"use strict";

/* ============================================================
 * CONFIGURATION
 * ============================================================
 */

/*
 * Configuration lives in assets/config.json and is loaded
 * asynchronously at startup (see START).
 */
let CONFIG = {};
const CONFIG_URL = "assets/config.json";

/* ============================================================
 * Translations
 * ============================================================
 */

/*
 * Translations live in assets/i18n.json and are loaded
 * asynchronously at startup (see START).
 */
let TRANSLATIONS = {};
const I18N_URL = "assets/i18n.json";

/* ============================================================
 * Detect language
 * ============================================================
 */

function detectLanguage() {
  /*
   * Saved language choice takes precedence.
   */
  try {
    const saved = localStorage.getItem("jitsiLauncherLanguage");

    if (saved && TRANSLATIONS[saved]) {
      return saved;
    }
  } catch (error) {
    /*
     * localStorage can be blocked, e.g. in private mode.
     */
  }

  const languages = navigator.languages || [navigator.language];

  for (const language of languages) {
    if (!language) {
      continue;
    }

    const languageCode = language
      .toLowerCase()
      .split("-")[0];

    if (TRANSLATIONS[languageCode]) {
      return languageCode;
    }
  }

  /*
   * English is the default/fallback.
   */
  return "en";
}

let currentLanguage = "en";
let translation = {};

/* ============================================================
 * Apply translations to webpage
 * ============================================================
 */

function applyTranslations() {
  document.documentElement.lang = currentLanguage;
  if (translation.pageTitle) {
    document.title = translation.pageTitle;
  }

  document
    .querySelectorAll("[data-i18n]")
    .forEach((element) => {
      const key = element.dataset.i18n;
      const value = getTranslation(key);

      if (value !== null) {
        element.textContent = value;
      }
    });

  /*
   * Translate placeholders of input fields.
   */
  document
    .querySelectorAll("[data-i18n-placeholder]")
    .forEach((element) => {
      const value = getTranslation(element.dataset.i18nPlaceholder);

      if (value !== null) {
        element.placeholder = value;
      }
    });
}

/*
 * Read a translation by path.
 *
 * Example:
 *
 * "downloads.windows.title"
 *
 * resolves to:
 *
 * translation.downloads.windows.title
 */
function getTranslation(key) {
  const parts = key.split(".");
  let value = translation;

  for (const part of parts) {
    if (
      value === null ||
      value === undefined ||
      typeof value !== "object" ||
      !(part in value)
    ) {
      return null;
    }

    value = value[part];
  }

  return typeof value === "string" ? value : null;
}

/* ============================================================
 * LANGUAGE MENU
 * ============================================================
 */

const LANGUAGE_NAMES = {
  en: "English",
  de: "Deutsch",
  fr: "Français",
  zh: "中文"
};

const LANGUAGE_FLAGS = {
  en: "assets/images/uk.svg",
  de: "assets/images/de.svg",
  fr: "assets/images/fr.svg",
  zh: "assets/images/cn.svg"
};

function updateLanguageMenu() {
  langFlag.src = LANGUAGE_FLAGS[currentLanguage];
  langLabel.textContent = LANGUAGE_NAMES[currentLanguage];

  langDropdown
    .querySelectorAll("button[data-lang]")
    .forEach((item) => {
      item.classList.toggle(
        "active",
        item.dataset.lang === currentLanguage
      );
    });
}

function setLanguage(language) {
  if (!TRANSLATIONS[language]) {
    return;
  }

  currentLanguage = language;
  translation = TRANSLATIONS[language];

  try {
    localStorage.setItem("jitsiLauncherLanguage", language);
  } catch (error) {
    /*
     * localStorage can be blocked, e.g. in private mode.
     */
  }

  applyTranslations();
  updateLanguageMenu();
}

function toggleLanguageMenu() {
  const isOpen = langDropdown.classList.toggle("open");

  langButton.setAttribute(
    "aria-expanded",
    isOpen ? "true" : "false"
  );
}

function closeLanguageMenu() {
  langDropdown.classList.remove("open");
  langButton.setAttribute("aria-expanded", "false");
}

/* ============================================================
 * NAV MENU (Hamburger)
 * ============================================================
 */

function toggleNavMenu() {
  const isOpen = navActions.classList.toggle("open");

  navToggle.setAttribute("aria-expanded", isOpen ? "true" : "false");
}

function closeNavMenu() {
  navActions.classList.remove("open");
  navToggle.setAttribute("aria-expanded", "false");
}

