using System;
using System.Collections;
using System.Diagnostics;
using System.Globalization;
using System.Reflection;
using System.Xml;
using System.IO;
using System.Security.Principal;

using Microsoft.Win32;
using Microsoft.Crm.Callout;
using CrmSdk;

namespace Microsoft.Crm.Sdk.FullSample.CalloutSample2
{
   class CalloutComponent: CrmCalloutBase
   {
      private string GetPath()
      {
         string retval = null;
         RegistryKey key = Registry.LocalMachine.OpenSubKey( 
            "Software\\Microsoft\\MSCRM", false);
         retval = (string)key.GetValue("CRM_Server_InstallDir");
         retval = Path.Combine(retval, @"server\bin\assembly\");
      
         key.Close();
         return retval;
      }

      /// <summary>
      /// Note that the Network Service system user account under which
      /// all callouts execut must have write permission to the 
      /// <CRM server install dir>\server\bin\assembly folder
      /// in order for the following method to work.
      /// </summary>
      /// <param name="message"></param>
      private void WriteToFile(string message)
      {
         using (StreamWriter sw = File.CreateText( 
                  Path.Combine(GetPath(), "callout_test_output.txt"))) 
         {
            sw.WriteLine(message);
         }
      }

      public override PreCalloutReturnValue PreCreate(
         CalloutUserContext   userContext,  
         CalloutEntityContext entityContext,
         ref string       entityXml,
         ref string       errorMessage
         )
      {
         try
         {
            XmlDocument xd = new XmlDocument();
            xd.LoadXml(entityXml);

            // Initialize a NameTable object.
            NameTable nt = new NameTable();

            // Initialize a namespace manager. 
            XmlNamespaceManager nsmgr = new XmlNamespaceManager(nt);

            // Add the required prefix/namespace pairs to the namespace
            // manager. Add a default namespace first.
            nsmgr.AddNamespace("crm",
                "http://schemas.microsoft.com/crm/2006/WebServices");
            nsmgr.AddNamespace("xsi",
                "http://www.w3.org/2001/XMLSchema-instance");

            // For a list of available Entity Type Codes, refer to the SDK
            // documentation.
            switch (entityContext.EntityTypeCode)
            {
                // Account
                case 1:
                // Use the Document Object Model (DOM) to locate and
                // change the account's name.
                foreach (XmlElement element in
                        xd.GetElementsByTagName("Property"))
                {
                    if (element.Attributes.GetNamedItem("Name").Value == "name")
                    {
                        element.FirstChild.InnerText = 
                            "Read account  " + element.InnerText;
                        break;
                    }
                }
                break;

                // Task
                case 4212:
                // To demonstrate an alternate technique, use an XPath
                // query to locate value for task subject. You must prefix
                // each element in the entity Xml with the Microsoft CRM
                // namespace. 
                XmlNode node = xd.SelectSingleNode(
                    "//crm:Property[@Name='subject']/crm:Value", nsmgr);

                // Set node's InnerText property to the new subject value.
                if (node != null)
                    node.InnerText = "Read task " + node.InnerText;
                break;
            }
            entityXml = xd.OuterXml;
         }
         catch(Exception e)
         {
            throw e;
         }
         return PreCalloutReturnValue.Continue;
      }
  
      public override PreCalloutReturnValue PreUpdate(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         ref string       entityXml,
         ref string       errorMessage
         )
      {
         return PreCalloutReturnValue.Stop;
      }

      public override PreCalloutReturnValue PreAssign(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         Guid         assignedToId,
         ref string       errorMessage
         )
      {
         return PreCalloutReturnValue.Stop;
      }

      public override PreCalloutReturnValue PreDelete(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         ref string errorMessage
         )
      {
         errorMessage = "Aborting delete";
         return PreCalloutReturnValue.Abort;
      }

      public override PreCalloutReturnValue PreSetState(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         ref int        newStateCode,
         ref int        newStatusCode,
         ref string       errorMessage
         )
      {
         return PreCalloutReturnValue.Continue;
      }

      public override PreCalloutReturnValue PreMerge(
         CalloutUserContext   userContext,
         CalloutEntityContext masterEntityContext,
         CalloutEntityContext subordinateEntityContext,
         ref string       mergeUpdateEntityXml,
         ref string       errorMessage
         )
      {
         return PreCalloutReturnValue.Abort;
      }
     
      public override void PostCreate(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         String         postImageEntityXml
         )
      {
         WriteToFile(
            String.Format("PostCreate called.\npostImage = {0}",
                          postImageEntityXml));
      } 

      public override void PostUpdate(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         String         preImageEntityXml,
         String         postImageEntityXml
         )
      {
         WriteToFile( String.Format( 
            "PostUpdate called\n preImage = {0}\n postImage = {1}",
            preImageEntityXml, postImageEntityXml));
      }

      public override void PostAssign(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         String         preImageEntityXml,
         String         postImageEntityXml
         )
      {
         WriteToFile(
            String.Format(
            "PostAssign called\n preImage = {0}\n postImage = {1}",
            preImageEntityXml, postImageEntityXml));
      }

      public override void PostDelete(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         String         preImageEntityXml
         )
      {
         WriteToFile(
            String.Format("PostDelete called\n preImage = {0}",
            preImageEntityXml));
      }

      public override void PostSetState(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         String preImageEntityXml,
         String postImageEntityXml
         )
      {
         WriteToFile(
            String.Format(
            "PostSetState called\n preImage = {0}\n postImage = {1}",
            preImageEntityXml, postImageEntityXml));
      }

      public override void PostMerge(
         CalloutUserContext   userContext,
         CalloutEntityContext entityContext,
         String preImageMasterEntityXml,
         String preImageSubordinateEntityXml,
         String postImageMasterEntityXml
         )
      {
         WriteToFile( String.Format(
            "PostMerge called\n preMasterImage = {0}\npreSubImage = {1}\n postMasterImage = {2}",
            preImageMasterEntityXml,
            preImageSubordinateEntityXml,
            postImageMasterEntityXml));
      }
   }
}