/**
 * Extract locale from URL pathname and validate it
 */
interface I18nLocales {
    locales: string[];
}
/**
 * Extract language code from pathname if it exists and is valid
 * @param pathname - The URL pathname (e.g., '/zh/about' or '/en-US/products')
 * @returns The language code if found and valid, null otherwise
 *
 * @example
 * extractLocaleFromPathname('/zh/about') // 'zh'
 * extractLocaleFromPathname('/en-US/products') // 'en-US'
 * extractLocaleFromPathname('/notlang/about') // null
 * extractLocaleFromPathname('/about') // null
 */
export declare function extractLocaleFromPathname(pathname: string): string | null;
/**
 * Extract locale from pathname and check if it's supported by the app
 * @param pathname - The URL pathname
 * @param i18n - The i18n instance to check supported locales
 * @returns The language code if found, valid, and supported, null otherwise
 *
 * @example
 * extractSupportedLocaleFromPathname('/zh/about', i18n) // 'zh' if supported
 * extractSupportedLocaleFromPathname('/eng/about', i18n) // null if not supported
 */
export declare function extractSupportedLocaleFromPathname(pathname: string, i18n: I18nLocales): string | null;
/**
 * Get the best locale based on priority:
 * 1. URL pathname locale (if valid and supported)
 * 2. Provided fallback locale (cookie/localStorage)
 * 3. Default locale
 *
 * @param pathname - The URL pathname
 * @param i18n - The i18n instance
 * @param fallbackLocale - The fallback locale from cookie/localStorage
 * @param defaultLocale - The default locale
 * @param availableLocales - Optional array of all available locales (including auto-discovered)
 * @returns The best locale based on priority
 *
 * @example
 * getBestLocale('/zh/about', i18n, 'en', 'fr') // 'zh' if supported
 * getBestLocale('/xyz/about', i18n, 'en', 'fr') // 'en' (fallback)
 * getBestLocale('/about', i18n, null, 'fr') // 'fr' (default)
 */
export declare function getBestLocale(pathname: string, i18n: I18nLocales, fallbackLocale: string | null | undefined, defaultLocale: string, availableLocales?: string[]): string;
/**
 * Check if a locale should be loaded based on pathname priority
 * Returns true if the pathname locale takes precedence over current locale
 *
 * @param pathname - The URL pathname
 * @param i18n - The i18n instance
 * @param currentLocale - The current locale
 * @returns True if pathname locale should override current locale
 */
export declare function shouldUsePathnameLocale(pathname: string, i18n: I18nLocales, currentLocale: string): boolean;
export {};