// SignedProperties.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.Xml;

namespace Microsoft.Xades
{
    /// <summary>
    /// The SignedProperties element contains a number of properties that are
    /// collectively signed by the XMLDSIG signature
    /// </summary>
    public class SignedProperties
    {
        #region Constants
        /// <summary>
        /// Default value for the SignedProperties Id attribute
        /// </summary>
        public const string DefaultSignedPropertiesId = "SignedPropertiesId";
        #endregion

        #region Private variables
        private string id;
        private SignedSignatureProperties signedSignatureProperties;
        private SignedDataObjectProperties signedDataObjectProperties;
        #endregion

        #region Public properties

        /// <summary>
        /// This Id is used to be able to point the signature reference to this
        /// element.  It is initialized by default.
        /// </summary>
        public string Id
        {
            get
            {
                return this.id;
            }
            set
            {
                this.id = value;
            }
        }

        /// <summary>
        /// The properties that qualify the signature itself or the signer are
        /// included as content of the SignedSignatureProperties element
        /// </summary>
        public SignedSignatureProperties SignedSignatureProperties
        {
            get
            {
                return this.signedSignatureProperties;
            }
            set
            {
                this.signedSignatureProperties = value;
            }
        }

        /// <summary>
        /// The SignedDataObjectProperties element contains properties that qualify
        /// some of the signed data objects
        /// </summary>
        public SignedDataObjectProperties SignedDataObjectProperties
        {
            get
            {
                return this.signedDataObjectProperties;
            }
            set
            {
                this.signedDataObjectProperties = value;
            }
        }
        #endregion

        #region Constructors
        /// <summary>
        /// Default constructor
        /// </summary>
        public SignedProperties()
        {
            this.id = DefaultSignedPropertiesId;
            this.signedSignatureProperties = new SignedSignatureProperties();
            this.signedDataObjectProperties = new SignedDataObjectProperties();
        }
        #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 (!String.IsNullOrEmpty(this.id))
            {
                retVal = true;
            }

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

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

            return retVal;
        }

        /// <summary>
        /// Load state from an XML element
        /// </summary>
        /// <param name="xmlElement">XML element containing new state</param>
        public void LoadXml(System.Xml.XmlElement xmlElement)
        {
            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:SignedSignatureProperties", xmlNamespaceManager);
            if (xmlNodeList.Count == 0)
            {
                throw new CryptographicException("SignedSignatureProperties missing");
            }
            this.signedSignatureProperties = new SignedSignatureProperties();
            this.signedSignatureProperties.LoadXml((XmlElement)xmlNodeList.Item(0));

            xmlNodeList = xmlElement.SelectNodes("xsd:SignedDataObjectProperties", xmlNamespaceManager);
            if (xmlNodeList.Count != 0)
            {
                this.signedDataObjectProperties = new SignedDataObjectProperties();
                this.signedDataObjectProperties.LoadXml((XmlElement)xmlNodeList.Item(0));
            }
        }

        /// <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("xades", "SignedProperties", XadesSignedXml.XadesNamespaceUri);
            if (!String.IsNullOrEmpty(this.id))
            {
                retVal.SetAttribute("Id", this.id);
            }

            if (this.signedSignatureProperties != null)
            {
                retVal.AppendChild(creationXmlDocument.ImportNode(this.signedSignatureProperties.GetXml(), true));
            }
            else
            {
                throw new CryptographicException("SignedSignatureProperties should not be null");
            }

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

            return retVal;
        }
        #endregion
    }
}