<?php
/** Shared session checks. Database, form and session keys retain their legacy names. */
function requireLogin(string $loginUrl): void {
    if (session_status() !== PHP_SESSION_ACTIVE) {
        session_start();
    }
    if (!isset($_SESSION['uname'])) {
        header('Location: ' . $loginUrl);
        exit;
    }
}

function hasPermission(string $permission): bool {
    return !empty($_SESSION[$permission]);
}

function requirePermission(string $permission, string $message): void {
    if (!hasPermission($permission)) {
        http_response_code(403);
        exit($message);
    }
}

function isPasswordValid(string $password): bool {
    return strlen($password) >= 8
        && preg_match('/[0-9]/', $password) === 1
        && preg_match('/[A-Z]/', $password) === 1;
}