import { TBlackHole, TContext } from "@digital-alchemy/core";
import { Packet } from "mqtt";
export type MqttMessageTransformer = (payload: Buffer) => unknown;
export interface MqttSubscriberParameter {
    index: number;
    transform?: "json" | "text" | MqttMessageTransformer;
    type: "payload" | "topic" | "packet" | "params";
}
export type MQTTParseFormat = "none" | "json";
export interface SubscriptionOptions {
    noLocal?: boolean;
    qualityOfService?: number;
    retainAsPublished?: boolean;
    retainHandling?: number;
}
export type MQTTSubscribeOptions<DATA = unknown> = {
    topic: string | string[];
    exec: MqttCallback<DATA>;
    context: TContext;
    parse?: MQTTParseFormat;
    options?: SubscriptionOptions;
};
export type MqttCallback<DATA = unknown> = (payload: DATA, packet?: Packet) => TBlackHole;