-- MAIN --

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

namespace GW2TPv2
{
    class Program
    {
        public static void Main(string[] args)
        {

            GW2TP c = new GW2TP();
            Console.WriteLine(c.getBasket());
            c.connectToTp("XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX");
            Console.WriteLine(c.getBasket());
            c.queryListing(19697);
            Console.WriteLine(c.getBasket());

            string test = c.getBasket();

            // Order o = JsonConvert.DeserializeObject<Order>(test);

            Console.ReadLine();
        }
    }
}




-- GW2TP --
using System.Runtime.Serialization;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

namespace GW2TPv2
{
    class GW2TP
    {
        private HttpClient httpClient;                 // Does HTTP requests
        private HttpClientHandler httpClientHandler;   // Sets optional parameters
        private CookieContainer cookieContainer;       // Holds cookies we need to send
        private Uri baseAddress;                       // Url of the TP
        private Uri itemListingsAddress;               // Url to get in-game item listings
        //private string sessionId;                    // Our session id from in-game
        private string basket;                         // Temporarily holds data

        public GW2TP()
        {
            setup();
        }

        ~GW2TP()
        {
            httpClient.Dispose();
        }

        public string getBasket()
        {
            return basket;
        }

        private void setup()
        {
            // Initial setup
            setAddresses();
            createCookieContainer();
            createHttpClientHandler();

            basket = "pie";
        }

        private void setAddresses()
        {
            // Our base url address is the TP
            baseAddress = new Uri("http://tradingpost-dfw-live.ncplatform.net");
            itemListingsAddress = new Uri("https://tradingpost-dfw-live.ncplatform.net/ws/listings.json?id=");
        }

        private void createCookieContainer()
        {
            // Create our cookie container that will
            // hold cookies we set (namely the session id)
            cookieContainer = new CookieContainer();
        }

        private void createHttpClientHandler()
        {
            // Create the custom http handler so we can
            // bind this to our custom cookie container
            // and use custom cookies in http requests
            // made by HttpClient
            httpClientHandler = new HttpClientHandler()
            {
                CookieContainer = cookieContainer,
                UseCookies = true
            };
        }

        private void createHttpClient()
        {
            // Instantiate a HttpClient with our
            // custom HttpClientHandler
            httpClient = new HttpClient(httpClientHandler)
            {
                BaseAddress = baseAddress
            };

            // Add other custom headers if necessary
            httpClient.DefaultRequestHeaders.Add("user-agent", "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; WOW64; Trident/6.0)");

            httpClient.MaxResponseContentBufferSize = 256000;
        }

        private void addCookie(string cookieName, string cookieValue)
        {
            // Add a cookie to our http request
            cookieContainer.Add(baseAddress, new Cookie(cookieName, cookieValue));
        }

        public async void connectToTp(string sessionId)
        {
            // Create a HttpClient if one isn't
            // already instantiated
            if (httpClient == null)
            {
                createHttpClient();
            }

            // Add our session id to the http request
            addCookie("s", sessionId);

            // Connect to the TP
            basket = await query(baseAddress.ToString());
        }

        private async Task<string> query(string url)
        {
            // This can throw exceptions, warning!
            try
            {
                // Send an asyncronous GET reqest
                HttpResponseMessage httpResponse = await httpClient.GetAsync(url);
                httpResponse.EnsureSuccessStatusCode();

                // The content of the return message is
                // saved in "basket"
                basket = await httpResponse.Content.ReadAsStringAsync();
                return basket;
            }
            catch (HttpRequestException hre)
            {
                Console.WriteLine("HttpRequestException:");
                Console.WriteLine(hre.ToString());
            }
            catch (Exception ex)
            {
                Console.WriteLine("Exception:");
                Console.WriteLine(ex.ToString());
            }

            return "";
        }

        public async void queryListing(int itemId, bool buys = true, bool sells = true)
        {
            // Create our url to query the item listings
            string url = itemListingsAddress.ToString() + itemId.ToString();

            // Append additional parameters if we don't want
            // buy or sell orders
            url = (!buys) ? url + "&buys=false" : url;
            url = (!sells) ? url + "&sells=false" : url;

            basket = await query(url);
        }
    }
}