using System;
using System.Net;
using System.Net.Sockets;
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;
using System.Web;

namespace AspNetTools
{
    public static class WebSocketForwardModule
    {
        public static void ForwardCurrentContext(string opKey, string opValue, IPEndPoint endPoint, int bufferSize = 1024)
        {
            var ctx = HttpContext.Current;
            var req = HttpContext.Current.Request;
            if (req.QueryString[opKey] == opValue)
            {
                ctx.Handler = null;
                var rsp = HttpContext.Current.Response;
                //if (ctx.IsDebuggingEnabled == false && req.IsSecureConnection == false)
                //{
                //    rsp.ContentType = "text/html";
                //    rsp.Write("Prod env is Secure Connection required");
                //    ctx.ApplicationInstance.CompleteRequest();
                //    return;
                //}

                if (ctx.IsWebSocketRequest)
                {
                    ctx.AcceptWebSocketRequest(async (ws) =>
                    {
                        var fcl = new TcpClient();
                        fcl.Connect(endPoint);
                        var ns = fcl.GetStream();

                        var tIn = Task.Run(async () =>
                        {
                            var buf = new byte[bufferSize];
                            var arrSeg = new ArraySegment<byte>(buf);
                            while (ws.WebSocket.CloseStatus.HasValue == false)
                            {
                                var x = await ws.WebSocket.ReceiveAsync(arrSeg, CancellationToken.None);
                                await ns.WriteAsync(buf, 0, x.Count);
                            }
                        });

                        var tOut = Task.Run(async () =>
                        {
                            var buf = new byte[bufferSize];
                            while (ws.WebSocket.CloseStatus.HasValue == false)
                            {
                                var count = await ns.ReadAsync(buf, 0, buf.Length);
                                var arrSeg = new ArraySegment<byte>(buf, 0, count);
                                await ws.WebSocket.SendAsync(arrSeg, WebSocketMessageType.Binary, true, CancellationToken.None);
                            }
                        });

                        Task.WaitAll(tIn, tOut);
                        fcl.Close();
                    });
                }
                else
                {
                    rsp.ContentType = "text/html";
                    rsp.Write("Welcome back. Master!");
                }
            }
        }
    }
}