(() => {
  "use strict";

  const translations = {
    en: {
      output: "OUTPUT", searchPlayers: "Search for network players", logout: "LOG OUT",
      rendererLocal: "LOCAL", defaultPlaylist: "Default",
      playbackControls: "Playback controls", previousTrack: "Previous track",
      playOrPause: "Play or pause", play: "Play", pause: "Pause", stop: "Stop",
      nextTrack: "Next track", playbackPosition: "Playback position",
      repeatMode: "Repeat mode", setVolume: "Set volume", volume: "Volume",
      musicLibrary: "MUSIC LIBRARY", upFolder: "Up one folder", currentFolder: "Current folder",
      noLibraryConfigured: "No library configured.", folderContents: "Folder contents",
      nowPlaying: "NOW PLAYING", nothingSelected: "Nothing selected yet",
      addTrackHint: "Add a track from the library", playlists: "Playlists",
      newPlaylist: "New playlist", playlist: "PLAYLIST", clearList: "CLEAR LIST",
      emptyPlaylist: "This playlist is empty.", emptyPlaylistHint: "Use ＋ next to a track or folder.",
      title: "TITLE", album: "ALBUM", duration: "DURATION", actions: "Actions",
      connecting: "Connecting…", signIn: "Sign in", username: "Username",
      password: "Password", noLibrary: "No library", playNow: "Play {name} now",
      addNamed: "Add {name}", loadingNamed: "Loading {name}…", addingNamed: "Adding {name}…",
      playlistName: "Playlist name", removePlaylist: "Remove playlist",
      removeNamed: "Remove {name}", oneTrack: "track", manyTracks: "tracks",
      repeatOff: "Repeat off", repeatAll: "Repeat all", repeatOne: "Repeat one track",
      channels: "channels", oneChannel: "channel", searchingPlayers: "Searching for network players…",
      authUnknown: "Authentication status unknown: {message}", noConnection: "No connection: {message}",
      loggedOut: "You have been logged out.", volumePercent: "Set volume, {value} percent",
    },
    nl: {
      output: "UITVOER", searchPlayers: "Netwerkspelers zoeken", logout: "UITLOGGEN",
      rendererLocal: "LOKAAL", defaultPlaylist: "Standaard",
      playbackControls: "Afspeelbediening", previousTrack: "Vorige track",
      playOrPause: "Afspelen of pauzeren", play: "Afspelen", pause: "Pauzeren", stop: "Stoppen",
      nextTrack: "Volgende track", playbackPosition: "Afspeelpositie",
      repeatMode: "Herhaalmodus", setVolume: "Volume instellen", volume: "Volume",
      musicLibrary: "MUZIEKBIBLIOTHEEK", upFolder: "Eén map omhoog", currentFolder: "Huidige map",
      noLibraryConfigured: "Geen bibliotheek geconfigureerd.", folderContents: "Mapinhoud",
      nowPlaying: "NU AAN HET SPELEN", nothingSelected: "Nog niets gekozen",
      addTrackHint: "Voeg een track toe vanuit de bibliotheek", playlists: "Afspeellijsten",
      newPlaylist: "Nieuwe afspeellijst", playlist: "AFSPEELLIJST", clearList: "LIJST WISSEN",
      emptyPlaylist: "Deze afspeellijst is leeg.", emptyPlaylistHint: "Gebruik ＋ bij een track of map.",
      title: "TITEL", album: "ALBUM", duration: "DUUR", actions: "Acties",
      connecting: "Verbinden…", signIn: "Aanmelden", username: "Gebruikersnaam",
      password: "Wachtwoord", noLibrary: "Geen bibliotheek", playNow: "{name} nu afspelen",
      addNamed: "{name} toevoegen", loadingNamed: "{name} laden…", addingNamed: "{name} toevoegen…",
      playlistName: "Naam van de afspeellijst", removePlaylist: "Afspeellijst verwijderen",
      removeNamed: "{name} verwijderen", oneTrack: "track", manyTracks: "tracks",
      repeatOff: "Herhalen uit", repeatAll: "Alles herhalen", repeatOne: "Eén track herhalen",
      channels: "kanalen", oneChannel: "kanaal", searchingPlayers: "Netwerkspelers zoeken…",
      authUnknown: "Authenticatiestatus onbekend: {message}", noConnection: "Geen verbinding: {message}",
      loggedOut: "Je bent uitgelogd.", volumePercent: "Volume instellen, {value} procent",
    },
    de: {
      output: "AUSGABE", searchPlayers: "Netzwerkplayer suchen", logout: "ABMELDEN",
      rendererLocal: "LOKAL", defaultPlaylist: "Standard",
      playbackControls: "Wiedergabesteuerung", previousTrack: "Vorheriger Titel",
      playOrPause: "Wiedergeben oder pausieren", play: "Wiedergeben", pause: "Pausieren", stop: "Stoppen",
      nextTrack: "Nächster Titel", playbackPosition: "Wiedergabeposition",
      repeatMode: "Wiederholungsmodus", setVolume: "Lautstärke einstellen", volume: "Lautstärke",
      musicLibrary: "MUSIKBIBLIOTHEK", upFolder: "Einen Ordner nach oben", currentFolder: "Aktueller Ordner",
      noLibraryConfigured: "Keine Bibliothek konfiguriert.", folderContents: "Ordnerinhalt",
      nowPlaying: "AKTUELLE WIEDERGABE", nothingSelected: "Noch nichts ausgewählt",
      addTrackHint: "Titel aus der Bibliothek hinzufügen", playlists: "Wiedergabelisten",
      newPlaylist: "Neue Wiedergabeliste", playlist: "WIEDERGABELISTE", clearList: "LISTE LEEREN",
      emptyPlaylist: "Diese Wiedergabeliste ist leer.", emptyPlaylistHint: "Verwenden Sie ＋ neben einem Titel oder Ordner.",
      title: "TITEL", album: "ALBUM", duration: "DAUER", actions: "Aktionen",
