/**
* @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;
	};
};