feat: tell which of my playlists contain a song

internal/adapter/in/api/api.go

@@ -117,6 +117,7 @@ func New(s Services, metrics prometheus.Registerer, tracer trace.TracerProvider,
 	srv.handle(mux, protocol.RouteListMyPlaylistItems, srv.listMyPlaylistItems)
 	srv.handle(mux, protocol.RouteAddMyPlaylistItem, srv.addMyPlaylistItem)
 	srv.handleLimit(mux, protocol.RouteRemoveMyPlaylistItems, maxBatchBodyBytes, srv.removeMyPlaylistItems)
+	srv.handle(mux, protocol.RouteListMyTrackPlaylists, srv.listMyTrackPlaylists)
 	srv.handleLimit(mux, protocol.RouteCopyMyPlaylistItems, maxBatchBodyBytes, srv.copyMyPlaylistItems)
 	srv.handleLimit(mux, protocol.RouteMoveMyPlaylistItems, maxBatchBodyBytes, srv.moveMyPlaylistItems)
 	srv.handle(mux, protocol.RouteListRooms, srv.listRooms)

internal/adapter/in/api/api_test.go

@@ -201,6 +201,10 @@ func TestPlaylistBatchBodyLimit(t *testing.T) {
 	if got := send(t, server, http.MethodPost, "/api/me/playlists/"+favorites+"/removals", tooLarge, auth...); got != want {
 		t.Errorf("超过批量上限的请求体 = %#v，期望 %#v", got, want)
 	}
+	want = failure(protocol.ErrorCodeInvalidArgument, "请求体不能超过 64 KiB")
+	if got := send(t, server, http.MethodPost, "/api/me/playlist-memberships", `{"tracks":`+list+`}`, auth...); got != want {
+		t.Errorf("其他接口超过 64 KiB 的请求体 = %#v，期望 %#v", got, want)
+	}
 }
 
 func TestMalformedPathParametersAreNotFound(t *testing.T) {

internal/adapter/in/api/playlist.go

@@ -108,6 +108,18 @@ func (s *server) removeMyPlaylistItems(ctx context.Context, c call) (any, error)
 	return nil, s.Playlists.Remove(ctx, c.member.ID, c.r.PathValue("id"), tracksOf(req.Tracks))
 }
 
+func (s *server) listMyTrackPlaylists(ctx context.Context, c call) (any, error) {
+	req, err := protocol.DecodeListMyTrackPlaylistsRequest(c.body)
+	if err != nil {
+		return nil, err
+	}
+	ids, err := s.Playlists.Containing(ctx, c.member.ID, trackOf(req.Track))
+	if err != nil {
+		return nil, err
+	}
+	return protocol.ListMyTrackPlaylistsResponse{PlaylistIds: ids}, nil
+}
+
 func (s *server) copyMyPlaylistItems(ctx context.Context, c call) (any, error) {
 	req, err := protocol.DecodeCopyMyPlaylistItemsRequest(c.body)
 	if err != nil {

internal/adapter/out/postgres/internal/query/playlists.sql.go

@@ -452,3 +452,36 @@ func (q *Queries) TouchPlaylist(ctx context.Context, id string) error {
 	_, err := q.db.Exec(ctx, touchPlaylist, id)
 	return err
 }
+
+const trackPlaylists = `-- name: TrackPlaylists :many
+SELECT p.id FROM playlists p
+JOIN playlist_items i ON i.playlist_id = p.id
+WHERE p.owner_id = $1 AND i.source = $2 AND i.track_id = $3
+ORDER BY p.id
+`
+
+type TrackPlaylistsParams struct {
+	OwnerID string
+	Source  string
+	TrackID string
+}
+
+func (q *Queries) TrackPlaylists(ctx context.Context, arg TrackPlaylistsParams) ([]string, error) {
+	rows, err := q.db.Query(ctx, trackPlaylists, arg.OwnerID, arg.Source, arg.TrackID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []string
+	for rows.Next() {
+		var id string
+		if err := rows.Scan(&id); err != nil {
+			return nil, err
+		}
+		items = append(items, id)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}

internal/adapter/out/postgres/playlists.go

@@ -218,6 +218,17 @@ func (s *Store) RemovePlaylistItems(ctx context.Context, ownerID, id string, tra
 	return nil
 }
 
