<?php

/**
 * Joomla! Content Management System
 *
 * @copyright  (C) 2014 Open Source Matters, Inc. <https://www.joomla.org>
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\CMS\Cache\Storage;

use Joomla\CMS\Cache\CacheStorage;
use Joomla\CMS\Cache\Exception\CacheConnectingException;
use Joomla\CMS\Factory;
use Joomla\CMS\Log\Log;

// phpcs:disable PSR1.Files.SideEffects
\defined('_JEXEC') or die;
// phpcs:enable PSR1.Files.SideEffects

/**
 * Redis cache storage handler for PECL
 *
 * @since  3.4
 */
class RedisStorage extends CacheStorage
{
    /**
     * Redis connection object
     *
     * @var    \Redis
     * @since  3.4
     */
    protected static $_redis = null;

    /**
     * Persistent session flag
     *
     * @var    boolean
     * @since  3.4
     */
    protected $_persistent = false;

    /**
     * Constructor
     *
     * @param   array  $options  Optional parameters.
     *
     * @since   3.4
     */
    public function __construct($options = [])
    {
        parent::__construct($options);

        if (static::$_redis === null) {
            $this->getConnection();
        }
    }

    /**
     * Create the Redis connection
     *
     * @return  \Redis|boolean  Redis connection object on success, boolean on failure
     *
     * @since   3.4
     * @note    As of 4.0 this method will throw a JCacheExceptionConnecting object on connection failure
     */
    protected function getConnection()
    {
        if (static::isSupported() == false) {
            return false;
        }

        $app = Factory::getApplication();

        $this->_persistent = $app->get('redis_persist', true);

        $server = [
            'host' => $app->get('redis_server_host', 'localhost'),
            'port' => $app->get('redis_server_port', 6379),
            'auth' => $app->get('redis_server_auth', null),
            'db'   => (int) $app->get('redis_server_db', null),
        ];

        // If you are trying to connect to a socket file, ignore the supplied port
        if ($server['host'][0] === '/') {
            $server['port'] = 0;
        }

        static::$_redis = new \Redis();

        try {
            if ($this->_persistent) {
                $connection = static::$_redis->pconnect($server['host'], $server['port']);
            } else {
                $connection = static::$_redis->connect($server['host'], $server['port']);
            }
        } catch (\RedisException $e) {
            $connection = false;
            Log::add($e->getMessage(), Log::DEBUG);
        }

        if ($connection == false) {
            static::$_redis = null;

            throw new CacheConnectingException('Redis connection failed', 500);
        }

        try {
            $auth = $server['auth'] ? static::$_redis->auth($server['auth']) : true;
        } catch (\RedisException $e) {
            $auth = false;
            Log::add($e->getMessage(), Log::DEBUG);
        }

        if ($auth === false) {
            static::$_redis = null;

            throw new CacheConnectingException('Redis authentication failed', 500);
        }

        $select = static::$_redis->select($server['db']);

        if ($select == false) {
            static::$_redis = null;

            throw new CacheConnectingException('Redis failed to select database', 500);
        }

        try {
            static::$_redis->ping();
        } catch (\RedisException $e) {
            static::$_redis = null;

            throw new CacheConnectingException('Redis ping failed', 500);
        }

        return static::$_redis;
    }

    /**
     * Check if the cache contains data stored by ID and group
     *
     * @param   string  $id     The cache data ID
     * @param   string  $group  The cache data group
     *
     * @return  boolean
     *
     * @since   3.7.0
     */
    public function contains($id, $group)
    {
        if (static::isConnected() == false) {
            return false;
        }

        // Redis exists returns integer values lets convert that to boolean see: https://redis.io/commands/exists
        return (bool) static::$_redis->exists($this->_getCacheId($id, $group));
    }

    /**
     * Get cached data by ID and group
     *
     * @param   string   $id         The cache data ID
     * @param   string   $group      The cache data group
     * @param   boolean  $checkTime  True to verify cache time expiration threshold
     *
     * @return  mixed  Boolean false on failure or a cached data object
     *
     * @since   3.4
     */
    public function get($id, $group, $checkTime = true)
    {
        if (static::isConnected() == false) {
            return false;
        }

        return static::$_redis->get($this->_getCacheId($id, $group));
    }

    /**
     * Get all cached data
     *
     * @return  mixed  Boolean false on failure or a cached data object
     *
     * @since   3.4
     */
    public function getAll()
    {
        if (static::isConnected() == false) {
            return false;
        }

        $allKeys = static::$_redis->keys('*');
        $data    = [];
        $secret  = $this->_hash;

        if (!empty($allKeys)) {
            foreach ($allKeys as $key) {
                $namearr = explode('-', $key);

                if ($namearr !== false && $namearr[0] == $secret && $namearr[1] === 'cache') {
                    $group = $namearr[2];

                    if (!isset($data[$group])) {
                        $item = new CacheStorageHelper($group);
                    } else {
                        $item = $data[$group];
                    }

                    $item->updateSize(\strlen($key) * 8);
                    $data[$group] = $item;
                }
            }
        }

        return $data;
    }

    /**
     * Store the data to cache by ID and group
     *
     * @param   string  $id     The cache data ID
     * @param   string  $group  The cache data group
     * @param   string  $data   The data to store in cache
     *
     * @return  boolean
     *
     * @since   3.4
     */
    public function store($id, $group, $data)
    {
        if (static::isConnected() == false) {
            return false;
        }

        static::$_redis->setex($this->_getCacheId($id, $group), $this->_lifetime, $data);

        return true;
    }

    /**
     * Remove a cached data entry by ID and group
     *
     * @param   string  $id     The cache data ID
     * @param   string  $group  The cache data group
     *
     * @return  boolean
     *
     * @since   3.4
     */
    public function remove($id, $group)
    {
        if (static::isConnected() == false) {
            return false;
        }

        return (bool) static::$_redis->del($this->_getCacheId($id, $group));
    }

    /**
     * Clean cache for a group given a mode.
     *
     * group mode    : cleans all cache in the group
     * notgroup mode : cleans all cache not in the group
     *
     * @param   string  $group  The cache data group
     * @param   string  $mode   The mode for cleaning cache [group|notgroup]
     *
     * @return  boolean
     *
     * @since   3.4
     */
    public function clean($group, $mode = null)
    {
        if (static::isConnected() == false) {
            return false;
        }

        $allKeys = static::$_redis->keys('*');

        if ($allKeys === false) {
            $allKeys = [];
        }

        $secret = $this->_hash;

        foreach ($allKeys as $key) {
            if (strpos($key, $secret . '-cache-' . $group . '-') === 0 && $mode === 'group') {
                static::$_redis->del($key);
            }

            if (strpos($key, $secret . '-cache-' . $group . '-') !== 0 && $mode !== 'group') {
                static::$_redis->del($key);
            }
        }

        return true;
    }

    /**
     * Test to see if the storage handler is available.
     *
     * @return  boolean
     *
     * @since   3.4
     */
    public static function isSupported()
    {
        return class_exists('\\Redis');
    }

    /**
     * Test to see if the Redis connection is available.
     *
     * @return  boolean
     *
     * @since   3.4
     */
    public static function isConnected()
    {
        return static::$_redis instanceof \Redis;
    }
}
