refactor: remove Gorse integration and implement HotRank feature

- Removed Gorse-related configurations, handlers, and dependencies from the codebase.
- Introduced HotRank feature with configuration options for ranking posts based on recent activity.
- Updated application structure to support HotRank processing, including new caching mechanisms and database interactions.
- Cleaned up related DTOs and repository methods to reflect the removal of Gorse and the addition of HotRank functionality.

internal/repository/comment_repo.go

@@ -72,7 +72,6 @@ func (r *CommentRepository) Delete(id string) error {
 			if err := tx.Model(&model.Post{}).Where("id = ?", comment.PostID).
 				UpdateColumns(map[string]interface{}{
 					"comments_count": gorm.Expr("comments_count - 1"),
-					"hot_score":      gorm.Expr("likes_count * 2 + (comments_count - 1) * 3 + views_count * 0.1"),
 					"updated_at":     gorm.Expr("updated_at"),
 				}).Error; err != nil {
 				return err
@@ -102,7 +101,6 @@ func (r *CommentRepository) ApplyPublishedStats(comment *model.Comment) error {
 		if err := tx.Model(&model.Post{}).Where("id = ?", comment.PostID).
 			UpdateColumns(map[string]any{
 				"comments_count": gorm.Expr("comments_count + 1"),
-				"hot_score":      gorm.Expr("likes_count * 2 + (comments_count + 1) * 3 + views_count * 0.1"),
 				"updated_at":     gorm.Expr("updated_at"),
 			}).Error; err != nil {
 			return err

internal/repository/post_repo.go

@@ -1,12 +1,13 @@
 package repository
 
 import (
-	"carrot_bbs/internal/model"
-	"carrot_bbs/internal/pkg/cursor"
 	"context"
 	"strings"
 	"time"
 
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/pkg/cursor"
+
 	"gorm.io/gorm"
 )
 
@@ -258,12 +259,10 @@ func (r *PostRepository) Like(postID, userID string) error {
 			return err
 		}
 
-		// 增加帖子点赞数并同步热度分
-		// 点赞属于统计字段更新，不应影响帖子内容更新时间（updated_at）
+		// 增加帖子点赞数（热门排序由定时任务写 Redis ZSET / top_ids，不写库）
 		return tx.Model(&model.Post{}).Where("id = ?", postID).
 			UpdateColumns(map[string]any{
 				"likes_count": gorm.Expr("likes_count + 1"),
-				"hot_score":   gorm.Expr("(likes_count + 1) * 2 + comments_count * 3 + views_count * 0.1"),
 				"updated_at":  gorm.Expr("updated_at"),
 			}).Error
 	})
@@ -277,12 +276,9 @@ func (r *PostRepository) Unlike(postID, userID string) error {
 			return result.Error
 		}
 		if result.RowsAffected > 0 {
-			// 减少帖子点赞数并同步热度分
-			// 取消点赞属于统计字段更新，不应影响帖子内容更新时间（updated_at）
 			return tx.Model(&model.Post{}).Where("id = ?", postID).
 				UpdateColumns(map[string]any{
 					"likes_count": gorm.Expr("likes_count - 1"),
-					"hot_score":   gorm.Expr("(likes_count - 1) * 2 + comments_count * 3 + views_count * 0.1"),
 					"updated_at":  gorm.Expr("updated_at"),
 				}).Error
 		}
@@ -350,7 +346,7 @@ func (r *PostRepository) Favorite(postID, userID string) error {
 		return tx.Model(&model.Post{}).Where("id = ?", postID).
 			UpdateColumns(map[string]any{
 				"favorites_count": gorm.Expr("favorites_count + 1"),
-				"updated_at":    gorm.Expr("updated_at"),
+				"updated_at":      gorm.Expr("updated_at"),
 			}).Error
 	})
 }
@@ -367,7 +363,7 @@ func (r *PostRepository) Unfavorite(postID, userID string) error {
 			return tx.Model(&model.Post{}).Where("id = ?", postID).
 				UpdateColumns(map[string]any{
 					"favorites_count": gorm.Expr("favorites_count - 1"),
-					"updated_at":    gorm.Expr("updated_at"),
+					"updated_at":      gorm.Expr("updated_at"),
 				}).Error
 		}
 		return nil
@@ -411,10 +407,8 @@ func (r *PostRepository) IsFavoritedBatch(postIDs []string, userID string) map[s
 // IncrementViews 增加帖子观看量
 func (r *PostRepository) IncrementViews(postID string) error {
 	return r.db.Model(&model.Post{}).Where("id = ?", postID).
-		// 浏览量属于统计字段，不应影响帖子内容更新时间（updated_at）
 		UpdateColumns(map[string]interface{}{
 			"views_count": gorm.Expr("views_count + 1"),
-			"hot_score":   gorm.Expr("likes_count * 2 + comments_count * 3 + (views_count + 1) * 0.1"),
 			"updated_at":  gorm.Expr("updated_at"),
 		}).Error
 }
@@ -469,7 +463,7 @@ func (r *PostRepository) GetFollowingPosts(userID string, page, pageSize int) ([
 	return posts, total, err
 }
 
