<?php

// +----------------------------------------------------------------------

// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]

// +----------------------------------------------------------------------

// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.

// +----------------------------------------------------------------------

// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )

// +----------------------------------------------------------------------

// | Author: liu21st <liu21st@gmail.com>

// +----------------------------------------------------------------------



defined('THINK_PATH') or exit();

/**

 * 系统行为扩展：静态缓存读取

 * @category   Think

 * @package  Think

 * @subpackage  Behavior

 * @author   liu21st <liu21st@gmail.com>

 */

class ReadHtmlCacheBehavior extends Behavior {

    protected $options   =  array(

            'HTML_CACHE_ON'     =>  false,

            'HTML_CACHE_TIME'   =>  60,

            'HTML_CACHE_RULES'  =>  array(),

            'HTML_FILE_SUFFIX'  =>  '.html',

        );



    // 行为扩展的执行入口必须是run

    public function run(&$params){

        // 开启静态缓存

        if(C('HTML_CACHE_ON'))  {

            $cacheTime = $this->requireHtmlCache();

            if( false !== $cacheTime && $this->checkHTMLCache(HTML_FILE_NAME,$cacheTime)) { //静态页面有效

                // 读取静态页面输出

                readfile(HTML_FILE_NAME);

                exit();

            }

        }

    }



    // 判断是否需要静态缓存

    static private function requireHtmlCache() {

        // 分析当前的静态规则

         $htmls = C('HTML_CACHE_RULES'); // 读取静态规则

         if(!empty($htmls)) {

            $htmls = array_change_key_case($htmls);

            // 静态规则文件定义格式 actionName=>array('静态规则','缓存时间','附加规则')

            // 'read'=>array('{id},{name}',60,'md5') 必须保证静态规则的唯一性 和 可判断性

            // 检测静态规则

            $moduleName = strtolower(MODULE_NAME);

            $actionName = strtolower(ACTION_NAME);

            if(isset($htmls[$moduleName.':'.$actionName])) {

                $html   =   $htmls[$moduleName.':'.$actionName];   // 某个模块的操作的静态规则

            }elseif(isset($htmls[$moduleName.':'])){// 某个模块的静态规则

                $html   =   $htmls[$moduleName.':'];

            }elseif(isset($htmls[$actionName])){

                $html   =   $htmls[$actionName]; // 所有操作的静态规则

            }elseif(isset($htmls['*'])){

                $html   =   $htmls['*']; // 全局静态规则

            }elseif(isset($htmls['empty:index']) && !class_exists(MODULE_NAME.'Action')){

                $html   =    $htmls['empty:index']; // 空模块静态规则

            }elseif(isset($htmls[$moduleName.':_empty']) && $this->isEmptyAction(MODULE_NAME,ACTION_NAME)){

                $html   =    $htmls[$moduleName.':_empty']; // 空操作静态规则

            }

            if(!empty($html)) {

                // 解读静态规则

                $rule   = $html[0];

                // 以$_开头的系统变量

                $rule   = preg_replace('/{\$(_\w+)\.(\w+)\|(\w+)}/e',"\\3(\$\\1['\\2'])",$rule);

                $rule   = preg_replace('/{\$(_\w+)\.(\w+)}/e',"\$\\1['\\2']",$rule);

                // {ID|FUN} GET变量的简写

                $rule   = preg_replace('/{(\w+)\|(\w+)}/e',"\\2(\$_GET['\\1'])",$rule);

                $rule   = preg_replace('/{(\w+)}/e',"\$_GET['\\1']",$rule);

                // 特殊系统变量

                $rule   = str_ireplace(

                    array('{:app}','{:module}','{:action}','{:group}'),

                    array(APP_NAME,MODULE_NAME,ACTION_NAME,defined('GROUP_NAME')?GROUP_NAME:''),

                    $rule);

                // {|FUN} 单独使用函数

                $rule  = preg_replace('/{|(\w+)}/e',"\\1()",$rule);

                if(!empty($html[2])) $rule    =   $html[2]($rule); // 应用附加函数

                $cacheTime = isset($html[1])?$html[1]:C('HTML_CACHE_TIME'); // 缓存有效期

                // 当前缓存文件

                define('HTML_FILE_NAME',HTML_PATH . $rule.C('HTML_FILE_SUFFIX'));

                return $cacheTime;

            }

        }

        // 无需缓存

        return false;

    }



    /**

     * 检查静态HTML文件是否有效

     * 如果无效需要重新更新

     * @access public

     * @param string $cacheFile  静态文件名

     * @param integer $cacheTime  缓存有效期

     * @return boolean

     */

    static public function checkHTMLCache($cacheFile='',$cacheTime='') {

        if(!is_file($cacheFile)){

            return false;

        }elseif (filemtime(C('TEMPLATE_NAME')) > filemtime($cacheFile)) {

            // 模板文件如果更新静态文件需要更新

            return false;

        }elseif(!is_numeric($cacheTime) && function_exists($cacheTime)){

            return $cacheTime($cacheFile);

        }elseif ($cacheTime != 0 && NOW_TIME > filemtime($cacheFile)+$cacheTime) {

            // 文件是否在有效期

            return false;

        }

        //静态文件有效

        return true;

    }



    //检测是否是空操作

    static private function isEmptyAction($module,$action) {

        $className  =   $module.'Action';

        $class      =   new $className;

        return !method_exists($class,$action);

    }



}