using System;
using System.Collections.Generic;
using System.Text;
using System.Xml.Xsl;
using System.Xml;
using System.Diagnostics;
using System.IO;

// copyright 2008 Dexter Legaspi

namespace AP.Utilities.BizTalkDynamicMap
{
    interface IDynamicMapLoader
    {
        XslCompiledTransform LoadDynamicMap(object key);
    }

    public class BizTalkDynamicMap
    {
        public string Transform(object key, object input)
        {
            try
            {

                IDynamicMapLoader loader = DynamicMapLoaderFactory.GetDefaultDynamicMapLoader();

                Trace.Assert(loader != null);

                XslCompiledTransform map = loader.LoadDynamicMap(key);

                XmlReader input_doc = XmlReader.Create(new StringReader(input.ToString()));
                StringWriter output_doc = new StringWriter();
                XmlWriterSettings xs = map.OutputSettings.Clone();
                
                map.Transform(input_doc, XmlWriter.Create(output_doc, xs));

                return output_doc.ToString();
            }
            catch 
            {
                return "";
            }
            
        }
    }

    internal class DynamicMapLoaderFactory
    {
        public static IDynamicMapLoader GetDefaultDynamicMapLoader()
        {
            return new BasicDynamicMapLoader();
        }

        public static IDynamicMapLoader GetDynamicMapLoader(string loader_name)
        {
            switch (loader_name)
            {              
                default:
                    return new BasicDynamicMapLoader();
            }
        }
    }

    internal class BasicDynamicMapLoader : IDynamicMapLoader
    {
        #region IDynamicMapLoader Members

        const string LOOKUPS_FILE = @"c:\eai\components\maplookups.xml";        

        public XslCompiledTransform LoadDynamicMap(object key)
        {
            XmlDocument doc = new XmlDocument();
            XslCompiledTransform xsl = new XslCompiledTransform();

            try
            {
                doc.Load(LOOKUPS_FILE);
                Trace.WriteLine("map lookups file load ok.");

                Trace.WriteLine("key = " + key.ToString());
                string xsl_uri = doc.SelectSingleNode(String.Format("//Map[@Name='{0}']/@Uri", key.ToString())).Value;
                Trace.WriteLine("xsl_uri = " + key.ToString());
               
                xsl.Load(xsl_uri);

                return xsl;
            }
            catch (Exception e)
            {
                // I got an exception, bitch!
                Trace.WriteLine("exception: " + e);
                return null;
            }            
        }

        #endregion
    }
}