-- Migration 132: Add cancellation rules to subscriptions
-- Adds fields for notice period, cancellation date, and termination order tracking

ALTER TABLE sag_subscriptions
ADD COLUMN IF NOT EXISTS notice_period_days INTEGER DEFAULT 30 CHECK (notice_period_days >= 0),
ADD COLUMN IF NOT EXISTS cancelled_at TIMESTAMP,
ADD COLUMN IF NOT EXISTS cancelled_by_user_id INTEGER REFERENCES users(user_id),
ADD COLUMN IF NOT EXISTS cancellation_sag_id INTEGER REFERENCES sag_sager(id),
ADD COLUMN IF NOT EXISTS cancellation_reason TEXT;

CREATE INDEX IF NOT EXISTS idx_sag_subscriptions_cancelled_at ON sag_subscriptions(cancelled_at);

COMMENT ON COLUMN sag_subscriptions.notice_period_days IS 'Number of days notice required for cancellation (default 30)';
COMMENT ON COLUMN sag_subscriptions.cancelled_at IS 'When the cancellation was requested';
COMMENT ON COLUMN sag_subscriptions.cancelled_by_user_id IS 'User who requested cancellation';
COMMENT ON COLUMN sag_subscriptions.cancellation_sag_id IS 'Case created for the cancellation process';
COMMENT ON COLUMN sag_subscriptions.cancellation_reason IS 'Reason for cancellation';