feat(feed): add ListLatest

internal/feed/repo.go

@@ -0,0 +1,30 @@
+package feed
+
+import (
+	"context"
+	"feedsystem_video_go/internal/video" // 引入视频实体
+	"time"
+
+	"gorm.io/gorm"
+)
+
+type FeedRepository struct {
+	db *gorm.DB
+}
+
+func NewFeedRepository(db *gorm.DB) *FeedRepository {
+	return &FeedRepository{db: db}
+}
+
+func (repo *FeedRepository) ListLatest(ctx context.Context, limit int, latestBefore time.Time) ([]video.Video, error) {
+	var videos []video.Video
+	query := repo.db.WithContext(ctx).Model(&video.Video{}).
+		Order("create_time DESC")
+	if !latestBefore.IsZero() {
+		query = query.Where("create_time < ?", latestBefore)
+	}
+	if err := query.Limit(limit).Find(&videos).Error; err != nil {
+		return nil, err
+	}
+	return videos, nil
+}

internal/feed/service.go

@@ -0,0 +1,41 @@
+package feed
+
+import (
+	"context"
+	"feedsystem_video_go/internal/video"
+	"time"
+)
+
+type FeedService struct {
+	repo *FeedRepository
+}
+
+type FeedResponse struct {
+	VideoList []video.Video `json:"video_list"`
+	NextTime  time.Time     `json:"next_time"`
+	HasMore   bool          `json:"has_more"`
+}
+
+func NewFeedService(repo *FeedRepository) *FeedService {
+	return &FeedService{repo: repo}
+}
+
+func (f *FeedService) ListLatest(ctx context.Context, limit int, latestBefore time.Time) (FeedResponse, error) {
+	videos, err := f.repo.ListLatest(ctx, limit, latestBefore)
+	if err != nil {
+		return FeedResponse{}, err
+	}
+	var nextTime time.Time
+	if len(videos) > 0 {
+		nextTime = videos[len(videos)-1].CreateTime
+	} else {
+		nextTime = time.Time{}
+	}
+	hasMore := len(videos) == limit
+	resp := FeedResponse{
+		VideoList: videos,
+		NextTime:  nextTime,
+		HasMore:   hasMore,
+	}
+	return resp, nil
+}