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feat(api): add tab-based post feed endpoints with cursor pagination
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Add support for different post feed types via tab parameter:
- follow: posts from followed users (requires authentication)
- hot: trending posts using Gorse most_liked_weekly or database fallback
- recommend: personalized recommendations with random offset for diversity
- latest: default chronological feed

The cursor pagination detection is also improved to check for parameter
existence rather than non-empty string value.
This commit is contained in:
lafay
2026-03-21 02:24:11 +08:00
parent 57058b04da
commit 687ac92aea
3 changed files with 267 additions and 4 deletions
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34
internal/handler/post_handler.go
View File

@@ -147,8 +147,9 @@ func (h *PostHandler) RecordView(c *gin.Context) {
// List 获取帖子列表（支持游标分页和偏移分页）
func (h *PostHandler) List(c *gin.Context) {
// 检查是否使用游标分页
cursorStr := c.Query("cursor")
if cursorStr != "" {
// 当 cursor 参数存在时（包括空字符串），使用游标分页
_, cursorExists := c.GetQuery("cursor")
if cursorExists {
h.ListByCursor(c)
return
}
@@ -220,6 +221,7 @@ func (h *PostHandler) List(c *gin.Context) {
func (h *PostHandler) ListByCursor(c *gin.Context) {
userID := c.Query("user_id")
currentUserID := c.GetString("user_id")
tab := c.Query("tab")
// 解析游标分页请求
req := h.parseCursorRequest(c)
@@ -227,8 +229,32 @@ func (h *PostHandler) ListByCursor(c *gin.Context) {
// 判断是否包含待审核帖子
includePending := userID != "" && userID == currentUserID
// 调用游标分页服务
result, err := h.postService.ListByCursor(c.Request.Context(), userID, includePending, req)
var result *cursor.CursorPageResult[*model.Post]
var err error
// 根据 tab 参数选择不同的获取方式
switch tab {
case "follow":
// 获取关注用户的帖子，需要登录
if currentUserID == "" {
response.Unauthorized(c, "请先登录")
return
}
result, err = h.postService.GetFollowingPostsByCursor(c.Request.Context(), currentUserID, req)
case "hot":
// 获取热门帖子
result, err = h.postService.GetHotPostsByCursor(c.Request.Context(), req)
case "recommend":
// 推荐帖子（从Gorse获取个性化推荐）
result, err = h.postService.GetRecommendedPostsByCursor(c.Request.Context(), currentUserID, req)
case "latest":
// 最新帖子
result, err = h.postService.ListByCursor(c.Request.Context(), userID, includePending, req)
default:
// 默认获取最新帖子
result, err = h.postService.ListByCursor(c.Request.Context(), userID, includePending, req)
}
if err != nil {
response.InternalServerError(c, "failed to get posts")
return

110
internal/repository/post_repo.go
View File

@@ -906,3 +906,113 @@ func (r *PostRepository) GetUserPostsByCursor(ctx context.Context, userID string
return cursor.NewCursorPageResult(posts, nextCursor, prevCursor, hasMore), nil
}
// GetFollowingPostsByCursor 游标分页获取关注用户的帖子
func (r *PostRepository) GetFollowingPostsByCursor(ctx context.Context, userID string, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error) {
db := r.getDB(ctx).WithContext(ctx)
// 子查询：获取当前用户关注的所有用户ID
subQuery := db.Model(&model.Follow{}).Where("follower_id = ?", userID).Select("following_id")
// 构建基础查询
query := db.Model(&model.Post{}).Where("user_id IN (?) AND status = ?", subQuery, model.PostStatusPublished)
// 使用游标构建器
builder := cursor.NewBuilder(query, cursor.SortByCreatedAtDesc).
WithCursor(req.Cursor, req.Direction).
WithPageSize(req.PageSize)
if builder.Error() != nil {
// 无效游标，返回空列表
return cursor.NewCursorPageResult[*model.Post]([]*model.Post{}, "", "", false), nil
}
// 执行查询
var posts []*model.Post
query = builder.Build().Preload("User").Preload("Images")
if err := query.Find(&posts).Error; err != nil {
return nil, err
}
// 构建响应
pageSize := builder.GetPageSize()
hasMore := cursor.HasMore(len(posts), pageSize)
if hasMore {
posts = posts[:pageSize]
}
// 生成游标
var nextCursor, prevCursor string
if len(posts) > 0 {
if hasMore {
lastPost := posts[len(posts)-1]
nextCursor = cursor.NewCursor(
cursor.FormatTime(lastPost.CreatedAt),
lastPost.ID,
cursor.SortByCreatedAtDesc,
).Encode()
}
firstPost := posts[0]
prevCursor = cursor.NewCursor(
cursor.FormatTime(firstPost.CreatedAt),
firstPost.ID,
cursor.SortByCreatedAtDesc,
).Encode()
}
return cursor.NewCursorPageResult(posts, nextCursor, prevCursor, hasMore), nil
}
// GetHotPostsByCursor 游标分页获取热门帖子
func (r *PostRepository) GetHotPostsByCursor(ctx context.Context, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error) {
db := r.getDB(ctx).WithContext(ctx)
// 构建基础查询 - 热门帖子按热度分数排序
query := db.Model(&model.Post{}).Where("status = ?", model.PostStatusPublished).
Order("hot_score DESC, created_at DESC")
// 使用游标构建器
builder := cursor.NewBuilder(query, cursor.SortByCreatedAtDesc).
WithCursor(req.Cursor, req.Direction).
WithPageSize(req.PageSize)
if builder.Error() != nil {
// 无效游标，返回空列表
return cursor.NewCursorPageResult[*model.Post]([]*model.Post{}, "", "", false), nil
}
// 执行查询
var posts []*model.Post
query = builder.Build().Preload("User").Preload("Images")
if err := query.Find(&posts).Error; err != nil {
return nil, err
}
// 构建响应
pageSize := builder.GetPageSize()
hasMore := cursor.HasMore(len(posts), pageSize)
if hasMore {
posts = posts[:pageSize]
}
// 生成游标
var nextCursor, prevCursor string
if len(posts) > 0 {
if hasMore {
lastPost := posts[len(posts)-1]
nextCursor = cursor.NewCursor(
cursor.FormatTime(lastPost.CreatedAt),
lastPost.ID,
cursor.SortByCreatedAtDesc,
).Encode()
}
firstPost := posts[0]
prevCursor = cursor.NewCursor(
cursor.FormatTime(firstPost.CreatedAt),
firstPost.ID,
cursor.SortByCreatedAtDesc,
).Encode()
}
return cursor.NewCursorPageResult(posts, nextCursor, prevCursor, hasMore), nil
}

