using System;
using System.Collections;
using System.Reflection;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.Xml;
using Kreta.Resources;

namespace Kreta.EESZTInterface.STS
{
    class PrefixedSignedXML : SignedXml
    {
        private string signatureValueId;

        public PrefixedSignedXML(XmlDocument document)
            : base(document)
        { }

        public PrefixedSignedXML(XmlElement element)
            : base(element)
        { }

        public PrefixedSignedXML()
            : base()
        { }

        /// <summary>
        /// Setting this property will add an ID attribute to the SignatureValue element.
        /// This is required when constructing a XAdES-T signature.
        /// </summary>
        public string SignatureValueId
        {
            get
            {
                return this.signatureValueId;
            }
            set
            {
                this.signatureValueId = value;
            }
        }

        public override XmlElement GetIdElement(XmlDocument doc, string id)
        {
            // check to see if it's a standard ID reference
            XmlElement idElem = base.GetIdElement(doc, id);

            if (idElem == null)
            {
                XmlNamespaceManager nsManager = new XmlNamespaceManager(doc.NameTable);
                nsManager.AddNamespace("wsu", Namespaces.wsuNs);

                idElem = doc.SelectSingleNode("//*[@wsu:Id=\"" + id + "\"]", nsManager) as XmlElement;
            }

            return idElem;
        }

        /// <summary>
        /// Copy of System.Security.Cryptography.Xml.SignedXml.ComputeSignature() which will end up calling
        /// our own GetC14NDigest with a namespace prefix for all XmlDsig nodes
        /// </summary>
        public new void ComputeSignature()
        {
            this.BuildDigestedReferences();
            AsymmetricAlgorithm signingKey = this.SigningKey;
            if (signingKey == null)
            {
                throw new CryptographicException(EESZTInterfaceResource.CryptographyXmlLoadKeyFailed);
            }
            if (this.SignedInfo.SignatureMethod == null)
            {
                if (!(signingKey is DSA))
                {
                    if (!(signingKey is RSA))
                    {
                        throw new CryptographicException(EESZTInterfaceResource.CryptographyXmlCreatedKeyFailed);
                    }
                    if (this.SignedInfo.SignatureMethod == null)
                    {
                        this.SignedInfo.SignatureMethod = STSValues.signatureMethodRSAValue;
                    }
                }
                else
                {
                    this.SignedInfo.SignatureMethod = STSValues.signatureMethodDSAValue;
                }
            }
            SignatureDescription description = CryptoConfig.CreateFromName(this.SignedInfo.SignatureMethod) as SignatureDescription;
            if (description == null)
            {
                throw new CryptographicException(EESZTInterfaceResource.CryptographyXmlSignatureDescriptionNotCreated);
            }
            HashAlgorithm hash = description.CreateDigest();
            if (hash == null)
            {
                throw new CryptographicException(EESZTInterfaceResource.CryptographyXmlCreateHashAlgorithmFailed);
            }
            //this.GetC14NDigest(hash);
            this.GetC14NDigest(hash, "ds");
            //
            this.m_signature.SignatureValue = description.CreateFormatter(signingKey).CreateSignature(hash);
        }

        /// <summary>
        /// Returns the XML representation of the this object
        /// </summary>
        /// <returns>XML element containing the state of this object</returns>
        public new XmlElement GetXml()
        {
            XmlElement retVal;
            XmlNodeList xmlNodeList;
            XmlNamespaceManager xmlNamespaceManager;

            retVal = base.GetXml();
            if (this.signatureValueId != null && this.signatureValueId != "")
            { //Id on Signature value is needed for XAdES-T. We inject it here.
                xmlNamespaceManager = new XmlNamespaceManager(retVal.OwnerDocument.NameTable);
                xmlNamespaceManager.AddNamespace("ds", SignedXml.XmlDsigNamespaceUrl);
                xmlNodeList = retVal.SelectNodes("ds:SignatureValue", xmlNamespaceManager);
                if (xmlNodeList.Count > 0)
                {
                    ((XmlElement)xmlNodeList[0]).SetAttribute("Id", this.signatureValueId);
                }
            }

            // Add "ds" namespace prefix to all XmlDsig nodes in the signature
            SetPrefix("ds", retVal);

            return retVal;
        }

        /// <summary>
        /// Copy of System.Security.Cryptography.Xml.SignedXml.BuildDigestedReferences() which will add a "ds" 
        /// namespace prefix to all XmlDsig nodes
        /// </summary>
        private void BuildDigestedReferences()
        {
            ArrayList references = this.SignedInfo.References;

            //this.m_refProcessed = new bool[references.Count];
            Type SignedXml_Type = typeof(SignedXml);
            FieldInfo SignedXml_m_refProcessed = SignedXml_Type.GetField("m_refProcessed", BindingFlags.NonPublic | BindingFlags.Instance);
            SignedXml_m_refProcessed.SetValue(this, new bool[references.Count]);
            //

