void AssertContextDoesNotIncludeToken(IOAuthContext context)
 {
   if (context.Token != null)
   {
     throw Error.RequestForTokenMustNotIncludeTokenInContext(context);
   }
 }

 public ConsumerRequest(IOAuthSession oauthSession, IOAuthContext context, IOAuthConsumerContext consumerContext, ICertificateFactory clientSslCertificateFactory)
 {
     _oauthSession = oauthSession;
     _context = context;
     _consumerContext = consumerContext;
     _clientSslCertificateFactory = clientSslCertificateFactory;
 }

 protected virtual void InspectRequest(IOAuthContext context)
 {
     foreach (IContextInspector inspector in _inspectors)
     {
         inspector.InspectContext(context);
     }
 }

    public void SignContextWithToken(IOAuthContext context, IToken token)
    {
      context.Token = token.Token;
      context.TokenSecret = token.TokenSecret;

      SignContext(context);
    }

    public void InspectContext(ProviderPhase phase, IOAuthContext context)
    {
      if (phase != ProviderPhase.CreateAccessToken) {
        return;
      }

      var authMode = context.XAuthMode;
      if (string.IsNullOrEmpty(authMode)) {
        throw Error.EmptyXAuthMode(context);
      }

      if (!_validateModeFunc(authMode)) {
        throw Error.InvalidXAuthMode(context);
      }

      var username = context.XAuthUsername;
      if (string.IsNullOrEmpty(username)) {
        throw Error.EmptyXAuthUsername(context);
      }

      var password = context.XAuthPassword;
      if (string.IsNullOrEmpty(password)) {
        throw Error.EmptyXAuthPassword(context);
      }

      if (!_authenticateFunc(username, password)) {
        throw Error.FailedXAuthAuthentication(context);
      }
    }

		public void InspectContext(ProviderPhase phase, IOAuthContext context)
		{
			if (!_nonceStore.RecordNonceAndCheckIsUnique(context, context.Nonce))
			{
				throw Error.NonceHasAlreadyBeenUsed(context);
			}
		}

 public IConsumerRequest CreateConsumerRequest(IOAuthContext context, IOAuthConsumerContext consumerContext, IToken token)
 {
 	if (context == null) throw new ArgumentNullException("context");
 	if (consumerContext == null) throw new ArgumentNullException("consumerContext");
 	
 	return new ConsumerRequest(context, consumerContext, token);
 }

    public RequestForAccessStatus GetStatusOfRequestForAccess(IOAuthContext requestContext)
    {
      if (requestContext.ConsumerKey == "key" && requestContext.Token == "requestkey")
        return RequestForAccessStatus.Granted;

      return RequestForAccessStatus.Unknown;
    }

		static void ValidateCallbackUrlIsPartOfRequest(IOAuthContext context)
		{
			if (string.IsNullOrEmpty(context.CallbackUrl))
			{
				throw Error.MissingRequiredOAuthParameter(context, Parameters.OAuth_Callback);
			}
		}

 public void InspectContext(IOAuthContext context)
 {
     if (!_consumerStore.IsConsumer(context))
     {
         throw Error.UnknownConsumerKey(context);
     }
 }

 public ConsumerRequest(IOAuthContext context, IOAuthConsumerContext consumerContext, IToken token, ICertificateFactory clientSslCertificateFactory)
 {
     _context = context;
     _consumerContext = consumerContext;
     _token = token;
     _clientSslCertificateFactory = clientSslCertificateFactory;
 }

		public bool AuthenticateClient(IOAuthContext context)
		{
			Client actual = ClientRepo.FindClient(context.Client.ClientId);
			if (actual == null) return false;

			return actual.ClientSecret == context.Client.ClientSecret;
		}

 public OAuthException(IConsumerResponse consumerResponse, IOAuthContext requestContext, OAuthProblemReport problemReport)
     : base(problemReport.ProblemAdvice)
 {
     ConsumerResponse = consumerResponse;
     Report = problemReport;
     Context = requestContext;
 }

		public ConsumerRequest(IOAuthContext context, IOAuthConsumerContext consumerContext, IToken token)
		{
			if (context == null) throw new ArgumentNullException("context");
			if (consumerContext == null) throw new ArgumentNullException("consumerContext");
			_context = context;
			_consumerContext = consumerContext;
			_token = token;
		}

    public void ConsumeRequestToken(IOAuthContext requestContext)
    {
      EnsureTestConsumer(requestContext);

      if (requestContext.Token != "requestkey")
        throw new OAuthException(requestContext, OAuthProblems.TokenRejected,
                                 "The supplied request token is unknown to the provider.");
    }

    public void ConsumeAccessToken(IOAuthContext accessContext)
    {
      EnsureTestConsumer(accessContext);

      if (accessContext.Token != "accesskey")
        throw new OAuthException(accessContext, OAuthProblems.TokenRejected,
                                 "The supplied access token is unknown to the provider.");
    }

		public virtual IToken GrantRequestToken(IOAuthContext context)
		{
			AssertContextDoesNotIncludeToken(context);

			InspectRequest(ProviderPhase.GrantRequestToken, context);

			return _tokenStore.CreateRequestToken(context);
		}

        IContextSignatureImplementation FindImplementationForAuthContext(IOAuthContext authContext)
        {
            IContextSignatureImplementation impl =
              _implementations.FirstOrDefault(i => i.MethodName == authContext.SignatureMethod);

            if (impl != null) return impl;

            throw Error.UnknownSignatureMethod(authContext.SignatureMethod);
        }

    public static Exception MissingRequiredOAuthParameter(IOAuthContext context, string parameterName)
    {
      var exception = new OAuthException(context, OAuthProblems.ParameterAbset,
                                         string.Format("Missing required parameter : {0}", parameterName));

      exception.Report.ParametersAbsent.Add(parameterName);

      return exception;
    }

        public ActionResult A(IOAuthContext context)
        {
            var tokenRepository = new TokenRepository();
            var tokenStore = new SampleMemoryTokenStore(tokenRepository);

            var t = tokenStore.CreateRequestToken(context);

            return new EmptyResult();
        }