<?php
     
defin e('TOKEN', 'www.luchg.com');
$valid = new ApiValid();
 
// 权限验证
if($valid->checkSignature()){
    // 验证通过，处理消息
    $msg = new MSG();
    $msg->handleMsg();
}else{
    echo '没有权限';
    exit();
}
 
 
// 消息处理
class MSG{
 
    public function handleMsg(){
        // 接收消息
        $postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
 
        // 判断是否为空
        if(!empty($postStr)){
            // 从 XML 中读取消息
            $requestMsg = $this->readMsg($postStr);
 
            // 返回消息内容
            $responseMsg = array();
            // 接收用户
            $responseMsg['ToUserName'] = $requestMsg->FromUserName;
            // 发送用户
            $responseMsg['FromUserName'] = $requestMsg->ToUserName;
            // 发送时间
            $responseMsg['CreateTime'] = time();
 
            // 发送内容
            $sendMsg = "";
 
            // 判断消息类型
            switch($requestMsg->MsgType){
 
 				// 文本消息
                case 'text':
					$responseMsg['MsgType'] = 'text';

					if(stristr($requestMsg->Content, 'h')){
						$responseMsg['Content'] = '您好,我是小L,请回复数字选择服务.' . "\n\n"
							. '1. 最新天气预报.[格式 1.上海]' . "\n"
							. '2. 最新IT数码资讯.' . "\n"
							. '3. 高性价比数码推荐.' . "\n"
							. '4. 来个笑话.';
					}else if(stristr($requestMsg->Content, '1')){
						$responseMsg['Content'] = '天气预报';
					}else if(stristr($requestMsg->Content, '2')){
						$responseMsg['Content'] = 'IT数码资讯';
					}else if(stristr($requestMsg->Content, '3')){
						$responseMsg['Content'] = '数码推荐';
					}else if(stristr($requestMsg->Content, '4')){
						$responseMsg['Content'] = '笑话';
					}else{
						$responseMsg['Content'] = '未知功能.请回复[h]查看所有服务.';
					}

					break;
 
                // 其他类型
                default:
 
                    $responseMsg['MsgType'] = 'text';
                    $responseMsg['Content'] = '目前仅支持对文字内容回复.请回复[h]查看所有服务.';
 
                    break;
            }
 
            // 创建 XML 消息并返回
            $sendMsg = $this->createTextMsg($responseMsg);
            echo $sendMsg;
        }else{
            echo '';
            exit;
        }
    }
 
    /**
     * 从 XML 中读取消息内容
     * @param  [type] $xml [description]
     * @return [type]      [description]
     */
    private function readMsg($xml){
        return simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA);
    }
 
    /**
     * 创建 XML 类型的消息
     * @param  [type] $msg [description]
     * @return [type]      [description]
     */
    private function createTextMsg($msg){
        $xml = 
            "<xml>
                <ToUserName><![CDATA[%s]]></ToUserName>
                <FromUserName><![CDATA[%s]]></FromUserName>
                <CreateTime>%s</CreateTime>
                <MsgType><![CDATA[%s]]></MsgType>
                <Content><![CDATA[%s]]></Content>
            </xml>";
 
        $resultStr = sprintf($xml, $msg['ToUserName'], $msg['FromUserName'], $msg['CreateTime'],
            $msg['MsgType'], $msg['Content']);
        return $resultStr;
    }
}
 
 
/**
 * 验证登录
 */
class ApiValid{
 
    public function valid(){
        $echoStr = $_GET['echostr'];
 
        if($this->checkSignature()){
            echo $echoStr;
            exit;
        }
    }
 
    public function checkSignature(){
 
        $signature = $_GET['signature'];
        $timestamp = $_GET['timestamp'];
        $nonce = $_GET['nonce'];    
                 
        $token = TOKEN;
        $tmpArr = array($token, $timestamp, $nonce);
        sort($tmpArr, SORT_STRING);
        $tmpStr = implode( $tmpArr );
        $tmpStr = sha1( $tmpStr );
         
        if( $tmpStr == $signature ){
            return true;
        }else{
            return false;
        }
    }
 
}