using System;
using System.Collections;
using System.Reflection;

/// <header>
/// <wox>
///     <version>1.0</version>
///     <author>Carlos R. Jaimez Gonzalez</author>
///     <author>Simon M. Lucas</author>
///     <site>http://woxserializer.sourceforge.net/</site>
/// </wox>
/// <wox>
///     <version>1.5</version>
///     <author>Steven M Lewis</author>
/// </wox>
/// <wox>
///     <version>2.0</version>
///     <author>George A Smith</author>
///     <svn>http://woxserializer.sourceforge.net/</svn>
///     <note>XML form for vs 2 is more compact and therefor incompatible with vs 1</note>
/// </wox>
/// </header>

namespace wox.serial
{
    /// <summary>
    /// This is a simple object to XML serializer. The SimpleWriter class
    /// extends WoxWriter. It takes a C# object and a XMLwriter object.
    /// It writes (converts) an object to XML, and writes it using the XMLwriter
    /// to the specified storage media.
    /// </summary>

    public class SimpleWriter : Serial, WoxWriter
    {
        private readonly Hashtable mInstanceToIDs = new Hashtable();
        private readonly WoxHandlers mWoxHandlers;

        private int mNextID = 1;

        // not much point writing out final values - at least not yet -
        // the reader is not able to set them (though there's probably
        // a hidden way of doing this)

        public SimpleWriter( WoxHandlers pWoxHandlers )
        {
            mWoxHandlers = pWoxHandlers;
        }

        #region WoxWriter Members

        public string CreateIDfor( object pObject )
        {
            string zID = (mNextID++).ToString();
            mInstanceToIDs.Add( pObject, zID );
            return zID;
        }

        /// <summary>
        /// This method is the entry point to write an object in XML.
        /// </summary>
        /// <param name="pObject">The object to be serialized</param>
        /// <param name="pField">Optional Field information to augment the Type infomation</param>
        /// <param name="pWriter"></param>
        /// <param name="pJustType"></param>
        public void Write( object pObject, FieldInfo pField, XMLwriter pWriter, bool pJustType )
        {
            if ( pObject == null )
            {
                pWriter.WriteStartElement( OBJECT );
                pWriter.WriteEndElement();
                return;
            }
            if ( mInstanceToIDs.ContainsKey( pObject ) )
            {
                pWriter.WriteStartElement( OBJECT );
                pWriter.WriteAttributeString( IDREF, mInstanceToIDs[pObject].ToString() );
                pWriter.WriteEndElement();
                return;
            }

            Type zNativeType = pObject.GetType();

            WoxHandler zWoxHandler = mWoxHandlers.GetNativeHandler( zNativeType );

            if ( pJustType && !zWoxHandler.SupportsJustTypeWriting() )
            {
                throw new ApplicationException( "No significant Type infomation for: " + zNativeType );
            }

            zWoxHandler.WriteObject( mWoxHandlers, this, pObject, null, pWriter, pJustType );
        }

        #endregion
    }
}