update

internal/service/street_snap_service.go

@@ -0,0 +1,134 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"net/http"
+
+	"fashionapi/internal/dto"
+	"fashionapi/internal/model"
+	"fashionapi/internal/pkg/hashid"
+	"fashionapi/internal/repository"
+)
+
+// StreetSnapService 街拍业务接口。
+type StreetSnapService interface {
+	List(ctx context.Context, q dto.StreetSnapQuery) ([]dto.PublicStreetSnap, int64, error)
+	Detail(ctx context.Context, id string) (*dto.PublicStreetSnapDetail, error)
+	// Popular 返回热度前 N 个街拍（按图片数降序），供 SSG 首页热门街拍展示。
+	Popular(ctx context.Context, limit int) ([]dto.PublicStreetSnap, error)
+}
+
+type streetSnapService struct {
+	repo repository.StreetSnapRepository
+}
+
+// NewStreetSnapService 创建街拍服务。
+func NewStreetSnapService(repo repository.StreetSnapRepository) StreetSnapService {
+	return &streetSnapService{repo: repo}
+}
+
+// ErrStreetSnapNotFound 街拍不存在。
+var ErrStreetSnapNotFound = NewError(http.StatusNotFound, "street snap not found")
+
+// List 查询街拍列表，并按需附带每条的前 N 张图。
+func (s *streetSnapService) List(ctx context.Context, q dto.StreetSnapQuery) ([]dto.PublicStreetSnap, int64, error) {
+	q.Normalize()
+
+	rows, total, err := s.repo.List(ctx, q)
+	if err != nil {
+		return nil, 0, internalErr(err.Error())
+	}
+
+	list := make([]dto.PublicStreetSnap, 0, len(rows))
+	ids := make([]uint32, 0, len(rows))
+	for _, r := range rows {
+		ids = append(ids, r.ID)
+		list = append(list, dto.PublicStreetSnap{
+			UID:        hashid.Encode(r.ID),
+			Title:      r.Title,
+			Cover:      r.Cover,
+			ImageCount: r.ImageCount,
+		})
+	}
+
+	if q.Images > 0 && len(list) > 0 {
+		if err := s.attachImages(ctx, list, ids, q.Images); err != nil {
+			return nil, 0, internalErr(err.Error())
+		}
+	}
+	return list, total, nil
+}
+
+// attachImages 用单次 IN 查询为列表批量补齐图片，避免前端逐条请求详情。
+func (s *streetSnapService) attachImages(ctx context.Context, list []dto.PublicStreetSnap, ids []uint32, limit int) error {
+	grouped, err := s.repo.ImagesBySnapIDs(ctx, ids)
+	if err != nil {
+		return err
+	}
+	for i := range list {
+		imgs, ok := grouped[ids[i]]
+		if !ok {
+			continue
+		}
+		if len(imgs) > limit {
+			imgs = imgs[:limit]
+		}
+		list[i].Images = toPublicSnapImages(imgs)
+	}
+	return nil
+}
+
+// Detail 查询街拍详情，含完整图片集。
+func (s *streetSnapService) Detail(ctx context.Context, id string) (*dto.PublicStreetSnapDetail, error) {
+	snap, err := s.repo.FindByID(ctx, id)
+	if err != nil {
+		if errors.Is(err, repository.ErrNotFound) {
+			return nil, ErrStreetSnapNotFound
+		}
+		return nil, internalErr(err.Error())
+	}
+
+	imgs, err := s.repo.ListImages(ctx, id)
+	if err != nil {
+		return nil, internalErr(err.Error())
+	}
+
+	return &dto.PublicStreetSnapDetail{
+		UID:    hashid.Encode(snap.ID),
+		Title:  snap.Title,
+		Cover:  snap.Cover,
+		Images: toPublicSnapImages(imgs),
+	}, nil
+}
+
+// IDs 返回全部街拍的编码 uid（供 SSG 枚举详情页路径使用，对外暴露的即编码串）。
+// Popular 返回热度前 N 个街拍（按图片数降序），供 SSG 首页热门街拍展示。
+func (s *streetSnapService) Popular(ctx context.Context, limit int) ([]dto.PublicStreetSnap, error) {
+	rows, err := s.repo.Popular(ctx, limit)
+	if err != nil {
+		return nil, internalErr(err.Error())
+	}
+	list := make([]dto.PublicStreetSnap, 0, len(rows))
+	for _, r := range rows {
+		list = append(list, dto.PublicStreetSnap{
+			UID:        hashid.Encode(r.ID),
+			Title:      r.Title,
+			Cover:      r.Cover,
+			ImageCount: r.ImageCount,
+		})
+	}
+	return list, nil
+}
+
+// toPublicSnapImages 把图片实体映射为对外结构（只保留 url 与名称）。
+func toPublicSnapImages(imgs []model.StreetSnapImage) []dto.PublicArticleImage {
+	if len(imgs) == 0 {
+		return nil
+	}
+	out := make([]dto.PublicArticleImage, 0, len(imgs))
+	for _, im := range imgs {
+		out = append(out, dto.PublicArticleImage{Image: im.Image, Name: im.Name})
+	}
+	return out
+}