fix(recommendation): broaden You-might-like fallback to liked album/track artists (#790)

The fallback pulled artists only from explicit artist-likes (general_likes_artists), but most users like albums and tracks far more than artists — so the artists row still came up thin (a couple of tiles) even with a rich library, while the albums row filled fine. Broaden both fallbacks to "entities you've shown affinity for": - artist fallback = explicit artist-likes ∪ artists of liked albums ∪ artists of liked tracks. - album fallback = explicit album-likes ∪ albums of liked tracks. New dedicated queries (ListYouMightLike{Artist,Album}FallbackForUser) replace the narrow Rediscover-fallback reuse; same projection so the Go layer still converts directly. (Aliased + fully-qualified the UNION arms — sqlc merges UNION scopes, so unqualified user_id was ambiguous across the three like tables.) Test: 12 liked TRACKS by distinct artists, no artist-likes → the artist row now fills from their artists (was empty before). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-11 23:55:08 -04:00
parent 26c368c35e
commit c7adf2c87a
4 changed files with 249 additions and 7 deletions
@@ -91,6 +91,70 @@ func (q *Queries) InsertYouMightLikeArtist(ctx context.Context, arg InsertYouMig
 	return err
 }

+const listYouMightLikeAlbumFallbackForUser = `-- name: ListYouMightLikeAlbumFallbackForUser :many
+WITH liked_album_ids AS (
+    SELECT likb.album_id AS album_id
+      FROM general_likes_albums likb
+     WHERE likb.user_id = $1
+    UNION
+    SELECT trk.album_id AS album_id
+      FROM general_likes likt
+      JOIN tracks trk ON trk.id = likt.track_id
+     WHERE likt.user_id = $1
+)
+SELECT albums.id, albums.title, albums.sort_title, albums.artist_id, albums.release_date, albums.mbid, albums.cover_art_path, albums.created_at, albums.updated_at, albums.cover_art_source, albums.cover_art_sources_version, artists.name AS artist_name
+FROM liked_album_ids lai
+JOIN albums ON albums.id = lai.album_id
+JOIN artists ON artists.id = albums.artist_id
+ORDER BY md5(albums.id::text || current_date::text)
+LIMIT $2
+`
+
+type ListYouMightLikeAlbumFallbackForUserParams struct {
+	UserID pgtype.UUID
+	Limit  int32
+}
+
+type ListYouMightLikeAlbumFallbackForUserRow struct {
+	Album      Album
+	ArtistName string
+}
+
+// Broad "albums you've shown affinity for" pool: explicitly liked albums PLUS
+// the albums of liked tracks. Same projection as ListYouMightLikeAlbumsForUser.
+func (q *Queries) ListYouMightLikeAlbumFallbackForUser(ctx context.Context, arg ListYouMightLikeAlbumFallbackForUserParams) ([]ListYouMightLikeAlbumFallbackForUserRow, error) {
+	rows, err := q.db.Query(ctx, listYouMightLikeAlbumFallbackForUser, arg.UserID, arg.Limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []ListYouMightLikeAlbumFallbackForUserRow
+	for rows.Next() {
+		var i ListYouMightLikeAlbumFallbackForUserRow
+		if err := rows.Scan(
+			&i.Album.ID,
+			&i.Album.Title,
+			&i.Album.SortTitle,
+			&i.Album.ArtistID,
+			&i.Album.ReleaseDate,
+			&i.Album.Mbid,
+			&i.Album.CoverArtPath,
+			&i.Album.CreatedAt,
+			&i.Album.UpdatedAt,
+			&i.Album.CoverArtSource,
+			&i.Album.CoverArtSourcesVersion,
+			&i.ArtistName,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const listYouMightLikeAlbumsForUser = `-- name: ListYouMightLikeAlbumsForUser :many
 SELECT albums.id, albums.title, albums.sort_title, albums.artist_id, albums.release_date, albums.mbid, albums.cover_art_path, albums.created_at, albums.updated_at, albums.cover_art_source, albums.cover_art_sources_version, artists.name AS artist_name
 FROM you_might_like_albums yml
@@ -149,6 +213,90 @@ func (q *Queries) ListYouMightLikeAlbumsForUser(ctx context.Context, arg ListYou
 	return items, nil
 }

