const notify = `
CREATE OR REPLACE FUNCTION notify_event() RETURNS TRIGGER AS $$
    DECLARE
        record RECORD;
        id UUID;
        payload JSON;
    BEGIN
    IF (TG_OP = 'DELETE') THEN
        id = OLD.id;
    ELSE
        id = NEW.id;
    END IF;

    payload = json_build_object(
        'table', TG_TABLE_NAME,
        'action', TG_OP,
        'id', id
    );

    PERFORM pg_notify('events', payload::text);

    RETURN NULL;
    END;

$$ LANGUAGE plpgsql;
`;

const trigger = table => `
CREATE TRIGGER notify_${table}_event
AFTER INSERT OR UPDATE OR DELETE ON ${table}
    FOR EACH ROW EXECUTE PROCEDURE notify_event();
`;

exports.up = async knex => {
    await knex.raw(notify);
    await knex.raw(trigger('accounts'));
    await knex.raw(trigger('games'));
    await knex.raw(trigger('instances'));
};

exports.down = async () => {};