<?php

/**
 * Part of the Joomla Framework Session Package
 *
 * @copyright  Copyright (C) 2005 - 2021 Open Source Matters, Inc. All rights reserved.
 * @license    GNU General Public License version 2 or later; see LICENSE
 */

namespace Joomla\Session\Validator;

use Joomla\Input\Input;
use Joomla\Session\SessionInterface;
use Joomla\Session\ValidatorInterface;

/**
 * Interface for validating a part of the session
 *
 * @since  2.0.0
 */
class ForwardedValidator implements ValidatorInterface
{
    /**
     * The Input object.
     *
     * @var    Input
     * @since  2.0.0
     */
    private $input;

    /**
     * The session object.
     *
     * @var    SessionInterface
     * @since  2.0.0
     */
    private $session;

    /**
     * Constructor
     *
     * @param   Input             $input    The input object
     * @param   SessionInterface  $session  DispatcherInterface for the session to use.
     *
     * @since   2.0.0
     */
    public function __construct(Input $input, SessionInterface $session)
    {
        $this->input   = $input;
        $this->session = $session;
    }

    /**
     * Validates the session
     *
     * @param   boolean  $restart  Flag if the session should be restarted
     *
     * @return  void
     *
     * @since   2.0.0
     */
    public function validate(bool $restart = false): void
    {
        if ($restart) {
            $this->session->set('session.client.forwarded', null);
        }

        $xForwardedFor = $this->input->server->getString('HTTP_X_FORWARDED_FOR', '');

        // Record proxy forwarded for in the session in case we need it later
        if (!empty($xForwardedFor) && filter_var($xForwardedFor, FILTER_VALIDATE_IP) !== false) {
            $this->session->set('session.client.forwarded', $xForwardedFor);
        }
    }
}