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

package nju.seec.helper.service.impl;

import nju.seec.helper.dao.ChooseDAO;
import nju.seec.helper.dao.CourseDAO;
import nju.seec.helper.dao.NoticeDAO;
import nju.seec.helper.dto.notice.NoticeDTO;
import nju.seec.helper.dto.user.LoginUser;
import nju.seec.helper.entity.Course;
import nju.seec.helper.entity.Notice;
import nju.seec.helper.service.MessageService;
import nju.seec.helper.service.NoticeService;
import nju.seec.helper.service.util.AuthUtils;
import nju.seec.helper.service.util.StringUtils;
import nju.seec.helper.util.enums.MessageType;
import nju.seec.helper.vo.NoticeVO;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.Set;

/**
 * @author cst
 */
@Service
public class NoticeServiceImpl implements NoticeService {
    private final CourseDAO courseDAO;
    private final ChooseDAO chooseDAO;
    private final NoticeDAO noticeDAO;

    private final MessageService messageService;

    public NoticeServiceImpl(CourseDAO courseDAO, ChooseDAO chooseDAO, NoticeDAO noticeDAO, MessageService messageService) {
        this.courseDAO = courseDAO;
        this.chooseDAO = chooseDAO;
        this.noticeDAO = noticeDAO;
        this.messageService = messageService;
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public NoticeVO createNotice(LoginUser user, NoticeDTO noticeDTO) {
        Course course = courseDAO.findCourseById(noticeDTO.getCourseId());
        AuthUtils.checkDataAuth(user.getId(), course.getTeacher().getId(), "您无权创建该课程的公告");
        Notice notice = new Notice()
                .setCourseId(noticeDTO.getCourseId())
                .setTeacherId(user.getId())
                .setTitle(noticeDTO.getTitle())
                .setContent(noticeDTO.getContent());

        Set<Long> studentIds = chooseDAO.findStudentIdsByCourseId(noticeDTO.getCourseId());
        messageService.createMessage(studentIds, MessageType.NOTICE_NEW, String.format("[%s] 发布了新公告", course.getName()), null);
        return new NoticeVO(noticeDAO.save(notice));
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public NoticeVO modifyNotice(LoginUser user, Long noticeId, NoticeDTO noticeDTO) {
        Notice notice = noticeDAO.findNoticeById(noticeId);
        AuthUtils.checkDataAuth(user.getId(), notice.getTeacherId(), "您无权修改该公告");
        notice.setTitle(noticeDTO.getTitle())
                .setContent(noticeDTO.getContent());
        return new NoticeVO(noticeDAO.save(notice));
    }

    @Transactional(readOnly = true)
    @Override
    public Page<NoticeVO> getNoticesByCourse(LoginUser user, Long courseId, String key, Pageable pageable) {
        return findByCourseIdAndKey(courseId, key, pageable).map(NoticeVO::new);
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public void deleteNotice(LoginUser user, Long noticeId) {
        Notice notice = noticeDAO.findNoticeById(noticeId);
        AuthUtils.checkDataAuth(user.getId(), notice.getTeacherId(), "您无权删除该公告");
        noticeDAO.deleteById(noticeId);
    }

    @Transactional(readOnly = true)
    @Override
    public NoticeVO getOneNotice(LoginUser user, Long noticeId) {
        return new NoticeVO(noticeDAO.findNoticeById(noticeId));
    }

    private Page<Notice> findByCourseIdAndKey(Long courseId, String key, Pageable pageable) {
        String keyPattern = StringUtils.keyPattern(key);

        return noticeDAO.findAll(
                (Specification<Notice>) (root, query, cb) -> cb.and(
                        cb.equal(root.get("courseId"), courseId)
//                        , cb.or(cb.like(root.get("title"), keyPattern), cb.like(root.get("content"), keyPattern))
                ),
                pageable);
    }
}