const WebSocket = require('ws');

function sleep(ms) {
    return new Promise(r => setTimeout(r, ms));
}

function rand(min, max) {
    return Math.floor(Math.random() * (max - min + 1) + min);
}

let nextMsgId = 1;

async function handleSocket(socket) {
    let nick = 'nick' + nextMsgId++;
    let mask = nick + '!' + nick + '@host.net';

    let w = (line) => {
        let d = (new Date()).toISOString();
        let out = line
            .replace('$nick', nick)
            .replace('$mask', mask);

        out = `@msgid=${nextMsgId++};time=${d}; ${out}`;
        socket.send(out);
    }

    let joinChannel = async (chan) => {
        let users = [];
        w(`:$mask JOIN ${chan}`);
        
        while(true) {
            await sleep(rand(100, 700));

            // 25% chance of joining a user
            if (users.length < 1000 && rand(1, 100) < 25) {
                let newNick = 'user' + nextMsgId++;
                users.push(newNick);
                w(`:${newNick}!${newNick}@host.net JOIN ${chan}`);
            }

            // 2% chance of parting a user
            if (users.length > 3 && rand(1, 100) < 2) {
                let idx = rand(0, users.length-1);
                let partedUser = users.splice(idx, 1);
                w(`:${partedUser}!${partedUser}@host.net PART ${chan}`);
            }

            let from = users[rand(0, users.length-1)];
            w(`:${from}!${from}@host.net PRIVMSG ${chan} :some message`);
        }
    };

    await sleep(1000);
    w(':srv.net 001 $nick :Welcome to the flood net');
    w(':srv.net 005 $nick ACCEPT=30 AWAYLEN=200 CALLERID=g CASEMAPPING=ascii CHANLIMIT=#:20 CHANMODES=Zbegw,k,FHJdfjl,BCDMNOPRScimnprstuz CHANNELLEN=64 CHANTYPES=# ELIST=CMNTU ESILENCE=CcdiNnPpTtx EXCEPTS=e EXTBAN=,BCNORSUacjmrsz :are supported by this server');
    w(':srv.net 005 $nick EXTJWT=1 HOSTLEN=64 KEYLEN=32 KICKLEN=255 LINELEN=512 MAXLIST=begw:100 MAXTARGETS=20 MODES=20 MONITOR=30 NAMESX NETWORK=floodnet NICKLEN=30 :are supported by this server');
    w(':srv.net 375 $nick :srv.net of the day');
    w(':srv.net 372 $nick :the motd');
    w(':srv.net 376 $nick :End of message of the day');

    joinChannel('#chan1');
    joinChannel('#chan2');
    joinChannel('#chan3');
}

const server = new WebSocket.Server({ port: 10666 });
server.on('connection', handleSocket);