// XadesObject.cs
//
// XAdES Starter Kit for Microsoft .NET 3.5 (and above)
// 2010 Microsoft France
// Published under the CECILL-B Free Software license agreement.
// (http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.txt)
// 
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, 
// WHETHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED 
// WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE. 
// THE ENTIRE RISK OF USE OR RESULTS IN CONNECTION WITH THE USE OF THIS CODE 
// AND INFORMATION REMAINS WITH THE USER.

using System;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.Xml;

namespace Microsoft.Xades
{
    /// <summary>
    /// This class represents the unique object of a XAdES signature that
    /// contains all XAdES information
    /// </summary>
    public class XadesObject
    {
        #region Private variable
        private string id;
        private QualifyingProperties qualifyingProperties;
        #endregion

        #region Public properties
        /// <summary>
        /// Id attribute of the XAdES object
        /// </summary>
        public string Id
        {
            get
            {
                return this.id;
            }
            set
            {
                this.id = value;
            }
        }

        /// <summary>
        /// The QualifyingProperties element acts as a container element for
        /// all the qualifying information that should be added to an XML
        /// signature
        /// </summary>
        public QualifyingProperties QualifyingProperties
        {
            get
            {
                return this.qualifyingProperties;
            }
            set
            {
                this.qualifyingProperties = value;
            }
        }
        #endregion

        #region Constructors
        /// <summary>
        /// Default constructor
        /// </summary>
        public XadesObject()
        {
            this.qualifyingProperties = new QualifyingProperties();
        }
        #endregion

        #region Public methods
        /// <summary>
        /// Check to see if something has changed in this instance and needs to be serialized
        /// </summary>
        /// <returns>Flag indicating if a member needs serialization</returns>
        public bool HasChanged()
        {
            bool retVal = false;

            if (this.id != null && this.id != "")
            {
                retVal = true;
            }

            if (this.qualifyingProperties != null && this.qualifyingProperties.HasChanged())
            {
                retVal = true;
            }

            return retVal;
        }

        /// <summary>
        /// Load state from an XML element
        /// </summary>
        /// <param name="xmlElement">XML element containing new state</param>
        /// <param name="counterSignedXmlElement">Element containing parent signature (needed if there are counter signatures)</param>
        public void LoadXml(XmlElement xmlElement, XmlElement counterSignedXmlElement)
        {
            XmlNamespaceManager xmlNamespaceManager;
            XmlNodeList xmlNodeList;

            if (xmlElement == null)
            {
                throw new ArgumentNullException("xmlElement");
            }
            if (xmlElement.HasAttribute("Id"))
            {
                this.id = xmlElement.GetAttribute("Id");
            }
            else
            {
                this.id = "";
            }

            xmlNamespaceManager = new XmlNamespaceManager(xmlElement.OwnerDocument.NameTable);
            xmlNamespaceManager.AddNamespace("xsd", XadesSignedXml.XadesNamespaceUri);

            xmlNodeList = xmlElement.SelectNodes("xsd:QualifyingProperties", xmlNamespaceManager);
            if (xmlNodeList.Count == 0)
            {
                throw new CryptographicException("QualifyingProperties missing");
            }
            this.qualifyingProperties = new QualifyingProperties();
            this.qualifyingProperties.LoadXml((XmlElement)xmlNodeList.Item(0), counterSignedXmlElement);

            xmlNodeList = xmlElement.SelectNodes("xsd:QualifyingPropertiesReference", xmlNamespaceManager);
            if (xmlNodeList.Count != 0)
            {
                throw new CryptographicException("Current implementation can't handle QualifyingPropertiesReference element");
            }
        }

        /// <summary>
        /// Returns the XML representation of the this object
        /// </summary>
        /// <returns>XML element containing the state of this object</returns>
        public XmlElement GetXml()
        {
            XmlDocument creationXmlDocument;
            XmlElement retVal;

            creationXmlDocument = new XmlDocument();
            retVal = creationXmlDocument.CreateElement("ds", "Object", SignedXml.XmlDsigNamespaceUrl);
            if (this.id != null && this.id != "")
            {
                retVal.SetAttribute("Id", this.id);
            }

            if (this.qualifyingProperties != null && this.qualifyingProperties.HasChanged())
            {
                retVal.AppendChild(creationXmlDocument.ImportNode(this.qualifyingProperties.GetXml(), true));
            }

            return retVal;
        }
        #endregion
    }
}
