backend/src/main/java/nju/seec/helper/service/impl/ReplyServiceImpl.java

package nju.seec.helper.service.impl;

import lombok.extern.slf4j.Slf4j;
import nju.seec.helper.dao.CommentDAO;
import nju.seec.helper.dao.ReplyDAO;
import nju.seec.helper.dao.SlideDAO;
import nju.seec.helper.dao.UserDAO;
import nju.seec.helper.dto.reply.ReplyDTO;
import nju.seec.helper.aspect.auth.LoginUser;
import nju.seec.helper.entity.Comment;
import nju.seec.helper.entity.Reply;
import nju.seec.helper.entity.Slide;
import nju.seec.helper.service.MessageService;
import nju.seec.helper.service.ReplyService;
import nju.seec.helper.service.util.AuthUtils;
import nju.seec.helper.enums.ExceptionType;
import nju.seec.helper.enums.MessageType;
import nju.seec.helper.exception.HelperException;
import nju.seec.helper.vo.ReplyVO;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.Collections;

/**
 * @author cst
 */
@Slf4j
@Service
public class ReplyServiceImpl implements ReplyService {
    private final SlideDAO slideDAO;
    private final CommentDAO commentDAO;
    private final ReplyDAO replyDAO;
    private final UserDAO userDAO;

    private final MessageService messageService;

    public ReplyServiceImpl(SlideDAO slideDAO, CommentDAO commentDAO, ReplyDAO replyDAO, UserDAO userDAO, MessageService messageService) {
        this.slideDAO = slideDAO;
        this.commentDAO = commentDAO;
        this.replyDAO = replyDAO;
        this.userDAO = userDAO;
        this.messageService = messageService;
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public ReplyVO createReply(LoginUser user, ReplyDTO replyDTO) {
        Comment comment = commentDAO.findCommentById(replyDTO.getCommentId());
        AuthUtils.checkDataAuth(user.getId(), slideDAO.findSlideById(comment.getSlideId()).getTeacher().getId(), "您无权回复该评论");

        if (comment.getReply() != null) {
            throw HelperException.of(ExceptionType.CONFLICT, "该评论已回复");
        }
        Reply reply = new Reply()
                .setComment(comment)
                .setTeacher(userDAO.findUserById(user.getId()))
                .setContent(replyDTO.getContent());
        comment.setReply(reply);
        reply.setComment(comment);
        reply = replyDAO.save(reply);

        // 增加通知
        if (!user.getId().equals(comment.getUser().getId())) {
            Slide slide = slideDAO.findSlideById(comment.getSlideId());
            messageService.createMessage(Collections.singleton(comment.getUser().getId()), MessageType.COMMENT_REPLY, String.format("您在 [%s] - [%s] 第%d页发表的讨论帖已收到回复", slide.getCourse().getName(), slide.getName(), comment.getPageNumber()), slide.getId());
        }

        return new ReplyVO(reply);
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public void deleteReply(LoginUser user, Long replyId) {
        Reply reply = replyDAO.findReplyById(replyId);
        AuthUtils.checkDataAuth(user.getId(), reply.getTeacher().getId(), "您无权删除该评论");

        Comment comment = reply.getComment();
        comment.setReply(null);
        replyDAO.delete(reply);
    }
}