export {};

declare global {
  /**
   * A helper class which assists with localization and string translation
   */
  class Localization {
    /**
     * @param serverLanguage - The default language configuration setting for the server
     */
    constructor(serverLanguage?: string);

    /**
     * The target language for localization
     * @defaultValue `"en"`
     */
    lang: string;

    /**
     * The package authorized to provide default language configurations
     * @defaultValue `"core"`
     */
    defaultModule: string;

    /**
     * The translation dictionary for the target language
     * @defaultValue `{}`
     */
    translations: Localization.Translations;

    /**
     * Fallback translations if the target keys are not found
     * @defaultValue `{}`
     */
    protected _fallback: Localization.Translations;

    /**
     * Initialize the Localization module
     * Discover available language translations and apply the current language setting
     * @returns A Promise which resolves once languages are initialized
     */
    initialize(): Promise<void>;

    /**
     * Perform one-time localization of the fields in a DataModel schema, translating their label and hint properties.
     * @param model   - The DataModel class to localize
     * @param options - Options which configure how localization is performed
     *
     * @example
     * JavaScript class definition and localization call.
     * ```js
     * class MyDataModel extends foundry.abstract.DataModel {
     *   static defineSchema() {
     *     return {
     *       foo: new foundry.data.fields.StringField(),
     *       bar: new foundry.data.fields.NumberField()
     *     };
     *   }
     *   static LOCALIZATION_PREFIXES = ["MYMODULE.MYDATAMODEL"];
     * }
     *
     * Hooks.on("i18nInit", () => {
     *   Localization.localizeDataModel(MyDataModel);
     * });
     * ```
     *
     * JSON localization file
     * ```json
     * {
     *   "MYMODULE": {
     *     "MYDATAMODEL": {
     *       "FIELDS" : {
     *         "foo": {
     *           "label": "Foo",
     *           "hint": "Instructions for foo"
     *         },
     *         "bar": {
     *           "label": "Bar",
     *           "hint": "Instructions for bar"
     *         }
     *       }
     *     }
     *   }
     * }
     * ```
     */
    static localizeDataModel(
      model: foundry.abstract.DataModel.AnyConstructor,
      options?: Localization.LocalizeDataModelOptions,
    ): void;

    /**
     * Set a language as the active translation source for the session
     * @param lang - A language string in CONFIG.supportedLanguages
     * @returns A Promise which resolves once the translations for the requested language are ready
     */
    setLanguage(lang: string): Promise<void>;

    /**
     * Discover the available supported languages from the set of packages which are provided
     */
    protected _discoverSupportedLanguages(): Record<string, string>;

    /**
     * Prepare the dictionary of translation strings for the requested language
     * @param lang - The language for which to load translations
     * @returns The retrieved translations object
     */
    protected _getTranslations(lang: string): Promise<Localization.Translations>;

    /**
     * Reduce the languages array provided by a package to an array of file paths of translations to load
     * @param pkg  - The package data
     * @param lang - The target language to filter on
     * @returns An array of translation file paths
     */
    protected _filterLanguagePaths(pkg: World | Module | System, lang: string): string[];

    /**
     * Load a single translation file and return its contents as processed JSON
     * @param src - The translation file path to load
     * @returns The loaded translation dictionary
     */
    protected _loadTranslationFile(src: string): Promise<Localization.Translations>;

    /**
     * Return whether a certain string has a known translation defined.
     * @param stringId - The string key being translated
     * @param fallback - Allow fallback translations to count?
     */
    has(stringId: string, fallback?: boolean): boolean;

    /**
     * Localize a string by drawing a translation from the available translations dictionary, if available
     * If a translation is not available, the original string is returned
     * @param stringId - The string ID to translate
     * @returns The translated string
     *
     * @example <caption>Localizing a simple string in JavaScript</caption>
     * ```typescript
     * {
     *   "MYMODULE.MYSTRING": "Hello, this is my module!"
     * }
     * game.i18n.localize("MYMODULE.MYSTRING"); // Hello, this is my module!
     * ```
     *
     * @example <caption>Localizing a simple string in Handlebars</caption>
     * ```handlebars
     * {{localize "MYMODULE.MYSTRING"}} <!-- Hello, this is my module! -->
     * ```
     */
    localize(stringId: string): string;

    /**
     * Localize a string including variable formatting for input arguments.
     * Provide a string ID which defines the localized template.
     * Variables can be included in the template enclosed in braces and will be substituted using those named keys.
     *
     * @param stringId - The string ID to translate
     * @param data     - Provided input data
     *                   (defaultValue: `{}`)
     * @returns The translated and formatted string
     *

     * @example <caption>Localizing a formatted string in JavaScript</caption>
     * ```typescript
     * {
     *   "MYMODULE.GREETING": "Hello {name}, this is my module!"
     * }
     * game.i18n.format("MYMODULE.GREETING" {name: "Andrew"}); // Hello Andrew, this is my module!
     * ```
     *
     * @example <caption>Localizing a formatted string in Handlebars</caption>
     * ```handlebars
     * {{localize "MYMODULE.GREETING" name="Andrew"}} <!-- Hello, this is my module! -->
     * ```
     */
    format(stringId: string, data?: Record<string, unknown>): string;

    /**
     * Retreive list formatter configured to the world's language setting.
     * @see {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/ListFormat/ListFormat | Intl.ListFormat}
     */
    getListFormatter(options?: Localization.GetListFormatterOptions): Intl.ListFormat;

    /**
     * Sort an array of objects by a given key in a localization-aware manner.
     * @param objects - The objects to sort, this array will be mutated
     * @param key     - The key to sort the objects by. This can be provided in dot-notation.
     */
    // TODO(LukeAbby): Should be constrainted to dot property keys of `objects`
    sortObjects<T extends object>(objects: Array<T>, key: string): T[];
  }

  namespace Localization {
    interface Translations {
      [K: string]: string | Translations;
    }

    interface LocalizeDataModelOptions {
      /**
       * An array of localization key prefixes to use. If not specified, prefixes
       * are learned from the DataModel.LOCALIZATION_PREFIXES static property.
       */
      prefixes?: string[] | undefined;

      /**
       * A localization path prefix used to prefix all field names within this model. This is generally not required.
       */
      prefixPath?: string | undefined;
    }

    interface GetListFormatterOptions {
      /**
       * The list formatter style, either "long", "short", or "narrow".
       */
      style?: Intl.ListFormatStyle | undefined;

      /**
       * The list formatter type, either "conjunction", "disjunction", or "unit".
       */
      type?: Intl.ListFormatType | undefined;
    }
  }
}