/* ============================================================
 * THEME
 * ============================================================
 */

const THEME_KEY = "jitsiLauncherTheme";

function savedTheme() {
  try {
    const saved = localStorage.getItem(THEME_KEY);

    if (saved === "dark" || saved === "light") {
      return saved;
    }
  } catch (error) {
    /*
     * localStorage can be blocked, e.g. in private mode.
     */
  }

  return null;
}

function systemIsDark() {
  return window.matchMedia("(prefers-color-scheme: dark)").matches;
}

function detectTheme() {
  /*
   * Saved choice takes precedence, otherwise system setting.
   */
  return savedTheme() || (systemIsDark() ? "dark" : "light");
}

let currentTheme = detectTheme();

function updateThemeToggle() {
  themeIconSun.classList.toggle("hidden", currentTheme !== "dark");
  themeIconMoon.classList.toggle("hidden", currentTheme === "dark");
}

function applyTheme() {
  document.documentElement.classList.toggle("dark", currentTheme === "dark");
  updateThemeToggle();
}

function toggleTheme() {
  currentTheme = currentTheme === "dark" ? "light" : "dark";

  try {
    localStorage.setItem(THEME_KEY, currentTheme);
  } catch (error) {
    /*
     * localStorage can be blocked, e.g. in private mode.
     */
  }

  applyTheme();
}

/* ============================================================
 * BACKGROUND IMAGE
 * ============================================================
 */

function applyBackgroundImage() {
  if (!CONFIG.backgroundImage) {
    return;
  }

  document.body.style.backgroundImage = `url("${CONFIG.backgroundImage}")`;
  document.body.style.backgroundSize = "cover";
  document.body.style.backgroundPosition = "center";
}

/* ============================================================
 * LOGO
 * ============================================================
 */

function applyLogo() {
  if (!CONFIG.logo) {
    return;
  }

  logoImage.src = CONFIG.logo;
  logoBar.classList.remove("hidden");
}

/* ============================================================
 * FAVICONS
 * ============================================================
 */

/*
 * Overwrite the default icons from launch.html
 * (CONFIG.favicons in assets/config.json).
 */
function applyFavicons() {
  if (!CONFIG.favicons) {
    return;
  }

  if (CONFIG.favicons.ico) {
    faviconIco.href = CONFIG.favicons.ico;
  }

  if (CONFIG.favicons.svg) {
    faviconSvg.href = CONFIG.favicons.svg;
  }

  if (CONFIG.favicons.appleTouch) {
    appleTouchIcon.href = CONFIG.favicons.appleTouch;
  }
}

/* ============================================================
 * NEXTCLOUD BUTTON
 * ============================================================
 */

/*
 * Only show if a Nextcloud instance is configured
 * (CONFIG.nextcloudBase in assets/config.json).
 */
function applyNextcloudButton() {
  if (!CONFIG.nextcloudBase || !createNextcloudButton) {
    return;
  }

  createNextcloudButton.classList.remove("hidden");
}

/* ============================================================
 * ADHOC BUTTON
 * ============================================================
 */

/*
 * Only show if explicitly enabled
 * (CONFIG.allowAdhocMeetings in assets/config.json).
 */
function applyAdhocButton() {
  if (!CONFIG.allowAdhocMeetings || !createAdhocButton) {
    return;
  }

  createAdhocButton.classList.remove("hidden");
}

/* ============================================================
 * DOM elements
 * ============================================================
 */

const launcher = document.getElementById("launcher");
const starting = document.getElementById("starting");
const fallback = document.getElementById("fallback");
const invalidRoom = document.getElementById("invalidRoom");
const meetingCreator = document.getElementById("meetingCreator");
const roomName = document.getElementById("roomName");
const openButton = document.getElementById("openButton");
const retryButton = document.getElementById("retryButton");
const browserLink = document.getElementById("browserLink");
const windowsDownload = document.getElementById("windowsDownload");
const macosDownload = document.getElementById("macosDownload");
const linuxDownload = document.getElementById("linuxDownload");
const iosDownload = document.getElementById("iosDownload");
const androidDownload = document.getElementById("androidDownload");
const otherDownload = document.getElementById("otherDownload");
const windowsLink = document.getElementById("windowsLink");
const macosLink = document.getElementById("macosLink");
const linuxLink = document.getElementById("linuxLink");
const iosLink = document.getElementById("iosLink");
const androidLink = document.getElementById("androidLink");
const createNewMeetingButton = document.getElementById("createNewMeetingButton");
const createNewFromLauncherButton = document.getElementById("createNewFromLauncherButton");

/* Meeting Creator DOM elements */
const meetingNameInput = document.getElementById("meetingName");
const meetingDescriptionInput = document.getElementById("meetingDescription");
const meetingStartInput = document.getElementById("meetingStart");
const meetingEndInput = document.getElementById("meetingEnd");
const meetingOrganizerInput = document.getElementById("meetingOrganizer");
const createMeetingButton = document.getElementById("createMeetingButton");
const createNextcloudButton = document.getElementById('createNextcloudButton');
const createAdhocButton = document.getElementById("createAdhocButton");
const cancelCreateButton = document.getElementById("cancelCreateButton");
const icsSuccess = document.getElementById("icsSuccess");
const nextcloudStatus = document.getElementById('nextcloudStatus');
const nextcloudError = document.getElementById('nextcloudError');
const downloadIcsLink = document.getElementById("downloadIcsLink");
const adhocResult = document.getElementById("adhocResult");
const adhocLink = document.getElementById("adhocLink");
const copyAdhocLinkButton = document.getElementById("copyAdhocLinkButton");

