feat: GetTrends 趋势查询并行化 (errgroup)

- 使用 golang.org/x/sync/errgroup 将 4 个独立 DB 查询并行执行
- Energy/Comments/Likes/Favorites 趋势查询不再串行阻塞
- golang.org/x/sync 由 indirect 改为 direct 依赖

internal/service/trends_service.go

@@ -1,6 +1,10 @@
 package service
 
-import "fmt"
+import (
+	"fmt"
+
+	"golang.org/x/sync/errgroup"
+)
 
 // TrendResult 趋势返回结构
 type TrendResult struct {
@@ -12,10 +16,10 @@ type TrendResult struct {
 
 // TrendsService Studio 趋势分析服务
 type TrendsService struct {
-	energyRepo    EnergyTrendStore
-	commentRepo   CommentTrendStore
-	likeRepo      LikeTrendStore
-	favoriteRepo  FavoriteTrendStore
+	energyRepo   EnergyTrendStore
+	commentRepo  CommentTrendStore
+	likeRepo     LikeTrendStore
+	favoriteRepo FavoriteTrendStore
 }
 
 // NewTrendsService 构造函数
@@ -28,32 +32,50 @@ func NewTrendsService(energyRepo EnergyTrendStore, commentRepo CommentTrendStore
 	}
 }
 
-// GetTrends 获取指定时间范围的趋势数据
+// GetTrends 获取指定时间范围的趋势数据（并行查询四项趋势）
 func (s *TrendsService) GetTrends(userID uint, since string) (*TrendResult, error) {
-	energy, err := s.energyRepo.AggregateEnergyByAuthor(userID, since)
-	if err != nil {
-		return nil, fmt.Errorf("查询赋能趋势: %w", err)
+	result := &TrendResult{}
+	g := new(errgroup.Group)
+
+	g.Go(func() error {
+		var err error
+		result.Energy, err = s.energyRepo.AggregateEnergyByAuthor(userID, since)
+		if err != nil {
+			return fmt.Errorf("查询赋能趋势: %w", err)
+		}
+		return nil
+	})
+
+	g.Go(func() error {
+		var err error
+		result.Comments, err = s.commentRepo.AggregateCommentsByAuthor(userID, since)
+		if err != nil {
+			return fmt.Errorf("查询评论趋势: %w", err)
+		}
+		return nil
+	})
+
+	g.Go(func() error {
+		var err error
+		result.Likes, err = s.likeRepo.AggregateLikesByAuthor(userID, since)
+		if err != nil {
+			return fmt.Errorf("查询点赞趋势: %w", err)
+		}
+		return nil
+	})
+
+	g.Go(func() error {
+		var err error
+		result.Favorites, err = s.favoriteRepo.AggregateFavoritesByAuthor(userID, since)
+		if err != nil {
+			return fmt.Errorf("查询收藏趋势: %w", err)
+		}
+		return nil
+	})
+
+	if err := g.Wait(); err != nil {
+		return nil, err
 	}
 
-	comments, err := s.commentRepo.AggregateCommentsByAuthor(userID, since)
-	if err != nil {
-		return nil, fmt.Errorf("查询评论趋势: %w", err)
-	}
-
-	likes, err := s.likeRepo.AggregateLikesByAuthor(userID, since)
-	if err != nil {
-		return nil, fmt.Errorf("查询点赞趋势: %w", err)
-	}
-
-	favorites, err := s.favoriteRepo.AggregateFavoritesByAuthor(userID, since)
-	if err != nil {
-		return nil, fmt.Errorf("查询收藏趋势: %w", err)
-	}
-
-	return &TrendResult{
-		Energy:    energy,
-		Comments:  comments,
-		Likes:     likes,
-		Favorites: favorites,
-	}, nil
+	return result, nil
 }