function getTranslation(obj, path) {
    return path.reduce((xs, x) => (xs && xs[x] !== undefined) ? xs[x] : undefined, obj);
}

function changeLanguage(lang) {
    document.cookie = `lang=${lang};path=/;max-age=31536000;SameSite=None${window.location.protocol === 'https:' ? '; Secure' : ''}`;

    fetch(`/assets/i18n/${lang}.json`)
    .then(response => response.json())
    .then(translations => {
        document.querySelectorAll('[data-i18n]').forEach(elem => {
            const keys = elem.getAttribute('data-i18n').split('.');
            const translation = getTranslation(translations, keys);
            if (translation !== undefined) {
                // If the element is an input, update its value; otherwise, update its innerHTML
                if (elem.tagName.toLowerCase() === 'input') {
                    elem.value = translation;
                } else {
                    elem.innerHTML = translation;
                }
            }
        });

        document.querySelectorAll('[data-i18n-placeholder]').forEach(elem => {
            const keys = elem.getAttribute('data-i18n-placeholder').split('.');
            const translation = getTranslation(translations, keys);
            if (translation !== undefined) {
                elem.placeholder = translation;
            }
        });
    });

    document.getElementById('languageSelect').value = lang;
}


function getCookie(name) {
    let cookieArray = document.cookie.split(';');
    for(let i = 0; i < cookieArray.length; i++) {
        let cookiePair = cookieArray[i].split('=');
        if(name == cookiePair[0].trim()) {
            return decodeURIComponent(cookiePair[1]);
        }
    }
    return null;
}

function initializeLanguage() {
    const availableLanguages = ['en', 'de']; // Extend as necessary

    let userLang = getCookie('lang');

    if (!userLang) {
        let systemLang = navigator.language.split('-')[0];
        userLang = availableLanguages.includes(systemLang) ? systemLang : 'en';
    }

    changeLanguage(userLang);
}

// Run the initialization function when the page loads
initializeLanguage();