const translations = window.translations;

const languageLocales = {
    vi: 'vi_VN',
    ru: 'ru_RU',
    en: 'en_US',
    zh: 'zh_CN',
    de: 'de_DE',
    fr: 'fr_FR'
};

let currentLang = 'vi';
let currentWeatherCondition = 'weather_loading';
let tomorrowWeatherCondition = 'weather_loading';

function getWeatherPresentation(code) {
    if (code === 0) return { key: 'weather_clear', icon: 'fa-sun', color: 'text-amber-500' };
    if (code === 1) return { key: 'weather_mainly_clear', icon: 'fa-cloud-sun', color: 'text-amber-500' };
    if (code === 2) return { key: 'weather_partly_cloudy', icon: 'fa-cloud-sun', color: 'text-amber-500' };
    if (code === 3) return { key: 'weather_overcast', icon: 'fa-cloud', color: 'text-gray-500' };
    if ([45, 48].includes(code)) return { key: 'weather_fog', icon: 'fa-smog', color: 'text-gray-500' };
    if ([51, 53, 55, 56, 57].includes(code)) return { key: 'weather_drizzle', icon: 'fa-cloud-rain', color: 'text-sky-500' };
    if ([61, 63, 65, 66, 67].includes(code)) return { key: 'weather_rain', icon: 'fa-cloud-rain', color: 'text-sky-600' };
    if ([71, 73, 75, 77].includes(code)) return { key: 'weather_snow', icon: 'fa-snowflake', color: 'text-sky-500' };
    if ([80, 81, 82, 85, 86].includes(code)) return { key: 'weather_showers', icon: 'fa-cloud-showers-heavy', color: 'text-sky-600' };
    if ([95, 96, 99].includes(code)) return { key: 'weather_thunderstorm', icon: 'fa-cloud-bolt', color: 'text-indigo-500' };
    return { key: 'weather_partly_cloudy', icon: 'fa-cloud-sun', color: 'text-amber-500' };
}

function hasLanguage(lang) {
    return Object.hasOwn(translations, lang);
}

function translateWeather(key) {
    return translations[currentLang][key] || translations.en[key];
}

function renderWeatherCondition() {
    const condition = document.getElementById('weather-condition');
    if (condition) condition.textContent = translateWeather(currentWeatherCondition);

    const currentForecastCondition = document.getElementById('weather-current-condition');
    if (currentForecastCondition) currentForecastCondition.textContent = translateWeather(currentWeatherCondition);

    const tomorrowForecastCondition = document.getElementById('weather-tomorrow-condition');
    if (tomorrowForecastCondition) tomorrowForecastCondition.textContent = translateWeather(tomorrowWeatherCondition);
}

function formatForecastDate(isoDate, lang) {
    const [year, month, day] = isoDate.split('-').map(Number);
    const date = new Date(year, month - 1, day, 12);
    return new Intl.DateTimeFormat(languageLocales[lang].replace('_', '-'), {
        weekday: 'short',
        month: 'short',
        day: 'numeric'
    }).format(date);
}

function isValidForecast(current, daily) {
    return Number.isFinite(current?.temperature_2m)
        && Number.isFinite(current?.weather_code)
        && Array.isArray(daily?.time)
        && daily.time.length >= 2
        && /^\d{4}-\d{2}-\d{2}$/.test(daily.time[1])
        && [daily.weather_code, daily.temperature_2m_max, daily.temperature_2m_min].every(values => Array.isArray(values) && values.length >= 2)
        && Number.isFinite(daily.weather_code[1])
        && [daily.temperature_2m_max[0], daily.temperature_2m_min[0], daily.temperature_2m_max[1], daily.temperature_2m_min[1]].every(Number.isFinite);
}

function setWeatherRange(id, value) {
    const element = document.getElementById(id);
    if (element) element.textContent = Number.isFinite(value) ? `${Math.round(value)}°` : '--°';
}