/* Navbar DOM elements */
const navbar = document.querySelector(".navbar");
const navToggle = document.getElementById("navToggle");
const navActions = document.getElementById("navActions");

/* Language menu DOM elements */
const langMenu = document.getElementById("langMenu");
const langButton = document.getElementById("langButton");
const langDropdown = document.getElementById("langDropdown");
const langFlag = document.getElementById("langFlag");
const langLabel = document.getElementById("langLabel");

/* Invalid room view DOM elements */
const missingRoomTitle = document.getElementById("missingRoomTitle");
const missingRoomError = document.getElementById("missingRoomError");
const invalidNameTitle = document.getElementById("invalidNameTitle");
const invalidNameError = document.getElementById("invalidNameError");
const invalidRoomName = document.getElementById("invalidRoomName");

/* Logo DOM elements */
const logoBar = document.getElementById("logoBar");
const logoImage = document.getElementById("logoImage");

/* Favicon DOM elements */
const faviconIco = document.getElementById("faviconIco");
const faviconSvg = document.getElementById("faviconSvg");
const appleTouchIcon = document.getElementById("appleTouchIcon");

/* Theme DOM elements */
const themeButton = document.getElementById("themeButton");
const themeIconSun = document.getElementById("themeIconSun");
const themeIconMoon = document.getElementById("themeIconMoon");

/* ============================================================
 * GET ROOM FROM QUERY-PARAMETER
 * ============================================================
 *
 * Example:
 *
 * https://<YOURJITSIINSTANCEADDRESS>/launch.html?room=abc-defg-hij
 *
 * results in:
 *
 * abc-defg-hij
 *
 * ============================================================
 */

function getRoom() {
  const params = new URLSearchParams(
    window.location.search
  );

  /*
   * Parameter missing.
   */
  if (!params.has("room")) {
    return null;
  }

  /*
   * Prevent whitespace etc.
   *
   * "?room=" without a value yields an empty string.
   */
  return params.get("room").trim();
}

/* ============================================================
 * VALIDATE ROOM
 * ============================================================
 *
 * Jitsi room names can contain rather different
 * characters depending on the configuration.
 *
 * We only prevent control characters and obvious
 * URL manipulation here.
 *
 * ============================================================
 */

const ROOM_PATTERN = /^[A-Za-z0-9-]+$/;

function isValidRoom(room) {
  if (!room) {
    return false;
  }

  /*
   * Only letters, numbers and hyphens.
   */
  return ROOM_PATTERN.test(room);
}

/* ============================================================
 * JITSI WEB URL
 * ============================================================
 */

function createBrowserUrl(room) {
  return (
    "https://" +
    CONFIG.jitsiHost +
    "/" +
    encodeURIComponent(room)
  );
}

/* ============================================================
 * JITSI DESKTOP PROTOCOL URL
 * ============================================================
 */

function createAppUrl(room) {
  return (
    "jitsi-meet://" +
    CONFIG.jitsiHost +
    "/" +
    encodeURIComponent(room)
  );
}

/* ============================================================
 * JITSI ANDROID URL
 * ============================================================ */

/*
 * The Android app registers "org.jitsi.meet", not the
 * desktop scheme. Chrome & co. require intent://; without
 * the app Chrome offers the Play Store entry from "package=".
 * Firefox ignores intent:// but knows the custom scheme.
 */

function createAndroidIntentUrl(room) {
  return (
    "intent://" +
    CONFIG.jitsiHost +
    "/" +
    encodeURIComponent(room) +
    "#Intent;scheme=org.jitsi.meet;package=org.jitsi.meet;end"
  );
}

/*
 * The mobile apps (iOS, Firefox on Android) register
 * "org.jitsi.meet", not the desktop scheme.
 */
const APP_SCHEME = "org.jitsi.meet://";

function createAppSchemeUrl(room) {
  return (
    APP_SCHEME +
    CONFIG.jitsiHost +
    "/" +
    encodeURIComponent(room)
  );
}

/* ============================================================
 * URL BY PLATFORM/BROWSER
 * ============================================================ */

function selectProtocolUrl(room) {
  const os = detectOperatingSystem();

  /*
   * The iOS app only knows the app scheme.
   */
  if (os === "ios") {
    return createAppSchemeUrl(room);
  }

  if (os !== "android") {
    return createAppUrl(room);
  }

  return detectBrowser() === "firefox"
    ? createAppSchemeUrl(room)
    : createAndroidIntentUrl(room);
}

/* ============================================================
 * DETECT OPERATING SYSTEM
 * ============================================================
 */

