feat(P3): 私信 + #话题标签 + @提及 完成

backend/internal/video/comment_service.go

@@ -6,6 +6,7 @@ import (
 	"feedsystem_video_go/internal/middleware/rabbitmq"
 	rediscache "feedsystem_video_go/internal/middleware/redis"
 	"feedsystem_video_go/internal/apierror"
+	"regexp"
 	"strings"
 
 	"gorm.io/gorm"
@@ -57,6 +58,7 @@ func (s *CommentService) Publish(ctx context.Context, comment *Comment) error {
 		}
 	}
 	if mysqlEnqueued && redisEnqueued {
+		s.notifyMentions(ctx, comment)
 		return nil
 	}
 
@@ -83,6 +85,7 @@ func (s *CommentService) Publish(ctx context.Context, comment *Comment) error {
 	if !redisEnqueued {
 		UpdatePopularityCache(ctx, s.cache, comment.VideoID, 1)
 	}
+	s.notifyMentions(ctx, comment)
 	return nil
 }
 
@@ -115,3 +118,38 @@ func (s *CommentService) GetAll(ctx context.Context, videoID uint) ([]Comment, e
 	}
 	return s.repo.GetAllComments(ctx, videoID)
 }
+
+var mentionRegex = regexp.MustCompile(`@(\w+)`)
+
+func (s *CommentService) notifyMentions(ctx context.Context, comment *Comment) {
+	matches := mentionRegex.FindAllStringSubmatch(comment.Content, -1)
+	if len(matches) == 0 {
+		return
+	}
+	seen := make(map[string]bool)
+	for _, m := range matches {
+		username := m[1]
+		if seen[username] || username == comment.Username {
+			continue
+		}
+		seen[username] = true
+		var accID uint
+		if err := s.repo.db.WithContext(ctx).Table("accounts").Where("username = ?", username).Select("id").Scan(&accID).Error; err != nil || accID == 0 {
+			continue
+		}
+		notif := struct {
+			RecipientID uint
+			SenderID    uint
+			Type        string
+			TargetID    uint
+			Content     string
+		}{
+			RecipientID: accID,
+			SenderID:    comment.AuthorID,
+			Type:        "mention",
+			TargetID:    comment.VideoID,
+			Content:     comment.Username + " 在评论中提到了你",
+		}
+		s.repo.db.WithContext(ctx).Table("notifications").Create(&notif)
+	}
+}

backend/internal/video/tag_entity.go

@@ -0,0 +1,30 @@
+package video
+
+import "regexp"
+
+type Tag struct {
+	ID   uint   `gorm:"primaryKey" json:"id"`
+	Name string `gorm:"uniqueIndex;type:varchar(100);not null" json:"name"`
+}
+
+type VideoTag struct {
+	ID      uint `gorm:"primaryKey"`
+	VideoID uint `gorm:"index;not null"`
+	TagID   uint `gorm:"index;not null"`
+}
+
+var tagRegex = regexp.MustCompile(`#([\p{L}\p{N}_]+)`)
+
+func ExtractTags(text string) []string {
+	matches := tagRegex.FindAllStringSubmatch(text, -1)
+	seen := make(map[string]bool)
+	var tags []string
+	for _, m := range matches {
+		tag := m[1]
+		if !seen[tag] {
+			seen[tag] = true
+			tags = append(tags, tag)
+		}
+	}
+	return tags
+}

backend/internal/video/video_service.go

@@ -60,8 +60,14 @@ func (vs *VideoService) Publish(ctx context.Context, video *Video) error {
 		if err := tx.Create(&msg).Error; err != nil {
 			return err
 		}
-		return nil
 
+		tags := ExtractTags(video.Title + " " + video.Description)
+		for _, tagName := range tags {
+			var tag Tag
+			tx.Where("name = ?", tagName).FirstOrCreate(&tag, Tag{Name: tagName})
+			tx.Create(&VideoTag{VideoID: video.ID, TagID: tag.ID})
+		}
+		return nil
 	})
 	return err