function setWeatherIcon(id, presentation) {
    const icon = document.getElementById(id);
    if (icon) icon.className = `fa-solid ${presentation.icon} text-4xl ${presentation.color}`;
}

async function loadWeatherForecast() {
    const temperature = document.getElementById('weather-temperature');
    const icon = document.getElementById('weather-icon');
    const currentForecastTemperature = document.getElementById('weather-current-temperature');
    const tomorrowDate = document.getElementById('weather-tomorrow-date');

    try {
        const response = await fetch('https://api.open-meteo.com/v1/forecast?latitude=12.2388&longitude=109.1967&current=temperature_2m,weather_code&daily=weather_code,temperature_2m_max,temperature_2m_min&timezone=Asia%2FHo_Chi_Minh&forecast_days=2');
        if (!response.ok) throw new Error('Weather request failed');

        const { current, daily } = await response.json();
        if (!isValidForecast(current, daily)) throw new Error('Weather response is incomplete');

        const currentPresentation = getWeatherPresentation(current.weather_code);
        const tomorrowPresentation = getWeatherPresentation(daily.weather_code[1]);
        const currentTemperature = `${Math.round(current.temperature_2m)}°C`;
        if (temperature) temperature.textContent = currentTemperature;
        if (currentForecastTemperature) currentForecastTemperature.textContent = currentTemperature;
        if (icon) icon.className = `fa-solid ${currentPresentation.icon} text-2xl ${currentPresentation.color}`;
        setWeatherIcon('weather-current-icon', currentPresentation);
        setWeatherIcon('weather-tomorrow-icon', tomorrowPresentation);
        setWeatherRange('weather-today-high', daily.temperature_2m_max[0]);
        setWeatherRange('weather-today-low', daily.temperature_2m_min[0]);
        setWeatherRange('weather-tomorrow-high', daily.temperature_2m_max[1]);
        setWeatherRange('weather-tomorrow-low', daily.temperature_2m_min[1]);

        if (tomorrowDate) {
            tomorrowDate.dateTime = daily.time[1];
            tomorrowDate.textContent = formatForecastDate(daily.time[1], currentLang);
        }

        currentWeatherCondition = currentPresentation.key;
        tomorrowWeatherCondition = tomorrowPresentation.key;
    } catch {
        if (temperature) temperature.textContent = '--°C';
        if (currentForecastTemperature) currentForecastTemperature.textContent = '--°C';
        if (icon) icon.className = 'fa-solid fa-cloud text-2xl text-gray-400';
        setWeatherIcon('weather-current-icon', { icon: 'fa-cloud', color: 'text-gray-400' });
        setWeatherIcon('weather-tomorrow-icon', { icon: 'fa-cloud', color: 'text-gray-400' });
        setWeatherRange('weather-today-high', NaN);
        setWeatherRange('weather-today-low', NaN);
        setWeatherRange('weather-tomorrow-high', NaN);
        setWeatherRange('weather-tomorrow-low', NaN);
        if (tomorrowDate) {
            tomorrowDate.textContent = '';
            tomorrowDate.removeAttribute('datetime');
        }
        currentWeatherCondition = 'weather_unavailable';
        tomorrowWeatherCondition = 'weather_unavailable';
    }

    renderWeatherCondition();
}

function getPreferredLanguage() {
    const supported = Object.keys(translations);
    const preferences = navigator.languages?.length
        ? navigator.languages
        : [navigator.language];

    for (const locale of preferences) {
        const language = locale.toLowerCase().split(/[-_]/)[0];
        if (supported.includes(language)) return language;
    }

    return 'vi';
}

function getRequestedLanguage() {
    const requested = new URLSearchParams(window.location.search).get('lang');
    return hasLanguage(requested) ? requested : null;
}

function setLanguage(lang) {
    if (!hasLanguage(lang)) lang = 'vi';
    currentLang = lang;
    document.querySelectorAll('[data-i18n]').forEach(el => {
        const key = el.getAttribute('data-i18n');
        if (translations[lang] && translations[lang][key]) {
            el.textContent = translations[lang][key];
        }
    });