/*
 * Parse once (assets/lib/ua-parser.min.js).
 * If the library is missing, the page stays usable.
 */
const uaResult =
  typeof UAParser === "function"
    ? new UAParser().getResult()
    : { os: {}, browser: {} };

/*
 * UAParser names -> internal shortcuts.
 * iPadOS reports as macOS – touch points count as iOS.
 */
const OS_NAMES = {
  Android: "android",
  iOS: "ios",
  Windows: "windows",
  macOS: "macos",
  Linux: "linux",
  Ubuntu: "linux",
  Debian: "linux",
  Fedora: "linux",
  Mint: "linux",
  CentOS: "linux",
  openSUSE: "linux",
  Raspbian: "linux"
};

const BROWSER_NAMES = {
  Edge: "edge",
  "Mobile Edge": "edge",
  Firefox: "firefox",
  "Mobile Firefox": "firefox",
  Chrome: "chrome",
  "Mobile Chrome": "chrome",
  "Chrome Headless": "chrome",
  "Chrome WebView": "chrome",
  "Samsung Internet": "chrome",
  Safari: "safari",
  "Mobile Safari": "safari"
};

function detectOperatingSystem() {
  /*
   * Chrome in "desktop mode" on Android sends a desktop
   * UA (e.g. X11; Linux). Client hints reveal the real
   * system. Firefox/Safari do not support them.
   */
  const hints = navigator.userAgentData;
  if (hints && hints.platform === "Android") {
    return OS_NAMES.Android;
  }

  /*
   * iPadOS masquerades as macOS – touch points give the
   * iPad away. The platform check also works without the
   * ua-parser loaded.
   */
  if (
    navigator.maxTouchPoints > 1 &&
    (navigator.platform === "MacIntel" || uaResult.os.name === "macOS")
  ) {
    return OS_NAMES.iOS;
  }

  return OS_NAMES[uaResult.os.name] || "unknown";
}

/* ============================================================
 * DETECT BROWSER
 * ============================================================
 */

function detectBrowser() {
  return BROWSER_NAMES[uaResult.browser.name] || "unknown";
}

/* ============================================================
 * DOWNLOADS
 * ============================================================
 */

function configureDownloads() {
  const os = detectOperatingSystem();

  windowsDownload.classList.add("hidden");
  macosDownload.classList.add("hidden");
  linuxDownload.classList.add("hidden");
  iosDownload.classList.add("hidden");
  androidDownload.classList.add("hidden");
  otherDownload.classList.add("hidden");

  /* Windows */
  if (os === "windows") {
    windowsLink.href = CONFIG.downloads.windows;
    windowsDownload.classList.remove("hidden");
    return;
  }

  /* macOS */
  if (os === "macos") {
    macosLink.href = CONFIG.downloads.macos;
    macosDownload.classList.remove("hidden");
    return;
  }

  /* Linux */
  if (os === "linux") {
    linuxLink.href = CONFIG.downloads.linux;
    linuxDownload.classList.remove("hidden");
    return;
  }

  /* iOS */
  if (os === "ios") {
    iosLink.href = CONFIG.downloads.ios;
    iosDownload.classList.remove("hidden");
    return;
  }

  /* Android */
  if (os === "android") {
    androidLink.href = CONFIG.downloads.android;
    androidDownload.classList.remove("hidden");
    return;
  }

  /* Everything else */
  otherDownload.classList.remove("hidden");
}

/* ============================================================
 * SHOW FALLBACK
 * ============================================================
 */

function showFallback() {
  starting.classList.add("hidden");
  launcher.classList.add("hidden");
  fallback.classList.remove("hidden");

  configureDownloads();
}

/* ============================================================
 * START JITSI DESKTOP
 * ============================================================
 */

function launchJitsi() {
  const room = getRoom();

  if (!isValidRoom(room)) {
    return;
  }

  const protocolUrl = selectProtocolUrl(room);
  const browserUrl = createBrowserUrl(room);

  /*
   * Prepare the browser fallback.
   */
  browserLink.href = browserUrl;

  /*
   * Set the UI to the "starting" state.
   */
  launcher.classList.add("hidden");
  fallback.classList.add("hidden");
  starting.classList.remove("hidden");

  let completed = false;
  let timeout = null;

  /*
   * Invisible iframe for the protocol handler.
   */
  const iframe = document.createElement("iframe");
  iframe.style.display = "none";

  /*
   * Clean up.
   */
  function cleanup() {
    if (completed) {
      return;
    }

    completed = true;

    if (timeout !== null) {
      clearTimeout(timeout);
    }

    iframe.remove();
  }

  /*
   * --------------------------------------------------------
   * IMPORTANT:
   *
   * Do not use "blur" as a success criterion anymore.
   *
   * The browser can also trigger blur when showing
   * the protocol dialog.
   *
   * If the user cancels the dialog, the page stays
   * visible and our timeout keeps running.
   * --------------------------------------------------------
   */

  document.body.appendChild(iframe);

