import { $Present, $Says, asPresent, asSays, fromPresent, fromSays, Present, Says } from "../gen/simple-chat-protocol.js";
import { during, observe } from "../runtime/dataspace.js";
import { Assertion, Handle, Ref, Turn } from "../runtime/actor.js";
import { attachReadline } from './readline.js';
import { Embedded } from "@preserves/core";

export default function (t: Turn, ds_ptr: Embedded<Ref>) {
    const ds = ds_ptr.embeddedValue;

    let username = '';
    let usernameHandle: Handle | undefined;

    function updateUsername(t: Turn, u: string) {
        username = u;
        usernameHandle = t.replace(ds, usernameHandle, fromPresent(Present(username)));
    }
    updateUsername(t, 'user' + process.pid);

    observe(t, ds, $Present, during(async (_t, e0) => {
        const e = asPresent(e0);
        console.log(`${e.username} arrived`);
        return (_t) => console.log(`${e.username} departed`);
    }));

    observe(t, ds, $Says, {
        message(_t: Turn, u0: Assertion): void {
            const u = asSays(u0);
            console.log(`${u.who}: ${u.what}`);
        },
    });

    attachReadline(t, {
        retract(t) { t.stopActor(); },
        message(t, line: string) {
            if (line.toLowerCase().startsWith('/nick ')) {
                updateUsername(t, line.slice(5).trimLeft());
            } else {
                t.message(ds, fromSays(Says({ who: username, what: line })));
            }
        },
    });
}