fix: reduce duplicate home recommendations

backend/internal/api/api.go

@@ -156,41 +156,60 @@ func (s *Server) handleGetTheme(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) handleHome(w http.ResponseWriter, r *http.Request) {
-	// 首页优先展示封面已经生成好的视频，避免新盘扫盘时大量黑封面占满首页。
-	// 候选仍按发布时间覆盖最近 200 个，随后随机洗牌；封面不足时再用普通可见视频补齐。
-	const candidatePool = 200
-	readyItems, _, err := s.Catalog.ListVideos(r.Context(), catalog.ListParams{
-		Sort: "latest", Page: 1, PageSize: candidatePool, ThumbnailReadyOnly: true,
-	})
+	// 首页优先从全量已有封面的视频里随机抽取，避免只在最近一小段候选中反复出现。
+	excludeIDs := parseVideoIDQuery(r, "exclude", 120)
+	items, err := s.Catalog.RandomVideosWithReadyThumbnailsExcluding(r.Context(), excludeIDs, homePageSize)
 	if err != nil {
 		writeErr(w, http.StatusInternalServerError, err)
 		return
 	}
-	rand.Shuffle(len(readyItems), func(i, j int) {
-		readyItems[i], readyItems[j] = readyItems[j], readyItems[i]
-	})
-
-	items := appendUniqueVideos(nil, readyItems, homePageSize)
-	if len(items) > homePageSize {
-		items = items[:homePageSize]
-	}
 	if len(items) < homePageSize {
-		fallback, _, err := s.Catalog.ListVideos(r.Context(), catalog.ListParams{
-			Sort: "latest", Page: 1, PageSize: candidatePool,
-		})
+		fallbackExclude := append([]string{}, excludeIDs...)
+		for _, item := range items {
+			if item != nil {
+				fallbackExclude = append(fallbackExclude, item.ID)
+			}
+		}
+		fallback, err := s.Catalog.RandomVideosExcluding(r.Context(), fallbackExclude, homePageSize-len(items))
 		if err != nil {
 			writeErr(w, http.StatusInternalServerError, err)
 			return
 		}
-		rand.Shuffle(len(fallback), func(i, j int) {
-			fallback[i], fallback[j] = fallback[j], fallback[i]
-		})
 		items = appendUniqueVideos(items, fallback, homePageSize)
 	}
 	w.Header().Set("Cache-Control", "no-store")
 	writeJSON(w, http.StatusOK, mapVideos(items))
 }
 
+func parseVideoIDQuery(r *http.Request, key string, limit int) []string {
+	if r == nil {
+		return nil
+	}
+	values := r.URL.Query()[key]
+	if len(values) == 0 {
+		return nil
+	}
+	seen := map[string]struct{}{}
+	out := make([]string, 0, len(values))
+	for _, value := range values {
+		for _, id := range strings.Split(value, ",") {
+			id = strings.TrimSpace(id)
+			if id == "" {
+				continue
+			}
+			if _, ok := seen[id]; ok {
+				continue
+			}
+			seen[id] = struct{}{}
+			out = append(out, id)
+			if limit > 0 && len(out) >= limit {
+				return out
+			}
+		}
+	}
+	return out
+}
+
 func appendUniqueVideos(dst []*catalog.Video, candidates []*catalog.Video, limit int) []*catalog.Video {
 	if len(dst) >= limit {
 		return dst[:limit]

backend/internal/api/api_test.go

@@ -166,6 +166,59 @@ func TestHandleHomePrioritizesVideosWithReadyThumbnails(t *testing.T) {
 	}
 }
 