  /*
   * Start the protocol handler.
   *
   * Firefox ignores external protocols from iframes –
   * start the custom scheme directly in the main navigation.
   */
  try {
    if (protocolUrl.startsWith(APP_SCHEME)) {
      window.location.href = protocolUrl;
    } else {
      iframe.src = protocolUrl;
    }
  } catch (error) {
    console.error(
      "Error opening the Jitsi Protocol Handler:",
      error
    );

    cleanup();
    showFallback();

    return;
  }

  /*
   * --------------------------------------------------------
   * FALLBACK
   * --------------------------------------------------------
   *
   * We wait regardless of whether the browser briefly
   * loses focus.
   *
   * If Jitsi starts successfully:
   *
   *   -> Jitsi comes to the foreground
   *   -> the user no longer sees this page
   *
   * If the user cancels the browser dialog:
   *
   *   -> this page stays visible
   *   -> the timeout expires
   *   -> the fallback is shown
   * --------------------------------------------------------
   */

  timeout = setTimeout(() => {
    if (completed) {
      return;
    }

    cleanup();
    showFallback();
  }, CONFIG.launchTimeout);
}

/* ============================================================
 * ROOM NAME
 * ============================================================
 */

/*
 * Convert special characters to the closest ASCII
 * character.
 *
 * Example:
 *
 * "Grundstück" becomes "Grundstueck"
 * "François" becomes "Francois"
 */
function transliterate(text) {
  const extras = {
    "ß": "ss",
    "ẞ": "ss",
    "æ": "ae",
    "Æ": "ae",
    "œ": "oe",
    "Œ": "oe",
    "ø": "o",
    "Ø": "o"
  };

  return text
    .normalize("NFD")
    .replace(/[\u0300-\u036f]/g, "")
    .replace(/[ßẞæÆœŒøØ]/g, (char) => extras[char]);
}

/*
 * Derive a valid room name from the meeting name.
 *
 * Example:
 *
 * "Grund Stück Planung" becomes "grund-stuck-planung"
 */
function createRoomName(meetingName) {
  return transliterate(meetingName)
    .toLowerCase()
    .replace(/\s+/g, "-")
    .replace(/[^a-z0-9-]/g, "");
}

/* ============================================================
 * ICS FILE GENERATION
 * ============================================================
 */

const ICS_LINE_LIMIT = 75;

/*
 * UTF-8 byte length of a string.
 */
function byteLength(text) {
  let length = 0;

  for (const char of text) {
    const code = char.codePointAt(0);

    length += code <= 0x7f ? 1 : code <= 0x7ff ? 2 : code <= 0xffff ? 3 : 4;
  }

  return length;
}

/*
 * Escape a text value per RFC 5545: backslash first,
 * then semicolon and comma, newlines as literal "\n".
 */
function escapeICS(text) {
  return text
    .replace(/\\/g, "\\\\")
    .replace(/;/g, "\\;")
    .replace(/,/g, "\\,")
    .replace(/\r?\n/g, "\\n");
}

/*
 * Fold lines longer than 75 octets into CRLF + space
 * continuations (RFC 5545).
 */
function foldICS(content) {
  return content
    .split("\r\n")
    .map((line) => {
      if (byteLength(line) <= ICS_LINE_LIMIT) {
        return line;
      }

      const parts = [];
      let current = "";

      for (const char of line) {
        if (byteLength(current + char) > ICS_LINE_LIMIT) {
          parts.push(current);
          current = " " + char;
        } else {
          current += char;
        }
      }

      parts.push(current);

      return parts.join("\r\n");
    })
    .join("\r\n");
}

function generateICS(meetingName, description, startTime, endTime, organizer) {
  /* Generate a unique room name from the meeting name */
  const roomName = createRoomName(meetingName);
  const meetingUrl = createLaunchUrl(roomName);

  /* Format dates for ICS */
  const formatICSDate = (date) => {
    const pad = (num) => num.toString().padStart(2, '0');
    const year = date.getFullYear();
    const month = pad(date.getMonth() + 1);
    const day = pad(date.getDate());
    const hours = pad(date.getHours());
    const minutes = pad(date.getMinutes());
    const seconds = pad(date.getSeconds());
    return `${year}${month}${day}T${hours}${minutes}${seconds}`;
  };

  const uid = `jitsi-${Date.now()}@${CONFIG.jitsiHost}`;
  const dtStamp = formatICSDate(new Date());
  const dtStart = formatICSDate(startTime);
  const dtEnd = formatICSDate(endTime);

