#region License, Terms and Author(s)

//

// ELMAH - Error Logging Modules and Handlers for ASP.NET

// Copyright (c) 2007 Atif Aziz. All rights reserved.

//

//  Author(s):

//

//      Atif Aziz, http://www.raboof.com

//

// This library is free software; you can redistribute it and/or modify it 

// under the terms of the New BSD License, a copy of which should have 

// been delivered along with this distribution.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 

// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

//

#endregion



[assembly: Elmah.Scc("$Id: ErrorMailHtmlFormatter.cs 25 2007-05-04 23:24:03Z azizatif $")]



namespace Elmah

{

    #region Imports



    using System;



    using TextWriter = System.IO.TextWriter;

    using HttpUtility = System.Web.HttpUtility;

    using NameValueCollection = System.Collections.Specialized.NameValueCollection;

    using HtmlTextWriter = System.Web.UI.HtmlTextWriter;

    using Html32TextWriter = System.Web.UI.Html32TextWriter;

    using HtmlTextWriterTag = System.Web.UI.HtmlTextWriterTag;

    using HtmlTextWriterAttribute = System.Web.UI.HtmlTextWriterAttribute;



    #endregion



    /// <summary>

    /// Formats the HTML to display the details of a given error that is

    /// suitable for sending as the body of an e-mail message.

    /// </summary>

    

    public class ErrorMailHtmlFormatter : ErrorTextFormatter

    {

        private HtmlTextWriter _writer;

        private Error _error;



        /// <summary>

        /// Returns the text/html MIME type that is the format provided 

        /// by this <see cref="ErrorTextFormatter"/> implementation.

        /// </summary>



        public override string MimeType

        { 

            get { return "text/html"; }

        }



        /// <summary>

        /// Formats a complete HTML document describing the given 

        /// <see cref="Error"/> instance.

        /// </summary>



        public override void Format(TextWriter writer, Error error)

        {

            if (writer == null)

                throw new ArgumentNullException("writer");



            if (error == null)

                throw new ArgumentNullException("error");



            //

            // Create a HTML writer on top of the given writer and

            // write out the document. Note that the incoming 

            // writer and error parameters are promoted to members

            // during formatting in order to avoid passing them

            // as context to each downstream method responsible

            // for rendering a part of the document. The important 

            // assumption here is that Format will never be called

            // from more than one thread at the same time.

            //



            Html32TextWriter htmlWriter = new Html32TextWriter(writer);



            htmlWriter.RenderBeginTag(HtmlTextWriterTag.Html);



            _writer = htmlWriter;

            _error = error;



            try

            {

                RenderHead();

                RenderBody();

            }

            finally

            {

                _writer = null;

                _error = null;

            }



            htmlWriter.RenderEndTag(); // </html>

            htmlWriter.WriteLine();

        }



        /// <summary>

        /// Gets the <see cref="HtmlTextWriter"/> used for HTML formatting.

        /// </summary>

        /// <remarks>

        /// This property is only available to downstream methods in the

        /// context of the <see cref="Format"/> method call.

        /// </remarks>



        protected HtmlTextWriter Writer

        {

            get { return _writer; }

        }



        /// <summary>

        /// Gets the <see cref="Error"/> object for which a HTML document

        /// is being formatted.

        /// </summary>

        /// <remarks>

        /// This property is only available to downstream methods in the

        /// context of the <see cref="Format"/> method call.

        /// </remarks>



        protected Error Error

        {

            get { return _error; }

        }



        /// <summary>

        /// Renders the &lt;head&gt; section of the HTML document.

        /// </summary>

        

        protected virtual void RenderHead()

        {

            HtmlTextWriter writer = this.Writer;



            writer.RenderBeginTag(HtmlTextWriterTag.Head);

    

            //

            // Write the document title and style.

            //

    

            writer.RenderBeginTag(HtmlTextWriterTag.Title);

            writer.Write("Error: ");

            HttpUtility.HtmlEncode(this.Error.Message, writer);

            writer.RenderEndTag(); // </title>

            writer.WriteLine();



            RenderStyle();



            writer.RenderEndTag(); // </head>

            writer.WriteLine();

        }



        /// <summary>

        /// Renders the &lt;body&gt; section of the HTML document.

        /// </summary>



        protected virtual void RenderBody()

        {

            HtmlTextWriter writer = this.Writer;



            writer.RenderBeginTag(HtmlTextWriterTag.Body);



            RenderSummary();



            if (this.Error.Detail.Length != 0)

            {

                RenderDetail();   

            }



            RenderCollections();

            

            RenderFooter();



            writer.RenderEndTag(); // </body>

            writer.WriteLine();

        }



        /// <summary>

        /// Renders the footer content that appears at the end of the 

        /// HTML document body.

        /// </summary>



        protected virtual void RenderFooter()

        {

            HtmlTextWriter writer = this.Writer;



            writer.RenderBeginTag(HtmlTextWriterTag.P);

            PoweredBy poweredBy = new PoweredBy();

            poweredBy.RenderControl(writer);

            writer.RenderEndTag();

        }



        /// <summary>

        /// Renders the &lt;style&gt; element along with in-line styles

        /// used to format the body of the HTML document.

