import { EventEmitter } from "node:events";
import * as pcsc from "./addon.node";
import { type Err } from "./addon.node";
import { Reader } from "./reader";
export { type Err };
export import MAX_READERS = pcsc.MAX_READERS;
/**
 * Represents a PCSC client connection. Provides notifications for reader
 * connection state changes via an {@link EventEmitter} interface.
 *
 * ## Events
 * - **`"error"` [ {@link Err} ]** - Emitted when an error is encountered
 *   while monitoring for reader state updates in the background thread.
 * - **`"reader"` [ {@link Reader} ]** - Emitted once for each card reader when
 *   it is detected (connected/re-connected to the system) and also once for
 *   each reader that is already connected when monitoring is {@link start}ed.
 *
 * ## Example
 * ```ts
 * import * as pcsc from "pcsc-mini";
 *
 * const client = new pcsc.Client()
 *   .on("reader", onReader);
 *   .on("error", onError);
 *   .start(); // Start monitoring for reader state changes.
 *
 * function onError(err: pcsc.Err) {
 *   console.error("Unexpected PCSC error:", err);
 *   client.stop();
 * };
 *
 * function onReader(reader: pcsc.Reader) {
 *   console.log(`Reader detected: ${reader}`);
 *   // ...
 * }
 * ```
 */
export declare class Client extends EventEmitter<{
    error: [Err];
    reader: [Reader];
}> {
    #private;
    constructor(addon?: typeof pcsc);
    /**
     * The reader identified by `name`, if it is currently connected.
     */
    reader(name: string): Reader | undefined;
    /**
     * `true` if the reader state monitoring thread is currently running.
     */
    running(): boolean;
    /**
     * Start monitoring for reader status changes.
     *
     * A subsequent call to {@link stop} will stop monitoring and detach
     * this client.
     *
     * @throws {@link Err}
     */
    start(): Client;
    /**
     * Stop monitoring for reader status changes and detach the client from the
     * PCSC server. Any in-progress transmissions will be cancelled.
     *
     * Monitoring can be resumed with another call to {@link start};
     *
     * @throws {@link Err}
     */
    stop(): void;
}