  /*
   * One property per line, CRLF endings, folded at
   * 75 octets (RFC 5545).
   */
  const lines = [
    "BEGIN:VCALENDAR",
    "VERSION:2.0",
    `PRODID:-//Jitsi Meeting Launcher//NONSGML (${CONFIG.jitsiLauncher})//EN`,
    "CALSCALE:GREGORIAN",
    "METHOD:PUBLISH",
    "BEGIN:VEVENT",
    `UID:${uid}`,
    `DTSTAMP:${dtStamp}`,
    `DTSTART:${dtStart}`,
    `DTEND:${dtEnd}`,
    `SUMMARY:${escapeICS(meetingName)}`,
    `DESCRIPTION:${escapeICS(description)}`,
    `LOCATION:${meetingUrl}`,
    `ORGANIZER:MAILTO:${organizer}`,
    "STATUS:CONFIRMED",
    `URL:${meetingUrl}`,
    "SEQUENCE:0",
    "TRANSP:OPAQUE",
    "BEGIN:VALARM",
    "ACTION:DISPLAY",
    "DESCRIPTION:Reminder",
    "TRIGGER:-PT15M",
    "END:VALARM",
    "END:VEVENT",
    "END:VCALENDAR"
  ];

  const icsContent = foldICS(lines.join("\r\n")) + "\r\n";

  return {
    content: icsContent,
    roomName: roomName,
    url: meetingUrl
  };
}

let icsObjectUrl = null;

/*
 * Download URL for the ICS content. Revokes the URL of
 * the previous download.
 */
function downloadICS(content) {
  const blob = new Blob([content], { type: 'text/calendar;charset=utf-8' });

  if (icsObjectUrl !== null) {
    URL.revokeObjectURL(icsObjectUrl);
  }

  icsObjectUrl = URL.createObjectURL(blob);

  return icsObjectUrl;
}

const MINUTES_STEP = 15;
const DEFAULT_DURATION_MINUTES = 30;

/*
 * Round minutes up to the 15-minute grid.
 *
 * Example:
 *
 * 14:07 becomes 14:15
 * 14:50 becomes 15:00
 */
function roundMinutes(date) {
  const rounded = new Date(date);

  rounded.setSeconds(0, 0);
  rounded.setMinutes(
    Math.ceil(date.getMinutes() / MINUTES_STEP) * MINUTES_STEP
  );

  return rounded;
}

/*
 * Format local time for datetime-local.
 *
 * Example:
 *
 * January 1, 2026, 14:15 becomes "2026-01-01T14:15"
 */
function formatLocal(date) {
  const pad = (num) => num.toString().padStart(2, "0");

  return (
    date.getFullYear() +
    "-" +
    pad(date.getMonth() + 1) +
    "-" +
    pad(date.getDate()) +
    "T" +
    pad(date.getHours()) +
    ":" +
    pad(date.getMinutes())
  );
}

function showMeetingCreator() {
  /* Hide all other views */
  launcher.classList.add("hidden");
  starting.classList.add("hidden");
  fallback.classList.add("hidden");
  invalidRoom.classList.add("hidden");

  /* Show meeting creator */
  meetingCreator.classList.remove("hidden");

  /* Reset form */
  meetingNameInput.value = '';
  meetingDescriptionInput.value = '';
  meetingStartInput.value = '';
  meetingEndInput.value = '';
  meetingOrganizerInput.value = '';
  icsSuccess.classList.add("hidden");
  adhocResult.classList.add("hidden");

  /* Set default start and end times */
  const start = roundMinutes(new Date());
  const end = new Date(
    start.getTime() + DEFAULT_DURATION_MINUTES * 60 * 1000
  );

  meetingStartInput.value = formatLocal(start);
  meetingEndInput.value = formatLocal(end);
}

function openNextcloudCalendarCreator() {
    const meetingName =
        meetingNameInput.value.trim();

    const description =
        meetingDescriptionInput.value.trim();

    const startTime =
        meetingStartInput.value;

    const endTime =
        meetingEndInput.value;

    const organizer =
        meetingOrganizerInput.value.trim();

    if (!meetingName) {
        alert(getTranslation('creator.meetingNameRequired') || 'Please enter a meeting name.');
        meetingNameInput.focus();
        return;
    }

    if (!startTime || !endTime) {
        alert(getTranslation('creator.startTimeRequired') || 'Please select a start time.');
        return;
    }

    const start = new Date(startTime);
    const end = new Date(endTime);

    if (Number.isNaN(start.getTime()) ||
        Number.isNaN(end.getTime())) {
        alert('Invalid start or end date.');
        return;
    }

    if (end <= start) {
        alert(getTranslation('creator.endAfterStart') || 'End time must be after start time.');
        return;
    }

    /*
     * Nextcloud validates the email server-side and
     * aborts with an error page otherwise.
     */
    const emailPattern = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;

    if (organizer && !emailPattern.test(organizer)) {
        alert(getTranslation('creator.organizerInvalid') || 'Please enter a valid organizer email address.');
        return;
    }

