<?php

// (c) Copyright 2002-2019 by authors of the Tiki Wiki CMS Groupware Project
//
// All Rights Reserved. See copyright.txt for details and a complete list of authors.
// Licensed under the GNU LESSER GENERAL PUBLIC LICENSE. See license.txt for details.
// $Id$

/**
 * Class CacheLibRedis
 *
 * Requires PHP-Redis
 */

class CacheLibRedis
{
    private $redis;

    public function __construct()
    {
        global $prefs;
        if (empty($this->redis)) {
            $this->redis = new Redis();
            $success = $this->redis->pconnect($prefs["redis_host"], $prefs["redis_port"], $prefs["redis_timeout"]);
            if (! $success) {
                throw new Exception('Unable to connect to Redis.');
            }
            if ($prefs['redis_prefix']) {
                // This option automatically prefixes ALL keys provided as input to Redis
                $this->redis->setOption(Redis::OPT_PREFIX, $prefs['redis_prefix']);
            }
        }
    }

    public function __destruct()
    {
        $this->redis->close();
    }

    private function getKey($key, $type)
    {
        $key = $type . md5($key);
        return $key;
    }

    private function findKeys($pattern)
    {
        global $prefs;
        $keys = $this->redis->keys($pattern);
        if ($prefs['redis_prefix']) {
            // Need to strip prefix as it will be re-added
            $keys = substr_replace($keys, '', 0, strlen($prefs['redis_prefix']));
        }
        return $keys;
    }

    public function cacheItem($key, $data, $type = '')
    {
        global $prefs;
        $key = $this->getKey($key, $type);
        if ($prefs['redis_expiry']) {
            return $this->redis->setEx($key, $prefs['redis_expiry'], $data);
        } else {
            return $this->redis->set($key, $data);
        }
    }

    public function isCached($key, $type = '')
    {
        $key = $this->getKey($key, $type);
        return $this->redis->exists($key);
    }

    public function getCached($key, $type = '', $lastModif = false)
    {
        $key = $this->getKey($key, $type);
        return $this->redis->get($key);
    }

    public function invalidate($key, $type = '')
    {
        $key = $this->getKey($key, $type);
        return $this->redis->del([$key]);
    }

    public function empty_type_cache($type)
    {
        $keys = $this->findKeys($type . '*');
        return $this->redis->del($keys);
    }

    public function flush()
    {
        global $prefs;
        if ($prefs['redis_prefix']) {
            $keys = $this->findKeys('*');
            $this->redis->del($keys);
        } else {
            $this->redis->flushAll();
        }
        return;
    }
}