SpringBootBlog/src/main/java/cc/bnblogs/service/CommentService.java

package cc.bnblogs.service;

import cc.bnblogs.common.MailHelper;
import cc.bnblogs.common.PageHelper;
import cc.bnblogs.common.WebSite;
import cc.bnblogs.mapper.ArticleMapper;
import cc.bnblogs.mapper.CommentMapper;
import cc.bnblogs.pojo.Article;
import cc.bnblogs.pojo.Comment;
import cc.bnblogs.utils.UpdateUtil;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;

import java.util.Date;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;

/**
 * @author zfp@bnblogs.cc
 * @createTime: 2022/10/17
 */
@Service
public class CommentService {

    private final CommentMapper commentMapper;

    private final MailHelper mailHelper;
    private final WebSite webSite;
    private final ArticleMapper articleMapper;

    public CommentService(CommentMapper commentMapper, MailHelper mailHelper, WebSite webSite, ArticleMapper articleMapper) {
        this.commentMapper = commentMapper;
        this.mailHelper = mailHelper;
        this.webSite = webSite;
        this.articleMapper = articleMapper;
    }

    /**
     * 获取所有评论
     *
     * @return 评论列表
     */
    public List<Comment> list() {
        return commentMapper.findAll();
    }

    /**
     * 根据是否view的取值返回评论数(null:表示所有)
     * @param view 是否已读
     * @return 评论个数
     */
    public long count(Boolean view) {
        return Objects.isNull(view) ?
                commentMapper.count(): commentMapper.countCommentByView(view);
    }

    /**
     * 根据id查询评论对象
     *
     * @param id 评论id
     * @return id对应的评论对象
     */
    public Comment detail(Integer id) {
        return commentMapper.findById(id).orElse(null);
    }

    /**
     * 保存评论
     *
     * @param comment 待保存的评论对象
     */
    public void save(Comment comment) {
        // 如果是新评论
        if (Objects.isNull(comment.getId())) {
            // 有人在你的网站评论了
            sendMailToWebsite(comment.getArticle().getId());
            comment.setCreated(new Date());
            comment.setView(false);
            if (comment.getPid() != 0) {
                // 有人回复了你的评论
                sendMailToComment(comment.getArticle().getId(), comment.getPid(), comment.getContent());
                // 展示它的父评论
                Comment parent = detail(comment.getPid());
                comment.setContent("@" + parent.getNickname() + ": " + comment.getContent());
                comment.setPid(findCommentPid(comment.getPid()));
            }
            commentMapper.save(comment);
        }
        // 修改评论内容
        else {
            Comment one = detail(comment.getId());
            UpdateUtil.copyNullProperties(comment, one);
            commentMapper.save(one);
        }
    }

    /**
     * 网站有人留言了发送一封邮件给站长
     *
     * @param id 文章id
     */
    public void sendMailToWebsite(Integer id) {
        Article article = articleMapper.findById(id).orElse(null);
        if (Objects.isNull(article)) {
            return;
        }
        String content = "<p>\n" + "    你的文章 <a href=\"" + webSite.getDomain() + "/" + id + ".html\">" + article.getTitle()
                + "</a>收到了新评论，" +
                "<a href=\"" + webSite.getDomain() + "/" + id + ".html\">" + "点此</a>" + "查看\n" + "</p>\n" +
                "<p style=\"text-align:right ;\">\n" + "时间：\n" + new Date() + "</p>";
        mailHelper.sendMail(webSite.getMail(), webSite.getTitle() + "收到新评论", content);
    }

    /**
     * 异步方法: 有人回复了你的评论，需要给你发送一封邮件
     *
     * @param id    文章id
     * @param cid   被评论的评论id
     * @param reply 回复内容
     */
    public void sendMailToComment(Integer id, Integer cid, String reply) {
        Article article = articleMapper.findById(id).orElse(null);
        if (Objects.isNull(article)) {
            return;
        }
        Comment comment = commentMapper.findById(cid).orElse(null);
        if (Objects.isNull(comment)) {
            return;
        }
        String content = "<p>\n" + "    你在<a href=\"" + webSite.getDomain() + "\">" + webSite.getTitle() + "</a>对 <a href=\"" + webSite.getDomain() + "/" + article.getId() + ".html\">" + article.getTitle() + "</a>文章的评论收到了新回复，回复内容如下：\n" + "</p>\n" + "<p>\n" + reply + "</p>\n" + "<p style=\"text-align:right ;\">\n" + "   一一发件人：" + webSite.getTitle() + "</p>\n" + "<p style=\"text-align:right ;\">\n" + "时间：" + new Date() + "</p>\n" + "<p style=\"text-align:right ;\">\n" + "    此邮件是由" + webSite.getTitle() + "自动发送，请勿回复 \n" + " </p>";
        mailHelper.sendMail(comment.getEmail(), webSite.getTitle() + "收到新回复", content);
    }

    /**
     * 递归查找直到找到最原始评论
     *
     * @param id 评论id
     * @return 祖先评论的id
     */
    private Integer findCommentPid(Integer id) {
        Comment comment = detail(id);
        // 直到找到某个评论的pid为0，因为他就是最原始的评论
        if (comment.getPid() == 0) {
            return comment.getId();
        }
        return findCommentPid(comment.getPid());
    }

    /**
     * 根据id删除评论对象
     *
     * @param id 待删除评论的id
     */
    public void delete(Integer id) {
        commentMapper.deleteById(id);
    }

    /**
     * 返回文章的评论
     *
     * @param id         文章id
     * @param pageNumber 初始页号
     * @return 评论分页
     */
    public PageHelper<Comment> show(Integer id, int pageNumber) {
        // 每页显示5个评论
        Page<Comment> page = commentMapper.findAllByArticleAndPidOrderByCreatedDesc(Article.builder().id(id).build(), 0, PageRequest.of(pageNumber - 1, 5));
        // 评论内容-当前页数-评论总数-总页数
        return PageHelper.<Comment>builder().rows(page.getContent().stream().peek(x -> x.setChildren(commentMapper.findAllByPidOrderByCreatedDesc(x.getId()))).collect(Collectors.toList())).currentPage(pageNumber).total(page.getTotalElements()).totalPages(page.getTotalPages()).build();
    }

    public void readAll() {
        commentMapper.readAll();
    }

    public PageHelper<Comment> list(Boolean view, Integer pageNumber, Integer pageSize) {
        Pageable pageable = PageRequest.of(pageNumber-1,pageSize, Sort.by(Sort.Direction.DESC,"created"));
        Page<Comment> page = Objects.isNull(view) ?  commentMapper.findAll(pageable) : commentMapper.findAllByView(view,pageable);
        return PageHelper.<Comment>builder()
                        .rows(page.getContent())
                        .total(page.getTotalElements())
                        .build();
    }
}