    /*
     * Use exactly the same room-generation logic as the
     * existing ICS creation.
     */
    const roomName = createRoomName(meetingName);

    const meetingUrl =
        createLaunchUrl(roomName);

    const params = new URLSearchParams();

    params.set('summary', meetingName);

    if (description) {
        params.set('description', description);
    }

    params.set('start', startTime);
    params.set('end', endTime);

    if (organizer) {
        params.set('organizer', organizer);
    }

    params.set('location', meetingUrl);
    params.set('url', meetingUrl);

    const nextcloudUrl =
        CONFIG.nextcloudBase +
        '/index.php/apps/atocal/confirm?' +
        params.toString();

    window.location.href = nextcloudUrl;
}

function createMeeting() {
  const meetingName = meetingNameInput.value.trim();
  const description = meetingDescriptionInput.value.trim();
  const startTime = new Date(meetingStartInput.value);
  const endTime = new Date(meetingEndInput.value);
  const organizer = meetingOrganizerInput.value.trim();

  if (!meetingName) {
    alert(getTranslation('creator.meetingNameRequired') || 'Please enter a meeting name');
    return;
  }

  if (!ROOM_PATTERN.test(createRoomName(meetingName))) {
    alert(getTranslation('creator.meetingNameInvalid') || 'Meeting name may only contain letters, numbers and hyphens');
    return;
  }

  if (!meetingStartInput.value) {
    alert(getTranslation('creator.startTimeRequired') || 'Please select a start time');
    return;
  }

  if (!meetingEndInput.value) {
    alert(getTranslation('creator.endTimeRequired') || 'Please select an end time');
    return;
  }

  if (startTime >= endTime) {
    alert(getTranslation('creator.endAfterStart') || 'End time must be after start time');
    return;
  }

  if (!organizer) {
    alert(getTranslation('creator.organizerRequired') || 'Please enter an organizer email');
    return;
  }

  const emailPattern = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
  if (!emailPattern.test(organizer)) {
    alert(getTranslation('creator.organizerInvalid') || 'Please enter a valid organizer email address');
    return;
  }

  /* Generate ICS */
  const icsData = generateICS(meetingName, description || meetingName, startTime, endTime, organizer);

  /* Create download link */
  downloadIcsLink.href = downloadICS(icsData.content);
  downloadIcsLink.download = `${icsData.roomName}.ics`;

  /* Show success message */
  icsSuccess.classList.remove("hidden");
  adhocResult.classList.add("hidden");

  /* Scroll to success message */
  icsSuccess.scrollIntoView({ behavior: 'smooth' });
}

/* ============================================================
 * ADHOC LINK
 * ============================================================
 */

/*
 * Time span after which the "Copied!" text returns
 * to the normal button label.
 */
const COPY_RESET_MS = 2000;

/*
 * Launch URL that opens the meeting in the Jitsi client.
 *
 * Example:
 *
 * "projekt-kickoff" becomes
 * https://meet.bnvb.eu/launch.html?room=projekt-kickoff
 */
function createLaunchUrl(roomName) {
  return `https://${CONFIG.jitsiLauncher}/launch.html?room=${encodeURIComponent(roomName)}`;
}

function createAdhocLink() {
  const meetingName = meetingNameInput.value.trim();

  if (!meetingName) {
    alert(getTranslation('creator.meetingNameRequired') || 'Please enter a meeting name');
    return;
  }

  const roomName = createRoomName(meetingName);

  if (!ROOM_PATTERN.test(roomName)) {
    alert(getTranslation('creator.meetingNameInvalid') || 'Meeting name may only contain letters, numbers and hyphens');
    return;
  }

  const url = createLaunchUrl(roomName);

  adhocLink.href = url;
  adhocLink.textContent = url;
  icsSuccess.classList.add("hidden");
  adhocResult.classList.remove("hidden");
  adhocResult.scrollIntoView({ behavior: 'smooth' });
}

async function copyAdhocLink() {
  const url = adhocLink.href;

  /* Clipboard API, with a fallback for older browsers */
  try {
    await navigator.clipboard.writeText(url);
  } catch (error) {
    const input = document.createElement('textarea');
    input.value = url;
    document.body.appendChild(input);
    input.select();
    document.execCommand('copy');
    document.body.removeChild(input);
  }

  /* Brief feedback, then back to the normal label */
  copyAdhocLinkButton.textContent = getTranslation('creator.copiedLabel') || 'Copied!';
  setTimeout(() => {
    copyAdhocLinkButton.textContent = getTranslation('creator.copyLinkButton') || 'Copy Link';
  }, COPY_RESET_MS);
}

function cancelCreateMeeting() {
  meetingCreator.classList.add("hidden");

  /* If there was a room parameter, show the launcher */
  const room = getRoom();
  if (isValidRoom(room)) {
    roomName.textContent = room;
    browserLink.href = createBrowserUrl(room);
    launcher.classList.remove("hidden");
  } else {
    invalidRoom.classList.remove("hidden");
  }
}

/* ============================================================
 * INITIALIZATION
 * ============================================================
 */

function initialize() {
  const room = getRoom();

