<?php
/* *********************************************************************
 * This Original Work is copyright of 51 Degrees Mobile Experts Limited.
 * Copyright 2019 51 Degrees Mobile Experts Limited, 5 Charlotte Close,
 * Caversham, Reading, Berkshire, United Kingdom RG4 7BY.
 *
 * This Original Work is licensed under the European Union Public Licence (EUPL)
 * v.1.2 and is subject to its terms as set out below.
 *
 * If a copy of the EUPL was not distributed with this file, You can obtain
 * one at https://opensource.org/licenses/EUPL-1.2.
 *
 * The 'Compatible Licences' set out in the Appendix to the EUPL (as may be
 * amended by the European Commission) shall be deemed incompatible for
 * the purposes of the Work and the provisions of the compatibility
 * clause in Article 5 of the EUPL shall not apply.
 *
 * If using the Work as, or as part of, a network application, by
 * including the attribution notice(s) required under Article 5 of the EUPL
 * in the end user terms of the application under an appropriate heading,
 * such notice(s) shall fulfill the requirements of that article.
 * ********************************************************************* */



namespace fiftyone\pipeline\engines;

use fiftyone\pipeline\engines\DataKeyedCache;

/**
 * An extension of the cache class that stores a cache in a user's session
 * if PHP sessions are active
*/
class SessionCache extends DataKeyedCache
{
    public function __construct($cacheTime = 0)
    {
        $this->cacheTime = $cacheTime;
    }

    public function set($key, $value)
    {
        $cacheKey = \json_encode($key);

        if (session_id()) {
            $cacheEntry = array(
                "time" => time(),
                "data" => serialize($value)
            );

            $_SESSION[$cacheKey] = $cacheEntry;
        }
    }

    public function get($key)
    {
        $cacheKey = json_encode($key);

        if (session_id() && isset($_SESSION[$cacheKey])) {
            $cacheEntry = $_SESSION[$cacheKey];

            // Check if timestamp greater than that set

            if (time() - $cacheEntry["time"] < $this->cacheTime) {
                return unserialize($cacheEntry["data"]);
            } else {
                unset($_SESSION[$cacheKey]);

                return null;
            }
        };
    }
}
