
    );

    utcHourContainer.style.left = (docCenter - utcOffset - HOUR_WIDTH / 2) + "px";
    hourNameContainer.style.left = (docCenter - utcOffset) + "px";
    hourIconContainer.style.left = (docCenter - utcOffset) + "px";
    localHourContainer.style.left = (docCenter - localOffset - HOUR_WIDTH / 2) + "px";
    marker.style.left = docCenter + "px";

    for (var nameSpan of document.getElementsByClassName("active")) {
        nameSpan.classList.remove("active");
    }

    var currentNameSpan = document.getElementById("h-present-" + utcHour);
    currentNameSpan.classList.add("active");
};

const showSettingsPanel = () => {
    settingsPanel.style.display = "block";
};

const hideSettingsPanel = () => {
    settingsPanel.style.display = "none";
};

const createClock = () => {
    for (round = 0; round < 3; round++) {
        let prefix;
        switch (round) {
            case 0:
                prefix = "past";
                break;
            case 1:
                prefix = "present";
                break;
            case 2:
                prefix = "future";
                break;
        }
        for (hour = 0; hour < 24; hour++) {
            var nameClass;

            if (hour < 6) {
                nameClass = "winter";
            } else if (hour < 12) {
                nameClass = "spring";
            } else if (hour < 18) {
                nameClass = "summer";
            } else {
                nameClass = "autumn";
            }

            let utcSpan = document.createElement("span");
            utcSpan.id = "u-" + prefix + "-" + hour;
            utcSpan.innerHTML = "U " + zeroPad(hour, 2);
            utcHourContainer.appendChild(utcSpan);

            let localSpan = document.createElement("span");
            localSpan.id = "l-" + prefix + "-" + hour;
            localSpan.innerHTML = zeroPad(hour, 2);
            localHourContainer.appendChild(localSpan);

            let hourNameSpan = document.createElement("span");
            hourNameSpan.id = "h-" + prefix + "-" + hour;
            hourNameSpan.classList.add(nameClass);
            hourNameSpan.innerHTML = HOUR_NAMES[hour];
            hourNameContainer.appendChild(hourNameSpan);

            let hourIconSpan = document.createElement("span");
            hourIconSpan.id = "i-" + prefix + "-" + hour;
            hourIconSpan.classList.add(nameClass);
            hourIconSpan.innerHTML = HOUR_ICONS[hour];
            hourIconContainer.appendChild(hourIconSpan);
        }
    }
};

const initSettings = () => {
    var timeZoneSelector = document.getElementById("timezone-selector");

    if (!options.timezone) {
        options.timezone = moment.tz.guess();
    }

    for (tzname of moment.tz.names()) {
        var tzElem = document.createElement("option");
        tzElem.innerHTML = tzname;

        if (tzname == options.timezone) {
            tzElem.selected = true;
        }

        timeZoneSelector.appendChild(tzElem);
    }

    timeZoneSelector.addEventListener("change", () => {
        options.timezone = timeZoneSelector.value;
        console.log(options)
        updateClock();
        saveSettings();
    })

    var localeSelector = document.getElementById("locale-selector");

    if (!options.locale) {
        options.locale = moment.locale();
    }

    for (localename of moment.locales()) {
        var locElem = document.createElement("option");
        locElem.innerHTML = localename;

        if (localename == options.locale) {
            locElem.selected = true;
        }

        localeSelector.appendChild(locElem);
    }

    localeSelector.addEventListener("change", () => {
        options.locale = localeSelector.value;
        updateClock();
        saveSettings();
    });

    var showSecondsOption = document.getElementById("show-seconds-option");

    showSecondsOption.checked = options.showSeconds;

    showSecondsOption.addEventListener("click", () => {
        options.showSeconds = showSecondsOption.checked;
        updateClock();
        saveSettings();
    });

    showSettingsButton.addEventListener("click", showSettingsPanel);
    closeSettingsButton.addEventListener("click", hideSettingsPanel);
}

const run = () => {
    document.documentElement.style.setProperty("--hour-width", HOUR_WIDTH + "px");

    createClock();
    initSettings();

    addEventListener("resize", updateClock);
    updateClock();
    setInterval(updateClock, 1000);
}

var options = loadSettings();

let utcHourContainer = document.getElementById("utc-hours-inner");
let hourNameContainer = document.getElementById("hour-names-inner");
let hourIconContainer = document.getElementById("hour-icons-inner");
let localHourContainer = document.getElementById("local-hours-inner");
let currentTimeContainer = document.getElementById("current-time");
let showSettingsButton = document.getElementById("settings-button");
let closeSettingsButton = document.getElementById("settings-close");
let settingsPanel = document.getElementById("settings-wrapper")
let marker = document.getElementById("marker");

run();