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后端 Go+Gin：认证/CSRF/限流、板块、帖子、评论、点赞、通知、用户资料、置顶推荐；前端 Next.js 16：发帖/编辑/删除、搜索、分页、点赞、通知中心、设置；基础设施 docker-compose 与配置模板；添加 .gitignore 与专有许可证（保留所有权利）

backend/service/comment.go

@@ -0,0 +1,122 @@
+package service
+
+import (
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/freefire/jiang13-bbs/model"
+	"gorm.io/gorm"
+)
+
+// CommentService 评论服务
+type CommentService struct {
+	db *gorm.DB
+}
+
+func NewCommentService(db *gorm.DB) *CommentService {
+	return &CommentService{db: db}
+}
+
+// ListByPost 获取帖子的评论列表
+func (s *CommentService) ListByPost(postID uint) ([]model.Comment, error) {
+	var comments []model.Comment
+	err := s.db.Where("post_id = ? AND status = ?", postID, model.ContentStatusPublished).
+		Order("created_at ASC").
+		Preload("User").
+		Find(&comments).Error
+	return comments, err
+}
+
+// Create 创建评论
+func (s *CommentService) Create(userID, postID uint, content string) (*model.Comment, error) {
+	content = strings.TrimSpace(content)
+	if content == "" {
+		return nil, errors.New("评论内容不能为空")
+	}
+
+	// 检查帖子是否存在且未锁定评论
+	var post model.Post
+	if err := s.db.First(&post, postID).Error; err != nil {
+		return nil, errors.New("帖子不存在")
+	}
+
+	comment := &model.Comment{
+		PostID:  postID,
+		UserID:  userID,
+		Content: content,
+		Status:  model.ContentStatusPublished,
+	}
+	if err := s.db.Create(comment).Error; err != nil {
+		return nil, err
+	}
+	// 更新帖子评论数
+	s.db.Model(&post).UpdateColumn("comment_count", gorm.Expr("comment_count + 1"))
+	// 预加载用户
+	s.db.Preload("User").First(comment, comment.ID)
+	return comment, nil
+}
+
+// UserCommentItem 用户评论列表项（含帖子标题便于跳转）
+type UserCommentItem struct {
+	ID        uint      `json:"id"`
+	PostID    uint      `json:"post_id"`
+	PostTitle string    `json:"post_title"`
+	Content   string    `json:"content"`
+	CreatedAt time.Time `json:"created_at"`
+}
+
+// ListByUser 获取指定用户发表的评论（含所属帖子标题）
+func (s *CommentService) ListByUser(userID uint, page, size int) ([]UserCommentItem, int64, error) {
+	if page < 1 {
+		page = 1
+	}
+	if size < 1 || size > 50 {
+		size = 20
+	}
+	query := s.db.Table("comments").
+		Select("comments.id, comments.post_id, posts.title AS post_title, comments.content, comments.created_at").
+		Joins("JOIN posts ON posts.id = comments.post_id").
+		Where("comments.user_id = ? AND comments.status = ? AND posts.deleted_at IS NULL", userID, model.ContentStatusPublished)
+
+	var total int64
+	if err := query.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+	var items []UserCommentItem
+	offset := (page - 1) * size
+	if err := query.Order("comments.created_at DESC").Offset(offset).Limit(size).Scan(&items).Error; err != nil {
+		return nil, 0, err
+	}
+	return items, total, nil
+}
+
+// CountByUser 统计用户评论数（仅统计未删除帖子上的评论，与列表保持一致）
+func (s *CommentService) CountByUser(userID uint) (int64, error) {
+	var total int64
+	err := s.db.Table("comments").
+		Joins("JOIN posts ON posts.id = comments.post_id").
+		Where("comments.user_id = ? AND comments.status = ? AND posts.deleted_at IS NULL", userID, model.ContentStatusPublished).
+		Count(&total).Error
+	return total, err
+}
+
+// Delete 删除评论（仅作者或管理员可操作）
+func (s *CommentService) Delete(commentID, userID uint, role string) error {
+	var comment model.Comment
+	if err := s.db.First(&comment, commentID).Error; err != nil {
+		return errors.New("评论不存在")
+	}
+	// 权限校验：作者本人或管理员
+	if comment.UserID != userID && role != RoleAdmin {
+		return errors.New("无权限删除此评论")
+	}
+	// 软删除
+	if err := s.db.Delete(&comment).Error; err != nil {
+		return err
+	}
+	// 更新帖子评论数
+	s.db.Model(&model.Post{}).Where("id = ?", comment.PostID).
+		UpdateColumn("comment_count", gorm.Expr("GREATEST(comment_count - 1, 0)"))
+	return nil
+}