import { Provider, InjectionToken } from '@angular/core';

type DefaultModuleImport = Promise<{
    [key: string]: unknown;
    default?: unknown;
}>;

declare enum G11nDebug {
    SHOW_KEYS = 0,
    DUMMY_TRANSLATIONS = 1,
    NO_DEBUG = 2
}

interface G11nOptions {
    /**
     * The default language to use when no language is detected or provided.
     * @example 'en', 'fr-CH'
     * @default 'fr-CH'
     */
    defaultLanguage?: string;
    /**
     * The default currency code used for formatting values.
     * Must be a valid ISO 4217 currency code.
     * @example 'USD', 'EUR', 'CHF'
     * @default 'CHF'
     */
    defaultCurrency?: string;
    /**
     * Whether to automatically detect and use the browser's language (via navigator.language).
     * @default true
     */
    useNavigatorLanguage?: boolean;
    /**
     * Whether to load Angular locale extra data (e.g. pluralization rules, date formats).
     * @default false
     */
    loadLocaleExtra?: boolean;
    /**
     * Enables or disables the translation system.
     * If false, only locale-based formatting will be applied.
     * @default true
     */
    useTranslations?: boolean;
    /**
     * Root path where translation files are located.
     * @default '/translations' (or '/assets/translations' for legacy apps)
     */
    rootTranslationsPath?: string;
    /**
     * List of translation scopes to load from the root translations folder.
     * Each scope typically represents a feature/module-specific translation folder.
     * @example ['common', 'auth', 'dashboard']
     * @default []
     */
    translationScopes?: string[];
    /**
     * Name of the query parameter used to override the active language.
     * @example '?lang=en'
     * @default 'lang'
     */
    queryParamName?: string;
    /**
     * Storage mechanism used to persist user preferences.
     * Typically localStorage or sessionStorage.
     * @default localStorage
     */
    storage?: Storage;
    /**
     * Debug configuration for logging and development diagnostics.
     * @default G11nDebug.NO_DEBUG
     */
    debug?: G11nDebug;
}

interface G11nFeature<T = Provider> {
    providers: T[];
}

interface G11nLocale {
    base: () => DefaultModuleImport;
    extra?: () => DefaultModuleImport;
    datefns?: () => DefaultModuleImport;
    translationFilename?: string;
}

/**
 * @internal
 */
declare const DEFAULT_OPTIONS: G11nOptions;
declare const currentLanguage: () => string;
declare const setLanguage: (value: string) => void;
/**
 * Initializes G11N providers.
 * @internal
 * @returns An array of Angular providers for G11N initialization.
 */
declare const init: () => Provider[];

declare const LOCALES: InjectionToken<Record<string, G11nLocale>>;
declare const G11N_OPTIONS: InjectionToken<G11nOptions>;

export { DEFAULT_OPTIONS, G11N_OPTIONS, G11nDebug, LOCALES, currentLanguage, init, setLanguage };
export type { DefaultModuleImport, G11nFeature, G11nLocale, G11nOptions };