            //this.m_refLevelCache = new int[references.Count];
            FieldInfo SignedXml_m_refLevelCache = SignedXml_Type.GetField("m_refLevelCache", BindingFlags.NonPublic | BindingFlags.Instance);
            SignedXml_m_refLevelCache.SetValue(this, new int[references.Count]);
            //

            //ReferenceLevelSortOrder comparer = new ReferenceLevelSortOrder();
            Assembly System_Security_Assembly = Assembly.Load("System.Security, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a");
            Type ReferenceLevelSortOrder_Type = System_Security_Assembly.GetType("System.Security.Cryptography.Xml.SignedXml+ReferenceLevelSortOrder");
            ConstructorInfo ReferenceLevelSortOrder_Constructor = ReferenceLevelSortOrder_Type.GetConstructor(new Type[] { });
            Object comparer = ReferenceLevelSortOrder_Constructor.Invoke(null);
            //

            //comparer.References = references;
            PropertyInfo ReferenceLevelSortOrder_References = ReferenceLevelSortOrder_Type.GetProperty("References", BindingFlags.Public | BindingFlags.Instance);
            ReferenceLevelSortOrder_References.SetValue(comparer, references, null);
            //

            ArrayList list2 = new ArrayList();
            foreach (Reference reference in references)
            {
                list2.Add(reference);
            }

            list2.Sort((IComparer)comparer);

            //CanonicalXmlNodeList refList = new CanonicalXmlNodeList();
            Type CanonicalXmlNodeList_Type = System_Security_Assembly.GetType("System.Security.Cryptography.Xml.CanonicalXmlNodeList");
            ConstructorInfo CanonicalXmlNodeList_Constructor = CanonicalXmlNodeList_Type.GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, new Type[] { }, null);
            Object refList = CanonicalXmlNodeList_Constructor.Invoke(null);
            //

            //
            MethodInfo CanonicalXmlNodeList_Add = CanonicalXmlNodeList_Type.GetMethod("Add", BindingFlags.Public | BindingFlags.Instance);
            //

            foreach (DataObject obj2 in this.m_signature.ObjectList)
            {
                //refList.Add(obj2.GetXml());
                XmlElement xml = obj2.GetXml();
                SetPrefix("ds", xml); // <---
                CanonicalXmlNodeList_Add.Invoke(refList, new object[] { xml });
                //
            }

            //
            FieldInfo SignedXml_m_containingDocument = SignedXml_Type.GetField("m_containingDocument", BindingFlags.NonPublic | BindingFlags.Instance);
            Type Reference_Type = typeof(Reference);
            MethodInfo Reference_UpdateHashValue = Reference_Type.GetMethod("UpdateHashValue", BindingFlags.NonPublic | BindingFlags.Instance);
            //

            foreach (Reference reference2 in list2)
            {
                if (reference2.DigestMethod == null)
                {
                    reference2.DigestMethod = STSValues.digestMethodSHA1Value;
                }
                //reference2.UpdateHashValue(this.m_containingDocument, refList);
                object m_containingDocument = SignedXml_m_containingDocument.GetValue(this);
                Reference_UpdateHashValue.Invoke(reference2, new object[] { m_containingDocument, refList });
                // 

                if (reference2.Id != null)
                {
                    //refList.Add(reference2.GetXml());
                    XmlElement xml = reference2.GetXml();
                    SetPrefix("ds", xml); // <---
                    CanonicalXmlNodeList_Add.Invoke(refList, new object[] { xml });
                    //
                }
            }
        }

        /// <summary>
        /// Copy of System.Security.Cryptography.Xml.SignedXml.GetC14NDigest() which will add a
        /// namespace prefix to all XmlDsig nodes
        /// </summary>
        private byte[] GetC14NDigest(HashAlgorithm hash, string prefix)
        {
            //if (!this.bCacheValid || !this.SignedInfo.CacheValid)
            //{
            Type SignedXml_Type = typeof(SignedXml);
            FieldInfo SignedXml_bCacheValid = SignedXml_Type.GetField("bCacheValid", BindingFlags.NonPublic | BindingFlags.Instance);
            bool bCacheValid = (bool)SignedXml_bCacheValid.GetValue(this);
            Type SignedInfo_Type = typeof(SignedInfo);
            PropertyInfo SignedInfo_CacheValid = SignedInfo_Type.GetProperty("CacheValid", BindingFlags.NonPublic | BindingFlags.Instance);
            bool CacheValid = (bool)SignedInfo_CacheValid.GetValue(this.SignedInfo, null);

            FieldInfo SignedXml__digestedSignedInfo = SignedXml_Type.GetField("_digestedSignedInfo", BindingFlags.NonPublic | BindingFlags.Instance);

            if (!bCacheValid || !CacheValid)
            {
                //
                //string securityUrl = (this.m_containingDocument == null) ? null : this.m_containingDocument.BaseURI;
                FieldInfo SignedXml_m_containingDocument = SignedXml_Type.GetField("m_containingDocument", BindingFlags.NonPublic | BindingFlags.Instance);
                XmlDocument m_containingDocument = (XmlDocument)SignedXml_m_containingDocument.GetValue(this);
                string securityUrl = m_containingDocument?.BaseURI;
                //

