feat(db): add similarity lookup queries (ListActiveContextualLikesForUser, GetCurrentSessionVectorForUser)

internal/db/dbq/contextual_likes.sql.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.31.1
+//   sqlc v1.27.0
 // source: contextual_likes.sql
 
 package dbq
@@ -33,6 +33,43 @@ func (q *Queries) InsertContextualLike(ctx context.Context, arg InsertContextual
 	return err
 }
 
+const listActiveContextualLikesForUser = `-- name: ListActiveContextualLikesForUser :many
+SELECT track_id, session_vector
+FROM contextual_likes
+WHERE user_id = $1
+  AND deleted_at IS NULL
+  AND session_vector IS NOT NULL
+`
+
+type ListActiveContextualLikesForUserRow struct {
+	TrackID       pgtype.UUID
+	SessionVector []byte
+}
+
+// Returns all the user's active (non-soft-deleted) contextual_likes with
+// non-null vectors. Cardinality is bounded by the user's actual like-while-
+// playing history — typically tens to low hundreds. Used by the engine to
+// compute contextual_match_score for the candidate pool.
+func (q *Queries) ListActiveContextualLikesForUser(ctx context.Context, userID pgtype.UUID) ([]ListActiveContextualLikesForUserRow, error) {
+	rows, err := q.db.Query(ctx, listActiveContextualLikesForUser, userID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []ListActiveContextualLikesForUserRow
+	for rows.Next() {
+		var i ListActiveContextualLikesForUserRow
+		if err := rows.Scan(&i.TrackID, &i.SessionVector); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const softDeleteContextualLikesForUserTrack = `-- name: SoftDeleteContextualLikesForUserTrack :exec
 UPDATE contextual_likes
 SET deleted_at = now()