/**
 * @author Martin Karkowski
 * @email m.karkowski@zema.de
 * @create date 2021-08-03 17:32:16
 * @modify date 2021-08-03 21:14:12
 * @desc [description]
 */
import { ILogger } from "js-logger";
import { MqttClient } from "mqtt";
import { ValidLoggerDefinition } from "../../logger/getLogger";
import { NopeObservable } from "../../observables/nopeObservable";
import { EventnameToEventType, ICommunicationInterface } from "../../types/nope";
/**
 * Default implementation of an {@link ICommunicationInterface}.
 *
 * This layer will use mqtt to connect and transport messages.
 *
 * Defaultly all messages will be subscribed on the following topics:
 * - `+/nope/<eventname>`
 *
 * Defaultly all messages will be published on the following topics:
 * - `<preTopic>/nope/<eventname>`
 * - `preTopic` is set to the hostname.
 *
 * The Layer is able to forward data, events etc to default ports.
 * Asume data is emitted using the `dataChanged` emit. If the flag
 * `forwardToCustomTopics` is set to true, the path of the data will
 * directly forward to mqtt.
 */
export declare class MQTTLayer implements ICommunicationInterface {
    uri: string;
    preTopic: string;
    qos: 0 | 1 | 2;
    forwardToCustomTopics: boolean;
    protected _client: MqttClient;
    protected _cbs: Map<string, Set<(...args: any[]) => void>>;
    protected _logger: ILogger;
    connected: NopeObservable<boolean>;
    considerConnection: boolean;
    /**
     * See {@link ICommunicationInterface.id}
     */
    id: string;
    /**
     * Creates an instance of MQTTLayer.
     * @param {string} uri Uri of the Broker. e.g. `mqtt://localhost:1883` or `ws://localhost:9000`.
     * @param {ValidLoggerDefinition} [logger="info"] Logger level
     * @param {string} [preTopic=hostname()] Defaultly all messages will be published on the following topics: `<preTopic>/nope/<eventname>`. `preTopic` is defaultly set to the hostname of the node in which `NoPE` is running.
     * @param {(0 | 1 | 2)} [qos=2] The QOS of mqtt. see https://www.hivemq.com/blog/mqtt-essentials-part-6-mqtt-quality-of-service-levels/ for more details. Default = Exactly once. Otherwise there might be an issue.
     * @param {boolean} [forwardToCustomTopics=true] The Layer is able to forward data, events etc to default ports. This flag enables this behavior
     * @memberof MQTTLayer
     */
    constructor(uri: string, logger?: ValidLoggerDefinition, preTopic?: string, qos?: 0 | 1 | 2, forwardToCustomTopics?: boolean);
    /**
     * See {@link ICommunicationInterface.on}
     */
    on<T extends keyof EventnameToEventType>(eventname: T, cb: (data: EventnameToEventType[T]) => void): Promise<void>;
    /**
     * See {@link ICommunicationInterface.emit}
     */
    emit<T extends keyof EventnameToEventType>(eventname: T, data: EventnameToEventType[T]): Promise<void>;
    readonly receivesOwnMessages: boolean;
    protected _adaptTopic(topic: string): string;
    /**
     * Internal Function to subscribe to a topic using a specific callback
     * @param topic the topic, which should be subscribed to
     * @param callback the callback to call
     * @returns
     */
    protected _on(topic: string, callback: (...args: any[]) => void): Promise<void>;
    /**
     * Internal function to remove a susbcription from a topic.
     * To be precise, we only remove the callback.
     * @param topic the topic, which should be unsubscribed
     * @param callback the callback to unsubscribe
     * @returns
     */
    protected _off(topic: string, callback: (...args: any[]) => void): Promise<void>;
    /**
     * Internal function to publish data on the given topic
     * @param topic The topic to publish the data on
     * @param data The data to publish
     * @returns
     */
    protected _emit(topic: string, data: any): Promise<void>;
    /**
     * Function to dispose the Interface.
     * @returns nothing
     */
    dispose(): Promise<void>;
}