+func (s *Store) TrackPlaylists(ctx context.Context, ownerID string, t track.Track) ([]string, error) {
+	ids, err := s.q.TrackPlaylists(ctx, query.TrackPlaylistsParams{OwnerID: ownerID, Source: string(t.Source), TrackID: t.ID})
+	if err != nil {
+		return nil, fmt.Errorf("查询曲目 %s 所在的歌单：%w", t.ID, err)
+	}
+	if ids == nil {
+		ids = []string{}
+	}
+	return ids, nil
+}
+
 func (s *Store) CopyPlaylistItems(ctx context.Context, ownerID, fromID, toID string, tracks []track.Track, limit int) (int, error) {
 	var added int64
 	err := s.owned(ctx, ownerID, fromID)

internal/adapter/out/postgres/playlists_test.go

@@ -512,6 +512,30 @@ func TestConcurrentRemovalsAndDeletesDoNotDeadlock(t *testing.T) {
 	}
 }
 
+func TestTrackPlaylistsOnlyListsOwnPlaylists(t *testing.T) {
+	store, _ := newStore(t)
+	alice := registered(t, store, "alice")
+	bob := registered(t, store, "bob")
+	favorites := favoritesOf(t, store, alice.ID)
+	commute := filled(t, store, alice.ID, "通勤", "1")
+	filled(t, store, alice.ID, "空", "2")
+	bobFavorites := favoritesOf(t, store, bob.ID)
+	if err := store.AddPlaylistItem(t.Context(), alice.ID, favorites, songItem("1"), 10); err != nil {
+		t.Fatal(err)
+	}
+	if err := store.AddPlaylistItem(t.Context(), bob.ID, bobFavorites, songItem("1"), 10); err != nil {
+		t.Fatal(err)
+	}
+	ids, err := store.TrackPlaylists(t.Context(), alice.ID, songItem("1").Track)
+	if want := []string{favorites, commute}; err != nil || !slices.Equal(ids, want) {
+		t.Errorf("所在的歌单 = %v, %v，期望只有本人的 %v", ids, err, want)
+	}
+	ids, err = store.TrackPlaylists(t.Context(), alice.ID, songItem("3").Track)
+	if err != nil || ids == nil || len(ids) != 0 {
+		t.Errorf("不在任何歌单里的歌 = %#v, %v，期望空切片", ids, err)
+	}
+}
+
 func TestMovePlaylistItems(t *testing.T) {
 	store, _ := newStore(t)
 	alice := registered(t, store, "alice")

internal/app/playlist/playlist.go

@@ -124,6 +124,13 @@ func (s *Service) Remove(ctx context.Context, memberID, id string, tracks []trac
 	return s.playlists.RemovePlaylistItems(ctx, memberID, id, tracks)
 }
 
+func (s *Service) Containing(ctx context.Context, memberID string, t track.Track) ([]string, error) {
+	if err := s.registered(ctx, memberID); err != nil {
+		return nil, err
+	}
+	return s.playlists.TrackPlaylists(ctx, memberID, t)
+}
+
 func (s *Service) Copy(ctx context.Context, memberID, fromID, toID string, tracks []track.Track) (int, error) {
 	if err := s.registered(ctx, memberID); err != nil {
 		return 0, err

internal/app/playlist/playlist_test.go

@@ -119,6 +119,9 @@ func TestGuestCannotUsePlaylists(t *testing.T) {
 	if _, err := f.svc.Add(t.Context(), guest.ID, "any", sunny); !errors.Is(err, ErrNotRegistered) {
 		t.Errorf("游客收藏 = %v，期望 ErrNotRegistered", err)
 	}
+	if _, err := f.svc.Containing(t.Context(), guest.ID, sunny); !errors.Is(err, ErrNotRegistered) {
+		t.Errorf("游客查询所在的歌单 = %v，期望 ErrNotRegistered", err)
+	}
 	if err := f.svc.Remove(t.Context(), guest.ID, "any", []track.Track{sunny}); !errors.Is(err, ErrNotRegistered) {
 		t.Errorf("游客批量移出 = %v，期望 ErrNotRegistered", err)
 	}

