Initial backend repository commit.

Set up project files and add .gitignore to exclude local build/runtime artifacts. Made-with: Cursor
2026-03-09 21:28:58 +08:00
commit 4d8f2ec997
102 changed files with 25022 additions and 0 deletions
--- a/internal/service/post_service.go
+++ b/internal/service/post_service.go
@@ -0,0 +1,593 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"strings"
+	"time"
+
+	"carrot_bbs/internal/cache"
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/pkg/gorse"
+	"carrot_bbs/internal/repository"
+)
+
+// 缓存TTL常量
+const (
+	PostListTTL         = 30 * time.Second // 帖子列表缓存30秒
+	PostListNullTTL     = 5 * time.Second
+	PostListJitterRatio = 0.15
+	anonymousViewUserID = "_anon_view"
+)
+
+// PostService 帖子服务
+type PostService struct {
+	postRepo             *repository.PostRepository
+	systemMessageService SystemMessageService
+	cache                cache.Cache
+	gorseClient          gorse.Client
+	postAIService        *PostAIService
+}
+
+// NewPostService 创建帖子服务
+func NewPostService(postRepo *repository.PostRepository, systemMessageService SystemMessageService, gorseClient gorse.Client, postAIService *PostAIService) *PostService {
+	return &PostService{
+		postRepo:             postRepo,
+		systemMessageService: systemMessageService,
+		cache:                cache.GetCache(),
+		gorseClient:          gorseClient,
+		postAIService:        postAIService,
+	}
+}
+
+// PostListResult 帖子列表缓存结果
+type PostListResult struct {
+	Posts []*model.Post
+	Total int64
+}
+
+// Create 创建帖子
+func (s *PostService) Create(ctx context.Context, userID, title, content string, images []string) (*model.Post, error) {
+	post := &model.Post{
+		UserID:  userID,
+		Title:   title,
+		Content: content,
+		Status:  model.PostStatusPending,
+	}
+
+	err := s.postRepo.Create(post, images)
+	if err != nil {
+		return nil, err
+	}
+
+	// 失效帖子列表缓存
+	cache.InvalidatePostList(s.cache)
+
+	// 同步到Gorse推荐系统（异步）
+	go s.reviewPostAsync(post.ID, userID, title, content, images)
+
+	// 重新查询以获取关联的 User 和 Images
+	return s.postRepo.GetByID(post.ID)
+}
+
+func (s *PostService) reviewPostAsync(postID, userID, title, content string, images []string) {
+	// 未启用AI时，直接发布
+	if s.postAIService == nil || !s.postAIService.IsEnabled() {
+		if err := s.postRepo.UpdateModerationStatus(postID, model.PostStatusPublished, "", "system"); err != nil {
+			log.Printf("[WARN] Failed to publish post without AI moderation: %v", err)
+		}
+		return
+	}
+
+	err := s.postAIService.ModeratePost(context.Background(), title, content, images)
+	if err != nil {
+		var rejectedErr *PostModerationRejectedError
+		if errors.As(err, &rejectedErr) {
+			if updateErr := s.postRepo.UpdateModerationStatus(postID, model.PostStatusRejected, rejectedErr.UserMessage(), "ai"); updateErr != nil {
+				log.Printf("[WARN] Failed to reject post %s: %v", postID, updateErr)
+			}
+			s.notifyModerationRejected(userID, rejectedErr.Reason)
+			return
+		}
+
+		// 规则审核不可用时，降级为发布，避免长时间pending
+		if updateErr := s.postRepo.UpdateModerationStatus(postID, model.PostStatusPublished, "", "system"); updateErr != nil {
+			log.Printf("[WARN] Failed to publish post %s after moderation error: %v", postID, updateErr)
+		}
+		log.Printf("[WARN] Post moderation failed, fallback publish post=%s err=%v", postID, err)
+		return
+	}
+
