using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.Mail;
using System.Reflection;
using System.Text;
using System.Threading;
using System.Web;

namespace DotNetPro.ErrorEmailer
{
    public class ErrorEmailerModule : IHttpModule
    {
        private HttpApplication context;

        public void Init(HttpApplication context)
        {
            this.context = context;
            context.Error += context_Error;
        }

        private void context_Error(object sender, EventArgs e)
        {
            LogToMail(context.Server.GetLastError());
        }

        private string text2Html(string html)
        {
            html = context.Server.HtmlEncode(html);
            html = html.Replace("\r\n", "<br/>");
            html = html.Replace("\n", "<br/>");
            return html;
        }

        private StringBuilder msg;

        public void LogToMail(Exception x)
        {
            msg = new StringBuilder();
            msg.Append("<style>\r\n");
            msg.Append("body,td,th{font:8pt tahoma}\r\n");
            msg.Append("table{background-color:#C0C0C0}\r\n");
            msg.Append("th{font-weight:bold;text-align:left;background-color:#C0C0C0;padding:4px}\r\n");
            msg.Append("td{vertical-align:top;background-color:#FFFBF0;padding:4px}\r\n");
            msg.Append("</style>\r\n");
            msg.Append("<table cellpadding=1 cellspacing=1>\r\n");

            if (x != null)
            {
                msg.Append("<tr><th colspan=2>Exception</th></tr>");
                msg.AppendFormat("<tr><td>Exception</td><td><pre>{0}</pre></td></tr>", x);
                msg.AppendFormat("<tr><td>Message</td><td>{0}</td></tr>", text2Html(x.Message));
                msg.AppendFormat("<tr><td>Source</td><td>{0}</td></tr>", text2Html(x.Source));
                msg.AppendFormat("<tr><td>StackTrace</td><td>{0}</td></tr>", text2Html(x.StackTrace));
                msg.AppendFormat("<tr><td>TargetSize</td><td>{0}</td></tr>", text2Html(x.TargetSite.ToString()));
            }


            addTitle("QueryString");

            foreach (string key in HttpContext.Current.Request.QueryString.AllKeys)
            {
                msg.AppendFormat("<tr><td>{0}</td><td>{1}&nbsp;</td></tr>", key, HttpContext.Current.Request.QueryString[key]);
            }

            addTitle("Form");

            foreach (string key in HttpContext.Current.Request.Form.AllKeys)
            {
                msg.AppendFormat("<tr><td>{0}</td><td>{1}&nbsp;</td></tr>", key, HttpContext.Current.Request.Form[key]);
            }

            addTitle("Server Variables");

            foreach (string key in HttpContext.Current.Request.ServerVariables.AllKeys)
            {
                msg.AppendFormat("<tr><td>{0}</td><td>{1}&nbsp;</td></tr>", key, HttpContext.Current.Request.ServerVariables[key]);
            }


            if (HttpContext.Current.Session != null)
            {
                addTitle("Session");
            

            foreach (string key in HttpContext.Current.Session)
            {
                msg.AppendFormat("<tr><td>{0}</td><td>{1}&nbsp;</td></tr>", key, HttpContext.Current.Session[key]);
            }
        }

        addTitle("Application");

            
            foreach (string key in HttpContext.Current.Application)
            {
                msg.AppendFormat("<tr><td>{0}</td><td>{1}&nbsp;</td></tr>", key, HttpContext.Current.Application[key]);
            }
            addTitle("Cookies");
            foreach (string key in HttpContext.Current.Request.Cookies.AllKeys)
            {
                msg.AppendFormat("<tr><td>{0}</td><td>{1}&nbsp;</td></tr>", key, HttpContext.Current.Request.Cookies[key].Value);
            }

            addValues(context.Context);
            addValues(context.Response);
            addValues(context.Server);
            if (context.Session != null)
            {
                addValues(context.Session);
            }
            addValues(context.User);
            addValues(context.User.Identity);
            addValues(Process.GetCurrentProcess());
            addValues(context.Request.LogonUserIdentity);
            addIenumerableValue(context.Request.LogonUserIdentity.Groups);
            addValues(AppDomain.CurrentDomain);
            addValues(AppDomain.CurrentDomain.SetupInformation);
            addValues(Thread.CurrentThread);

            addWebconfigDump();


            msg.Append("</table>");

            SmtpClient smtpSend = new SmtpClient();

            
            using (var emailMessage = new MailMessage())
            {

                emailMessage.To.Add(ConfigHandler.Instance.EmailTo);
                emailMessage.From = new MailAddress(ConfigHandler.Instance.EmailFrom);
                emailMessage.Subject = ConfigHandler.Instance.Subject;
                emailMessage.Body = msg.ToString();
                emailMessage.IsBodyHtml = true;

                smtpSend.Send(emailMessage);
            }
        }

        private void addWebconfigDump()
        {
            addTitle("Web.Config dump");
            string webConfigContents = File.ReadAllText(context.Server.MapPath("~/web.config"));
            msg.AppendFormat("<tr><td>Web.Config File</td><td><pre>{0}</pre></td></tr>", text2Html(webConfigContents));
        }  
        
        
        private void addValues(object inputObject)
        {
            addTitle("Object: " + inputObject.GetType().FullName);

            internalAddValue(inputObject);
        }

        private void internalAddValue(object inputObject)
        {
            List<PropertyInfo> propertyInfos = new List<PropertyInfo>(inputObject.GetType().GetProperties());

            foreach (PropertyInfo info in propertyInfos)
            {
                try
                {
                    object obj = info.GetValue(inputObject, null);
                    if (obj == null)
                    {
                        continue;
                    }
                    msg.AppendFormat("<tr><td>{0}</td><td>{1}&nbsp;</td></tr>", info.Name, obj.ToString());

                }
                catch (Exception)
                {
                    continue;
                }

            }
        }


        private void addIenumerableValue(IEnumerable inputObject)
        {
            addTitle("Object: " + inputObject.GetType().FullName);

            foreach (Object o in inputObject)
            {
                internalAddValue(o);
            }

        }

        private void addTitle(string titleName)
        {
            msg.Append("<tr><th colspan=2>" + titleName + "</th></tr>");
        }

        public void Dispose()
        {
            return;
        }
    }
}