import type { TimerOptions } from 'node:timers';
export declare let platform: Platform;
export declare function set_platform(_platform: Platform): void;
export interface NewWebSocketOptions {
    protocols?: string | string[];
    proxy?: string;
    /** 默认不启用 keep alive */
    keep_alive_duration?: undefined | number;
}
interface Platform {
    /** 在 nodejs 环境中 */
    nodejs: boolean;
    /** 在 browser 环境中 */
    browser: boolean;
    get_buffer(length: number): Uint8Array<ArrayBuffer>;
    encode(str: string): Uint8Array<ArrayBuffer>;
    delay(milliseconds: number, options?: TimerOptions): Promise<void>;
    strip_ansi(str: string): string;
    /** 根据环境 new 一个 undici 的 WebSocket 或者浏览器全局的 WebSocket */
    new_websocket(url: string | URL, options?: NewWebSocketOptions): Promise<WebSocket> | WebSocket;
}
export {};