//
// CipherReference.cs - CipherReference implementation for XML Encryption
// http://www.w3.org/2001/04/xmlenc#sec-CipherReference
//
// Author:
//      Tim Coleman (tim@timcoleman.com)
//
// Copyright (C) Tim Coleman, 2004

#if NET_2_0

using System.Xml;

namespace System.Security.Cryptography.Xml {
	public sealed class CipherReference : EncryptedReference {

		#region Constructors
	
		public CipherReference ()
			: base ()
		{
		}
	
		public CipherReference (string uri)
			: base (uri)
		{
		}
	
		public CipherReference (string uri, TransformChain tc)
			: base (uri, tc)
		{
		}
	
		#endregion // Constructors
	
		#region Methods

		public override XmlElement GetXml ()
		{
			return GetXml (new XmlDocument ());
		}

		internal override XmlElement GetXml (XmlDocument document)
		{
			XmlElement xel = document.CreateElement (XmlEncryption.ElementNames.CipherReference, EncryptedXml.XmlEncNamespaceUrl);

			xel.SetAttribute (XmlEncryption.AttributeNames.URI, Uri);

			if (TransformChain != null && TransformChain.Count > 0) {
				XmlElement xtr = document.CreateElement (XmlEncryption.ElementNames.Transforms, EncryptedXml.XmlEncNamespaceUrl);
				foreach (Transform t in TransformChain) 
					xtr.AppendChild (document.ImportNode (t.GetXml (), true));
				xel.AppendChild (xtr);
			}

			return xel;
		}

		public override void LoadXml (XmlElement value)
		{
			if (value == null)
				throw new ArgumentNullException ("value");
			if ((value.LocalName != XmlEncryption.ElementNames.CipherReference) || (value.NamespaceURI != EncryptedXml.XmlEncNamespaceUrl))
				throw new CryptographicException ("Malformed CipherReference element.");
			else {
				Uri = null;
				TransformChain = new TransformChain ();

				foreach (XmlNode n in value.ChildNodes) {
					if (n is XmlWhitespace)
						continue;

					switch (n.LocalName) {
					case XmlEncryption.ElementNames.Transforms:
						foreach (XmlNode xn in ((XmlElement) n).GetElementsByTagName (XmlSignature.ElementNames.Transform, XmlSignature.NamespaceURI)) {
							Transform t = null;
							switch (((XmlElement) xn).Attributes [XmlSignature.AttributeNames.Algorithm].Value) {
							case XmlSignature.AlgorithmNamespaces.XmlDsigBase64Transform:
								t = new XmlDsigBase64Transform ();
								break;
							case XmlSignature.AlgorithmNamespaces.XmlDsigC14NTransform:
								t = new XmlDsigC14NTransform ();
								break;
							case XmlSignature.AlgorithmNamespaces.XmlDsigC14NWithCommentsTransform:
								t = new XmlDsigC14NWithCommentsTransform ();
								break;
							case XmlSignature.AlgorithmNamespaces.XmlDsigEnvelopedSignatureTransform:
								t = new XmlDsigEnvelopedSignatureTransform ();
								break;
							case XmlSignature.AlgorithmNamespaces.XmlDsigXPathTransform:
								t = new XmlDsigXPathTransform ();
								break;
							case XmlSignature.AlgorithmNamespaces.XmlDsigXsltTransform:
								t = new XmlDsigXsltTransform ();
								break;
							default:
								continue;
							}

							t.LoadInnerXml (((XmlElement) xn).ChildNodes);
							TransformChain.Add (t);
						}
						break;
					}
				}
						
				if (value.HasAttribute (XmlEncryption.AttributeNames.URI))
					Uri = value.Attributes [XmlEncryption.AttributeNames.URI].Value;
			}
		}

		#endregion // Methods
	}
}

#endif