Visit-pack balance invariant: reviewer evidence pack

DO $$
BEGIN
  IF EXISTS (
    SELECT 1
    FROM "membership_plans"
    WHERE "name" <> '__staff_comp_credits__'
      AND "plan_type" = 'visit_pack'
      AND ("visit_count" IS NULL OR "visit_count" NOT BETWEEN 0.01 AND 99999999.99)
  ) THEN
    RAISE EXCEPTION 'membership_plans contains visit packs without a finite positive visit_count; deactivate and repair each plan before retrying migration 0194';
  END IF;
END
$$;
--> statement-breakpoint
ALTER TABLE "membership_plans" ADD CONSTRAINT "membership_plans_visit_pack_count_positive" CHECK ("membership_plans"."name" = '__staff_comp_credits__' OR "membership_plans"."plan_type" <> 'visit_pack' OR ("membership_plans"."visit_count" IS NOT NULL AND "membership_plans"."visit_count" BETWEEN 0.01 AND 99999999.99));

export function membershipPlanVisitBalance(
  plan: MembershipPlanBalanceSource,
): string | null {
  if (plan.planType !== "visit_pack") return null;
  if (
    plan.visitCount == null ||
    !isValidCreditAmount(plan.visitCount) ||
    Number(plan.visitCount) <= 0 ||
    Number(plan.visitCount) > 99999999.99
  ) {
    throw new Error("Visit-pack plan has no positive visit count");
  }
  return plan.visitCount;
}

const selectedPlan = plan[0];
try {
  membershipPlanVisitBalance(selectedPlan);
} catch {
  return c.json(
    {
      error:
        "This visit pack is missing a positive visit count. Choose another plan.",
    },
    409,
  );
}

const refundIdempotencyKey =
  reason === "invalid_plan"
    ? `invalid-plan-refund-${paymentRow.id}`
    : `duplicate-refund-${paymentRow.id}`;

let visitBalance: string | null;
try {
  visitBalance = membershipPlanVisitBalance(plan);
} catch {
  await refundRejectedMembership("invalid_plan");
  return;
}

await refundSquarePayment(squareClient, {
  paymentId: squarePaymentId,
  amount: formattedAmount,
  currency,
  reason:
    reason === "invalid_plan"
      ? "Visit-pack plan has no finite positive visit count"
      : "Customer already has an active membership",
  idempotencyKey: `refund-${payment.id}`,
});
await db
  .update(payments)
  .set({ status: "refunded", squarePaymentId, updatedAt: new Date() })
  .where(eq(payments.id, payment.id));

let visitBalance: string | null;
try {
  visitBalance = membershipPlanVisitBalance(plan);
} catch {
  await refundRejectedMembership("invalid_plan");
  return;
}