+	if err := s.postRepo.UpdateModerationStatus(postID, model.PostStatusPublished, "", "ai"); err != nil {
+		log.Printf("[WARN] Failed to publish post %s: %v", postID, err)
+		return
+	}
+
+	if s.gorseClient.IsEnabled() {
+		post, getErr := s.postRepo.GetByID(postID)
+		if getErr != nil {
+			log.Printf("[WARN] Failed to load published post for gorse sync: %v", getErr)
+			return
+		}
+		categories := s.buildPostCategories(post)
+		comment := post.Title
+		textToEmbed := post.Title + " " + post.Content
+		if upsertErr := s.gorseClient.UpsertItemWithEmbedding(context.Background(), post.ID, categories, comment, textToEmbed); upsertErr != nil {
+			log.Printf("[WARN] Failed to upsert item to Gorse: %v", upsertErr)
+		}
+	}
+}
+
+func (s *PostService) notifyModerationRejected(userID, reason string) {
+	if s.systemMessageService == nil || strings.TrimSpace(userID) == "" {
+		return
+	}
+
+	content := "您发布的帖子未通过AI审核，请修改后重试。"
+	if strings.TrimSpace(reason) != "" {
+		content = fmt.Sprintf("您发布的帖子未通过AI审核，原因：%s。请修改后重试。", reason)
+	}
+
+	go func() {
+		if err := s.systemMessageService.SendSystemAnnouncement(
+			context.Background(),
+			[]string{userID},
+			"帖子审核未通过",
+			content,
+		); err != nil {
+			log.Printf("[WARN] Failed to send moderation reject notification: %v", err)
+		}
+	}()
+}
+
+// GetByID 根据ID获取帖子
+func (s *PostService) GetByID(ctx context.Context, id string) (*model.Post, error) {
+	return s.postRepo.GetByID(id)
+}
+
+// Update 更新帖子
+func (s *PostService) Update(ctx context.Context, post *model.Post) error {
+	err := s.postRepo.Update(post)
+	if err != nil {
+		return err
+	}
+
+	// 失效帖子详情缓存和列表缓存
+	cache.InvalidatePostDetail(s.cache, post.ID)
+	cache.InvalidatePostList(s.cache)
+
+	return nil
+}
+
+// Delete 删除帖子
+func (s *PostService) Delete(ctx context.Context, id string) error {
+	err := s.postRepo.Delete(id)
+	if err != nil {
+		return err
+	}
+
+	// 失效帖子详情缓存和列表缓存
+	cache.InvalidatePostDetail(s.cache, id)
+	cache.InvalidatePostList(s.cache)
+
+	// 从Gorse中删除帖子（异步）
+	go func() {
+		if s.gorseClient.IsEnabled() {
+			if err := s.gorseClient.DeleteItem(context.Background(), id); err != nil {
+				log.Printf("[WARN] Failed to delete item from Gorse: %v", err)
+			}
+		}
+	}()
+
+	return nil
+}
+
+// List 获取帖子列表（带缓存）
+func (s *PostService) List(ctx context.Context, page, pageSize int, userID string) ([]*model.Post, int64, error) {
+	cacheSettings := cache.GetSettings()
+	postListTTL := cacheSettings.PostListTTL
+	if postListTTL <= 0 {
+		postListTTL = PostListTTL
+	}
+	nullTTL := cacheSettings.NullTTL
+	if nullTTL <= 0 {
+		nullTTL = PostListNullTTL
+	}
+	jitter := cacheSettings.JitterRatio
+	if jitter <= 0 {
+		jitter = PostListJitterRatio
+	}
+
+	// 生成缓存键（包含 userID 维度，避免过滤查询与全量查询互相污染）
+	cacheKey := cache.PostListKey("latest", userID, page, pageSize)
+
+	result, err := cache.GetOrLoadTyped[*PostListResult](
+		s.cache,
+		cacheKey,
+		postListTTL,
+		jitter,
+		nullTTL,
+		func() (*PostListResult, error) {
+			posts, total, err := s.postRepo.List(page, pageSize, userID)
+			if err != nil {
+				return nil, err
+			}
+			return &PostListResult{Posts: posts, Total: total}, nil
+		},
+	)
+	if err != nil {
+		return nil, 0, err
+	}
+	if result == nil {
+		return []*model.Post{}, 0, nil
+	}
+
+	// 兼容历史脏缓存：旧缓存序列化会丢失 Post.User，导致前端显示“匿名用户”
+	// 这里检测并回源重建一次缓存，避免在 TTL 内持续返回缺失作者的数据。
+	missingAuthor := false
+	for _, post := range result.Posts {
