/** Matches web invoice-form default numbering. */
export function generateInvoiceNumber(now = new Date()): string {
  const date = [
    now.getFullYear(),
    String(now.getMonth() + 1).padStart(2, "0"),
    String(now.getDate()).padStart(2, "0"),
  ].join("");

  return `INV-${date}-${String(now.getTime()).slice(-6)}`;
}

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