/**
 * WebSocket Worker — runs WebSocket connection off the main thread.
 *
 * Communication with main thread via postMessage:
 *
 * Main → Worker:
 *   { type: 'connect', url: string, protocols?: string[] }
 *   { type: 'send', data: unknown }
 *   { type: 'disconnect' }
 *
 * Worker → Main:
 *   { type: 'open' }
 *   { type: 'message', data: unknown }
 *   { type: 'close', code: number, reason: string }
 *   { type: 'error', message: string }
 *   { type: 'state', state: SocketState }
 */
type SocketState = 'connecting' | 'connected' | 'reconnecting' | 'closed' | 'failed';
interface WorkerCommand {
    type: 'connect' | 'send' | 'disconnect' | 'reconnect';
    url?: string;
    protocols?: string[];
    data?: unknown;
    reconnect?: boolean;
    reconnectMaxDelay?: number;
    reconnectMaxRetries?: number;
    authFailureCloseCodes?: number[];
    heartbeatInterval?: number;
    heartbeatTimeout?: number;
    bufferSize?: number;
}
declare let ws: WebSocket | null;
declare let state: SocketState;
declare let buffer: unknown[];
declare let heartbeatTimer: ReturnType<typeof setInterval> | null;
declare let reconnectTimer: ReturnType<typeof setTimeout> | null;
declare let disposed: boolean;
declare let currentUrl: string;
declare let currentProtocols: string[];
declare let shouldReconnect: boolean;
declare let maxDelay: number;
declare let maxRetries: number;
declare let authFailureCloseCodes: Set<number>;
declare let heartbeatInterval: number;
declare let heartbeatTimeout: number;
declare let lastInboundAt: number;
declare let maxBuffer: number;
declare let backoffDelay: number;
declare let reconnectAttempts: number;
declare function setState(s: SocketState): void;
declare function connect(url: string, protocols: string[]): void;
declare function doConnect(): void;
declare function send(data: unknown): void;
declare function disconnect(): void;
declare function flushBuffer(): void;
declare function startHeartbeat(): void;
declare function stopHeartbeat(): void;
declare function scheduleReconnect(): void;
declare function manualReconnect(): void;
declare function clearReconnect(): void;