export function fullName(user) {
    if (!user) return '';
    if (user.full_name) {
        return String(user.full_name).trim();
    }
    const parts = [user.surname, user.first_name, user.last_name].filter(Boolean);
    const name = parts.join(' ').trim();
    if (name) return name;
    if (user.username) return user.username;
    if (user.email) return user.email;
    return '';
}

export function displayName(user, youLabel = 'You') {
    if (!user) return '';
    return fullName(user) || youLabel;
}

export function initials(name) {
    const parts = (name || '?').trim().split(/\s+/);
    return (parts[0]?.[0] || '?') + (parts[1]?.[0] || '');
}

export function escapeHtml(value) {
    const div = document.createElement('div');
    div.textContent = value || '';
    return div.innerHTML;
}

export function formatTime(iso) {
    if (!iso) return '';
    if (window.CommDate?.formatTime) {
        return window.CommDate.formatTime(iso);
    }
    try {
        return new Intl.DateTimeFormat(undefined, { hour: '2-digit', minute: '2-digit' }).format(new Date(iso));
    } catch {
        return '';
    }
}

export function formatDateTime(iso) {
    if (!iso) return '-';
    if (window.CommDate?.formatDateTime) {
        return window.CommDate.formatDateTime(iso);
    }
    try {
        return new Intl.DateTimeFormat(undefined, {
            year: 'numeric',
            month: '2-digit',
            day: '2-digit',
            hour: '2-digit',
            minute: '2-digit',
        }).format(new Date(iso));
    } catch {
        return '-';
    }
}