+		if post != nil && post.UserID != "" && post.User == nil {
+			missingAuthor = true
+			break
+		}
+	}
+	if missingAuthor {
+		posts, total, loadErr := s.postRepo.List(page, pageSize, userID)
+		if loadErr != nil {
+			return nil, 0, loadErr
+		}
+		result = &PostListResult{Posts: posts, Total: total}
+		cache.SetWithJitter(s.cache, cacheKey, result, postListTTL, jitter)
+	}
+
+	return result.Posts, result.Total, nil
+}
+
+// GetLatestPosts 获取最新帖子（语义化别名）
+func (s *PostService) GetLatestPosts(ctx context.Context, page, pageSize int, userID string) ([]*model.Post, int64, error) {
+	return s.List(ctx, page, pageSize, userID)
+}
+
+// GetUserPosts 获取用户帖子
+func (s *PostService) GetUserPosts(ctx context.Context, userID string, page, pageSize int) ([]*model.Post, int64, error) {
+	return s.postRepo.GetUserPosts(userID, page, pageSize)
+}
+
+// Like 点赞
+func (s *PostService) Like(ctx context.Context, postID, userID string) error {
+	// 获取帖子信息用于发送通知
+	post, err := s.postRepo.GetByID(postID)
+	if err != nil {
+		return err
+	}
+
+	err = s.postRepo.Like(postID, userID)
+	if err != nil {
+		return err
+	}
+
+	// 失效帖子详情缓存
+	cache.InvalidatePostDetail(s.cache, postID)
+
+	// 发送点赞通知（不给自己发通知）
+	if s.systemMessageService != nil && post.UserID != userID {
+		go func() {
+			notifyErr := s.systemMessageService.SendLikeNotification(context.Background(), post.UserID, userID, postID)
+			if notifyErr != nil {
+				fmt.Printf("[DEBUG] Error sending like notification: %v\n", notifyErr)
+			} else {
+				fmt.Printf("[DEBUG] Like notification sent successfully\n")
+			}
+		}()
+	}
+
+	// 推送点赞行为到Gorse（异步）
+	go func() {
+		if s.gorseClient.IsEnabled() {
+			if err := s.gorseClient.InsertFeedback(context.Background(), gorse.FeedbackTypeLike, userID, postID); err != nil {
+				log.Printf("[WARN] Failed to insert like feedback to Gorse: %v", err)
+			}
+		}
+	}()
+
+	return nil
+}
+
+// Unlike 取消点赞
+func (s *PostService) Unlike(ctx context.Context, postID, userID string) error {
+	err := s.postRepo.Unlike(postID, userID)
+	if err != nil {
+		return err
+	}
+
+	// 失效帖子详情缓存
+	cache.InvalidatePostDetail(s.cache, postID)
+
+	// 删除Gorse中的点赞反馈（异步）
+	go func() {
+		if s.gorseClient.IsEnabled() {
+			if err := s.gorseClient.DeleteFeedback(context.Background(), gorse.FeedbackTypeLike, userID, postID); err != nil {
+				log.Printf("[WARN] Failed to delete like feedback from Gorse: %v", err)
+			}
+		}
+	}()
+
+	return nil
+}
+
+// IsLiked 检查是否点赞
+func (s *PostService) IsLiked(ctx context.Context, postID, userID string) bool {
+	return s.postRepo.IsLiked(postID, userID)
+}
+
+// Favorite 收藏
+func (s *PostService) Favorite(ctx context.Context, postID, userID string) error {
+	// 获取帖子信息用于发送通知
+	post, err := s.postRepo.GetByID(postID)
+	if err != nil {
+		return err
+	}
+
+	err = s.postRepo.Favorite(postID, userID)
+	if err != nil {
+		return err
+	}
+
+	// 失效帖子详情缓存
+	cache.InvalidatePostDetail(s.cache, postID)
+
+	// 发送收藏通知（不给自己发通知）
+	if s.systemMessageService != nil && post.UserID != userID {
+		go func() {
+			notifyErr := s.systemMessageService.SendFavoriteNotification(context.Background(), post.UserID, userID, postID)
+			if notifyErr != nil {
+				fmt.Printf("[DEBUG] Error sending favorite notification: %v\n", notifyErr)
+			} else {
+				fmt.Printf("[DEBUG] Favorite notification sent successfully\n")
+			}
+		}()
+	}
+
+	// 推送收藏行为到Gorse（异步）
