using System;
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
{
    public class DefaultObjectHandler : AbstractHandler, WoxDefaultHandler
    {
        public static readonly DefaultObjectHandler INSTANCE = new DefaultObjectHandler();

        protected DefaultObjectHandler()
        {
        }

        #region WoxIsAHandler Members

        public virtual bool IsFor( Type pType )
        {
            return true;
        }

        public override string[] GetForReadObjectWoxTypeNames()
        {
            return null; // Ask Us
        }

        public override Type GetNativeTypeFor( WoxHandlers pWoxHandlers, string pWoxType )
        {
            Type zType = CommonNativeType( pWoxHandlers, pWoxType );
            if ( zType == null )
            {
                throw new ApplicationException( "No Native Type for Wox Type: " + pWoxType );
            }
            return zType;
        }

        public override string GetWoxTypeFor( WoxHandlers pWoxHandlers, Type pType, FieldInfo pField, bool pJustType )
        {
            return CommonWoxType( pWoxHandlers, pType, null, pJustType );
        }

        public override bool WillReadObjectForWoxType( string pWoxType )
        {
            return true;
        }

        public override object ReadObject( WoxHandlers pWoxHandlers, WoxReader pWoxReader, XMLreader pReader )
        {
            XMLreader zSubtree = pReader.CreateSubtreeReader();
            zSubtree.ReadStartElement(); //position the cursor to our element

            try
            {
                string zWoxTypeName = pReader.GetAttribute( Serial.TYPE );

                Type zType = GetNativeTypeFor( pWoxHandlers, zWoxTypeName );

                if ( zType == null )
                {
                    throw new ApplicationException( "Unable to determine Native Type for Wox Type: " + zWoxTypeName );
                }

                if ( zType.IsEnum )
                {
                    String value = pReader.GetAttribute( Serial.VALUE );
                    return Enum.Parse( zType, value );
                }
                object zInstance = Util.CreateInstance( zType, zWoxTypeName );

                ProcessFields( pWoxHandlers, pWoxReader, zSubtree, zType, zInstance );

                return zInstance;
            }
            catch ( Exception e )
            {
                throw new ApplicationException( "Default Object Handler Read Object Exception is: " + e.Message, e );
            }
            finally
            {
                Consume( zSubtree );
            }
        }

        public override void WriteObject( WoxHandlers pWoxHandlers, WoxWriter pWoxWriter, object pObject, FieldInfo pField, XMLwriter pWriter, bool pJustType )
        {
            Type zType = pObject.GetType();
            pWriter.WriteStartElement( Serial.OBJECT );
            pWriter.WriteAttributeString( Serial.TYPE, CommonWoxType( pWoxHandlers, zType, pField, pJustType ) );

            if (pJustType)
            {
                ProcessFields(pWoxHandlers, pWoxWriter, pWriter, pJustType, zType, pObject);
            }
            else if (zType.IsEnum)
            {
                pWriter.WriteAttributeString( Serial.VALUE, pObject.ToString() );
            }
            else
            {
                pWriter.WriteAttributeString( Serial.ID, pWoxWriter.CreateIDfor( pObject ) );

                ProcessFields( pWoxHandlers, pWoxWriter, pWriter, pJustType, zType, pObject );
            }

            pWriter.WriteEndElement();
        }

        public override bool SupportsJustTypeWriting()
        {
            return true;
        }

        #endregion
    }
}