using System;
using System.Data;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Reflection;
using System.Collections.Specialized;
using System.Xml;
using umbraco;
using umbraco.cms.businesslogic.member;
using System.Web.SessionState;

namespace umbraco.presentation.umbracobase
{
    public class requestModule : IHttpModule
    {
        private HttpApplication mApp;

        #region IHttpModule Members

        public void Dispose()
        {
        }

        public void Init(HttpApplication httpApp)
        {
            //            httpApp.PostAuthorizeRequest += new EventHandler(httpApp_PreRequestHandlerExecute);
            httpApp.PostAcquireRequestState += new EventHandler(httpApp_PostAcquireRequestState);
            httpApp.PostMapRequestHandler += new EventHandler(httpApp_PostMapRequestHandler);
        }

        void httpApp_PostMapRequestHandler(object sender, EventArgs e)
        {
            //remove extension and split the url
            HttpApplication httpApp = (HttpApplication)sender;
            string url = httpApp.Context.Request.RawUrl;


            if (url.ToLower().StartsWith("/base/"))
            {

                if (httpApp.Context.Handler is IReadOnlySessionState || httpApp.Context.Handler is IRequiresSessionState)
                {
                    // no need to replace the current handler
                    return;
                }

                // swap the current handler
                httpApp.Context.Handler = new MyHttpHandler(httpApp.Context.Handler);

            }
        }

        void httpApp_PostAcquireRequestState(object sender, EventArgs e)
        {
            HttpApplication httpApp = (HttpApplication)sender;

            //remove extension and split the url
            string url = httpApp.Context.Request.RawUrl;


            if (url.ToLower().StartsWith("/base/"))
            {
                MyHttpHandler resourceHttpHandler = HttpContext.Current.Handler as MyHttpHandler;

                if (resourceHttpHandler != null)
                {
                    // set the original handler back
                    HttpContext.Current.Handler = resourceHttpHandler.OriginalHandler;
                }

                if (url.ToLower().Contains(".aspx"))
                    url = url.Substring(0, url.IndexOf(".aspx"));

                object[] urlArray = url.Split('/');

                //There has to be minimum 4 parts in the url for this to work... /base/library/method/[parameter].aspx
                if (urlArray.Length >= 4)
                {
                    string extensionAlias = urlArray[2].ToString();
                    string methodName = urlArray[3].ToString();

                    httpApp.Response.ContentType = "text/xml";
                    restExtension myExtension = new restExtension(extensionAlias, methodName);

                    if (myExtension.isAllowed)
                    {
                        string respone = invokeMethod(myExtension, urlArray);
                        if (respone.Substring(0, 7) == "<error>")
                        {
                            httpApp.Response.StatusCode = 500;
                            httpApp.Response.StatusDescription = "Internal Server Error";
                        }
                        httpApp.Response.Output.Write(respone);
                    }
                    else
                    {
                        httpApp.Response.StatusCode = 500;
                        httpApp.Response.StatusDescription = "Internal Server Error";
                        //Very static error msg...
                        httpApp.Response.Output.Write("<error>Extension not found or permission denied</error>");
                    }
                    //end the resposne
                    httpApp.Response.End();
                }
            }
        }




        private string invokeMethod(restExtension myExtension, object[] paras)
        {
            try
            {
                //So method is either not found or not valid... this should probably be moved... 
                if (!myExtension.method.IsPublic || !myExtension.method.IsStatic)
                    return "<error>Method has to be public and static</error>";
                else //And if it is lets continue trying to invoke it... 
                {
                    //lets check if we have parameters enough in the url..
                    if (myExtension.method.GetParameters().Length > (paras.Length - 4)) //Too few
                        return "<error>Not Enough parameters in url</error>";
                    else
                    {

                        //We have enough parameters... lets invoke..
                        //Create an instance of the type we need to invoke the method from.
                        Object obj = Activator.CreateInstance(myExtension.type);
                        Object response;

                        //umbracoBase.baseBinder bBinder = new baseBinder();

                        if (myExtension.method.GetParameters().Length == 0)
                        {
                            //response = myMethod.method.Invoke(obj, BindingFlags.Public | BindingFlags.Instance, bBinder, null, System.Globalization.CultureInfo.CurrentCulture);
                            response = myExtension.method.Invoke(obj, null); //Invoke with null as parameters as there are none
                        }

                        else
                        {
                            //We only need the parts of the url above the number 4 so we'll 
                            //recast those to objects and add them to the object[]

                            //Getting the right lenght.. 4 is the magic number dum di dum.. 
                            object[] methodParams = new object[(paras.Length - 4)];

                            int i = 0;

                            foreach (ParameterInfo pInfo in myExtension.method.GetParameters())
                            {
                                Type myType = Type.GetType(pInfo.ParameterType.ToString());
                                methodParams[(i)] = Convert.ChangeType(paras[i + 4], myType);
                                i++;
                            }

                            //Invoke with methodParams
                            //response = myMethod.method.Invoke(obj, BindingFlags.Public | BindingFlags.Instance, bBinder, methodParams, System.Globalization.CultureInfo.CurrentCulture);
                            response = myExtension.method.Invoke(obj, methodParams);
                        }

                        /*TODO - SOMETHING ALITTLE BETTER THEN ONLY CHECK FOR XPATHNODEITERATOR OR ELSE do ToString() */
                        if (response != null)
                        {
                            switch (myExtension.method.ReturnType.ToString())
                            {
                                case "System.Xml.XPath.XPathNodeIterator":
                                    return ((System.Xml.XPath.XPathNodeIterator)response).Current.OuterXml;
                                case "System.Xml.Linq.XDocument":
                                    return response.ToString();
                                case "System.Xml.XmlDocument":
                                    XmlDocument xmlDoc = (XmlDocument)response;
                                    StringWriter sw = new StringWriter();
                                    XmlTextWriter xw = new XmlTextWriter(sw);
                                    xmlDoc.WriteTo(xw);
                                    return sw.ToString();
                                default:
                                    string strResponse = ((string)response.ToString());

                                    if (myExtension.returnXML)
                                    {
                                        //do a quick "is this html?" check... if it is add CDATA... 
                                        if (strResponse.Contains("<") || strResponse.Contains(">"))
                                            strResponse = "<![CDATA[" + strResponse + "]]>";
                                        return "<value>" + strResponse + "</value>";
                                    }
                                    else
                                    {
                                        HttpContext.Current.Response.ContentType = "text/html";
                                        return strResponse;
                                    }
                            }
                        }
                        else
                        {
                            if (myExtension.returnXML)
                                return "<error>Null value returned</error>";
                            else
                                return string.Empty;
                        }



                    }
                }
            }

            catch (Exception ex)
            {
                //Overall exception handling... 
                return "<error><![CDATA[MESSAGE:\n" + ex.Message + "\n\nSTACKTRACE:\n" + ex.StackTrace + "\n\nINNEREXCEPTION:\n" + ex.InnerException + "]]></error>";
            }

        }


    }

    // a temp handler used to force the SessionStateModule to load session state
    public class MyHttpHandler : IHttpHandler, IRequiresSessionState
    {
        internal readonly IHttpHandler OriginalHandler;

        public MyHttpHandler(IHttpHandler originalHandler)
        {
            OriginalHandler = originalHandler;
        }

        public void ProcessRequest(HttpContext context)
        {
            // do not worry, ProcessRequest() will not be called, but let's be safe
            throw new InvalidOperationException("MyHttpHandler cannot process requests.");
        }

        public bool IsReusable
        {
            // IsReusable must be set to false since class has a member!
            get { return false; }
        }
    }
}
        #endregion