base2020/src/Net/LoopbackServer.ts

import { Callbag } from "callbag";

import { ClientMessage, MessageTypes, ServerMessage } from "./LockstepClient";

type Client<Input, State> = Callbag<ServerMessage<Input, State>, ClientMessage<Input, State>>;

export function Loopback<Input, State>(start: number, data?: Client<Input, State> | ClientMessage<Input, State>) {
    if(start != 0) return;

    const sink = data as Client<Input, State>;

    sink(0, (type: number, data?: Client<Input, State> | ClientMessage<Input, State>) => {
        if(type == 1) {
            // message from client; just reflect for now
            const message = data as ClientMessage<Input, State>;
            switch(message.t) {
                case MessageTypes.INPUT:
                    sink(1, message);
                    break;
            }
        }
    });
    sink(1, {t: MessageTypes.SET_STATE, s: {}});
};