using System.Net;
using System.Net.Sockets;

namespace SpeedTest.Server
{
    internal class Program
    {
        static void Main(string[] args)
        {
            if (args.Length < 2)
            {
                Console.WriteLine("Usage: SpeedTest.Server <IP> <Port>");
                return;
            }

            if (!IPAddress.TryParse(args[0], out IPAddress? ipAddress))
            {
                Console.WriteLine($"Invalid IP address: {args[0]}");
                return;
            }

            if (!int.TryParse(args[1], out int port) || port < 1 || port > 65535)
            {
                Console.WriteLine($"Invalid port: {args[1]}");
                return;
            }

            TcpListener? listener = null;
            try
            {
                listener = new TcpListener(ipAddress, port);
                listener.Start();
                Console.WriteLine($"Server started on {ipAddress}:{port}");
                Console.WriteLine("Waiting for client connection...");

                TcpClient client = listener.AcceptTcpClient();
                Console.WriteLine("Client connected!");

                NetworkStream stream = client.GetStream();
                long bytesInCurrentSecond = 0;
                bool isReceiving = true;

                // Thread để nhận dữ liệu
                Thread receiveThread = new Thread(() =>
                {
                    byte[] buffer = new byte[64 * 1024]; // 64KB buffer
                    try
                    {
                        while (isReceiving)
                        {
                            int bytesRead = stream.Read(buffer, 0, buffer.Length);
                            if (bytesRead == 0)
                            {
                                isReceiving = false;
                                break;
                            }

                            Interlocked.Add(ref bytesInCurrentSecond, bytesRead);
                        }
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine($"Receive thread error: {ex.Message}");
                        isReceiving = false;
                    }
                });

                receiveThread.Start();

                Console.WriteLine("Receiving data... (Press Ctrl+C to stop)");
                Console.WriteLine("Time\t\tBytes/s\t\tMB/s\t\tGB/s");

                // Main thread chỉ tính toán và in kết quả
                System.Diagnostics.Stopwatch stopwatch = System.Diagnostics.Stopwatch.StartNew();
                while (isReceiving)
                {
                    Thread.Sleep(1000); // Đợi đúng 1 giây

                    long bytesThisSecond = Interlocked.Exchange(ref bytesInCurrentSecond, 0);
                    
                    double bytesPerSecond = bytesThisSecond;
                    double mbPerSecond = bytesPerSecond / (1024.0 * 1024.0);
                    double gbPerSecond = bytesPerSecond / (1024.0 * 1024.0 * 1024.0);

                    Console.WriteLine($"{DateTime.Now:HH:mm:ss}\t{bytesPerSecond:N0}\t\t{mbPerSecond:F2}\t\t{gbPerSecond:F4}");
                }

                receiveThread.Join();
                Console.WriteLine("Client disconnected.");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error: {ex.Message}");
            }
            finally
            {
                listener?.Stop();
            }
        }
    }
}