<?php

class Redist{
	public $expireTime;
	public $server;
	
	private $_redis;
	
	private static $_instance;

	function __construct(){
		if(!extension_loaded("redis") && Yii::app()->params["user_login_cache"]["state"] == "on")
			throw new Exception("Redis extension is not loaded");
		
		$this->expireTime = isset(Yii::app()->params["user_login_cache"]["expire_time"]) ? Yii::app()->params["user_login_cache"]["expire_time"] : 3600;
		$server = Yii::app()->params["user_login_cache"]["servers"];
		
		$this->_redis = new Redis();
		$this->_redis->connect($server["host"], $server["port"]);
		if(isset($server['password'])){
            $this->_redis->auth($server['password']);
        }
		$this->_redis->setOption(Redis::OPT_SERIALIZER, Redis::SERIALIZER_PHP);
	}
	
	protected static function instance(){
		if(!is_object(self::$_instance)){
			self::$_instance = new self();
		}
		
		return self::$_instance;
	}
	
	public static function select($dbNum){
		return self::instance()->_redis->select($dbNum);
	}
	
	public static function keys($keys){
		return self::instance()->_redis->keys($keys);
	}
	
	public static function set($key, $val){
		$params = func_get_args();
		
		if(isset($params[2]))
			$expireTime = $params[2];
		else
			$expireTime = self::instance()->expireTime;
		
		return $expireTime === -1 ? self::instance()->_redis->set($key, $val) : self::instance()->_redis->setex($key, $expireTime, $val);
	}
	
	public static function add($key, $val){
		$params = func_get_args();
		if(isset($params[2]))
			$expireTime = $params[2];
		else
			$expireTime = self::instance()->expireTime;
		
		try{
			self::instance()->_redis->multi();
			self::instance()->_redis->setnx($key, $val);
			self::instance()->_redis->expire($key, $expireTime);
			self::instance()->_redis->exec();
			
			return true;
		}
		catch(RedisException $e){
			return false;
		}
	}
	
	public static function exists($key){
		return self::instance()->_redis->exists($key);
	}
	
	public static function get($key){
		return self::instance()->_redis->get($key);
	}
	
	public static function del($key){
		$keys = func_get_args();
		return self::instance()->_redis->del($keys);
	}
	
	public static function expire($key, $expireTime){
		return self::instance()->_redis->expire($key, $expireTime);
	}
}