-- +goose Up
ALTER TABLE game_exports ADD COLUMN released_at TIMESTAMPTZ;
DROP INDEX game_exports_active;
CREATE UNIQUE INDEX game_exports_active ON game_exports(game_id)
    WHERE state IN ('preparing', 'ready') AND released_at IS NULL;

-- +goose Down
-- Refuse rollback if retained ready exports cannot fit the old unique index.
DROP INDEX game_exports_active;
CREATE UNIQUE INDEX game_exports_active ON game_exports(game_id) WHERE state IN ('preparing', 'ready');
ALTER TABLE game_exports DROP COLUMN released_at;