<?php

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2019 - 2022, CodeIgniter Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package CodeIgniter
 * @author  EllisLab Dev Team
 * @copyright   Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright   Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
 * @copyright   Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
 * @license https://opensource.org/licenses/MIT MIT License
 * @link    https://codeigniter.com
 * @since   Version 3.0.0
 * @filesource
 */

defined('BASEPATH') or exit('No direct script access allowed');

/**
 * CodeIgniter Redis Caching Class
 *
 * @package    CodeIgniter
 * @subpackage Libraries
 * @category   Core
 * @author     Anton Lindqvist <anton@qvister.se>
 * @link
 */
class CI_Cache_redis extends CI_Driver
{
    /**
     * Default config
     *
     * @static
     * @var array
     */
    protected static $_default_config = array(
        'socket_type' => 'tcp',
        'host' => '127.0.0.1',
        'password' => null,
        'port' => 6379,
        'timeout' => 0
    );

    /**
     * Redis connection
     *
     * @var Redis
     */
    protected $_redis;

    /**
     * An internal cache for storing keys of serialized values.
     *
     * @var array
     */
    protected $_serialized = array();

    /**
     * del()/delete() method name depending on phpRedis version
     *
     * @var string
     */
    protected static $_delete_name;

    /**
     * sRem()/sRemove() method name depending on phpRedis version
     *
     * @var string
     */
    protected static $_sRemove_name;

    // ------------------------------------------------------------------------

    /**
     * Class constructor
     *
     * Setup Redis
     *
     * Loads Redis config file if present. Will halt execution
     * if a Redis connection can't be established.
     *
     * @return  void
     * @see     Redis::connect()
     */
    public function __construct()
    {
        if (! $this->is_supported()) {
            log_message('error', 'Cache: Failed to create Redis object; extension not loaded?');
            return;
        }

        if (! isset(static::$_delete_name, static::$_sRemove_name)) {
            if (version_compare(phpversion('redis'), '5', '>=')) {
                static::$_delete_name  = 'del';
                static::$_sRemove_name = 'sRem';
            } else {
                static::$_delete_name  = 'delete';
                static::$_sRemove_name = 'sRemove';
            }
        }

        $CI = & get_instance();

        if ($CI->config->load('redis', true, true)) {
            $config = array_merge(self::$_default_config, $CI->config->item('redis'));
        } else {
            $config = self::$_default_config;
        }

        $this->_redis = new Redis();

        try {
            if ($config['socket_type'] === 'unix') {
                $success = $this->_redis->connect($config['socket']);
            } else { // tcp socket
                $success = $this->_redis->connect($config['host'], $config['port'], $config['timeout']);
            }

            if (! $success) {
                log_message('error', 'Cache: Redis connection failed. Check your configuration.');
            }

            if (isset($config['password']) && ! $this->_redis->auth($config['password'])) {
                log_message('error', 'Cache: Redis authentication failed.');
            }
        } catch (RedisException $e) {
            log_message('error', 'Cache: Redis connection refused (' . $e->getMessage() . ')');
        }
    }

    // ------------------------------------------------------------------------

    /**
     * Get cache
     *
     * @param   string  $key    Cache ID
     * @return  mixed
     */
    public function get($key)
    {
        $value = $this->_redis->get($key);

        if ($value !== false && $this->_redis->sIsMember('_ci_redis_serialized', $key)) {
            return unserialize($value);
        }

        return $value;
    }

    // ------------------------------------------------------------------------

    /**
     * Save cache
     *
     * @param   string  $id Cache ID
     * @param   mixed   $data   Data to save
     * @param   int $ttl    Time to live in seconds
     * @param   bool    $raw    Whether to store the raw value (unused)
     * @return  bool    TRUE on success, FALSE on failure
     */
    public function save($id, $data, $ttl = 60, $raw = false)
    {
        if (is_array($data) or is_object($data)) {
            if (! $this->_redis->sIsMember('_ci_redis_serialized', $id) && ! $this->_redis->sAdd('_ci_redis_serialized', $id)) {
                return false;
            }

            isset($this->_serialized[$id]) or $this->_serialized[$id] = true;
            $data = serialize($data);
        } else {
            $this->_redis->{static::$_sRemove_name}('_ci_redis_serialized', $id);
        }

        return $this->_redis->set($id, $data, $ttl);
    }

    // ------------------------------------------------------------------------

    /**
     * Delete from cache
     *
     * @param   string  $key    Cache key
     * @return  bool
     */
    public function delete($key)
    {
        if ($this->_redis->{static::$_delete_name}($key) !== 1) {
            return false;
        }

        $this->_redis->{static::$_sRemove_name}('_ci_redis_serialized', $key);

        return true;
    }

    // ------------------------------------------------------------------------

    /**
     * Increment a raw value
     *
     * @param   string  $id Cache ID
     * @param   int $offset Step/value to add
     * @return  mixed   New value on success or FALSE on failure
     */
    public function increment($id, $offset = 1)
    {
        return $this->_redis->incrBy($id, $offset);
    }

    // ------------------------------------------------------------------------

    /**
     * Decrement a raw value
     *
     * @param   string  $id Cache ID
     * @param   int $offset Step/value to reduce by
     * @return  mixed   New value on success or FALSE on failure
     */
    public function decrement($id, $offset = 1)
    {
        return $this->_redis->decrBy($id, $offset);
    }

    // ------------------------------------------------------------------------

    /**
     * Clean cache
     *
     * @return  bool
     * @see     Redis::flushDB()
     */
    public function clean()
    {
        return $this->_redis->flushDB();
    }

    // ------------------------------------------------------------------------

    /**
     * Get cache driver info
     *
     * @param   string  $type   Not supported in Redis.
     *              Only included in order to offer a
     *              consistent cache API.
     * @return  array
     * @see     Redis::info()
     */
    public function cache_info($type = null)
    {
        return $this->_redis->info();
    }

    // ------------------------------------------------------------------------

    /**
     * Get cache metadata
     *
     * @param   string  $key    Cache key
     * @return  array
     */
    public function get_metadata($key)
    {
        $value = $this->get($key);

        if ($value !== false) {
            return array(
                'expire' => time() + $this->_redis->ttl($key),
                'data' => $value
            );
        }

        return false;
    }

    // ------------------------------------------------------------------------

    /**
     * Check if Redis driver is supported
     *
     * @return  bool
     */
    public function is_supported()
    {
        return extension_loaded('redis');
    }

    // ------------------------------------------------------------------------

    /**
     * Class destructor
     *
     * Closes the connection to Redis if present.
     *
     * @return  void
     */
    public function __destruct()
    {
        if ($this->_redis) {
            $this->_redis->close();
        }
    }
}