To Err is Human… to Handle, Divine

using System;
using System.Collections.Generic;
using System.Text;

namespace Jason.EnterpriseErrorHandler
{
    public class ErrorManager 
    {
        /*Begin Global Base Methodology*/
        internal const int MEMORY_STORE_DEFAULT_SIZE = 4096;
        static private ErrorManager Signleton = new ErrorManager();
        
        static public ErrorManager InstallApplicationErrorHandler()
        {
            System.AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(Signleton.ErrorHandler);
            //Signleton.attachedTo.Add(System.AppDomain.CurrentDomain);//We can be installed on many app domains? 
            return Signleton;
        }
        static public ErrorManager UnInstallApplicationErrorHandler()
        {
            //List<AppDomain> contextDomains = Signleton.attachedTo;
            //foreach( AppDomain apd in contextDomains)
            //    apd.UnhandledException -= new UnhandledExceptionEventHandler(Signleton.ErrorHandler);

            System.AppDomain.CurrentDomain.UnhandledException -= new UnhandledExceptionEventHandler(Signleton.ErrorHandler);
            return Signleton;
        }
        static public ErrorManager GetApplicationErrorHandler()
        {
            return Signleton;
        }        

        /*Begin Object Base Methodology*/
        Jason.EnterpriseErrorHandler.ConfigurationHandler.ErrorSubSystem cfg;
        System.Collections.Generic.List<System.AppDomain> attachedTo;

        private ErrorManager()
        {/*Called when singleton is first initilized*/
            try
            {
                attachedTo = new List<AppDomain>();
                cfg = System.Configuration.ConfigurationManager.GetSection("errorSubSystem")
                        as Jason.EnterpriseErrorHandler.ConfigurationHandler.ErrorSubSystem;
                if (cfg != null) System.Diagnostics.Debug.WriteLine(cfg.GetType().Name);
            }
            catch (Exception Ex)
            {
                System.Diagnostics.Debug.WriteLine(Ex.ToString());
            }

            return;
        }
         ~ErrorManager()
        {/*Since the Signleton holds a ref, this will only be called when the appdomin is asked to deconstruct.*/
            ErrorManager.UnInstallApplicationErrorHandler(); 
        }
        public void SimulateErrorCondition(Exception Ex){
            UnhandledExceptionEventArgs arg = new UnhandledExceptionEventArgs(Ex, false);
            this.ErrorHandler(this, arg);
        }
        private void ErrorHandler(Object sender, UnhandledExceptionEventArgs arg)
        {
            try
            {
                Exception Err = (Exception)arg.ExceptionObject;
                Type Key = arg.ExceptionObject.GetType();
                //iErrorPolicy Policy = null;
                while (Key != null)
                {
                    /*Lookup any Policies in order of most specific type first*/
                    //Policy = cfg.LookupPolicy(Key);
                    //if (Policy != null) Policy.ApplyInternalHandlerTo(Err);
                    if (cfg != null) cfg.invokeRelevantPolicy(Key,Err);

                    Key = Key.BaseType;/*Get More Generic Error Type*/
                }
            }
            catch (Exception Ex)
            {//Swallow errors because we are in a exception handler
                System.Diagnostics.Debug.WriteLine(Ex.ToString());
                //TODO: Merge the Argument error, with the current Ex error such that there is internal cause.
            }
        }
    }/*End ErrorManager*/
}