client.js

var net = require('net');
var util = require('util');
var events = require('events');

var Message = require('./message');

function Client() {
    var self = this;

    events.EventEmitter.call(this);

    self.on('raw', function(message) {
        console.log(message.toRaw());
        self.emit( message.command.toLowerCase(), message );
    });
}

util.inherits( Client, events.EventEmitter );

Client.prototype.connect = function(name, channel) {
    var self = this;

    self.connection = net.connect({
        host : 'hubbard.freenode.net',
        port : 6667,
    }, function() {
        self.connection.write(new Message( null, 'NICK', [name] ).toRaw());
        self.connection.write(new Message( null, 'USER', [name, '0', '*', name] ).toRaw());
        self.connection.write(new Message( null, 'JOIN', [channel] ).toRaw());
    });

    var buffer = '';
    self.connection.on('data', function(data) {
        buffer += data;
        var lines = buffer.split("\r\n");
        buffer = lines.pop();

        lines.forEach( function(line) {
            self.emit( 'raw', Message.parse( line ) )
        });
    });
};

var client = new Client();
client.connect('hakobe____', '#hakobe932');
client.on('privmsg', function(message) {
    if (message.params[1] === 'time') {
        client.connection.write( 
            new Message(
                null,
                'PRIVMSG',
                [ message.params[0], new Date().toString() ]
            ).toRaw()
        );
    }
});

message.js

function Message(prefix, command, params) {
    this.prefix = prefix;
    this.command = command;
    this.params = params || []; // Array

    this.parseUser();
    this.parseServer();
}

Message.parse = function(raw) {
    var m;

    m = raw.match(/^(?::([^ ]+)[ ]+)?([^ ]+)(.*)/);
    var prefix = m[1];
    var command = m[2];

    var rawParams = m[3];
    m = rawParams.trim().match(/^(.*?)(?:^|\s+):(.*)$/);
    var middle = (m ? m[1] : rawParams).trim();
    var trailing = m ? m[2] : null;
    var params = middle === '' ? [] : middle.split(' ');
    if (trailing) {
        params.push(trailing);
    }

    return new Message( prefix, command, params );
}

Message.prototype.toRaw = function() {
    var result = '';

    if (this.prefix) {
        result += ':' + this.prefix + ' ';
    }

    result += this.command + ' ';

    var params = this.params.concat();
    var trailing = params[ params.length - 1];
    if (
           typeof(trailing) !== 'undefined' 
        && (trailing.match(/\s/) || trailing === '')
    ) {
        params[ params.length - 1]  = ':' + trailing;
    }

    result += params.join(' ');
    result += "\r\n";

    return result;
};

Message.prototype.parseUser = function() {
    if (!this.prefix) { return; }

    var m;
    m = this.prefix.match(/^(\S+?)(?:!|$)/);
    if (m) { this.nick = m[1]; }
    m = this.prefix.match(/!(\S+?)(?:@|$)/);
    if (m) { this.user = m[1]; }
    m = this.prefix.match(/@(\S+)$/);
    if (m) { this.host = m[1]; }
};

Message.prototype.parseServer = function() {
    if (!this.prefix) { return; }

    if (/[!@]/.test(this.prefix)) { return; }
    this.server = this.prefix;
};

module.exports = Message;