import type { UndoSnapshot } from './types.js';
import type { TimeValue } from '../../core/types/time.js';
import type { SpinButtonHandler } from '../spin-buttons/spin-button-group/types.js';
/**
 * Normalises a pasted ISO-like string so that downstream parsers can handle it:
 * - Uppercases the `T` separator and any trailing `z` / `Z` in the timezone.
 * - When a full ISO datetime has no timezone suffix, interprets it as local time
 *   in the user's configured timezone (per ISO 8601) and converts to UTC.
 * Non-ISO input is returned unchanged.
 * @internal
 */
export declare function normalizeISOInput(input: string): string;
/**
 * Parses a time-only string to a full ISO UTC datetime string anchored at `2000-01-01`.
 * Accepts: `HH:MM`, `HH:MMZ`, `HH:MM:SS`, `HH:MM:SS.mmm`, with optional `Z` / `±hh:mm` offset.
 * Returns `null` if the input does not represent a valid time.
 * @internal
 */
export declare function parseTimeOnlyToISO(input: string): string | null;
/**
 * Parses a date-only string matched against the strict ISO 8601 date format (`YYYY-MM-DD`).
 * Returns a full ISO UTC midnight datetime string, or `null` if the input is not a valid date.
 * @internal
 */
export declare function parseDateOnlyToISO(input: string, anchor?: 'startOfDay' | 'endOfDay'): string | null;
/**
 * Captures the current state of a DateTimeInput's spinbuttons and expression input.
 * @internal
 */
export declare const captureUndoSnapshot: (spinButtonHandlers: Map<keyof Intl.DateTimeFormatPartTypesRegistry, SpinButtonHandler | null | undefined>, expressionRef: HTMLSpanElement | null | undefined, value: TimeValue | null, valueType: "expression" | "iso8601") => UndoSnapshot;
type DateFieldType = 'day' | 'month' | 'year';
export type PartialDate = Partial<Record<DateFieldType, number>>;
/**
 * Extracts a partial date from an input string using the user's regional date format.
 * Returns a `PartialDate` with `day`, `month`, and/or `year` fields mapped according
 * to the locale's field order. Handles incomplete inputs like `"12/"` or `"12.2024"`.
 * Returns `null` if no date pattern is found.
 * @internal
 */
export declare function tryParsePartialDate(input: string): PartialDate | null;
type TimeFieldType = 'hour' | 'minute' | 'second' | 'millisecond';
export type PartialTime = Partial<Record<TimeFieldType, number>> & {
    dayPeriod?: string;
};
/**
 * Extracts a partial time from an input string using the user's regional time format.
 * Returns a `PartialTime` with `hour`, `minute`, `second`, `millisecond`, and/or
 * `dayPeriod` fields. Requires two-digit hours, minutes, and seconds.
 * For 12-hour locales, optionally matches the locale-specific AM/PM label.
 * Returns `null` if no time pattern is found.
 * @internal
 */
export declare function tryParsePartialTime(input: string): PartialTime | null;
export type PartialDateTimeResult = {
    /** Normalized ISO string that can be applied to spin buttons. */
    iso: string;
    /**
     * If set, only these spin button parts should be updated (partial result).
     * When absent the result is complete and can be fed through the existing
     * paste pipeline (date-only / time-only / full ISO).
     */
    partsToUpdate?: Set<keyof Intl.DateTimeFormatPartTypesRegistry>;
};
/**
 * Converts partial date and/or time objects into an ISO-compatible string.
 *
 * - Complete date + complete time → full ISO datetime (no `partsToUpdate`).
 * - Complete date only → `"YYYY-MM-DD"` (no `partsToUpdate`).
 * - Complete time only → `"HH:MM[:SS[.mmm]]"` (no `partsToUpdate`).
 * - Partial fields → ISO string with defaults filled in, plus a `partsToUpdate`
 *   set that lists only the spin button parts that should actually be applied.
 * - No fields at all → `null`.
 *
 * A date is "complete" when it has `day`, `month`, and `year`.
 * A time is "complete" when it has `hour` and `minute`.
 * @internal
 */
export declare function partialDateTimeToISO(date: PartialDate | null, time: PartialTime | null): PartialDateTimeResult | null;
export {};