+func TestHandleHomeExcludesRecentlyShownVideos(t *testing.T) {
+	ctx := context.Background()
+	cat, err := catalog.Open(t.TempDir() + "/catalog.db")
+	if err != nil {
+		t.Fatalf("open catalog: %v", err)
+	}
+	t.Cleanup(func() {
+		if err := cat.Close(); err != nil {
+			t.Fatalf("close catalog: %v", err)
+		}
+	})
+
+	now := time.Now()
+	for i := 0; i < homePageSize+4; i++ {
+		id := "ready-video-" + strconv.Itoa(i)
+		if err := cat.UpsertVideo(ctx, &catalog.Video{
+			ID:           id,
+			DriveID:      "drive",
+			FileID:       id,
+			Title:        id,
+			ThumbnailURL: "https://thumb.example/" + id + ".jpg",
+			PublishedAt:  now.Add(time.Duration(i) * time.Minute),
+			CreatedAt:    now.Add(time.Duration(i) * time.Minute),
+			UpdatedAt:    now.Add(time.Duration(i) * time.Minute),
+		}); err != nil {
+			t.Fatalf("seed ready video %s: %v", id, err)
+		}
+	}
+
+	rr := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/home?exclude=ready-video-0&exclude=ready-video-1", nil)
+	(&Server{Catalog: cat}).handleHome(rr, req)
+
+	if rr.Code != http.StatusOK {
+		t.Fatalf("status = %d, body = %s", rr.Code, rr.Body.String())
+	}
+	var got []VideoDTO
+	if err := json.NewDecoder(rr.Body).Decode(&got); err != nil {
+		t.Fatalf("decode response: %v", err)
+	}
+	if len(got) != homePageSize {
+		t.Fatalf("home items = %d, want %d", len(got), homePageSize)
+	}
+	for _, item := range got {
+		if item.ID == "ready-video-0" || item.ID == "ready-video-1" {
+			t.Fatalf("home returned excluded video %q; items=%#v", item.ID, got)
+		}
+		if !strings.HasPrefix(item.ID, "ready-video-") {
+			t.Fatalf("home returned %q without a ready thumbnail; items=%#v", item.ID, got)
+		}
+	}
+}
+
 func TestHandleListLatestPrefersReadyThumbnails(t *testing.T) {
 	ctx := context.Background()
 	cat, err := catalog.Open(t.TempDir() + "/catalog.db")

backend/internal/catalog/catalog.go

@@ -932,6 +932,14 @@ func (c *Catalog) CountVisibleVideos(ctx context.Context) (int, error) {
 // 如果剩余可选数量 < limit，就返回所有可选项；调用方负责判断是否需要开新一轮。
 // limit <= 0 时返回 nil, nil。
 func (c *Catalog) RandomVideosExcluding(ctx context.Context, excludeIDs []string, limit int) ([]*Video, error) {
+	return c.randomVideosExcluding(ctx, excludeIDs, limit, false)
+}
+
+func (c *Catalog) RandomVideosWithReadyThumbnailsExcluding(ctx context.Context, excludeIDs []string, limit int) ([]*Video, error) {
+	return c.randomVideosExcluding(ctx, excludeIDs, limit, true)
+}
+
+func (c *Catalog) randomVideosExcluding(ctx context.Context, excludeIDs []string, limit int, thumbnailReadyOnly bool) ([]*Video, error) {
 	if limit <= 0 {
 		return nil, nil
 	}
@@ -940,6 +948,9 @@ func (c *Catalog) RandomVideosExcluding(ctx context.Context, excludeIDs []string
 	args := make([]any, 0, len(cleaned)+1)
 	whereSQL := `WHERE COALESCE(hidden, 0) = 0
 		           AND ` + uniqueVideoWhereSQL
+	if thumbnailReadyOnly {
+		whereSQL += " AND COALESCE(thumbnail_url, '') != ''"
+	}
 	if len(cleaned) > 0 {
 		placeholders := strings.Repeat("?,", len(cleaned))
 		placeholders = placeholders[:len(placeholders)-1]

