using System;

using System.Net;

using System.Text;

using System.IO;

using System.Xml;

using System.Collections.Generic;

using GoogleReaderNotifier.ReaderAPI.Data;

using System.Reflection;

using System.Windows.Forms;

using System.Drawing;



namespace GoogleReaderNotifier.ReaderAPI

{

	/// <summary>

	/// Summary description for GoogleReader.

	/// </summary>

	public class GoogleReader

	{

		#region Private variables



		private CookieCollection _Cookies = new CookieCollection();

		private CookieContainer _cookiesContainer = new CookieContainer();

		private bool _loggedIn = false;

		private string[] _loginAuth;

		private XmlDocument xdocAll;



		#endregion



		#region Public variables



		public string LoginError = "";

		public string[] ProxyUser = new string[3];



		#endregion



		public bool LoggedIn

        {

            get { return _loggedIn; }

        }



		#region Application Code



        // https://www.google.com/reader/atom/user/-/state/com.google/reading-list // get full feed of items

        

		public string Login(string username, string password)

		{

			_loggedIn = false;

			LoginError = "";



			HttpWebRequest req = CreateRequest("https://www.google.com/accounts/ClientLogin?service=reader");



			string exc = PostLoginForm(req, String.Format("accountType=GOOGLE&Email={0}&Passwd={1}&service=reader&source=GRaiN-Notifier-" + Assembly.GetExecutingAssembly().GetName().Version, Uri.EscapeDataString(username), Uri.EscapeDataString(password)));



			if (exc.IndexOf("System.Net.WebException") != -1)

			{

				LoginError += exc + "\r\n";

				if (ProxyUser[0] == "request")

					return "ProxyAuthRequired";

				return "CONNECT_ERROR";

			}



			try

			{

				string _helper = GetResponseString(req);

                _loggedIn = (_helper.IndexOf("error", StringComparison.OrdinalIgnoreCase) == -1) && (_helper.IndexOf("auth", StringComparison.OrdinalIgnoreCase) != -1);

				if (_loggedIn == true)

				{

					_loginAuth = _helper.Split('\n');

					foreach (string st in _loginAuth)

					{

						if (st != string.Empty)

						{

							string[] coo = st.Split('=');

							if (coo[0] == "SID")

								_cookiesContainer.Add(new Cookie(coo[0], coo[1], "/", ".google.com"));

						}

					}



				}

				else

				{

					LoginError += _helper + "\r\n";

				}

			}

			catch (Exception ex)

			{

				_loggedIn = false;

				string _exc = ex.ToString();

				LoginError += "Exception in GetResponseString. \r\n" + _exc + "\r\n";

			}



			if (!_loggedIn)

				return "AUTH_ERROR";

			else

				LoginError = string.Empty;

				return string.Empty;

        }



        private delegate string LocateUnreadItemIdentifierDelegate(string identifierSource);



        private string LocateFeedIdentifier(string identifierSource)

        {

            return identifierSource.Substring(identifierSource.LastIndexOf("/http") + 1);

        }



        private string LocateTagIdentifier(string identifierSource)

        {

            return identifierSource.Substring(identifierSource.LastIndexOf("/label/") + "/label/".Length);

        }



        public bool CollectUnreadFeeds(UnreadItemCollection unreadFeeds)

        {

            System.Diagnostics.Debug.Assert(unreadFeeds != null, "unreadFeeds must be assigned.");

            

            return CollectUnreadItems(unreadFeeds, null, null);

        }

		

        public bool CollectUnreadTags(UnreadItemCollection unreadTags, List<string> tagFilterList)

        {

            System.Diagnostics.Debug.Assert(unreadTags != null, "unreadTags must be assigned.");

            

            return CollectUnreadItems(null, unreadTags, tagFilterList);

        }



        public void CollectTags(List<String> tags)

        {

            System.Diagnostics.Debug.Assert(tags != null, "tags must be assigned.");



            if (!LoggedIn)

            {

                throw new Exception("Must be logged in to collect tags");

            }



            XmlDocument xdoc;

            string identifier;



            xdoc = this.GetTagListXMLDocument();



            tags.Clear();



            foreach (XmlNode node in xdoc.SelectNodes("//object/string[contains(.,'/label/') and contains(.,'user/')]"))

            {

                identifier = LocateTagIdentifier(node.InnerText);



                tags.Add(identifier);

            }

        }



        public bool CollectUnreadItems(UnreadItemCollection unreadFeeds, UnreadItemCollection unreadTags, List<string> identifierFilterList)