                //XmlResolver xmlResolver = this.m_bResolverSet ? this.m_xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), securityUrl);
                FieldInfo SignedXml_m_bResolverSet = SignedXml_Type.GetField("m_bResolverSet", BindingFlags.NonPublic | BindingFlags.Instance);
                bool m_bResolverSet = (bool)SignedXml_m_bResolverSet.GetValue(this);
                FieldInfo SignedXml_m_xmlResolver = SignedXml_Type.GetField("m_xmlResolver", BindingFlags.NonPublic | BindingFlags.Instance);
                XmlResolver m_xmlResolver = (XmlResolver)SignedXml_m_xmlResolver.GetValue(this);
                XmlResolver xmlResolver = m_bResolverSet ? m_xmlResolver : new XmlSecureResolver(new XmlUrlResolver(), securityUrl);
                //

                //XmlDocument document = Utils.PreProcessElementInput(this.SignedInfo.GetXml(), xmlResolver, securityUrl);
                Assembly System_Security_Assembly = Assembly.Load("System.Security, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a");
                Type Utils_Type = System_Security_Assembly.GetType("System.Security.Cryptography.Xml.Utils");
                MethodInfo Utils_PreProcessElementInput = Utils_Type.GetMethod("PreProcessElementInput", BindingFlags.NonPublic | BindingFlags.Static);
                XmlElement xml = this.SignedInfo.GetXml();
                SetPrefix(prefix, xml); // <---
                XmlDocument document = (XmlDocument)Utils_PreProcessElementInput.Invoke(null, new object[] { xml, xmlResolver, securityUrl });
                //

                //CanonicalXmlNodeList namespaces = (this.m_context == null) ? null : Utils.GetPropagatedAttributes(this.m_context);
                FieldInfo SignedXml_m_context = SignedXml_Type.GetField("m_context", BindingFlags.NonPublic | BindingFlags.Instance);
                MethodInfo Utils_GetPropagatedAttributes = Utils_Type.GetMethod("GetPropagatedAttributes", BindingFlags.NonPublic | BindingFlags.Static);
                object m_context = SignedXml_m_context.GetValue(this);
                object namespaces = (m_context == null) ? null : Utils_GetPropagatedAttributes.Invoke(null, new object[] { m_context });
                //

                // Utils.AddNamespaces(document.DocumentElement, namespaces);
                Type CanonicalXmlNodeList_Type = System_Security_Assembly.GetType("System.Security.Cryptography.Xml.CanonicalXmlNodeList");
                MethodInfo Utils_AddNamespaces = Utils_Type.GetMethod("AddNamespaces", BindingFlags.NonPublic | BindingFlags.Static, null, new Type[] { typeof(XmlElement), CanonicalXmlNodeList_Type }, null);
                Utils_AddNamespaces.Invoke(null, new object[] { document.DocumentElement, namespaces });
                //

                //Transform canonicalizationMethodObject = this.SignedInfo.CanonicalizationMethodObject;
                System.Security.Cryptography.Xml.Transform canonicalizationMethodObject = this.SignedInfo.CanonicalizationMethodObject;
                //

                canonicalizationMethodObject.Resolver = xmlResolver;

                //canonicalizationMethodObject.BaseURI = securityUrl;
                Type Transform_Type = typeof(System.Security.Cryptography.Xml.Transform);
                PropertyInfo Transform_BaseURI = Transform_Type.GetProperty("BaseURI", BindingFlags.NonPublic | BindingFlags.Instance);
                Transform_BaseURI.SetValue(canonicalizationMethodObject, securityUrl, null);
                //

                canonicalizationMethodObject.LoadInput(document);

                //this._digestedSignedInfo = canonicalizationMethodObject.GetDigestedOutput(hash);
                SignedXml__digestedSignedInfo.SetValue(this, canonicalizationMethodObject.GetDigestedOutput(hash));
                //

                //this.bCacheValid = true;
                SignedXml_bCacheValid.SetValue(this, true);
                //
            }

            //return this._digestedSignedInfo;
            byte[] _digestedSignedInfo = (byte[])SignedXml__digestedSignedInfo.GetValue(this);
            return _digestedSignedInfo;
            //
        }

        private void SetPrefix(string prefix, XmlNode node)
        {
            foreach (XmlNode n in node.ChildNodes)
                SetPrefix(prefix, n);
            if (node.NamespaceURI == Namespaces.dsNs)
            {
                node.Prefix = prefix;

            }
            else if (node.NamespaceURI == Namespaces.c14nNs)
            {
                node.Prefix = "ec";

            }
        }
    }
}