//------------------------------------------------------------
// Copyright (c) Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------
 
using System.Collections.Generic;
using System.Collections.ObjectModel;
 
using System.IdentityModel.Policy;
using System.IdentityModel.Selectors;
using System.IdentityModel.Tokens;
 
using System.Security.Claims;
 
 
namespace System.ServiceModel.Security
{
    internal class SecurityTokenAuthenticatorAdapter : SecurityTokenAuthenticator
    {
        SecurityTokenHandler _securityTokenHandler;
        ExceptionMapper _exceptionMapper;
 
        public SecurityTokenAuthenticatorAdapter(SecurityTokenHandler securityTokenHandler, ExceptionMapper exceptionMapper)
        {
            if (securityTokenHandler == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("securityTokenHandler");
            }
 
            if (exceptionMapper == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("exceptionMapper");
            }
 
            _securityTokenHandler = securityTokenHandler;
            _exceptionMapper = exceptionMapper;
        }
 
        protected override bool CanValidateTokenCore(SecurityToken token)
        {
            if (token == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("token");
            }
 
            return ((token.GetType() == _securityTokenHandler.TokenType) && (_securityTokenHandler.CanValidateToken));
        }
 
        protected sealed override ReadOnlyCollection<IAuthorizationPolicy> ValidateTokenCore(SecurityToken token)
        {
            IEnumerable<ClaimsIdentity> subjectCollection = null;
 
            try
            {
                subjectCollection = _securityTokenHandler.ValidateToken(token);
            }
            catch (Exception ex)
            {
                if (!_exceptionMapper.HandleSecurityTokenProcessingException(ex))
                {
                    throw;
                }
            }
 
            List<IAuthorizationPolicy> policies = new List<IAuthorizationPolicy>(1);
            policies.Add(new AuthorizationPolicy(subjectCollection));
            return policies.AsReadOnly();
        }
    }
}