<?php
session_start();
require_once __DIR__ . '/lang.php';

if (!isset($_SESSION['lang'])) {
    $_SESSION['lang'] = 'en';
}

if (isset($_GET['lang'])) {
    if ($_GET['lang'] === 'ar' || $_GET['lang'] === 'en') {
        $_SESSION['lang'] = $_GET['lang'];
        // Redirect to remove lang param
        header("Location: " . strtok($_SERVER["REQUEST_URI"], '?'));
        exit;
    }
}

function __($key) {
    global $translations;
    $lang = $_SESSION['lang'];
    return $translations[$lang][$key] ?? $key;
}

function is_rtl() {
    return $_SESSION['lang'] === 'ar';
}

function get_dir() {
    return is_rtl() ? 'rtl' : 'ltr';
}

function get_lang_name() {
    return $_SESSION['lang'] === 'ar' ? 'English' : 'العربية';
}

function get_lang_code() {
    return $_SESSION['lang'] === 'ar' ? 'en' : 'ar';
}

function calculate_age($dob) {
    if (empty($dob)) return '-';
    try {
        $birthDate = new DateTime($dob);
        $today = new DateTime('today');
        return $birthDate->diff($today)->y;
    } catch (Exception $e) {
        return '-';
    }
}