  /*
   * No room parameter: hide the messages,
   * only show the Create button.
   */
  if (room === null) {
    missingRoomTitle.classList.add("hidden");
    missingRoomError.classList.add("hidden");
    invalidNameTitle.classList.add("hidden");
    invalidNameError.classList.add("hidden");
    invalidRoom.classList.remove("hidden");
    createNewMeetingButton.classList.remove("hidden");
    return;
  }

  /*
   * Empty room parameter ("?room="):
   * show "No meeting specified".
   */
  if (room === "") {
    missingRoomTitle.classList.remove("hidden");
    missingRoomError.classList.remove("hidden");
    invalidNameTitle.classList.add("hidden");
    invalidNameError.classList.add("hidden");
    invalidRoom.classList.remove("hidden");
    createNewMeetingButton.classList.remove("hidden");
    return;
  }

  /*
   * Invalid room parameter: only show
   * the invalid-name message.
   */
  if (!isValidRoom(room)) {
    missingRoomTitle.classList.add("hidden");
    missingRoomError.classList.add("hidden");
    invalidNameTitle.classList.remove("hidden");
    invalidNameError.classList.remove("hidden");
    invalidRoomName.textContent = room;
    invalidRoom.classList.remove("hidden");
    createNewMeetingButton.classList.remove("hidden");
    return;
  }

  /*
   * Show the room.
   */
  roomName.textContent = room;

  /*
   * Prepare the browser fallback.
   */
  browserLink.href = createBrowserUrl(room);

  /*
   * Show the launcher.
   */
  launcher.classList.remove("hidden");

  /*
   * Hide the "Create New Meeting" button when a valid room is specified
   */
  createNewFromLauncherButton.classList.add("hidden");

  /*
   * Debug information.
   */
  console.log(
    "Jitsi Launcher",
    {
      language: currentLanguage,
      room: room,
      operatingSystem: detectOperatingSystem(),
      touchPoints: navigator.maxTouchPoints,
      browser: detectBrowser(),
      protocol: selectProtocolUrl(room),
      browserUrl: createBrowserUrl(room)
    }
  );
}

/* ============================================================
 * EVENTS
 * ============================================================
 */

openButton.addEventListener(
  "click",
  launchJitsi
);

retryButton.addEventListener(
  "click",
  launchJitsi
);

/* Meeting Creator Events */
createNewMeetingButton.addEventListener(
  "click",
  showMeetingCreator
);

createNewFromLauncherButton.addEventListener(
  "click",
  showMeetingCreator
);

createMeetingButton.addEventListener(
  "click",
  createMeeting
);

if (createNextcloudButton) {
  createNextcloudButton.addEventListener(
    'click',
    openNextcloudCalendarCreator
  );
}

createAdhocButton.addEventListener(
  "click",
  createAdhocLink
);

copyAdhocLinkButton.addEventListener(
  "click",
  copyAdhocLink
);

cancelCreateButton.addEventListener(
  "click",
  cancelCreateMeeting
);

/* Language menu events */
langButton.addEventListener(
  "click",
  toggleLanguageMenu
);

langDropdown.addEventListener(
  "click",
  (event) => {
    const item = event.target.closest("button[data-lang]");

    if (!item) {
      return;
    }

    setLanguage(item.dataset.lang);
    closeLanguageMenu();
  }
);

document.addEventListener(
  "click",
  (event) => {
    if (!langMenu.contains(event.target)) {
      closeLanguageMenu();
    }

    if (!navbar.contains(event.target)) {
      closeNavMenu();
    }
  }
);

/* Theme events */
themeButton.addEventListener(
  "click",
  toggleTheme
);

/* Hamburger events */
navToggle.addEventListener(
  "click",
  toggleNavMenu
);

/*
 * Follow the system if no choice is saved.
 */
window
  .matchMedia("(prefers-color-scheme: dark)")
  .addEventListener("change", () => {
    if (savedTheme() === null) {
      currentTheme = systemIsDark() ? "dark" : "light";
      applyTheme();
    }
  });

/* ============================================================
 * START
 * ============================================================
 */

async function loadConfig() {
  try {
    const response = await fetch(CONFIG_URL);
    CONFIG = await response.json();
  } catch (error) {
    /*
     * Without the file the launcher stays unusable –
     * report the error and continue with an empty config.
     */
    console.error("Error loading config:", error);
  }
}

async function loadTranslations() {
  try {
    const response = await fetch(I18N_URL);
    TRANSLATIONS = await response.json();
  } catch (error) {
    /*
     * Without the file the English text from the HTML stays.
     */
    console.error("Error loading translations:", error);
  }

  currentLanguage = detectLanguage();
  translation = TRANSLATIONS[currentLanguage] || {};
}

/*
 * Apply theme/logo immediately so nothing flickers –
 * text only after the translations have loaded.
 */
async function start() {
  applyTheme();

  await loadConfig();

  applyBackgroundImage();
  applyLogo();
  applyFavicons();
  applyNextcloudButton();
  applyAdhocButton();

  await loadTranslations();

  applyTranslations();
  updateLanguageMenu();
  initialize();
}

start();