Meebey.SmartIrc4net.IrcClient._Event_NICK C# (CSharp) Method

        private void _Event_NICK(IrcMessageData ircdata)
        {
            string oldnickname = ircdata.Nick;
            string newnickname = ircdata.Message;

            if (IsMe(ircdata.Nick)) {
                // nickname change is your own
                _Nickname = newnickname;
            }

            if (ActiveChannelSyncing) {
                IrcUser ircuser = GetIrcUser(oldnickname);

                // if we don't have any info about him, don't update him!
                // (only queries or ourself in no channels)
                if (ircuser != null) {
                    string[] joinedchannels = ircuser.JoinedChannels;

                    // update his nickname
                    ircuser.Nick = newnickname;
                    // remove the old entry
                    // remove first to avoid duplication, Foo -> foo
                    _IrcUsers.Remove(oldnickname);
                    // add him as new entry and new nickname as key
                    _IrcUsers.Add(newnickname, ircuser);
            #if LOG4NET
                    Logger.ChannelSyncing.Debug("updated nickname of: "+oldnickname+" to: "+newnickname);
            #endif
                    // now the same for all channels he is joined
                    Channel     channel;
                    ChannelUser channeluser;
                    foreach (string channelname in joinedchannels) {
                        channel     = GetChannel(channelname);
                        channeluser = GetChannelUser(channelname, oldnickname);
                        // remove first to avoid duplication, Foo -> foo
                        channel.UnsafeUsers.Remove(oldnickname);
                        channel.UnsafeUsers.Add(newnickname, channeluser);
                        if (channeluser.IsOp) {
                            channel.UnsafeOps.Remove(oldnickname);
                            channel.UnsafeOps.Add(newnickname, channeluser);
                        }
                        if (SupportNonRfc && ((NonRfcChannelUser)channeluser).IsHalfop) {
                            NonRfcChannel nchannel = (NonRfcChannel)channel;
                            nchannel.UnsafeHalfops.Remove(oldnickname);
                            nchannel.UnsafeHalfops.Add(newnickname, channeluser);
                        }
                        if (channeluser.IsVoice) {
                            channel.UnsafeVoices.Remove(oldnickname);
                            channel.UnsafeVoices.Add(newnickname, channeluser);
                        }
                    }
                }
            }

            if (OnNickChange != null) {
                OnNickChange(this, new NickChangeEventArgs(ircdata, oldnickname, newnickname));
            }
        }