using SafeMobileLib.Registration;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;

namespace SafeMobileLib.Helpers
{
    public class RegistrationHelper
    {
        public static Int16 TimeoutSeconds = 7;
        public static String GatewayIP = "127.0.0.1";

        public static async Task<RegistrationResponse> RegisterGateway(String appServerIP, Int16 registrationPort)
        {
            return await (Task.Factory.StartNew(() =>
            {
                try
                {
                    TcpClient client = new TcpClient();
                    IPEndPoint serverEndPoint = new IPEndPoint(IPAddress.Parse(appServerIP), registrationPort);
                    client.Connect(serverEndPoint);
                    NetworkStream clientStream = client.GetStream();
                    GatewayIP = (client.Client.LocalEndPoint.ToString().Split(":".ToCharArray()))[0];

                    UTF8Encoding encoding = new UTF8Encoding();
                    byte[] buffer = encoding.GetBytes("200");
                    clientStream.Write(buffer, 0, buffer.Length);
                    Utils.WriteLine($"Sent registration request to server {appServerIP}:{registrationPort}, waiting...");
                    byte[] message = new byte[1024];
                    //set read timeout to 10s
                    clientStream.ReadTimeout = TimeoutSeconds * 1000;

                    int result = clientStream.Read(message, 0, message.Length);
                    if (result < 1)
                        return new RegistrationResponse("");

                    String decodedString = encoding.GetString(message).Trim('\0');

                    return new RegistrationResponse(decodedString);
                }
                catch(Exception ex)
                {
                    Utils.WriteLine("Registration exception: " + ex.ToString(), ConsoleColor.Red);
                    return new RegistrationResponse("");
                }
            }));
        }
    }
}