-- Optimistic locking for the match actor, the hosting IRC account for
-- rejoining after a restart, and an undo log for rating changes.
ALTER TABLE match ADD COLUMN IF NOT EXISTS revision integer NOT NULL DEFAULT 0;
ALTER TABLE match ADD COLUMN IF NOT EXISTS irc_account text;

CREATE TABLE IF NOT EXISTS rating_change (
	id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
	match_id uuid NOT NULL REFERENCES match(id) ON DELETE CASCADE,
	subject text NOT NULL,
	subject_id text NOT NULL,
	before integer NOT NULL,
	after integer NOT NULL,
	won boolean NOT NULL,
	created_at timestamptz NOT NULL DEFAULT now()
);
CREATE INDEX IF NOT EXISTS idx_rating_change_match ON rating_change (match_id);
CREATE INDEX IF NOT EXISTS idx_rating_change_subject ON rating_change (subject_id);

-- Matches the previous process left mid-flight are resumed by the runtime.
CREATE INDEX IF NOT EXISTS idx_match_game_match_state ON match_game (match_id, state);