    // Reset language button styles
    Object.keys(translations).forEach(l => {
        const btn = document.getElementById(`btn-${l}`);
        if (btn) {
            if (l === lang) {
                btn.className = "px-2.5 py-1.5 font-bold rounded-lg transition bg-white text-brand-600 shadow-sm";
            } else {
                btn.className = "px-2.5 py-1.5 font-bold rounded-lg transition text-gray-600 hover:text-brand-600";
            }
        }
    });

    document.documentElement.lang = lang;
    const languageUrl = new URL(window.location.href);
    languageUrl.searchParams.set('lang', lang);
    history.replaceState(null, '', `${languageUrl.pathname}${languageUrl.search}${languageUrl.hash}`);

    const canonicalUrl = new URL(`/?lang=${lang}`, window.location.origin).href;
    document.getElementById('canonical-url').href = canonicalUrl;
    document.getElementById('meta-description').content = translations[lang].meta_description;
    document.getElementById('og-title').content = translations[lang].page_title;
    document.getElementById('og-description').content = translations[lang].meta_description;
    document.getElementById('og-url').content = canonicalUrl;
    document.getElementById('og-locale').content = languageLocales[lang];
    renderWeatherCondition();

    const tomorrowDate = document.getElementById('weather-tomorrow-date');
    if (tomorrowDate.dateTime) tomorrowDate.textContent = formatForecastDate(tomorrowDate.dateTime, lang);
}

function toggleMobileMenu() {
    const menu = document.getElementById('mobile-menu');
    menu.classList.toggle('hidden');
    document.getElementById('mobile-menu-toggle').setAttribute('aria-expanded', !menu.classList.contains('hidden'));
}

function filterAttractions(category, activeButton) {
    document.querySelectorAll('.filter-btn').forEach(btn => {
        btn.className = "filter-btn px-5 py-2 rounded-xl text-sm font-bold bg-white text-gray-600 hover:bg-gray-100 shadow-sm";
    });
    activeButton.className = "filter-btn active px-5 py-2 rounded-xl text-sm font-bold bg-brand-500 text-white shadow";

    document.querySelectorAll('.attraction-card').forEach(card => {
        if (category === 'all' || card.getAttribute('data-category') === category) {
            card.style.display = 'flex';
        } else {
            card.style.display = 'none';
        }
    });
}

async function handleBooking(event) {
    event.preventDefault();
    const form = event.currentTarget;
    const submitButton = form.querySelector('[type="submit"]');
    const status = document.getElementById('form-status');
    status.classList.add('hidden');
    submitButton.disabled = true;

    try {
        const response = await fetch(form.action, {
            method: form.method,
            body: new FormData(form),
            headers: { Accept: 'application/json' }
        });
        if (!response.ok) throw new Error('Form submission failed');

        form.reset();
        document.getElementById('success-modal').classList.remove('hidden');
    } catch {
        status.classList.remove('hidden');
    } finally {
        submitButton.disabled = false;
    }
}

function closeModal() {
    document.getElementById('success-modal').classList.add('hidden');
}

function bindEvents() {
    document.querySelectorAll('[data-lang]').forEach(btn => {
        btn.addEventListener('click', () => setLanguage(btn.dataset.lang));
    });

    document.getElementById('mobile-menu-toggle').addEventListener('click', toggleMobileMenu);
    document.querySelectorAll('.mobile-nav-link').forEach(link => {
        link.addEventListener('click', toggleMobileMenu);
    });

    document.querySelectorAll('.filter-btn').forEach(btn => {
        btn.addEventListener('click', () => filterAttractions(btn.dataset.filter, btn));
    });

    document.getElementById('booking-form').addEventListener('submit', handleBooking);
    document.getElementById('modal-close-btn').addEventListener('click', closeModal);
}

bindEvents();
setLanguage(getRequestedLanguage() || getPreferredLanguage());
loadWeatherForecast();
setInterval(loadWeatherForecast, 30 * 60 * 1000);