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

namespace Server;

class Program
{
    private const int Porta = 1322;

    private const int TimeoutLetturaMs = 5 * 60 * 1000;
    
    static void Main(string[] args)
    {
        Console.WriteLine("Hello, Server!");

        TcpListener? listener = null;
        Encoding utf8SenzaBom = new UTF8Encoding(false);

        try
        {
            IPAddress localAddr = IPAddress.Parse("127.0.0.1");

            listener = new TcpListener(localAddr, Porta);

            listener.Start();
            Console.WriteLine("Server avviato.");

            while (true)
            {
                using TcpClient client = listener.AcceptTcpClient();
                try
                {
                    client.ReceiveTimeout = TimeoutLetturaMs;

                    using NetworkStream stream = client.GetStream();
                    using StreamReader reader = new StreamReader(stream, utf8SenzaBom);
                    using StreamWriter writer = new StreamWriter(stream, utf8SenzaBom);

                    writer.AutoFlush = true;

                    writer.WriteLine("[CONNESSO] Scrivi 'exit' per chiudere");
                    string? messaggioDalClient;
                    while ((messaggioDalClient = reader.ReadLine()) != null)
                    {
                        Console.WriteLine("[Client] " + messaggioDalClient);

                        if (messaggioDalClient.Trim().ToLower() == "exit")
                        {
                            writer.WriteLine("[ADDIO]");
                            break;
                        }

                        writer.WriteLine("[SERVER] Messaggio ricevuto -> " + messaggioDalClient);
                    }

                    if (messaggioDalClient == null)
                    {
                        Console.WriteLine("Client è morto");
                    }
                }
                catch (IOException e)
                {
                    SocketException? causa = e.InnerException as SocketException;

                    if (causa != null && causa.SocketErrorCode == SocketError.TimedOut)
                    {
                        Console.WriteLine("Time out");
                    }
                    else
                    {
                        Console.WriteLine("Connessione terminata dal server: " + e.Message);
                    }

                    Console.WriteLine(e.Message);
                }
                catch (SocketException e)
                {
                    Console.WriteLine("errore di rete: " + e.Message);
                    switch (e.SocketErrorCode)
                    {
                        case SocketError.ConnectionRefused:
                            Console.WriteLine("Connessione rifiutata dal server");
                            break;
                        case SocketError.HostNotFound:
                            Console.WriteLine("Host non trovato");
                            break;
                        case SocketError.TimedOut:
                            Console.WriteLine("Time out");
                            break;
                        default:
                            Console.WriteLine(e.SocketErrorCode.ToString());
                            break;
                    }
                }
                catch (Exception e)
                {
                    Console.WriteLine("Errore: " + e.Message);
                }

                Console.WriteLine("Connessione terminata");
            }
        }
        catch (SocketException e)
        {
            switch (e.SocketErrorCode)
            {
                case SocketError.AddressAlreadyInUse:
                    Console.WriteLine("Indirizzo in uso");
                    break;
                case SocketError.AccessDenied:
                    Console.WriteLine("non te lo puoi permettere");
                    break;
                default:
                    Console.WriteLine("Errore: " + e.Message);
                    break;
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("Errore: " + e.Message);
        }
        finally
        {
            if (listener != null)
            {
                try
                {
                    listener.Stop();
                    Console.WriteLine("Server Terminato");
                }
                catch (SocketException e)
                {
                    Console.WriteLine("Errore nello spegnimento server: " + e.Message);
                }
            }
            Console.WriteLine("Premi un tasto per chiudere");
            Console.ReadKey();
        }
    }
}