+	go func() {
+		if s.gorseClient.IsEnabled() {
+			if err := s.gorseClient.InsertFeedback(context.Background(), gorse.FeedbackTypeStar, userID, postID); err != nil {
+				log.Printf("[WARN] Failed to insert favorite feedback to Gorse: %v", err)
+			}
+		}
+	}()
+
+	return nil
+}
+
+// Unfavorite 取消收藏
+func (s *PostService) Unfavorite(ctx context.Context, postID, userID string) error {
+	err := s.postRepo.Unfavorite(postID, userID)
+	if err != nil {
+		return err
+	}
+
+	// 失效帖子详情缓存
+	cache.InvalidatePostDetail(s.cache, postID)
+
+	// 删除Gorse中的收藏反馈（异步）
+	go func() {
+		if s.gorseClient.IsEnabled() {
+			if err := s.gorseClient.DeleteFeedback(context.Background(), gorse.FeedbackTypeStar, userID, postID); err != nil {
+				log.Printf("[WARN] Failed to delete favorite feedback from Gorse: %v", err)
+			}
+		}
+	}()
+
+	return nil
+}
+
+// IsFavorited 检查是否收藏
+func (s *PostService) IsFavorited(ctx context.Context, postID, userID string) bool {
+	return s.postRepo.IsFavorited(postID, userID)
+}
+
+// IncrementViews 增加帖子观看量并同步到Gorse
+func (s *PostService) IncrementViews(ctx context.Context, postID, userID string) error {
+	if err := s.postRepo.IncrementViews(postID); err != nil {
+		return err
+	}
+
+	// 同步浏览行为到Gorse（异步）
+	go func() {
+		if !s.gorseClient.IsEnabled() {
+			return
+		}
+
+		feedbackUserID := userID
+		if feedbackUserID == "" {
+			feedbackUserID = anonymousViewUserID
+		}
+
+		if err := s.gorseClient.InsertFeedback(context.Background(), gorse.FeedbackTypeRead, feedbackUserID, postID); err != nil {
+			log.Printf("[WARN] Failed to insert read feedback to Gorse: %v", err)
+		}
+	}()
+
+	return nil
+}
+
+// GetFavorites 获取收藏列表
+func (s *PostService) GetFavorites(ctx context.Context, userID string, page, pageSize int) ([]*model.Post, int64, error) {
+	return s.postRepo.GetFavorites(userID, page, pageSize)
+}
+
+// Search 搜索帖子
+func (s *PostService) Search(ctx context.Context, keyword string, page, pageSize int) ([]*model.Post, int64, error) {
+	return s.postRepo.Search(keyword, page, pageSize)
+}
+
+// GetFollowingPosts 获取关注用户的帖子（带缓存）
+func (s *PostService) GetFollowingPosts(ctx context.Context, userID string, page, pageSize int) ([]*model.Post, int64, error) {
+	cacheSettings := cache.GetSettings()
+	postListTTL := cacheSettings.PostListTTL
+	if postListTTL <= 0 {
+		postListTTL = PostListTTL
+	}
+	nullTTL := cacheSettings.NullTTL
+	if nullTTL <= 0 {
+		nullTTL = PostListNullTTL
+	}
+	jitter := cacheSettings.JitterRatio
+	if jitter <= 0 {
+		jitter = PostListJitterRatio
+	}
+
+	// 生成缓存键
+	cacheKey := cache.PostListKey("follow", userID, page, pageSize)
+
+	result, err := cache.GetOrLoadTyped[*PostListResult](
+		s.cache,
+		cacheKey,
+		postListTTL,
+		jitter,
+		nullTTL,
+		func() (*PostListResult, error) {
+			posts, total, err := s.postRepo.GetFollowingPosts(userID, page, pageSize)
+			if err != nil {
+				return nil, err
+			}
+			return &PostListResult{Posts: posts, Total: total}, nil
+		},
+	)
+	if err != nil {
+		return nil, 0, err
+	}
+	if result == nil {
+		return []*model.Post{}, 0, nil
+	}
+	return result.Posts, result.Total, nil
+}
+
+// GetHotPosts 获取热门帖子（使用Gorse非个性化推荐）
+func (s *PostService) GetHotPosts(ctx context.Context, page, pageSize int) ([]*model.Post, int64, error) {
+	// 如果Gorse启用，使用自定义的非个性化推荐器
+	if s.gorseClient.IsEnabled() {
+		offset := (page - 1) * pageSize
