优化

internal/repository/media_repository.go

@@ -232,6 +232,31 @@ func (r *MediaRepository) ExistsSiblingWithTMDbID(ctx context.Context, m *model.
 	return count > 0
 }
 
+// ListSeasonSiblings returns other episodes in the same season as m.
+// Prefers series_id; falls back to shared library+title+tm_db_id (anime scrape path).
+func (r *MediaRepository) ListSeasonSiblings(ctx context.Context, m *model.Media) ([]model.Media, error) {
+	if r == nil || m == nil || m.SeasonNum <= 0 || m.ID == "" {
+		return nil, nil
+	}
+	query := r.db.WithContext(ctx).Model(&model.Media{}).
+		Where("season_num = ? AND id <> ?", m.SeasonNum, m.ID)
+	if seriesID := strings.TrimSpace(m.SeriesID); seriesID != "" {
+		query = query.Where("series_id = ?", seriesID)
+	} else {
+		libraryID := strings.TrimSpace(m.LibraryID)
+		title := strings.TrimSpace(m.Title)
+		if libraryID == "" || title == "" || m.TMDbID <= 0 {
+			return nil, nil
+		}
+		query = query.Where("library_id = ? AND title = ? AND tm_db_id = ?", libraryID, title, m.TMDbID)
+	}
+	var rows []model.Media
+	if err := query.Find(&rows).Error; err != nil {
+		return nil, err
+	}
+	return rows, nil
+}
+
 // ListByLibrary returns paginated media items for a library.
 func (r *MediaRepository) ListByLibrary(ctx context.Context, libraryID string, offset, limit int) ([]model.Media, int64, error) {
 	return r.ListByLibraryFiltered(ctx, libraryID, offset, limit, MediaQueryFilter{IncludeNSFW: true})

internal/repository/media_segment_repository.go

@@ -3,6 +3,7 @@ package repository
 import (
 	"context"
 	"errors"
+	"time"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
@@ -84,3 +85,45 @@ func (r *MediaSegmentRepository) UpsertFetch(ctx context.Context, row *model.Med
 	}
 	return r.db.WithContext(ctx).Clauses(onConflict).Create(row).Error
 }
+
+// ListPrewarmCandidates returns media that should be refreshed from source:
+// no ledger, expired miss (fetched_at < missBefore), or expired hit (fetched_at < hitBefore).
+// Recently played items come first so hot titles recover coverage sooner.
+func (r *MediaSegmentRepository) ListPrewarmCandidates(
+	ctx context.Context,
+	source string,
+	missBefore, hitBefore time.Time,
+	limit int,
+) ([]model.Media, error) {
+	if r == nil || limit <= 0 {
+		return nil, nil
+	}
+	rows := make([]model.Media, 0, limit)
+	// 可查询：有 TMDb，且是剧集（有季集）或电影（无季集）。
+	err := r.db.WithContext(ctx).Raw(`
+SELECT m.*
+FROM media m
+LEFT JOIN media_segment_fetches f
+  ON f.media_id = m.id AND f.source = ? AND f.deleted_at IS NULL
+LEFT JOIN (
+  SELECT media_id, MAX(updated_at) AS last_played
+  FROM playback_histories
+  WHERE deleted_at IS NULL
+  GROUP BY media_id
+) ph ON ph.media_id = m.id
+WHERE m.deleted_at IS NULL
+  AND m.tm_db_id > 0
+  AND (
+    (m.season_num > 0 AND m.episode_num > 0)
+    OR (COALESCE(m.season_num, 0) = 0 AND COALESCE(m.episode_num, 0) = 0)
+  )
+  AND (
+    f.id IS NULL
+    OR (f.found = 0 AND f.fetched_at < ?)
+    OR (f.found = 1 AND f.fetched_at < ?)
+  )
+ORDER BY ph.last_played DESC
+LIMIT ?
+`, source, missBefore, hitBefore, limit).Scan(&rows).Error
+	return rows, err
+}

internal/repository/media_segment_repository_test.go

@@ -152,3 +152,56 @@ func TestUpsertFetchKeepsOneRowPerMediaAndSource(t *testing.T) {
 		t.Fatalf("ledger should be updated in place, got %#v", got)
 	}
 }
+
+func TestListSeasonSiblingsSharesLibraryTitleTMDb(t *testing.T) {
+	repos := newSegmentTestRepos(t)
+	ctx := t.Context()
+	eps := []*model.Media{
+		{Base: model.Base{ID: "a"}, LibraryID: "lib", Title: "Show", Path: "/a", SeasonNum: 1, EpisodeNum: 1, TMDbID: 99},
+		{Base: model.Base{ID: "b"}, LibraryID: "lib", Title: "Show", Path: "/b", SeasonNum: 1, EpisodeNum: 2, TMDbID: 99},
+		{Base: model.Base{ID: "c"}, LibraryID: "lib", Title: "Show", Path: "/c", SeasonNum: 2, EpisodeNum: 1, TMDbID: 99},
+	}
+	for _, ep := range eps {
+		if err := repos.DB.Create(ep).Error; err != nil {
+			t.Fatal(err)
+		}
+	}
+	got, err := repos.Media.ListSeasonSiblings(ctx, eps[0])
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got) != 1 || got[0].ID != "b" {
+		t.Fatalf("siblings = %#v, want only same-season ep b", got)
+	}
+}
+
+func TestListPrewarmCandidatesOrdersRecentPlaysFirst(t *testing.T) {
+	repos := newSegmentTestRepos(t)
+	ctx := t.Context()
+	now := time.Now()
+	for _, m := range []*model.Media{
+		{Base: model.Base{ID: "cold"}, Path: "/cold", TMDbID: 1},
+		{Base: model.Base{ID: "hot"}, Path: "/hot", TMDbID: 2},
+	} {
+		if err := repos.DB.Create(m).Error; err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := repos.DB.Create(&model.PlaybackHistory{
+		Base: model.Base{ID: "ph1"}, UserID: "u", MediaID: "hot",
+	}).Error; err != nil {
+		t.Fatal(err)
+	}
+	got, err := repos.MediaSegment.ListPrewarmCandidates(
+		ctx, "theintrodb", now.Add(-time.Hour), now.Add(-time.Hour), 10,
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got) < 2 {
+		t.Fatalf("candidates = %#v, want both", got)
+	}
+	if got[0].ID != "hot" {
+		t.Fatalf("first = %s, want hot (recently played)", got[0].ID)
+	}
+}