backend/internal/catalog/shorts_test.go

@@ -110,6 +110,62 @@ func TestRandomVideosExcluding(t *testing.T) {
 	}
 }
 
+func TestRandomVideosWithReadyThumbnailsExcluding(t *testing.T) {
+	ctx := context.Background()
+	cat, err := Open(t.TempDir() + "/catalog.db")
+	if err != nil {
+		t.Fatalf("open catalog: %v", err)
+	}
+	t.Cleanup(func() { _ = cat.Close() })
+
+	now := time.Now()
+	for i := 0; i < 4; i++ {
+		id := "ready-" + string(rune('a'+i))
+		if err := cat.UpsertVideo(ctx, &Video{
+			ID:           id,
+			DriveID:      "drive",
+			FileID:       "f-" + id,
+			Title:        id,
+			ThumbnailURL: "/p/thumb/" + id,
+			PublishedAt:  now,
+			CreatedAt:    now,
+			UpdatedAt:    now,
+		}); err != nil {
+			t.Fatalf("seed %s: %v", id, err)
+		}
+	}
+	for i := 0; i < 4; i++ {
+		id := "pending-" + string(rune('a'+i))
+		if err := cat.UpsertVideo(ctx, &Video{
+			ID:          id,
+			DriveID:     "drive",
+			FileID:      "f-" + id,
+			Title:       id,
+			PublishedAt: now,
+			CreatedAt:   now,
+			UpdatedAt:   now,
+		}); err != nil {
+			t.Fatalf("seed %s: %v", id, err)
+		}
+	}
+
+	got, err := cat.RandomVideosWithReadyThumbnailsExcluding(ctx, []string{"ready-a"}, 10)
+	if err != nil {
+		t.Fatalf("random ready excluding: %v", err)
+	}
+	if len(got) != 3 {
+		t.Fatalf("ready random count = %d, want 3", len(got))
+	}
+	for _, v := range got {
+		if v.ID == "ready-a" {
+			t.Fatal("excluded ready video was returned")
+		}
+		if v.ThumbnailURL == "" {
+			t.Fatalf("pending video %q was returned", v.ID)
+		}
+	}
+}
+
 func TestRandomVideosForPreferredVideoChoosesLeastPopulatedTag(t *testing.T) {
 	ctx := context.Background()
 	cat, err := Open(t.TempDir() + "/catalog.db")

src/data/videos.ts

@@ -1,8 +1,13 @@
 import type { VideoDetail, VideoItem } from "@/types";
 
 // 真实后端接口调用。未配置网盘时，各接口返回空数据。
-export function fetchHomeVideos(): Promise<VideoItem[]> {
-  return apiGet<VideoItem[]>("/api/home").catch(() => []);
+export function fetchHomeVideos(excludeIds?: string[]): Promise<VideoItem[]> {
+  const qs = new URLSearchParams();
+  for (const id of excludeIds ?? []) {
+    if (id.trim()) qs.append("exclude", id.trim());
+  }
+  const suffix = qs.toString() ? `?${qs.toString()}` : "";
+  return apiGet<VideoItem[]>(`/api/home${suffix}`).catch(() => []);
 }
 
 export function fetchListing(

src/pages/HomePage.tsx

@@ -10,6 +10,8 @@ import type { VideoItem } from "@/types";
 
 const DESKTOP_COUNT = 12;
 const MOBILE_COUNT = 8;
+const HOME_RECENT_KEY = "home.random.recentVideoIds";
+const HOME_RECENT_LIMIT = 72;
 
 function useIsMobile() {
   const [mobile, setMobile] = useState(window.innerWidth <= 640);
@@ -26,6 +28,35 @@ function useIsMobile() {
 let cachedRanking: VideoItem[] | null = null;
 let cachedLatest: VideoItem[] | null = null;
 
+function loadRecentHomeVideoIds(): string[] {
+  try {
+    const raw = window.localStorage.getItem(HOME_RECENT_KEY);
+    const parsed = raw ? JSON.parse(raw) : [];
+    return Array.isArray(parsed)
+      ? parsed.filter((id): id is string => typeof id === "string" && id.length > 0)
+      : [];
+  } catch {
+    return [];
+  }
+}
+
+function rememberHomeVideos(items: VideoItem[]) {
+  const merged = [...items.map((item) => item.id), ...loadRecentHomeVideoIds()];
+  const seen = new Set<string>();
+  const recent: string[] = [];
+  for (const id of merged) {
+    if (!id || seen.has(id)) continue;
+    seen.add(id);
+    recent.push(id);
+    if (recent.length >= HOME_RECENT_LIMIT) break;
+  }
+  try {
+    window.localStorage.setItem(HOME_RECENT_KEY, JSON.stringify(recent));
+  } catch {
+    // localStorage 不可用时只影响连续刷新去重，不影响首页展示。
+  }
+}
+
 export default function HomePage() {
   const [rankingVideos, setRankingVideos] = useState<VideoItem[]>(cachedRanking ?? []);
   const [latestVideos, setLatestVideos] = useState<VideoItem[]>(cachedLatest ?? []);
@@ -40,11 +71,13 @@ export default function HomePage() {
 
     let active = true;
     setLoading(true);
+    const excludeIds = loadRecentHomeVideoIds();
     Promise.all([
-      fetchHomeVideos(),
+      fetchHomeVideos(excludeIds),
       fetchListing(1, DESKTOP_COUNT, { sort: "latest" }),
     ]).then(([rankingItems, latestResult]) => {
       if (!active) return;
+      rememberHomeVideos(rankingItems);
       cachedRanking = rankingItems;
       cachedLatest = latestResult.items;
       setRankingVideos(rankingItems);