config.php

<?php

header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Methods: GET, POST, OPTIONS");
header("Access-Control-Allow-Headers: Content-Type");
header("Access-Control-Allow-Credentials: true");

// Respond if the request is OPTIONS (Preflight)
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
    http_response_code(200);
    exit();
}

// Setting Database
define('DB_HOST', 'localhost');
define('DB_NAME', 'phpchat');
define('DB_USER', 'root');
define('DB_PASS', '');

// Settings Chat
define('MAX_MESSAGES', 20); // Maximum number of messages

// Connect to Database
try {
    $pdo = new PDO(
        "mysql:host=" . DB_HOST . ";dbname=" . DB_NAME . ";charset=utf8mb4",
        DB_USER,
        DB_PASS,
        [
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            PDO::ATTR_EMULATE_PREPARES => false
        ]
    );
} catch (PDOException $e) {
    die("Connection failed: " . $e->getMessage());
}
?>