+		// 使用 most_liked_weekly 推荐器获取周热门
+		// 多取1条用于判断是否还有下一页
+		itemIDs, err := s.gorseClient.GetNonPersonalized(ctx, "most_liked_weekly", pageSize+1, offset, "")
+		if err != nil {
+			log.Printf("[WARN] Gorse GetNonPersonalized failed: %v, fallback to database", err)
+			return s.getHotPostsFromDB(ctx, page, pageSize)
+		}
+		if len(itemIDs) > 0 {
+			hasNext := len(itemIDs) > pageSize
+			if hasNext {
+				itemIDs = itemIDs[:pageSize]
+			}
+			posts, err := s.postRepo.GetByIDs(itemIDs)
+			if err != nil {
+				return nil, 0, err
+			}
+			// 近似 total：当 hasNext 为 true 时，按分页窗口估算，避免因脏数据/缺失数据导致总页数被低估
+			estimatedTotal := int64(offset + len(posts))
+			if hasNext {
+				estimatedTotal = int64(offset + pageSize + 1)
+			}
+			return posts, estimatedTotal, nil
+		}
+	}
+
+	// 降级：从数据库获取
+	return s.getHotPostsFromDB(ctx, page, pageSize)
+}
+
+// getHotPostsFromDB 从数据库获取热门帖子（降级路径）
+func (s *PostService) getHotPostsFromDB(ctx context.Context, page, pageSize int) ([]*model.Post, int64, error) {
+	// 直接查询数据库，不再使用本地缓存（Gorse失败降级时使用）
+	posts, total, err := s.postRepo.GetHotPosts(page, pageSize)
+	if err != nil {
+		return nil, 0, err
+	}
+	return posts, total, nil
+}
+
+// GetRecommendedPosts 获取推荐帖子
+func (s *PostService) GetRecommendedPosts(ctx context.Context, userID string, page, pageSize int) ([]*model.Post, int64, error) {
+	// 如果Gorse未启用或用户未登录，降级为热门帖子
+	if !s.gorseClient.IsEnabled() || userID == "" {
+		return s.GetHotPosts(ctx, page, pageSize)
+	}
+
+	// 计算偏移量
+	offset := (page - 1) * pageSize
+
+	// 从Gorse获取推荐列表
+	// 多取1条用于判断是否还有下一页
+	itemIDs, err := s.gorseClient.GetRecommend(ctx, userID, pageSize+1, offset)
+	if err != nil {
+		log.Printf("[WARN] Gorse recommendation failed: %v, fallback to hot posts", err)
+		return s.GetHotPosts(ctx, page, pageSize)
+	}
+
+	// 如果没有推荐结果，降级为热门帖子
+	if len(itemIDs) == 0 {
+		return s.GetHotPosts(ctx, page, pageSize)
+	}
+
+	hasNext := len(itemIDs) > pageSize
+	if hasNext {
+		itemIDs = itemIDs[:pageSize]
+	}
+
+	// 根据ID列表查询帖子详情
+	posts, err := s.postRepo.GetByIDs(itemIDs)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// 近似 total：当 hasNext 为 true 时，按分页窗口估算，避免因脏数据/缺失数据导致总页数被低估
+	estimatedTotal := int64(offset + len(posts))
+	if hasNext {
+		estimatedTotal = int64(offset + pageSize + 1)
+	}
+	return posts, estimatedTotal, nil
+}
+
+// buildPostCategories 构建帖子的类别标签
+func (s *PostService) buildPostCategories(post *model.Post) []string {
+	var categories []string
+
+	// 热度标签
+	if post.ViewsCount > 1000 {
+		categories = append(categories, "hot_high")
+	} else if post.ViewsCount > 100 {
+		categories = append(categories, "hot_medium")
+	}
+
+	// 点赞标签
+	if post.LikesCount > 100 {
+		categories = append(categories, "likes_100+")
+	} else if post.LikesCount > 50 {
+		categories = append(categories, "likes_50+")
+	} else if post.LikesCount > 10 {
+		categories = append(categories, "likes_10+")
+	}
+
+	// 评论标签
+	if post.CommentsCount > 50 {
+		categories = append(categories, "comments_50+")
+	} else if post.CommentsCount > 10 {
+		categories = append(categories, "comments_10+")
+	}
+
+	// 时间标签
+	age := time.Since(post.CreatedAt)
+	if age < 24*time.Hour {
+		categories = append(categories, "today")
+	} else if age < 7*24*time.Hour {
+		categories = append(categories, "this_week")
+	} else if age < 30*24*time.Hour {
+		categories = append(categories, "this_month")
+	}
+
+	return categories
+}