+const listYouMightLikeArtistFallbackForUser = `-- name: ListYouMightLikeArtistFallbackForUser :many
+WITH liked_artist_ids AS (
+    SELECT lika.artist_id AS artist_id
+      FROM general_likes_artists lika
+     WHERE lika.user_id = $1
+    UNION
+    SELECT alb.artist_id AS artist_id
+      FROM general_likes_albums likb
+      JOIN albums alb ON alb.id = likb.album_id
+     WHERE likb.user_id = $1
+    UNION
+    SELECT trk.artist_id AS artist_id
+      FROM general_likes likt
+      JOIN tracks trk ON trk.id = likt.track_id
+     WHERE likt.user_id = $1
+)
+SELECT artists.id, artists.name, artists.sort_name, artists.mbid, artists.created_at, artists.updated_at, artists.artist_thumb_path, artists.artist_fanart_path, artists.artist_art_source, artists.artist_art_sources_version,
+       cov.id AS cover_album_id,
+       cnt.album_count::bigint AS album_count
+FROM liked_artist_ids lai
+JOIN artists ON artists.id = lai.artist_id
+LEFT JOIN LATERAL (
+    SELECT id FROM albums
+    WHERE artist_id = artists.id AND cover_art_path IS NOT NULL
+    ORDER BY created_at DESC LIMIT 1
+) cov ON true
+LEFT JOIN LATERAL (
+    SELECT count(*) AS album_count
+    FROM albums WHERE artist_id = artists.id
+) cnt ON true
+ORDER BY md5(artists.id::text || current_date::text)
+LIMIT $2
+`
+
+type ListYouMightLikeArtistFallbackForUserParams struct {
+	UserID pgtype.UUID
+	Limit  int32
+}
+
+type ListYouMightLikeArtistFallbackForUserRow struct {
+	Artist       Artist
+	CoverAlbumID pgtype.UUID
+	AlbumCount   int64
+}
+
+// Broad "artists you've shown affinity for" pool to fill a thin
+// You-might-like artists row: explicitly liked artists PLUS the artists of
+// liked albums and liked tracks. Most users like albums/tracks far more than
+// they like artists explicitly, so the union is much deeper than
+// general_likes_artists alone. Daily-stable order; same projection as
+// ListYouMightLikeArtistsForUser so the Go layer reuses it directly.
+func (q *Queries) ListYouMightLikeArtistFallbackForUser(ctx context.Context, arg ListYouMightLikeArtistFallbackForUserParams) ([]ListYouMightLikeArtistFallbackForUserRow, error) {
+	rows, err := q.db.Query(ctx, listYouMightLikeArtistFallbackForUser, arg.UserID, arg.Limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []ListYouMightLikeArtistFallbackForUserRow
+	for rows.Next() {
+		var i ListYouMightLikeArtistFallbackForUserRow
+		if err := rows.Scan(
+			&i.Artist.ID,
+			&i.Artist.Name,
+			&i.Artist.SortName,
+			&i.Artist.Mbid,
+			&i.Artist.CreatedAt,
+			&i.Artist.UpdatedAt,
+			&i.Artist.ArtistThumbPath,
+			&i.Artist.ArtistFanartPath,
+			&i.Artist.ArtistArtSource,
+			&i.Artist.ArtistArtSourcesVersion,
+			&i.CoverAlbumID,
+			&i.AlbumCount,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const listYouMightLikeArtistsForUser = `-- name: ListYouMightLikeArtistsForUser :many
 SELECT artists.id, artists.name, artists.sort_name, artists.mbid, artists.created_at, artists.updated_at, artists.artist_thumb_path, artists.artist_fanart_path, artists.artist_art_source, artists.artist_art_sources_version,
       cov.id AS cover_album_id,
@@ -64,3 +64,62 @@ LEFT JOIN LATERAL (
 WHERE yml.user_id = $1
 ORDER BY yml.rank
 LIMIT $2;
+
+-- name: ListYouMightLikeArtistFallbackForUser :many
+-- Broad "artists you've shown affinity for" pool to fill a thin
+-- You-might-like artists row: explicitly liked artists PLUS the artists of
+-- liked albums and liked tracks. Most users like albums/tracks far more than
+-- they like artists explicitly, so the union is much deeper than
+-- general_likes_artists alone. Daily-stable order; same projection as
+-- ListYouMightLikeArtistsForUser so the Go layer reuses it directly.
+WITH liked_artist_ids AS (
+    SELECT lika.artist_id AS artist_id
+      FROM general_likes_artists lika
+     WHERE lika.user_id = $1
+    UNION
+    SELECT alb.artist_id AS artist_id
+      FROM general_likes_albums likb
+      JOIN albums alb ON alb.id = likb.album_id
+     WHERE likb.user_id = $1
+    UNION
+    SELECT trk.artist_id AS artist_id
+      FROM general_likes likt
+      JOIN tracks trk ON trk.id = likt.track_id
+     WHERE likt.user_id = $1
+)
+SELECT sqlc.embed(artists),
+       cov.id AS cover_album_id,
+       cnt.album_count::bigint AS album_count
+FROM liked_artist_ids lai
+JOIN artists ON artists.id = lai.artist_id
+LEFT JOIN LATERAL (
+    SELECT id FROM albums
+    WHERE artist_id = artists.id AND cover_art_path IS NOT NULL
+    ORDER BY created_at DESC LIMIT 1
+) cov ON true
+LEFT JOIN LATERAL (
+    SELECT count(*) AS album_count
+    FROM albums WHERE artist_id = artists.id
+) cnt ON true
+ORDER BY md5(artists.id::text || current_date::text)
+LIMIT $2;
+
+-- name: ListYouMightLikeAlbumFallbackForUser :many
+-- Broad "albums you've shown affinity for" pool: explicitly liked albums PLUS
+-- the albums of liked tracks. Same projection as ListYouMightLikeAlbumsForUser.
+WITH liked_album_ids AS (
+    SELECT likb.album_id AS album_id
+      FROM general_likes_albums likb
+     WHERE likb.user_id = $1
+    UNION
+    SELECT trk.album_id AS album_id
+      FROM general_likes likt
+      JOIN tracks trk ON trk.id = likt.track_id
+     WHERE likt.user_id = $1
+)
+SELECT sqlc.embed(albums), artists.name AS artist_name
+FROM liked_album_ids lai
+JOIN albums ON albums.id = lai.album_id
+JOIN artists ON artists.id = albums.artist_id
+ORDER BY md5(albums.id::text || current_date::text)
+LIMIT $2;