HornetComm

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace _03.HornetComm
{
    public class StartUp
    {
        public static void Main()
        {
            string messagePattern = @"(^[0-9]+) <-> ([A-Za-z0-9]+$)";
            string broadcastPattern = @"(^\D+) <-> ([A-Za-z0-9]+$)";

            Regex regexMessage = new Regex(messagePattern);
            Regex regexBroadcast = new Regex(broadcastPattern);

            List<string> messages = new List<string>();
            List<string> broadcasts = new List<string>();

            while (true)
            {
                string inputMessage = Console.ReadLine();
                if (inputMessage == "Hornet is Green")
                {
                    break;
                }
                Match matchMessage = regexMessage.Match(inputMessage);
                Match matchBroadcast = regexBroadcast.Match(inputMessage);

                if (matchMessage.Success)
                {
                    string recipientsCode = matchMessage.Groups[1].ToString();
                    string message = matchMessage.Groups[2].ToString();
                    char[] reversedRecipient = recipientsCode.ToCharArray();
                    Array.Reverse(reversedRecipient);
                    string recipientsCodeReversed = new string(reversedRecipient);
                    messages.Add(recipientsCodeReversed + " -> " + message);
                }
                else if (matchBroadcast.Success)
                {
                    string message = matchBroadcast.Groups[1].ToString();
                    string frequency = matchBroadcast.Groups[2].ToString();
                    char[] frequencyToArr = frequency.ToCharArray();

                    for (int i = 0; i < frequencyToArr.Length; i++)
                    {
                        if (Char.IsUpper(frequencyToArr[i]))
                        {
                            frequencyToArr[i] = Char.ToLower(frequencyToArr[i]);
                        }
                        else if (Char.IsLower(frequencyToArr[i]))
                        {
                            frequencyToArr[i] = Char.ToUpper(frequencyToArr[i]);
                        }
                    }

                    string frequencyChanged = new string(frequencyToArr);
                    broadcasts.Add(frequencyChanged + " -> " + message);
                }
            }
            Console.WriteLine("Broadcasts:");
            if (broadcasts.Count > 0)
            {
                foreach (var broadcast in broadcasts)
                {
                    Console.WriteLine(broadcast);
                }
            }
            else
            {
                Console.WriteLine("None");
            }
            Console.WriteLine("Messages:");
            if (messages.Count > 0)
            {
                foreach (var message in messages)
                {
                    Console.WriteLine(message);
                }
            }
            else
            {
                Console.WriteLine("None");
            }
        }
    }
}