<?php

/**
 * 缓存类
 */

namespace base;

class Cache {

    /**
     * 缓存配置
     * @var array
     */
    protected $config = array();

    /**
     * 配置名
     * @var string
     */
    public $cache = 'default';

    /**
     * 代理对象
     * @var null
     */
    public $proxyObj = null;

    /**
     * 代理缓存时间
     * @var integer
     */
    public $proxyExpire = 1800;

    /**
     * 缓存对象
     * @var array
     */
    protected static $objArr = array();

    /**
     * 构建函数
     * @param string $cache 缓存配置名
     */
    public function __construct( $cache = 'default' ) {
        if( $cache ){
            $this->cache = $cache;
        }
        $this->config = Config::get('CACHE.' . $this->cache);
        if( empty($this->config) || !isset($this->config['CACHE_TYPE']) ) {
            throw new \Exception($this->cache.' cache config error', 500);
        }
    }

    /**
     * 回调驱动
     * @param  string $method 回调方法
     * @param  array  $args   回调参数
     * @return object
     */
    public function __call($method, $args) {
        if( !isset(self::$objArr[$this->cache]) ){
            $cacheDriver = __NAMESPACE__.'\cache\\' . ucfirst( $this->config['CACHE_TYPE'] ).'Driver';
            if( !class_exists($cacheDriver) ) {
                throw new \Exception("Cache Driver '{$cacheDriver}' not found'", 500);
            }
            self::$objArr[$this->cache] = new $cacheDriver( $this->config );
        }

        if( $this->proxyObj ){ //proxy mode
            $key = md5( get_class($this->proxyObj) . '_'.$method.'_' . var_export($args) );
            $value = self::$objArr[$this->cache]->get($key);
            if( false===$value ){
                $value = call_user_func_array(array($this->proxyObj, $method), $args);
                self::$objArr[$this->cache]->set($key, $value, $this->proxyExpire);
            }
            return $value;
        }else{
            return call_user_func_array(array(self::$objArr[$this->cache], $method), $args);
        }
    }
}