<?php
header('Content-Type: application/json; charset=utf-8');

function json_ok($data) {
    echo json_encode($data, JSON_UNESCAPED_UNICODE);
    exit;
}

function json_error($message, $code = 400) {
    http_response_code($code);
    echo json_encode(['error' => $message], JSON_UNESCAPED_UNICODE);
    exit;
}

function require_auth() {
    if (empty($_SESSION['user_id'])) {
        json_error('Nicht angemeldet', 401);
    }
    return $_SESSION['user_id'];
}

function require_admin() {
    require_auth();
    if (empty($_SESSION['is_admin'])) {
        json_error('Keine Admin-Berechtigung', 403);
    }
    return $_SESSION['user_id'];
}

function get_method() {
    return $_SERVER['REQUEST_METHOD'];
}

function get_json_body() {
    $body = file_get_contents('php://input');
    return json_decode($body, true) ?: [];
}

function get_param($name, $default = null) {
    return $_GET[$name] ?? $default;
}