/**
 * @license Copyright (c) 2003-2026, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-licensing-options
 */
/**
 * @module utils/locale
 */
import { type ArrayOrItem } from './toarray.js';
import { type Message } from './translation-service.js';
import { type LanguageDirection } from './language.js';
/**
 * Represents the localization services.
 */
export declare class Locale {
    /**
     * The editor UI language code in the [ISO 639-1](https://en.wikipedia.org/wiki/ISO_639-1) format.
     *
     * If the {@link #contentLanguage content language} was not specified in the `Locale` constructor,
     * it also defines the language of the content.
     */
    readonly uiLanguage: string;
    /**
     * Text direction of the {@link #uiLanguage editor UI language}. Either `'ltr'` or `'rtl'`.
     */
    readonly uiLanguageDirection: LanguageDirection;
    /**
     * The editor content language code in the [ISO 639-1](https://en.wikipedia.org/wiki/ISO_639-1) format.
     *
     * Usually the same as the {@link #uiLanguage editor language}, it can be customized by passing an optional
     * argument to the `Locale` constructor.
     */
    readonly contentLanguage: string;
    /**
     * Text direction of the {@link #contentLanguage editor content language}.
     *
     * If the content language was passed directly to the `Locale` constructor, this property represents the
     * direction of that language.
     *
     * If the {@link #contentLanguage editor content language} was derived from the {@link #uiLanguage editor language},
     * the content language direction is the same as the {@link #uiLanguageDirection UI language direction}.
     *
     * The value is either `'ltr'` or `'rtl'`.
     */
    readonly contentLanguageDirection: LanguageDirection;
    /**
     * Translates the given message to the {@link #uiLanguage}. This method is also available in
     * {@link module:core/editor/editor~Editor#t `Editor`} and {@link module:ui/view~View#t `View`}.
     *
     * This method's context is statically bound to the `Locale` instance and **should always be called as a function**:
     *
     * ```ts
     * const t = locale.t;
     * t( 'Label' );
     * ```
     *
     * The message can be either a string or an object implementing the {@link module:utils/translation-service~Message} interface.
     *
     * The message may contain placeholders (`%<index>`) for value(s) that are passed as a `values` parameter.
     * For an array of values, the `%<index>` will be changed to an element of that array at the given index.
     * For a single value passed as the second argument, only the `%0` placeholders will be changed to the provided value.
     *
     * ```ts
     * t( 'Created file "%0" in %1ms.', [ fileName, timeTaken ] );
     * t( 'Created file "%0", fileName );
     * ```
     *
     * The message supports plural forms. To specify the plural form, use the `plural` property. Singular or plural form
     * will be chosen depending on the first value from the passed `values`. The value of the `plural` property is used
     * as a default plural translation when the translation for the target language is missing.
     *
     * ```ts
     * t( { string: 'Add a space', plural: 'Add %0 spaces' }, 1 ); // 'Add a space' for the English language.
     * t( { string: 'Add a space', plural: 'Add %0 spaces' }, 5 ); // 'Add 5 spaces' for the English language.
     * t( { string: '%1 a space', plural: '%1 %0 spaces' }, [ 2, 'Add' ] ); // 'Add 2 spaces' for the English language.
     *
     * t( { string: 'Add a space', plural: 'Add %0 spaces' }, 1 ); // 'Dodaj spację' for the Polish language.
     * t( { string: 'Add a space', plural: 'Add %0 spaces' }, 5 ); // 'Dodaj 5 spacji' for the Polish language.
     * t( { string: '%1 a space', plural: '%1 %0 spaces' }, [ 2, 'Add' ] ); // 'Dodaj 2 spacje' for the Polish language.
     * ```
     *
     *  * The message should provide an ID using the `id` property when the message strings are not unique and their
     * translations should be different.
     *
     * ```ts
     * translate( 'en', { string: 'image', id: 'ADD_IMAGE' } );
     * translate( 'en', { string: 'image', id: 'AN_IMAGE' } );
     * ```
     */
    readonly t: LocaleTranslate;
    /**
     * Object that contains translations.
     */
    translations?: Translations;
    /**
     * Creates a new instance of the locale class. Learn more about
     * {@glink getting-started/setup/ui-language configuring the language of the editor}.
     *
     * @param options Locale configuration.
     * @param options.uiLanguage The editor UI language code in the
     * [ISO 639-1](https://en.wikipedia.org/wiki/ISO_639-1) format. See {@link #uiLanguage}.
     * @param options.contentLanguage The editor content language code in the
     * [ISO 639-1](https://en.wikipedia.org/wiki/ISO_639-1) format. If not specified, the same as `options.language`.
     * See {@link #contentLanguage}.
     * @param options.translations Translations passed as a editor config parameter.
     */
    constructor({ uiLanguage, contentLanguage, translations }?: {
        readonly uiLanguage?: string;
        readonly contentLanguage?: string;
        readonly translations?: ArrayOrItem<Translations>;
    });
    /**
     * An unbound version of the {@link #t} method.
     */
    private _t;
}
/**
 * @param message A message that will be localized (translated).
 * @param values A value or an array of values that will fill message placeholders.
 * For messages supporting plural forms the first value will determine the plural form.
 */
export type LocaleTranslate = (message: string | Message, values?: number | string | ReadonlyArray<number | string>) => string;
/**
 * Translations object definition.
 */
export type Translations = {
    [language: string]: {
        dictionary: {
            [messageId: string]: string | ReadonlyArray<string>;
        };
        getPluralForm?: ((n: number) => number | boolean) | null;
    };
};