import type { Locale } from "date-fns";
import { vi as viDayPicker } from "react-day-picker/locale";
import type { AppLocale } from "./types.js";
export { getRegisteredLocales, resolveRegisteredLocale, resolveDefaultLocale, resolvePageLocale, } from "../i18n/locale-tags.js";
/** A react-day-picker locale: a date-fns `Locale` plus optional `labels`. */
export type DayPickerLocale = typeof viDayPicker;
export type AppLocaleConfig = {
    code: AppLocale;
    dateFns: Locale;
    dayPicker: DayPickerLocale;
};
/**
 * What `registerLocale` takes. Only `code` is required: without `dateFns` the date adapter is built
 * from `Intl` (month/weekday names, long date patterns, week start), and without `dayPicker` the
 * calendar uses that same adapter.
 */
export type RegisterLocaleInput = {
    /** Any BCP-47 tag — `de`, `pt-BR`, `en-GB`, `ar`. Canonicalised (`pt-br` → `pt-BR`). */
    code: string;
    /** This locale's strings. For a locale the library does not ship, its own namespaces too. */
    messages?: Record<string, unknown>;
    /** A date-fns locale (`import { de } from "date-fns/locale"`). */
    dateFns?: Locale;
    /** A react-day-picker locale (`import { de } from "react-day-picker/locale"`). */
    dayPicker?: DayPickerLocale;
};
/**
 * First day of the week for `code`, as date-fns counts it (0 = Sunday … 6 = Saturday).
 *
 * From `Intl.Locale#getWeekInfo` (or the older `.weekInfo` getter) where the engine has it; else
 * the pack's own `weekStartsOn`; else the region's CLDR first day, Monday (ISO 8601) by default.
 */
export declare function getLocaleWeekStart(code: string, pack?: Pick<Locale, "options">): 0 | 1 | 2 | 3 | 4 | 5 | 6;
/**
 * Every registered locale's date adapters. `vi`, `en` and `ja` are pre-registered with the packs
 * they always had; `registerLocale` adds the rest. Exported for compatibility — read it through
 * `getDateFnsLocale` / `getDayPickerLocale`, which also handle an unregistered tag.
 */
export declare const APP_LOCALE_CONFIG: Record<string, AppLocaleConfig>;
/** The three locales the library ships packs for. */
export declare const BUILT_IN_LOCALES: readonly ["vi", "en", "ja"];
/**
 * REGISTER A LOCALE — any BCP-47 tag (v32, gh#1219).
 *
 * The locale set used to be a closed union of three, so a German or Brazilian app could not get
 * German dates or a Monday/Sunday week from this package at all. Register once at startup, before
 * the first render:
 *
 * ```ts
 * import { de } from "date-fns/locale";
 * import { de as deDayPicker } from "react-day-picker/locale";
 * registerLocale({ code: "de", messages: deMessages, dateFns: de, dayPicker: deDayPicker });
 * ```
 *
 * Registering an already-registered tag updates it (messages merge; adapters given replace).
 * Returns the canonical tag.
 */
export declare function registerLocale(input: RegisterLocaleInput): AppLocale;
/** Whether `value` is a REGISTERED locale tag (exactly, after canonicalisation). */
export declare function isAppLocale(value: string | null | undefined): value is AppLocale;
/**
 * The registered locale that serves `tag` (`de-AT` → `de`), or — with one development warning —
 * the default locale (`<html lang>` if registered, else `en`).
 */
export declare function normalizeAppLocale(tag: string | null | undefined): AppLocale;
export declare function getDateFnsLocale(locale: AppLocale): Locale;
export declare function getDayPickerLocale(locale: AppLocale): DayPickerLocale;