fix(multiplayer): finalize empty ranked seasons

server/store/maintenance_sql.go

@@ -24,6 +24,12 @@ WHERE season_id = $1 AND rolled_over_at IS NULL
                   LEFT JOIN ranked_season_rollovers rr ON rr.season_id = $1 AND rr.player_id = r.player_id
                   WHERE rr.player_id IS NULL)`
 
+const MarkEmptySeasonsSQL = `UPDATE seasons s SET rolled_over_at = $1
+WHERE s.playlist = 'ranked' AND s.ends_at <= $1 AND s.rolled_over_at IS NULL
+  AND NOT EXISTS (SELECT 1 FROM ratings r
+                  LEFT JOIN ranked_season_rollovers rr ON rr.season_id = s.season_id AND rr.player_id = r.player_id
+                  WHERE rr.player_id IS NULL)`
+
 type dueSeasonRollover struct {
 	seasonID string
 	playerID string
@@ -36,6 +42,12 @@ func RolloverDueSeasons(ctx context.Context, db *sql.DB, now time.Time, limit in
 	if db == nil || now.IsZero() || limit < 1 || limit > 1000 {
 		return 0, fmt.Errorf("invalid season maintenance arguments")
 	}
+	// A season with no ranked profiles has no player row for DueSeasonRolloversSQL
+	// to return. Mark it here so maintenance remains idempotent instead of
+	// reconsidering the same empty season on every pass.
+	if _, err := db.ExecContext(ctx, MarkEmptySeasonsSQL, now); err != nil {
+		return 0, err
+	}
 	rows, err := db.QueryContext(ctx, DueSeasonRolloversSQL, now, limit)
 	if err != nil {
 		return 0, err

server/store/maintenance_sql_test.go

@@ -16,6 +16,11 @@ func TestMaintenanceSQLEnumeratesOnlyUnrolledRankedPlayers(t *testing.T) {
 			t.Fatalf("mark query missing %q", fragment)
 		}
 	}
+	for _, fragment := range []string{"s.playlist = 'ranked'", "s.ends_at <= $1", "s.rolled_over_at IS NULL", "NOT EXISTS", "ranked_season_rollovers"} {
+		if !contains(MarkEmptySeasonsSQL, fragment) {
+			t.Fatalf("empty-season query missing %q", fragment)
+		}
+	}
 }
 
 func TestRolloverDueSeasonsRejectsUnboundedMaintenance(t *testing.T) {

server/store/postgres_integration_test.go

@@ -1255,6 +1255,26 @@ func TestPostgreSQLRankedSeasonRolloverIsExactlyOnce(t *testing.T) {
 	}
 }
 
+func TestPostgreSQLEmptyRankedSeasonIsMarkedRolledOver(t *testing.T) {
+	db := openIntegrationPostgres(t)
+	applyIntegrationMigrations(t, db)
+	now := time.Now().UTC().Truncate(time.Microsecond)
+	ctx := context.Background()
+	if _, err := db.ExecContext(ctx, `INSERT INTO seasons (season_id, playlist, starts_at, ends_at) VALUES ('empty-season', 'ranked', $1, $2)`, now.Add(-12*7*24*time.Hour), now); err != nil {
+		t.Fatal(err)
+	}
+	if count, err := RolloverDueSeasons(ctx, db, now, 100); err != nil || count != 0 {
+		t.Fatalf("empty-season maintenance count=%d err=%v", count, err)
+	}
+	var rolledAt sql.NullTime
+	if err := db.QueryRowContext(ctx, `SELECT rolled_over_at FROM seasons WHERE season_id = 'empty-season'`).Scan(&rolledAt); err != nil {
+		t.Fatal(err)
+	}
+	if !rolledAt.Valid {
+		t.Fatal("empty ranked season was not marked rolled over")
+	}
+}
+
 func TestPostgreSQLMigrationsAreForwardExecutable(t *testing.T) {
 	db := openIntegrationPostgres(t)
 	applyIntegrationMigrations(t, db)