<?php
declare(strict_types=1);

if (session_status() === PHP_SESSION_NONE) {
    session_start();
}

function isLoggedIn(): bool {
    return isset($_SESSION['user_id']);
}

function requireLogin(): void {
    if (!isLoggedIn()) {
        header('Location: login.php');
        exit;
    }
}

function getCurrentUser(): ?array {
    if (!isLoggedIn()) return null;
    
    static $user;
    if (!$user) {
        $stmt = db()->prepare("SELECT u.*, c.name as company_name FROM users u JOIN companies c ON u.company_id = c.id WHERE u.id = ?");
        $stmt->execute([$_SESSION['user_id']]);
        $user = $stmt->fetch();
    }
    return $user;
}

function logout(): void {
    session_destroy();
    header('Location: login.php');
    exit;
}