-- Ensure every saved billing rule can be executed by the invoice job.
UPDATE sag_subscriptions
SET billing_schedule_type = 'interval_anchor',
    updated_at = CURRENT_TIMESTAMP
WHERE billing_interval IN ('daily', 'biweekly')
  AND billing_schedule_type IS DISTINCT FROM 'interval_anchor';

UPDATE sag_subscriptions
SET billing_schedule_type = 'fixed_day',
    updated_at = CURRENT_TIMESTAMP
WHERE billing_interval IN ('monthly', 'quarterly', 'yearly')
  AND billing_schedule_type = 'interval_anchor';

ALTER TABLE sag_subscriptions
    DROP CONSTRAINT IF EXISTS sag_subscriptions_runnable_schedule_check;
ALTER TABLE sag_subscriptions
    ADD CONSTRAINT sag_subscriptions_runnable_schedule_check CHECK (
        (billing_interval IN ('daily', 'biweekly') AND billing_schedule_type = 'interval_anchor')
        OR
        (billing_interval IN ('monthly', 'quarterly', 'yearly')
         AND billing_schedule_type IN ('fixed_day', 'first_business_day', 'last_business_day'))
    );

-- Existing legacy days 29-31 remain visible for manual review, but new/updated
-- fixed-day rules must always be executable.
ALTER TABLE sag_subscriptions
    DROP CONSTRAINT IF EXISTS sag_subscriptions_runnable_billing_day_check;
ALTER TABLE sag_subscriptions
    ADD CONSTRAINT sag_subscriptions_runnable_billing_day_check CHECK (
        billing_schedule_type <> 'fixed_day' OR billing_day BETWEEN 1 AND 28
    ) NOT VALID;