CampahApp.MainWindow.textBox_ChatlogInput_PreviewKeyDown C# (CSharp) Метод

        private void textBox_ChatlogInput_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            var input = (TextBox)sender;
            if (e.Key == Key.Enter)
            {
                FFACEInstance.Instance.Windower.SendString(input.Text);
                ChatInputBuffer.AddLine(input.Text);
            }

            if (e.Key == Key.Escape||e.Key == Key.Enter)
            {
                input.Clear();
                e.Handled = true;
            }

            if (e.Key == Key.Up)
                input.Text = ChatInputBuffer.Up(input.Text);
            if (e.Key == Key.Down)
                input.Text = ChatInputBuffer.Down();
            if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control || (Keyboard.Modifiers & ModifierKeys.Alt) == ModifierKeys.Alt)
            {
                Regex findname;
                int fields;
                string name = "";
                if (input.Text.Length >= 2 && input.Text.Substring(0, 2).ToLower() == "/t")
                {
                    findname = new Regex(@"/\S* (\S*)\s?(.*)");
                    fields = 2;
                }
                else
                {
                    findname = new Regex(@"/.*? (.*)");
                    fields = 1;
                }
                string text = input.Text.Trim();
                if (findname.IsMatch(input.Text))
                {
                    text = findname.Matches(input.Text)[0].Groups[fields].Value.Trim();
                    if (fields > 1)
                        name = findname.Matches(input.Text)[0].Groups[1].Value.Trim();
                }

                if (e.Key == Key.R)
                    input.Text = "/t " + Chatlog.Instance.LastTell(name) + " " + text;
                else if (e.Key == Key.T)
                    input.Text = "/t " + text;
                else if (e.Key == Key.P)
                    input.Text = "/p " + text;
                else if (e.Key == Key.L)
                    input.Text = "/l " + text;
                else if (e.Key == Key.S)
                    input.Text = "/s " + text;

                input.CaretIndex = input.Text.Length;
            }
        }