prs/prs.server/Engines/GPS/OEMListener.cs

using Comal.Classes;
using InABox.Core;
using InABox.DigitalMatter;
using NPOI.HSSF.Record.CF;
using PRSServer.Engines;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Media.Media3D;

namespace PRSServer
{
    internal class OEMListener
    {
        private TcpListener listener;

        private GPSDeviceCache Cache;
        private GPSUpdateQueue Queue;

        private object connectionsLock = new object();
        private List<OEMConnection> Connections = new();

        public int Port { get; set; }

        public OEMListener(int port, GPSDeviceCache cache, GPSUpdateQueue queue)
        {
            Port = port;
            Cache = cache;
            Queue = queue;
        }

        public void Start()
        {
            listener = new TcpListener(IPAddress.Any, Port);
            listener.Start();

            AcceptClient();
        }

        private void AcceptClient()
        {
            Logger.Send(LogType.Information, "", "Waiting for OEM connection.");
            listener.AcceptTcpClientAsync().ContinueWith(t =>
            {
                try
                {
                    Logger.Send(LogType.Information, "", $"OEM Connection opened; {Connections.Count} connections open.");
                    var connection = new OEMConnection(t.Result, Cache, Queue);
                    lock (connectionsLock)
                    {
                        Connections.Add(connection);
                    }

                    connection.OnCompletion = () =>
                    {
                        // When the connection finishes, we should remove it from our list.
                        lock (connectionsLock)
                        {
                            Logger.Send(LogType.Information, "", $"OEM Connection closed; {Connections.Count} connections still open.");
                            Connections.Remove(connection);
                        }
                    };

                    connection.Run();

                    // Accept a new client.
                    AcceptClient();
                }
                catch (Exception e)
                {
                    Logger.Send(LogType.Error, "", CoreUtils.FormatException(e));
                }
            }, TaskContinuationOptions.OnlyOnRanToCompletion);
        }

        public void Stop()
        {
            listener.Stop();
            
            lock (connectionsLock)
            {
                // Running in parallel because each connection can take a second to stop.
                Parallel.ForEach(Connections, connection =>
                {
                    connection.Stop();
                });
                Connections.Clear();
            }
        }
    }
}