import { addCalendarDays } from "@beenvoice/domain/time-zone";

/** 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 {
  return addCalendarDays(issueDate, 30);
}