/Source/facebook.Linq/Web/FacebookCallback.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Web;

using System.Web.SessionState;



namespace facebook.Web

{

	/// <summary>

	/// Facebook callback URL should be pointed to here

	/// </summary>

	public class FacebookCallback : IHttpHandler, IRequiresSessionState

	{

		public void ProcessRequest(HttpContext context)

		{

			var fc = FacebookContext.Get(context);

			var session = fc.Session;

			var authenticated = session.IsAuthenticated;

			if (!authenticated)

				authenticated = session.TryAuthenticating(context.Request);

			if (authenticated)

			{

				var page = Facebook.DefaultPage ?? "./?";

				if (page.Contains("?"))

					page += "&";

				else

					page += "?";

				page += HttpUtility.UrlDecode(context.Request.QueryString.ToString());

				context.Response.Redirect(page);

			}

			else

			{

				if (context.Request["app"].IsNotNullOrEmpty())

				{

					var appName = context.Request["app"];

					if (appName.Contains("?"))

						appName = appName.Substring(0, appName.IndexOf('?'));

					var requestUrl = context.Request.Url;

					var redirectedPageQueryString = HttpUtility.UrlEncode("?" + HttpUtility.UrlDecode(context.Request.QueryString.ToString()).Replace('?', '&'));

					var url = String.Format("http://apps.facebook.com/{0}/?redirectTo=http://{1}{2}{3}", appName, requestUrl.Host, requestUrl.AbsolutePath, redirectedPageQueryString);

					fc.RedirectTopFrame(url);

				}

				else if (Facebook.HasValidConfiguration)

				{

					fc.RedirectTopFrame(Facebook.FacebookLoginUrl);

				}

				else

				{

					context.Response.Write("Facebook configuration is missing. (facebook.Linq.APIKey, facebook.Linq.Secret, facebook.Linq.ApplicationID)");

				}

			}

		}







		public bool IsReusable

		{

			get

			{

				return false;

			}

		}

	}

}