        {

            bool result = true;

            //int unreadCount;

            XmlDocument xdoc;



            result = LoggedIn;

            

            if (result)

            {

                xdoc = this.GetAllUnreadCountsXMLDocument();

				xdocAll = this.GetSubscriptionListXMLDocument();



                // Collect feed information

                if (unreadFeeds != null)

                {

                    unreadFeeds.Clear();



					CollectUnreadItemsBySelectedNodes(xdoc, "//object/string[contains(.,'user/') and contains(.,'/state/com.google/reading-list')]", unreadFeeds, LocateFeedIdentifier, null);

                }





                // Collect tag information

                if (unreadTags != null)

                {

                    unreadTags.Clear();



                    CollectUnreadItemsBySelectedNodes(xdoc, "//object/string[contains(.,'/label/') and contains(.,'user/')]", unreadTags, LocateTagIdentifier, identifierFilterList);

                }

            }



            return result;

        }



        private void CollectUnreadItemsBySelectedNodes(XmlDocument xdoc, string nodeSelection, UnreadItemCollection unreadItems, LocateUnreadItemIdentifierDelegate locateIdentifierDelegate, List<string> identifierFilterList)

        {

            int unreadCount;

            UnreadItem unreadItem;

            string identifier;

			string feedName;

            bool addToList;



            foreach (XmlNode node in xdoc.SelectNodes(nodeSelection))

            {

                unreadCount = Convert.ToInt32(node.ParentNode.SelectSingleNode("number").InnerText);

                identifier = locateIdentifierDelegate(node.InnerText);

				feedName = GetFeedNameById(identifier);

                addToList = (unreadCount > 0) && ((identifierFilterList == null) || identifierFilterList.Contains(identifier));

                

                if (addToList)

                {

                    unreadItem = new UnreadItem();



                    unreadItem.Identifier = identifier;

					unreadItem.FeedName = feedName;

                    unreadItem.ArticleCount = unreadCount;



                    

                    unreadItems.Add(unreadItem);

                }

            }

        }        



        private XmlDocument GetAllUnreadCountsXMLDocument()

		{

			string url = "https://www.google.com/reader/api/0/unread-count?all=true";

            string theXml = GetResponseString(CreateRequest(url));



			XmlDocument xdoc = new XmlDocument();

			xdoc.LoadXml(theXml);



			return xdoc;

		}



		private XmlDocument GetTagListXMLDocument()

		{

			string url = "https://www.google.com/reader/api/0/tag/list";

			string theXml = GetResponseString(CreateRequest(url));



			XmlDocument xdoc = new XmlDocument();

			xdoc.LoadXml(theXml);



			return xdoc;

		}



		private XmlDocument GetSubscriptionListXMLDocument()

		{

			string url = "https://www.google.com/reader/api/0/subscription/list";

			string theXml = GetResponseString(CreateRequest(url));



			XmlDocument xdoc = new XmlDocument();

			xdoc.LoadXml(theXml);



			return xdoc;

		}



		private string GetFeedNameById(string feedId)

		{

			try

			{

				XmlNode node = xdocAll.SelectSingleNode("//string[@name='id' and .='feed/" + feedId + "']/../string[@name='title']");

				if (node != null)

					return node.InnerText;

				else

					return " - ";

			}

			catch{

				return " - ";

			}

		}



		#endregion 



		#region HTTP Functions



		public string GetResponseStrEx(String url)

		{

			string xstr = GetResponseString(CreateRequest(url));



			return xstr;

		}



		private string GetResponseString(HttpWebRequest req)

		{

			string responseString = null;

			try

			{

				HttpWebResponse res = (HttpWebResponse)req.GetResponse();

				res.Cookies = req.CookieContainer.GetCookies(req.RequestUri);

				_Cookies.Add(res.Cookies);

				

				using (StreamReader read = new StreamReader(res.GetResponseStream()))

				{

					responseString = read.ReadToEnd();

				}

				res.Close();

				//_currentHTML = responseString;

				

			}

			catch (WebException ex)

			{

				using (StreamReader read = new StreamReader(ex.Response.GetResponseStream()))

				{

					responseString = read.ReadToEnd();

				}

				//res.Close();

				string exc = ex.ToString();

				LoginError += responseString+"\r\n" +exc + "\r\n";

			}

			catch (Exception ex)

			{

				string exc = ex.ToString();

				LoginError += exc + "\r\n";

			}

			return responseString;

		}



		private string PostLoginForm(HttpWebRequest req, string p)