-// GetHotPosts 获取热门帖子（按点赞数和评论数排序）
+// GetHotPosts 热门榜降级：Redis 未就绪时按最新发布排序
 func (r *PostRepository) GetHotPosts(page, pageSize int) ([]*model.Post, int64, error) {
 	var posts []*model.Post
 	var total int64
@@ -477,15 +471,101 @@ func (r *PostRepository) GetHotPosts(page, pageSize int) ([]*model.Post, int64,
 	r.db.Model(&model.Post{}).Where("status = ?", model.PostStatusPublished).Count(&total)
 
 	offset := (page - 1) * pageSize
-	// 热门排序使用预计算热度分，避免每次请求进行表达式排序计算
 	err := r.db.Where("status = ?", model.PostStatusPublished).Preload("User").Preload("Images").
 		Offset(offset).Limit(pageSize).
-		Order("hot_score DESC, created_at DESC").
+		Order("created_at DESC").
 		Find(&posts).Error
 
 	return posts, total, err
 }
 
+// PostHotSnapshot 热门重算用字段
+type PostHotSnapshot struct {
+	ID             string    `gorm:"column:id"`
+	LikesCount     int       `gorm:"column:likes_count"`
+	CommentsCount  int       `gorm:"column:comments_count"`
+	FavoritesCount int       `gorm:"column:favorites_count"`
+	SharesCount    int       `gorm:"column:shares_count"`
+	ViewsCount     int       `gorm:"column:views_count"`
+	CreatedAt      time.Time `gorm:"column:created_at"`
+}
+
+// ListPublishedPostIDsSince 按发布时间倒序取 ID（热门候选池，避免全表扫快照）
+func (r *PostRepository) ListPublishedPostIDsSince(since time.Time, limit int) ([]string, error) {
+	if limit <= 0 {
+		return nil, nil
+	}
+	type row struct {
+		ID string `gorm:"column:id"`
+	}
+	var rows []row
+	err := r.db.Model(&model.Post{}).
+		Select("id").
+		Where("status = ? AND created_at >= ?", model.PostStatusPublished, since).
+		Order("created_at DESC").
+		Limit(limit).
+		Find(&rows).Error
+	if err != nil {
+		return nil, err
+	}
+	out := make([]string, 0, len(rows))
+	for _, x := range rows {
+		if x.ID != "" {
+			out = append(out, x.ID)
+		}
+	}
+	return out, nil
+}
+
+// ListPinnedPublishedPostIDs 已发布且置顶的帖子 ID（越新发布的置顶越靠前）
+func (r *PostRepository) ListPinnedPublishedPostIDs() ([]string, error) {
+	type row struct {
+		ID string `gorm:"column:id"`
+	}
+	var rows []row
+	err := r.db.Model(&model.Post{}).
+		Select("id").
+		Where("status = ? AND is_pinned = ?", model.PostStatusPublished, true).
+		Order("created_at DESC").
+		Find(&rows).Error
+	if err != nil {
+		return nil, err
+	}
+	out := make([]string, 0, len(rows))
+	for _, x := range rows {
+		if x.ID != "" {
+			out = append(out, x.ID)
+		}
+	}
+	return out, nil
+}
+
+// GetPostHotSnapshotsByIDs 仅拉取候选 ID 对应的热度字段（分批 IN 查询）
+func (r *PostRepository) GetPostHotSnapshotsByIDs(ids []string) ([]PostHotSnapshot, error) {
+	if len(ids) == 0 {
+		return nil, nil
+	}
+	const chunkSize = 400
+	var all []PostHotSnapshot
+	for i := 0; i < len(ids); i += chunkSize {
+		end := i + chunkSize
+		if end > len(ids) {
+			end = len(ids)
+		}
+		batch := ids[i:end]
+		var rows []PostHotSnapshot
+		err := r.db.Model(&model.Post{}).
+			Select("id", "likes_count", "comments_count", "favorites_count", "shares_count", "views_count", "created_at").
+			Where("status = ? AND id IN ?", model.PostStatusPublished, batch).
+			Find(&rows).Error
+		if err != nil {
+			return nil, err
+		}
+		all = append(all, rows...)
+	}
+	return all, nil
+}
+
 // GetByIDs 根据ID列表获取帖子（保持传入顺序）
 func (r *PostRepository) GetByIDs(ids []string) ([]*model.Post, error) {
 	if len(ids) == 0 {
@@ -995,9 +1075,9 @@ func (r *PostRepository) GetFollowingPostsByCursor(ctx context.Context, userID s
 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
+	// 热门游标降级：与 GetHotPosts 一致，按最新发布排序
 	query := db.Model(&model.Post{}).Where("status = ?", model.PostStatusPublished).
-		Order("hot_score DESC, created_at DESC")
+		Order("created_at DESC")
 
 	// 使用游标构建器
 	builder := cursor.NewBuilder(query, cursor.SortByCreatedAtDesc).