      connecting: "Verbinden…", signIn: "Anmelden", username: "Benutzername",
      password: "Passwort", noLibrary: "Keine Bibliothek", playNow: "{name} jetzt wiedergeben",
      addNamed: "{name} hinzufügen", loadingNamed: "{name} wird geladen…", addingNamed: "{name} wird hinzugefügt…",
      playlistName: "Name der Wiedergabeliste", removePlaylist: "Wiedergabeliste entfernen",
      removeNamed: "{name} entfernen", oneTrack: "Titel", manyTracks: "Titel",
      repeatOff: "Wiederholung aus", repeatAll: "Alles wiederholen", repeatOne: "Einen Titel wiederholen",
      channels: "Kanäle", oneChannel: "Kanal", searchingPlayers: "Netzwerkplayer werden gesucht…",
      authUnknown: "Authentifizierungsstatus unbekannt: {message}", noConnection: "Keine Verbindung: {message}",
      loggedOut: "Sie wurden abgemeldet.", volumePercent: "Lautstärke einstellen, {value} Prozent",
    },
    fr: {
      output: "SORTIE", searchPlayers: "Rechercher les lecteurs réseau", logout: "DÉCONNEXION",
      rendererLocal: "LOCAL", defaultPlaylist: "Par défaut",
      playbackControls: "Commandes de lecture", previousTrack: "Piste précédente",
      playOrPause: "Lire ou mettre en pause", play: "Lire", pause: "Pause", stop: "Arrêter",
      nextTrack: "Piste suivante", playbackPosition: "Position de lecture",
      repeatMode: "Mode répétition", setVolume: "Régler le volume", volume: "Volume",
      musicLibrary: "BIBLIOTHÈQUE MUSICALE", upFolder: "Dossier parent", currentFolder: "Dossier actuel",
      noLibraryConfigured: "Aucune bibliothèque configurée.", folderContents: "Contenu du dossier",
      nowPlaying: "LECTURE EN COURS", nothingSelected: "Aucune sélection",
      addTrackHint: "Ajoutez une piste depuis la bibliothèque", playlists: "Listes de lecture",
      newPlaylist: "Nouvelle liste de lecture", playlist: "LISTE DE LECTURE", clearList: "VIDER LA LISTE",
      emptyPlaylist: "Cette liste de lecture est vide.", emptyPlaylistHint: "Utilisez ＋ à côté d’une piste ou d’un dossier.",
      title: "TITRE", album: "ALBUM", duration: "DURÉE", actions: "Actions",
      connecting: "Connexion…", signIn: "Se connecter", username: "Nom d’utilisateur",
      password: "Mot de passe", noLibrary: "Aucune bibliothèque", playNow: "Lire {name} maintenant",
      addNamed: "Ajouter {name}", loadingNamed: "Chargement de {name}…", addingNamed: "Ajout de {name}…",
      playlistName: "Nom de la liste de lecture", removePlaylist: "Supprimer la liste de lecture",
      removeNamed: "Supprimer {name}", oneTrack: "piste", manyTracks: "pistes",
      repeatOff: "Répétition désactivée", repeatAll: "Tout répéter", repeatOne: "Répéter une piste",
      channels: "canaux", oneChannel: "canal", searchingPlayers: "Recherche des lecteurs réseau…",
      authUnknown: "État d’authentification inconnu : {message}", noConnection: "Aucune connexion : {message}",
      loggedOut: "Vous avez été déconnecté.", volumePercent: "Régler le volume, {value} pour cent",
    },
    es: {
      output: "SALIDA", searchPlayers: "Buscar reproductores de red", logout: "CERRAR SESIÓN",
      rendererLocal: "LOCAL", defaultPlaylist: "Predeterminada",
      playbackControls: "Controles de reproducción", previousTrack: "Pista anterior",
      playOrPause: "Reproducir o pausar", play: "Reproducir", pause: "Pausar", stop: "Detener",
      nextTrack: "Pista siguiente", playbackPosition: "Posición de reproducción",
      repeatMode: "Modo de repetición", setVolume: "Ajustar volumen", volume: "Volumen",
      musicLibrary: "BIBLIOTECA MUSICAL", upFolder: "Subir una carpeta", currentFolder: "Carpeta actual",
      noLibraryConfigured: "No hay ninguna biblioteca configurada.", folderContents: "Contenido de la carpeta",
      nowPlaying: "REPRODUCIENDO", nothingSelected: "Nada seleccionado",
      addTrackHint: "Añade una pista desde la biblioteca", playlists: "Listas de reproducción",
      newPlaylist: "Nueva lista de reproducción", playlist: "LISTA DE REPRODUCCIÓN", clearList: "VACIAR LISTA",
      emptyPlaylist: "Esta lista de reproducción está vacía.", emptyPlaylistHint: "Usa ＋ junto a una pista o carpeta.",
      title: "TÍTULO", album: "ÁLBUM", duration: "DURACIÓN", actions: "Acciones",
      connecting: "Conectando…", signIn: "Iniciar sesión", username: "Nombre de usuario",
      password: "Contraseña", noLibrary: "Sin biblioteca", playNow: "Reproducir {name} ahora",
      addNamed: "Añadir {name}", loadingNamed: "Cargando {name}…", addingNamed: "Añadiendo {name}…",
      playlistName: "Nombre de la lista de reproducción", removePlaylist: "Eliminar lista de reproducción",
      removeNamed: "Eliminar {name}", oneTrack: "pista", manyTracks: "pistas",
      repeatOff: "Repetición desactivada", repeatAll: "Repetir todo", repeatOne: "Repetir una pista",
      channels: "canales", oneChannel: "canal", searchingPlayers: "Buscando reproductores de red…",
      authUnknown: "Estado de autenticación desconocido: {message}", noConnection: "Sin conexión: {message}",
      loggedOut: "Has cerrado la sesión.", volumePercent: "Ajustar volumen, {value} por ciento",
    },
  };

