-- A round that is abandoned is not the same as a round that settled.
--
-- Settlement means an outcome was produced, which is why reveal_is_complete
-- requires a settled round to publish its seed. A round whose instance died
-- mid-flight has no outcome at all: there is nothing to reveal, and marking it
-- settled would either violate that constraint or, worse, publish a seed for a
-- round that never resolved.
--
-- Voiding is its own state: stakes are returned and the round is closed with no
-- result.

ALTER TABLE rounds ADD COLUMN voided_at TIMESTAMPTZ;

COMMENT ON COLUMN rounds.voided_at IS
    'Set when a round was abandoned and its stakes refunded. Mutually exclusive with settled_at.';

ALTER TABLE rounds ADD CONSTRAINT round_not_both_settled_and_void
    CHECK (settled_at IS NULL OR voided_at IS NULL);

CREATE INDEX rounds_unresolved_idx ON rounds (opened_at)
    WHERE settled_at IS NULL AND voided_at IS NULL;