		{

			string exc = string.Empty;

			req.ContentType = "application/x-www-form-urlencoded";

			req.Method = "POST";

			//req.Referer = _currentURL;

			byte[] b = Encoding.UTF8.GetBytes(p);

			req.ContentLength = b.Length;

			try

			{

				using (Stream s = req.GetRequestStream())

				{

					s.Write(b, 0, b.Length);

					s.Close();

				}

			}

			catch (Exception ex)

			{

				exc = ex.ToString();

				if (ex.GetType().Name == "WebException" && exc.IndexOf("(407)") != -1 && ProxyUser[0] !="missing")

				{

					ProxyUser[0] = "request";

				}

			}

			return exc;

		}



		private HttpWebRequest CreateRequest(string url)

		{

			HttpWebRequest req = WebRequest.Create(url) as HttpWebRequest;

			//WebProxy defaultProxy = WebProxy.GetDefaultProxy();

            IWebProxy defaultProxy = HttpWebRequest.GetSystemWebProxy();

			req.Proxy = defaultProxy; // if we wanted to disable proxying, can be done by setting to null I think

			if (ProxyUser[0] == "request")

			{

				DialogResult result = GetProxyUser(ref ProxyUser[1], ref ProxyUser[2]);

				if (result == DialogResult.OK && ProxyUser[1] != "" && ProxyUser[2] != "")

				{

					ProxyUser[0] = "exist";

				}

				else

				{

					ProxyUser[0] = "missing";

				}

			}

			if (ProxyUser[0] == "exist" && ProxyUser[1] != "" && ProxyUser[2] != "")

			{

				req.Proxy.Credentials = new NetworkCredential(ProxyUser[1], ProxyUser[2]);

			}

			//req.Proxy = null;

			//req.UserAgent = _user.UserAgent;

			req.UserAgent = "GRaiN/" + Assembly.GetExecutingAssembly().GetName().Version + "(Google Reader Notifier for Windows)";

			req.Referer = "http://yoni-zaf.appspot.com/notifier?version=" + Assembly.GetExecutingAssembly().GetName().Version;

			req.CookieContainer = _cookiesContainer;

			if (_loggedIn)

				req.Headers.Add("Authorization", "GoogleLogin auth=" + _loginAuth[2].Split('=')[1]);

			//req.Referer = _currentURL; // set the referring url properly to appear as a regular browser

			//_currentURL = url; // set the current url so the next request will have the right referring url ( might not work for sub pages )

			return req;

		}



		#endregion 



		public static DialogResult GetProxyUser(ref string userName, ref string passWord)

		{

			Form form = new Form();

			Label label = new Label();

			TextBox textBoxUser = new TextBox();

			TextBox textBoxPass = new TextBox();

			Button buttonOk = new Button();

			Button buttonCancel = new Button();



			form.Text = "GRaiN";

			label.Text = "Proxy require username and password:";

			textBoxUser.Text = userName;

			textBoxPass.Text = passWord;

			textBoxPass.UseSystemPasswordChar = true;



			buttonOk.Text = "OK";

			buttonCancel.Text = "Cancel";

			buttonOk.DialogResult = DialogResult.OK;

			buttonCancel.DialogResult = DialogResult.Cancel;



			label.SetBounds(9, 20, 372, 13);

			textBoxUser.SetBounds(12, 40, 372, 20);

			textBoxPass.SetBounds(12, 65, 372, 20);

			buttonOk.SetBounds(228, 92, 75, 23);

			buttonCancel.SetBounds(309, 92, 75, 23);



			label.AutoSize = true;

			textBoxUser.Anchor = textBoxUser.Anchor | AnchorStyles.Right;

			textBoxPass.Anchor = textBoxPass.Anchor | AnchorStyles.Right;

			buttonOk.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;

			buttonCancel.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;



			form.ClientSize = new Size(396, 125);

			form.Controls.AddRange(new Control[] { label, textBoxUser, textBoxPass, buttonOk, buttonCancel });

			form.ClientSize = new Size(Math.Max(300, label.Right + 10), form.ClientSize.Height);

			form.FormBorderStyle = FormBorderStyle.FixedDialog;

			form.StartPosition = FormStartPosition.CenterScreen;

			form.MinimizeBox = false;

			form.MaximizeBox = false;

			form.AcceptButton = buttonOk;

			form.CancelButton = buttonCancel;



			DialogResult dialogResult = form.ShowDialog();

			userName = textBoxUser.Text;

			passWord = textBoxPass.Text;

			return dialogResult;

		}

	}

}