// Copyright Epic Games, Inc. All Rights Reserved.
import { EventEmitter } from '../Event/EventEmitter';

/**
 * An interface to a transport protocol that is in charge of sending and receiving signalling messages.
 * Implement this interface to support your custom transport. You can then supply an instance of your
 * transport to the constructor of SignallingProtocol during startup.
 */
export interface ITransport extends EventEmitter {
    /**
     * Called when the protocol wants to send a message over the transport.
     * @param msg - The message to send over the transport.
     */
    sendMessage(msg: string): void;

    /**
     * Callback filled in by the SignallingProtocol and should be called by the transport when a new message arrives.
     */
    onMessage?: (msg: string) => void;

    /**
     * Connect to a given URL.
     * @param url - The URL for the transport to connect to.
     * @returns True if the connection was successful.
     */
    connect(url: string): boolean;

    /**
     * Disconnect this transport.
     * @param code - An optional disconnect code.
     * @param reason - A descriptive string for the disconnect reason.
     */
    disconnect(code?: number, reason?: string): void;

    /**
     * Should return true when the transport is connected and ready to send/receive messages.
     * @returns True if the transport is connected.
     */
    isConnected(): boolean;
}