import { $claimNick, $joinedUser, asNickClaim, fromJoin, fromNickConflict, fromUserInfo, Join, NickConflict, UserId, UserInfo } from "./gen/secure-chat-protocol.js";
import { Assertion, Handle, Ref, Turn } from "./actor.js";
import { observe, during, $Observe, asObserve } from "./dataspace.js";

export default function (t: Turn, ds: Ref) {
    let nextUserId: UserId = 0;

    const nicks = new Map<string, UserId>();
    const users = new Map<UserId, { infoHandle: Handle | undefined, nick: string | undefined }>();

    observe(t, ds, $claimNick, {
        assert(t: Turn, c0: Assertion): void {
            const c = asNickClaim(c0);
            if (nicks.has(c.name)) {
                t.message(c.k, fromNickConflict(NickConflict()));
            } else {
                t.message(c.k, true);
                let u = users.get(c.uid);
                if (!u) {
                    u = { infoHandle: void 0, nick: void 0 };
                    users.set(c.uid, u);
                }
                if (u.nick !== void 0) nicks.delete(u.nick);
                u.infoHandle = t.replace(ds, u.infoHandle, fromUserInfo(UserInfo(c)));
                u.nick = c.name;
                nicks.set(c.name, c.uid);
            }
        }
    });

    observe(t, ds, $Observe, during((t, o0) => {
        const o = asObserve(o0);
        if (o.label !== $joinedUser) return null;

        const uid: UserId = nextUserId++;
        const h = t.assert(o.observer, fromJoin(Join({
            uid,
            handle: ds,
        })));
        return t => t.retract(h);
    }));
}