(function () {
    var STORAGE_KEY = 'hyapp_h5_lang';
    var DEFAULT_LANG = 'en';
    var SUPPORTED = ['en', 'ar', 'tr', 'es'];
    var messages = {};
    var currentLang = '';

    function queryLang() {
        return new URLSearchParams(window.location.search).get('lang') || '';
    }

    function normalizeLang(value) {
        var lang = String(value || '')
            .trim()
            .toLowerCase()
            .replace('_', '-');
        if (!lang) return '';
        if (lang.indexOf('ar') === 0) return 'ar';
        if (lang.indexOf('tr') === 0) return 'tr';
        if (lang.indexOf('es') === 0) return 'es';
        return SUPPORTED.indexOf(lang) >= 0 ? lang : '';
    }

    function resolveLang() {
        return (
            normalizeLang(queryLang()) ||
            normalizeLang(window.localStorage.getItem(STORAGE_KEY)) ||
            normalizeLang(window.navigator.language) ||
            DEFAULT_LANG
        );
    }

    function load(lang) {
        var normalized = normalizeLang(lang) || DEFAULT_LANG;
        return window
            .fetch('../common/locales/' + normalized + '.json', {
                cache: 'no-store',
            })
            .then(function (response) {
                if (!response.ok) throw new Error('locale_not_found');
                return response.json();
            })
            .then(function (json) {
                messages = json || {};
                currentLang = normalized;
                window.localStorage.setItem(STORAGE_KEY, currentLang);
                apply();
                return messages;
            })
            .catch(function () {
                if (normalized === DEFAULT_LANG) {
                    messages = {};
                    currentLang = DEFAULT_LANG;
                    apply();
                    return messages;
                }
                return load(DEFAULT_LANG);
            });
    }

    function t(key, fallback) {
        return Object.prototype.hasOwnProperty.call(messages, key)
            ? messages[key]
            : fallback || key;
    }

    function apply(root) {
        var scope = root || document;
        document.documentElement.lang = currentLang || DEFAULT_LANG;
        document.documentElement.dir = currentLang === 'ar' ? 'rtl' : 'ltr';
        scope.querySelectorAll('[data-i18n]').forEach(function (node) {
            node.textContent = t(
                node.getAttribute('data-i18n'),
                node.textContent
            );
        });
        scope
            .querySelectorAll('[data-i18n-placeholder]')
            .forEach(function (node) {
                node.setAttribute(
                    'placeholder',
                    t(
                        node.getAttribute('data-i18n-placeholder'),
                        node.getAttribute('placeholder') || ''
                    )
                );
            });
        scope.querySelectorAll('[data-i18n-aria]').forEach(function (node) {
            node.setAttribute(
                'aria-label',
                t(
                    node.getAttribute('data-i18n-aria'),
                    node.getAttribute('aria-label') || ''
                )
            );
        });
        scope.querySelectorAll('[data-lang-option]').forEach(function (node) {
            node.classList.toggle(
                'is-active',
                node.getAttribute('data-lang-option') === currentLang
            );
        });
        scope.querySelectorAll('[data-current-lang]').forEach(function (node) {
            node.textContent = (currentLang || DEFAULT_LANG).toUpperCase();
        });
        window.dispatchEvent(
            new CustomEvent('hyapp:i18n-ready', {
                detail: { lang: currentLang, messages: messages },
            })
        );
    }

    function initLanguageMenu() {
        document.addEventListener('click', function (event) {
            var toggle = event.target.closest('[data-language-toggle]');
            var menu = document.querySelector('[data-language-menu]');
            if (toggle && menu) {
                var expanded = toggle.getAttribute('aria-expanded') === 'true';
                toggle.setAttribute(
                    'aria-expanded',
                    expanded ? 'false' : 'true'
                );
                menu.hidden = expanded;
                return;
            }
            var option = event.target.closest('[data-lang-option]');
            if (option) {
                if (menu) menu.hidden = true;
                var button = document.querySelector('[data-language-toggle]');
                if (button) button.setAttribute('aria-expanded', 'false');
                load(option.getAttribute('data-lang-option'));
                return;
            }
            if (menu && !event.target.closest('.language-switcher')) {
                menu.hidden = true;
                var languageButton = document.querySelector(
                    '[data-language-toggle]'
                );
                if (languageButton)
                    languageButton.setAttribute('aria-expanded', 'false');
            }
        });
    }

    window.HyAppI18n = {
        load: load,
        apply: apply,
        t: t,
        lang: function () {
            return currentLang || DEFAULT_LANG;
        },
        supported: SUPPORTED.slice(),
    };

    document.addEventListener('DOMContentLoaded', function () {
        initLanguageMenu();
        load(resolveLang());
    });
})();