Spark Scraper

ExWebClient.cs

using System.IO;
using System.Net;
using HtmlAgilityPack;

namespace MySparkScraper
{
    class ExWebClient
    {
        //The cookies will be here.
        private CookieContainer _cookies = new CookieContainer();

        //In case you need to clear the cookies
        public void ClearCookies()
        {
            _cookies = new CookieContainer();
        }

        public HtmlDocument Get(string url)
        {
            var request = (HttpWebRequest)WebRequest.Create(url);
            request.Proxy = WebRequest.DefaultWebProxy;
            request.Method = "GET";

            //This is the important part.
            request.CookieContainer = _cookies;

            var response = (HttpWebResponse)request.GetResponse();
            var stream = response.GetResponseStream();

            //When you get the response from the website, the cookies will be stored
            //automatically in "_cookies".

            using (var reader = new StreamReader(stream))
            {
                string html = reader.ReadToEnd();
                var doc = new HtmlDocument();
                doc.LoadHtml(html);
                return doc;
            }
        }

        public HtmlDocument Login(string url, string username, string password)
        {
            var request = (HttpWebRequest)WebRequest.Create(url);
            request.Proxy = WebRequest.DefaultWebProxy;
            byte[] send = System.Text.Encoding.Default.GetBytes(string.Format("loginSrc=ext&username={0}&password={1}&sign-in=Sign+In", username, password));
            request.ContentType = "application/x-www-form-urlencoded";
            request.ContentLength = send.Length;
            request.Method = "POST";
            request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36";
            request.Headers["Cache-Control"] = "no-cache";

            //This is the important part.
            request.CookieContainer = _cookies;

            Stream sout = request.GetRequestStream();
            sout.Write(send, 0, send.Length);
            sout.Flush();
            sout.Close();

            var response = (HttpWebResponse)request.GetResponse();
            
            var stream = response.GetResponseStream();

            //When you get the response from the website, the cookies will be stored
            //automatically in "_cookies".

            using (var reader = new StreamReader(stream))
            {
                string html = reader.ReadToEnd();
                var doc = new HtmlDocument();
                doc.LoadHtml(html);
                return doc;
            }
        }
    }
}

program.cs

using System;
using System.Linq;
using Newtonsoft.Json.Linq;

namespace MySparkScraper
{
    class Program
    {
        static void Main(string[] args)
        {
            var client = new ExWebClient();
            var doc1 = client.Get("https://www.spark.co.nz/myspark/");

            // find the login url
            var loginForm = doc1.DocumentNode.Descendants("form").FirstOrDefault(n => n.Attributes["name"] != null && n.Attributes["name"].Value == "myForm");
            var loginUrl = loginForm.Attributes["action"].Value.Replace("&", "&");

            client.Login(loginUrl, "<encoded email>", "<password>");

            var usageInfo = client.Get("https://www.spark.co.nz/portal/site/mytelecom-site/template.BINARYPORTLET/menuitem.c26e41f6aeaa53d794910bf3bc407ea0/resource.process/?javax.portlet.tpst=e0282410b21e6a6e85cdc707d5107ea0&javax.portlet.rid_e0282410b21e6a6e85cdc707d5107ea0=ajaxGetDataUsage&javax.portlet.rcl_e0282410b21e6a6e85cdc707d5107ea0=cacheLevelPage&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken");

            dynamic info = JObject.Parse(usageInfo.DocumentNode.InnerText);

            Console.WriteLine(string.Format("Used {0} of {1} {2} for period {3}", info.actionResult.dataUsed, 
                info.actionResult.dataCap, info.actionResult.dataUnit, info.actionResult.usagePeriod));
            Console.ReadLine();
        }
    }
}