namespace ServerMonitorAlert
{
    class Program
    {
        static void Main(string[] args)
        {

            Dictionary<string, string> Servers = new Dictionary<string, string>()
            {
               servers go here
            };


            Ping pingSender = new Ping();
            PingOptions options = new PingOptions();
            Servers nonRespondingServers = new Servers();
            List<Servers> failedServers = new List<Servers>();


            options.DontFragment = true;

            string data = "Please Respond";
            byte[] buffer = Encoding.ASCII.GetBytes(data);
            int timeout = 120;

            Console.WriteLine("Script Started: " + DateTime.Now);

            while (true)
            {

                try
                {
                    if (!Directory.Exists(@"C:\ServerMonitor")) { Directory.CreateDirectory(@"C:\ServerMonitor"); }
                    var currentDate = DateTime.Now.ToString("yyyy-MM-dd");
                    StringBuilder sbLogName = new StringBuilder();
                    sbLogName.Append(currentDate);
                    sbLogName.Append(".txt");

                    var file = File.Create(@"C:\ServerMonitor\" + sbLogName);
                    file.Close();

                    using (StreamWriter sw = new StreamWriter(@"C:\ServerMonitor\" + sbLogName))
                    using (SmtpClient client = new SmtpClient())
                    {
                        {
                            sw.WriteLine("Script Started: " + DateTime.Now + " (EST)");
                            sw.Flush();
                            client.Host = "smtp.office365.com";
                            String userName = "";
                            String password = ConfigurationManager.AppSettings["EmailPwd"];
                            client.Credentials = new System.Net.NetworkCredential(userName, password);
                            client.Port = 587;
                            client.EnableSsl = true;

                            foreach (KeyValuePair<string, string> server in pscServers)
                            {
                                PingReply reply = pingSender.Send(server.Value, timeout, buffer, options);

                                sw.WriteLine(DateTime.Now + ": " + server.Key + " ping status: " + reply.Status.ToString());
                                sw.Flush();
                                Console.WriteLine(DateTime.Now + ": " + server.Key + " ping status: " + reply.Status.ToString());

                                int count = 0;

                                while (count < 3)
                                {
                                    if (reply.Status == IPStatus.TimedOut || reply.Status == IPStatus.TimeExceeded || reply.Status == IPStatus.DestinationHostUnreachable)
                                    {
                                        sw.WriteLine(DateTime.Now + ": " + server.Key + " ping status: " + reply.Status.ToString() + " Redundant Check: " + count.ToString());
                                        sw.Flush();
                                        //Let's wait 15 seconds and try again just in case (false alert check)
                                        Thread.Sleep(15000);
                                        reply = pingSender.Send(server.Value, timeout, buffer, options);

                                    }
                                    count++;
                                }

                                if (reply.Status == IPStatus.Success)
                                {
                                    sw.WriteLine(DateTime.Now + " Ping Reply: " + reply.Status.ToString() + " Server: " + server.Key);
                                    sw.Flush();

                                    nonRespondingServers.ComputerName = server.Key;
                                    nonRespondingServers.IPAddress = server.Value;

                                    failedServers.Add(nonRespondingServers);
                                    continue;

                                }
                                if (failedServers.Count > 0)
                                {

                                    MailMessage msg = new MailMessage();
                                    msg.To.Add(new MailAddress("(email here)"));
                                    msg.From = new MailAddress(userName);
                                    msg.Subject = "(anything you want)";
                                    msg.IsBodyHtml = true;

                                    foreach (var fs in failedServers)
                                    {
                                        msg.Body =
                                             "<br>" + DateTime.Now + "</br>" +
                                            "<br> Affected Server: " + fs.ComputerName + "</br>" +
                                            "<br>" + " IP: " + fs.IPAddress + "</br>" +
                                            "<br>Ping Reply Status: " + reply.Status.ToString() + "</br>";

                                        client.Send(msg);
                                        SendSMSAlert("(twilio info)", "(twilio info)", fs.ComputerName, fs.IPAddress, reply.Status.ToString(), new string[] { "(phone numbers here)" });

                                    }
                                    failedServers.Clear();
                                }

                            }
                        }
                    }
                }
                catch (Exception ex)
                {

                    Console.WriteLine(ex.Message);
                    Console.ReadLine();
                }
                Thread.Sleep(60000);
            }

        }
        static void SendSMSAlert(string accountSID, string authToken, string serverName, string serverIP, string pingReplyStatus, string[] phoneNumbers)
        {
            foreach (var n in phoneNumbers)
            {
                TwilioClient.Init(accountSID, authToken);
                var smsMsg = MessageResource.Create(to: new PhoneNumber(n),
                    from: new PhoneNumber("(twilio number goes here)"),
                    body: DateTime.Now +
                           " Affected Server: " + serverName +
                            " IP: " + serverIP +
                            " Ping Reply Status: " + pingReplyStatus);
            }

        }
    }
}