06-User logs

namespace _06_User_logs
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Net;
    using System.Text.RegularExpressions;

    class Program
    {
        static void Main()
        {

            // Judge LINK: https://judge.softuni.bg/Contests/Compete/Index/209#5
            var logsDict = new SortedDictionary<string, Dictionary<string, int>>();

            while (true)
            {
                string[] inputCommand = Console.ReadLine()
                    .Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
                    .ToArray();

                if (inputCommand[0] == "end")
                {
                    break;
                }

                else
                {
                    //string regexValidateIPv4 = @"'\b((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}\b'";
                    string currentAddress = string.Join("", inputCommand[0]
                        .ToCharArray()
                        .Skip(3)
                        .ToArray());

                    string currentName = string.Join("", inputCommand[2]
                        .ToCharArray()
                        .Skip(5)
                        .ToArray());

                    bool isCurrentAddressValid = CheckAddress(currentAddress);

                    // Holds the current log address
                    var addressesLogs = new Dictionary<string, int>();

                    if (isCurrentAddressValid == true)
                    {
                        addressesLogs.Add(currentAddress, 1);

                        // If user is not present, add him.
                        if (logsDict.ContainsKey(currentName) == false)
                        {
                            logsDict.Add(currentName, addressesLogs);
                        }

                        else
                        {
                            // Check if user has logged from different addresses in order to add them.
                            if (logsDict[currentName].ContainsKey(currentAddress) == false)
                            {
                                logsDict[currentName].Add(currentAddress, 1);
                            }

                            // If not he has logged from previous IP.
                            else
                            {
                                logsDict[currentName][currentAddress]++;
                            }
                        }
                    }
                }
            }

            // PRINT
            foreach (var user in logsDict)
            {
                Console.WriteLine($"{user.Key}:");
                var addresses = user.Value;

                var lastAddress = addresses.Last();

                foreach (var address in addresses)
                {

                    if (address.Equals(lastAddress))
                    {
                        Console.WriteLine($"{address.Key} => {address.Value}.");
                    }

                    else
                    {
                        Console.Write($"{address.Key} => {address.Value}, ");
                    }
                }

            }
        }

        static bool CheckAddress(string address)
        {
            IPAddress validAddress;
            bool checkIfIPv6 = false;
            bool checkIfIPv4 = false;

            if (IPAddress.TryParse(address, out validAddress) == true)
            {
                checkIfIPv6 = validAddress.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6;
                checkIfIPv4 = validAddress.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork;

                // This maybe pointless... If parse is successful better to return TRUE ?
                if (checkIfIPv4 == true || checkIfIPv6 == true)
                {
                    return true;
                }

                return false;
            }

            return false;
        }
    }
}