        /// </summary>



        protected virtual void RenderStyle()

        {

            HtmlTextWriter writer = this.Writer;



            writer.RenderBeginTag(HtmlTextWriterTag.Style);



            writer.WriteLine(@"

                body { font-family: verdana, arial, helvetic; font-size: x-small; } 

                td, th, pre { font-size: x-small; } 

                #errorDetail { padding: 1em; background-color: #FFFFCC; } 

                #errorMessage { font-size: medium; font-style: italic; color: maroon; }

                h1 { font-size: small; }");

            

            writer.RenderEndTag(); // </style>

            writer.WriteLine();

        }



        /// <summary>

        /// Renders the details about the <see cref="Error" /> object in

        /// body of the HTML document.

        /// </summary>



        protected virtual void RenderDetail()

        {

            HtmlTextWriter writer = this.Writer;



            //

            // Write the full text of the error.

            //

    

            writer.AddAttribute(HtmlTextWriterAttribute.Id, "errorDetail");

            writer.RenderBeginTag(HtmlTextWriterTag.Pre);

            writer.InnerWriter.Flush();

            HttpUtility.HtmlEncode(this.Error.Detail, writer.InnerWriter);

            writer.RenderEndTag(); // </pre>

            writer.WriteLine();

        }



        /// <summary>

        /// Renders a summary about the <see cref="Error"/> object in

        /// body of the HTML document.

        /// </summary>



        protected virtual void RenderSummary()

        {

            HtmlTextWriter writer = this.Writer;

            Error error = this.Error;



            //

            // Write the error type and message.

            //

    

            writer.AddAttribute(HtmlTextWriterAttribute.Id, "errorMessage");

            writer.RenderBeginTag(HtmlTextWriterTag.P);

            HttpUtility.HtmlEncode(error.Type, writer);

            writer.Write(": ");

            HttpUtility.HtmlEncode(error.Message, writer);

            writer.RenderEndTag(); // </p>

            writer.WriteLine();

    

            //

            // Write out the time, in UTC, at which the error was generated.

            // 

    

            if (error.Time != DateTime.MinValue)

            {            

                writer.RenderBeginTag(HtmlTextWriterTag.P);

                writer.Write("Generated: ");

                HttpUtility.HtmlEncode(error.Time.ToString("r"), writer);

                writer.RenderEndTag(); // </p>

                writer.WriteLine();

            }

        }



        /// <summary>

        /// Renders the diagnostic collections of the <see cref="Error" /> object in

        /// body of the HTML document.

        /// </summary>



        protected virtual void RenderCollections()

        {

            RenderCollection(this.Error.ServerVariables, "Server Variables");

        }



        /// <summary>

        /// Renders a collection as a table in HTML document body.

        /// </summary>

        /// <remarks>

        /// This method is called by <see cref="RenderCollections"/> to 

        /// format a diagnostic collection from <see cref="Error"/> object.

        /// </remarks>



        protected virtual void RenderCollection(NameValueCollection collection, string caption)

        {

            if (collection == null || collection.Count == 0)

            {

                return;

            }



            HtmlTextWriter writer = this.Writer;



            writer.RenderBeginTag(HtmlTextWriterTag.H1);

            HttpUtility.HtmlEncode(caption, writer);

            writer.RenderEndTag(); // </h1>

            writer.WriteLine();



            //

            // Write a table with each key in the left column

            // and its value in the right column.

            //



            writer.AddAttribute(HtmlTextWriterAttribute.Cellpadding, "5");

            writer.AddAttribute(HtmlTextWriterAttribute.Cellspacing, "0");

            writer.AddAttribute(HtmlTextWriterAttribute.Border, "1");

            writer.AddAttribute(HtmlTextWriterAttribute.Width, "100%");

            writer.RenderBeginTag(HtmlTextWriterTag.Table);



            //

            // Write the column headings.

            //



            writer.AddAttribute(HtmlTextWriterAttribute.Valign, "top");

            writer.RenderBeginTag(HtmlTextWriterTag.Tr);



            writer.AddAttribute(HtmlTextWriterAttribute.Align, "left");

            writer.RenderBeginTag(HtmlTextWriterTag.Th);

            writer.Write("Name");

            writer.RenderEndTag(); // </th>



            writer.AddAttribute(HtmlTextWriterAttribute.Align, "left");

            writer.RenderBeginTag(HtmlTextWriterTag.Th);

            writer.Write("Value");

            writer.RenderEndTag(); // </th>



            writer.RenderEndTag(); // </tr>



            //

            // Write the main body of the table containing keys

            // and values in a two-column layout.

            //



            foreach (string key in collection.Keys)

            {

                writer.AddAttribute(HtmlTextWriterAttribute.Valign, "top");

                writer.RenderBeginTag(HtmlTextWriterTag.Tr);

                

                writer.RenderBeginTag(HtmlTextWriterTag.Td);

                HttpUtility.HtmlEncode(key, writer);

                writer.RenderEndTag(); // </td>

                

                writer.RenderBeginTag(HtmlTextWriterTag.Td);



                string value = Mask.NullString(collection[key]);



                if (value.Length != 0)

                {

                    HttpUtility.HtmlEncode(value, writer);

                }

                else

                {

                    writer.Write("&nbsp;");

                }



                writer.RenderEndTag(); // </td>



                writer.RenderEndTag(); // </tr>

            }



            writer.RenderEndTag(); // </table>

            writer.WriteLine();

        }

    }

}