import { TransactionI } from "../api/transactions/interface";
/**
 * resolvePaymentDueDate
 *
 * Returns the **effective** `paymentDueDate` (calendar day) to use for downstream
 * processing / API calls based on a list of transactions.
 *
 * ## Key idea
 * `paymentDueDate` is treated as a **date-only** concept (YYYY-MM-DD). We explicitly
 * ignore hours/minutes/seconds to avoid timezone shifting bugs (e.g. an ISO UTC
 * midnight timestamp appearing as the prior day in some local timezones).
 *
 * ## Rules (evaluated by calendar day)
 * 1) If **any** transaction has a valid `paymentDueDate` that is **today or in the past**,
 *    return **today**.
 *    - This matches the behavior where past-due transactions are processed on the current day.
 *
 * 2) If **all valid** `paymentDueDate` values are **in the future**, return the **closest / next**
 *    future date (the minimum future date).
 *
 * 3) If there are **no valid** `paymentDueDate` values (missing, null, or invalid),
 *    return **today**.
 *
 * ## Input handling
 * - Accepts `paymentDueDate` as a string (ISO timestamp or YYYY-MM-DD), Date, or Dayjs.
 * - For ISO strings like "2026-03-09T00:00:00.000Z", the resolver preserves the calendar
 *   day by extracting the "YYYY-MM-DD" portion rather than converting to a local Date/instant.
 *
 * ## Return value
 * - Returns a string in "YYYY-MM-DD" format suitable for use as a date-only API parameter.
 *
 * ## Examples
 * - Due dates: [2026-03-09, 2026-03-10], today=2026-03-08 => returns "2026-03-09"
 * - Due dates: [2026-03-01, 2026-03-10], today=2026-03-08 => returns "2026-03-08" (today)
 * - Due dates: [2026-03-01, 2026-03-02], today=2026-03-08 => returns "2026-03-08" (today)
 * - Due dates: [] / all null / invalid => returns "2026-03-08" (today)
 */
declare function resolvePaymentDueDate(transactionList: TransactionI[]): string;
export default resolvePaymentDueDate;