private function checkCanUserReply(DoctorPatientRef $ref)
 {
     $followupOwner = $ref->getFollowupOwner();
     $space = $ref->space;
     $canReplyFollowupOwner = false == $followupOwner->isNull() && $followupOwner->isOpenFollowup();
     $doctorChargeFlowProduct = ProductClient::getInstance()->getDoctorChargeFlowProduct($ref->space);
     $message = '';
     if (false == $canReplyFollowupOwner && false == $space->isCaseOpen()) {
         $message = '医生已经关闭了咨询区,您暂时不能向医生提问';
     } elseif ($ref->isClosePost()) {
         $message = '医患关系已关闭,无法继续交流';
     } elseif ($space->isChargeOpened() && $ref->isSpaceCanPost() == false && $doctorChargeFlowProduct instanceof Product && false == $ref->hasSpaceLeftAllowCnt()) {
         $message = '您和医生的交流次数已用完';
     }
     return $message;
 }