import { Injectable } from '@angular/core';
import { Config } from '../../config/config-tokens';
import { TranslationResources } from '../translation-resources';

@Injectable({
  providedIn: 'root',
  useExisting: Config,
})
export abstract class I18nConfig {
  i18n?: {
    /**
     * When there are missing translation resources for the active language, the fallback language will be used.
     */
    fallbackLang?: string | false;

    /**
     * Configuration for lazy loading of translation files.
     * For eager loading of translations please use config option `i18n.resources`
     */

    backend?: {
      /**
       * The path to JSON translations. It should contain placeholders:
       * - `{{lng}}` for language
       * - `{{ns}}` for the name of chunk.
       *
       * Example:
       * `assets/i18n-assets/{{lng}}/{{ns}}.json`
       */

      loadPath?: string;
    };

    /**
     * Reference to translation resources that are eagerly bundled with JS app.
     * For lazy loading of translations please use config option `i18n.backend` instead.
     */
    resources?: TranslationResources;

    /**
     * Logs i18n events (like loading translation resources) to the console. Don't use in production!
     */
    debug?: boolean;

    /**
     * Mapping that assigns keys' namespaces to specific chunks. The main purpose of chunks is to lazy load them.
     */
    chunks?: {
      [chunk: string]: string[];
    };
  };
}

declare module '../../config/config-tokens' {
  interface Config extends I18nConfig {}
}