internal/app/port/playlist.go

@@ -51,6 +51,8 @@ type Playlists interface {
 	AddPlaylistItem(ctx context.Context, ownerID, id string, item PlaylistItem, limit int) error
 	// 不在歌单里的歌忽略。
 	RemovePlaylistItems(ctx context.Context, ownerID, id string, tracks []track.Track) error
+	// 只看这个成员自己的歌单；没有命中时返回空切片。
+	TrackPlaylists(ctx context.Context, ownerID string, t track.Track) ([]string, error)
 	// 把 fromID 歌单里的这些歌连同元数据复制到 toID 歌单，返回复制的数量。fromID 不属于 ownerID 时返回 ErrPlaylistNotFound。
 	// 不在 fromID 里的和已在 toID 里的跳过；新复制的排在最前，tracks[0] 最靠前。
 	// 复制之后超过 limit 首时整批拒绝，返回 ErrPlaylistLimit。

internal/app/port/porttest/store.go

@@ -677,6 +677,18 @@ func (s *Store) RemovePlaylistItems(_ context.Context, ownerID, id string, track
 	return nil
 }
 
+func (s *Store) TrackPlaylists(_ context.Context, ownerID string, t track.Track) ([]string, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	ids := []string{}
+	for _, p := range s.playlists {
+		if p.owner == ownerID && slices.ContainsFunc(p.items, func(i port.PlaylistItem) bool { return i.Track == t }) {
+			ids = append(ids, p.id)
+		}
+	}
+	return ids, nil
+}
+
 func (s *Store) CopyPlaylistItems(_ context.Context, ownerID, fromID, toID string, tracks []track.Track, limit int) (int, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()

internal/bootstrap/media_test.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"log/slog"
 	"net/http"
+	"slices"
 	"strings"
 	"testing"
 	"time"
@@ -238,6 +239,13 @@ func TestPlaylistLinkTracks(t *testing.T) {
 		t.Errorf("歌单里的曲目 = %+v，期望一首 ID %s、封面 %s", items.Items, link, coverURL)
 	}
 
+	var memberships struct {
+		PlaylistIDs []string `json:"playlistIds"`
+	}
+	call("POST /api/me/playlist-memberships"+auth+"\n\n"+`{"track": {"source": "link", "id": "https://Example.com/Song.mp3"}}`, http.StatusOK, &memberships)
+	if !slices.Equal(memberships.PlaylistIDs, []string{favorites}) {
+		t.Errorf("换一种大小写查所在的歌单 = %v，期望 [%s]", memberships.PlaylistIDs, favorites)
+	}
 	call("POST /api/me/playlists/"+favorites+"/removals"+auth+"\n\n"+`{"tracks": [{"source": "link", "id": "hTTps://example.COM/Song.mp3"}]}`, http.StatusNoContent, nil)
 	call("GET /api/me/playlists/"+favorites+"/items"+auth, http.StatusOK, &items)
 	if len(items.Items) != 0 {

internal/bootstrap/testdata/http/playlists.txtar

@@ -226,6 +226,24 @@ Authorization: Bearer $alice
 200
 {"items": [{"id": "$favorites", "name": "我喜欢", "favorites": true, "trackCount": 2, "createdAtMs": 1, "updatedAtMs": 1, "coverUrl": "https://p1.music.126.net/qilixiang.jpg"}, {"id": "$commute", "name": "上班路上", "favorites": false, "trackCount": 2, "createdAtMs": 1, "updatedAtMs": 1, "coverUrl": "https://p1.music.126.net/example.jpg"}]}
 
+-- request --
+POST /api/me/playlist-memberships
+Authorization: Bearer $alice
+
+{"track": {"source": "netease", "id": "186016"}}
+-- response --
+200
+{"playlistIds": ["$favorites", "$commute"]}
+
+-- request --
+POST /api/me/playlist-memberships
+Authorization: Bearer $alice
+
+{"track": {"source": "netease", "id": "999"}}
+-- response --
+200
+{"playlistIds": []}
+
 -- request --
 POST /api/me/playlists/$favorites/removals
 Authorization: Bearer $alice