  const supported = Object.keys(translations);
  const requested = [...(navigator.languages || [navigator.language])]
    .filter(Boolean)
    .map((value) => value.toLowerCase().split("-")[0]);
  let language = requested.find((value) => supported.includes(value)) || "en";

  function t(key, values = {}) {
    const template = translations[language][key] ?? translations.en[key] ?? key;
    return template.replace(/\{(\w+)\}/g, (_match, name) => values[name] ?? `{${name}}`);
  }

  function apply(root = document) {
    document.documentElement.lang = language;
    root.querySelectorAll("[data-i18n]").forEach((element) => {
      element.textContent = t(element.dataset.i18n);
    });
    root.querySelectorAll("[data-i18n-title]").forEach((element) => {
      const value = t(element.dataset.i18nTitle);
      element.title = value;
      element.setAttribute("aria-label", value);
    });
    root.querySelectorAll("[data-i18n-aria]").forEach((element) => {
      element.setAttribute("aria-label", t(element.dataset.i18nAria));
    });
  }

  function setLanguage(value) {
    if (!supported.includes(value)) return;
    language = value;
    apply();
    window.dispatchEvent(new CustomEvent("rkt-language-change"));
  }

  window.RktTranslate = { apply, language: () => language, setLanguage, supported, t };
  window.addEventListener("DOMContentLoaded", () => apply());
})();