import { Message, MessageAttributes } from '@node-ts/bus-messages';
import { ClassConstructor } from '../util';
import { CustomHandler } from './custom-handler';
/**
 * Defines the types of messages that the bus can handle
 */
export type MessageBase = Message | object;
/**
 * Implemented by a class to indicate it acts as a handler for a given message
 */
export interface Handler<TMessage extends MessageBase = MessageBase, TMessageAttributes extends MessageAttributes = MessageAttributes> {
    /**
     * The type of message the class handles
     */
    messageType: ClassConstructor<TMessage>;
    /**
     * A function that is called each time a message of `messageType` is received
     * @param message The message read from the bus
     * @param attributes Attributes of the message read from the bus
     */
    handle(message: TMessage, attributes: TMessageAttributes): void | Promise<void>;
}
export type FunctionHandler<TMessage, TMessageAttributes extends MessageAttributes = MessageAttributes> = (message: TMessage, attributes: TMessageAttributes) => void | Promise<void>;
export type HandlerDefinition<TMessage = any, TMessageAttributes extends MessageAttributes = MessageAttributes> = FunctionHandler<TMessage, TMessageAttributes> | ClassConstructor<Handler<MessageBase, TMessageAttributes>> | ClassConstructor<CustomHandler<TMessage>>;
/**
 * A naive but best guess effort into if a handler is class based and should be resolved from a container
 */
export declare const isClassHandler: (handler: HandlerDefinition) => any;