// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System.Globalization;
using System.IdentityModel.Selectors;
using System.IdentityModel.Tokens;
using System.Text;
 
namespace System.ServiceModel.Security.Tokens
{
    public abstract class SecurityTokenParameters
    {
        internal const SecurityTokenInclusionMode defaultInclusionMode = SecurityTokenInclusionMode.AlwaysToRecipient;
        internal const bool defaultRequireDerivedKeys = true;
 
        private SecurityTokenInclusionMode _inclusionMode = defaultInclusionMode;
 
        protected SecurityTokenParameters(SecurityTokenParameters other)
        {
            if (other == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull(nameof(other));
            }
 
            RequireDerivedKeys = other.RequireDerivedKeys;
        }
 
        protected SecurityTokenParameters()
        {
            // empty
        }
 
        internal protected abstract bool HasAsymmetricKey { get; }
 
        public SecurityTokenInclusionMode InclusionMode
        {
            get
            {
                return _inclusionMode;
            }
            set
            {
                SecurityTokenInclusionModeHelper.Validate(value);
                _inclusionMode = value;
            }
        }
 
        public bool RequireDerivedKeys { get; set; } = defaultRequireDerivedKeys;
 
        internal protected abstract bool SupportsClientAuthentication { get; }
        internal protected abstract bool SupportsServerAuthentication { get; }
        internal protected abstract bool SupportsClientWindowsIdentity { get; }
 
        public SecurityTokenParameters Clone()
        {
            SecurityTokenParameters result = CloneCore();
 
            if (result == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new InvalidOperationException(SRP.Format(SRP.SecurityTokenParametersCloneInvalidResult, GetType().ToString())));
            }
 
            return result;
        }
 
        protected abstract SecurityTokenParameters CloneCore();
 
        internal protected abstract SecurityKeyIdentifierClause CreateKeyIdentifierClause(SecurityToken token, SecurityTokenReferenceStyle referenceStyle);
 
        internal SecurityKeyIdentifierClause CreateKeyIdentifierClause<TExternalClause, TInternalClause>(SecurityToken token, SecurityTokenReferenceStyle referenceStyle)
            where TExternalClause : SecurityKeyIdentifierClause
            where TInternalClause : SecurityKeyIdentifierClause
        {
            if (token == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull(nameof(token));
            }
 
            SecurityKeyIdentifierClause result;
 
            switch (referenceStyle)
            {
                default:
                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new NotSupportedException(
                        SRP.Format(SRP.TokenDoesNotSupportKeyIdentifierClauseCreation, token.GetType().Name, referenceStyle)));
                case SecurityTokenReferenceStyle.External:
                    result = token.CreateKeyIdentifierClause<TExternalClause>();
                    break;
                case SecurityTokenReferenceStyle.Internal:
                    result = token.CreateKeyIdentifierClause<TInternalClause>();
                    break;
            }
 
            return result;
        }
 
        internal SecurityKeyIdentifierClause CreateGenericXmlTokenKeyIdentifierClause(SecurityToken token, SecurityTokenReferenceStyle referenceStyle)
        {
            GenericXmlSecurityToken xmlToken = token as GenericXmlSecurityToken;
            if (xmlToken != null)
            {
                if (referenceStyle == SecurityTokenReferenceStyle.Internal && xmlToken.InternalTokenReference != null)
                {
                    return xmlToken.InternalTokenReference;
                }
 
                if (referenceStyle == SecurityTokenReferenceStyle.External && xmlToken.ExternalTokenReference != null)
                {
                    return xmlToken.ExternalTokenReference;
                }
            }
 
            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new MessageSecurityException(SRP.UnableToCreateTokenReference));
        }
 
        internal protected virtual bool MatchesKeyIdentifierClause(SecurityToken token, SecurityKeyIdentifierClause keyIdentifierClause, SecurityTokenReferenceStyle referenceStyle)
        {
            if (token == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull(nameof(token));
            }
 
            if (token is GenericXmlSecurityToken)
            {
                return MatchesGenericXmlTokenKeyIdentifierClause(token, keyIdentifierClause, referenceStyle);
            }
 
            bool result;
 
            switch (referenceStyle)
            {
                default:
                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new NotSupportedException(
                        SRP.Format(SRP.TokenDoesNotSupportKeyIdentifierClauseCreation, token.GetType().Name, referenceStyle)));
                case SecurityTokenReferenceStyle.External:
                    if (keyIdentifierClause is LocalIdKeyIdentifierClause)
                    {
                        result = false;
                    }
                    else
                    {
                        result = token.MatchesKeyIdentifierClause(keyIdentifierClause);
                    }
 
                    break;
                case SecurityTokenReferenceStyle.Internal:
                    result = token.MatchesKeyIdentifierClause(keyIdentifierClause);
                    break;
            }
 
            return result;
        }
 
        internal protected abstract void InitializeSecurityTokenRequirement(SecurityTokenRequirement requirement);
 
        internal bool MatchesGenericXmlTokenKeyIdentifierClause(SecurityToken token, SecurityKeyIdentifierClause keyIdentifierClause, SecurityTokenReferenceStyle referenceStyle)
        {
            if (token == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull(nameof(token));
            }
 
            bool result;
 
            GenericXmlSecurityToken xmlToken = token as GenericXmlSecurityToken;
 
            if (xmlToken == null)
            {
                result = false;
            }
            else if (referenceStyle == SecurityTokenReferenceStyle.External && xmlToken.ExternalTokenReference != null)
            {
                result = xmlToken.ExternalTokenReference.Matches(keyIdentifierClause);
            }
            else if (referenceStyle == SecurityTokenReferenceStyle.Internal)
            {
                result = xmlToken.MatchesKeyIdentifierClause(keyIdentifierClause);
            }
            else
            {
                result = false;
            }
 
            return result;
        }
 
        public override string ToString()
        {
            StringBuilder sb = new StringBuilder();
 
            sb.AppendLine(String.Format(CultureInfo.InvariantCulture, "{0}:", GetType().ToString()));
            sb.Append(String.Format(CultureInfo.InvariantCulture, "RequireDerivedKeys: {0}", RequireDerivedKeys.ToString()));
 
            return sb.ToString();
        }
    }
}