127
internal/service/post_service.go
View File

@@ -5,6 +5,7 @@ import (
"fmt"
"log"
"math/rand"
"strconv"
"strings"
"time"
@@ -45,6 +46,9 @@ type PostService interface {
ListByCursor(ctx context.Context, userID string, includePending bool, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error)
SearchByCursor(ctx context.Context, keyword string, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error)
GetUserPostsByCursor(ctx context.Context, userID string, includePending bool, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error)
GetFollowingPostsByCursor(ctx context.Context, userID string, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error)
GetHotPostsByCursor(ctx context.Context, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error)
GetRecommendedPostsByCursor(ctx context.Context, userID string, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error)
// 关注和推荐
GetFollowingPosts(ctx context.Context, userID string, page, pageSize int) ([]*model.Post, int64, error)
@@ -792,3 +796,126 @@ func (s *postServiceImpl) GetUserPostsByCursor(ctx context.Context, userID strin
return s.postRepo.GetUserPostsByCursor(ctx, userID, includePending, req)
}
// GetFollowingPostsByCursor 游标分页获取关注用户的帖子
func (s *postServiceImpl) GetFollowingPostsByCursor(ctx context.Context, userID string, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error) {
// 规范化请求参数
req.Normalize()
return s.postRepo.GetFollowingPostsByCursor(ctx, userID, req)
}
// GetHotPostsByCursor 游标分页获取热门帖子
func (s *postServiceImpl) GetHotPostsByCursor(ctx context.Context, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error) {
// 规范化请求参数
req.Normalize()
// 如果Gorse启用，使用自定义的非个性化推荐器
if s.gorseClient.IsEnabled() {
// 计算偏移量
offset := 0
if req.Cursor != "" {
// 尝试解析游标作为偏移量
if parsed, err := strconv.Atoi(req.Cursor); err == nil {
offset = parsed
}
}
// 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", req.PageSize+1, offset, "")
if err != nil {
log.Printf("[WARN] Gorse GetNonPersonalized failed: %v, fallback to database", err)
return s.getHotPostsByCursorFromDB(ctx, req)
}
if len(itemIDs) > 0 {
hasMore := len(itemIDs) > req.PageSize
if hasMore {
itemIDs = itemIDs[:req.PageSize]
}
posts, err := s.postRepo.GetByIDs(itemIDs)
if err != nil {
return nil, err
}
// 下一页的游标是当前偏移量 + 已获取数量
nextCursor := ""
if hasMore {
nextCursor = strconv.Itoa(offset + req.PageSize)
}
return &cursor.CursorPageResult[*model.Post]{
Items: posts,
NextCursor: nextCursor,
PrevCursor: "",
HasMore: hasMore,
}, nil
}
}
// 降级：从数据库获取
return s.getHotPostsByCursorFromDB(ctx, req)
}
// getHotPostsByCursorFromDB 从数据库游标分页获取热门帖子（降级路径）
func (s *postServiceImpl) getHotPostsByCursorFromDB(ctx context.Context, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error) {
return s.postRepo.GetHotPostsByCursor(ctx, req)
}
// GetRecommendedPostsByCursor 游标分页获取推荐帖子
func (s *postServiceImpl) GetRecommendedPostsByCursor(ctx context.Context, userID string, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Post], error) {
// 规范化请求参数
req.Normalize()
// 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.GetHotPostsByCursor(ctx, req)
}
// 计算偏移量：第一页使用随机偏移量，增加推荐多样性
var offset int
if req.Cursor == "" {
// 第一页随机偏移 0-50，让每次刷新看到不同的推荐内容
offset = rand.Intn(51)
} else {
// 尝试解析游标作为偏移量
if parsed, err := strconv.Atoi(req.Cursor); err == nil {
offset = parsed
}
}
// 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, req.PageSize+1, offset)
if err != nil {
log.Printf("[WARN] Gorse recommendation failed: %v, fallback to hot posts", err)
return s.GetHotPostsByCursor(ctx, req)
}
// 如果没有推荐结果，降级为热门帖子
if len(itemIDs) == 0 {
return s.GetHotPostsByCursor(ctx, req)
}
hasMore := len(itemIDs) > req.PageSize
if hasMore {
itemIDs = itemIDs[:req.PageSize]
}
// 根据ID列表查询帖子详情
posts, err := s.postRepo.GetByIDs(itemIDs)
if err != nil {
return nil, err
}
// 下一页的游标是当前偏移量 + 已获取数量
nextCursor := ""
if hasMore {
nextCursor = strconv.Itoa(offset + req.PageSize)
}
return &cursor.CursorPageResult[*model.Post]{
Items: posts,
NextCursor: nextCursor,
PrevCursor: "",
HasMore: hasMore,
}, nil
}