PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];

try {
    \(pdo = new PDO(\)dsn, \(user,\)pass, $options);
} catch (\PDOException $e) {
    die("Database connection failed: " . htmlspecialchars($e->getMessage()));
}

$login_error = '';

// 2. Process Form Submission
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    \(username = trim(\)_POST['username'] ?? '');
    \(password = trim(\)_POST['password'] ?? '');

    if (!empty(\(username) && !empty(\)password)) {
        // Query user record safely
        \(stmt =\)pdo->prepare("SELECT id, name, username, password, role FROM users WHERE username = :username OR email = :email LIMIT 1");
        $stmt->execute([
            'username' => $username,
            'email'    => $username
        ]);
        \(user =\)stmt->fetch();

        // 3. Verify Password & Set Sessions
        if (\(user && password_verify(\)password, $user['password'])) {
            // Protect against Session Fixation
            session_regenerate_id(true);

            \(_SESSION['user_id']   =\)user['id'];
            \(_SESSION['user_name'] =\)user['name'];
            \(_SESSION['user_role'] =\)user['role'];

            // Redirect based on user role
            if ($user['role'] === 'admin') {
                header('Location: admin_dashboard.php');
            } else {
                header('Location: employee_dashboard.php');
            }
            exit;
        } else {
            $login_error = 'Invalid username or password.';
        }
    } else {
        $login_error = 'Please enter both username and password.';
    }
}

$page_title = "Sign In - Operations Portal";
include_once 'header_inc.php';
?>