/** Matches web invoice-form default numbering. */
export function generateInvoiceNumber(): string {
  const date = new Date().toISOString().slice(0, 10).replace(/-/g, "");
  return `INV-${date}-${String(Date.now()).slice(-6)}`;
}

export function defaultDueDate(issueDate: Date): Date {
  const due = new Date(issueDate);
  due.setDate(due.getDate() + 30);
  return due;
}