/// <summary>
        /// Enumerates the segments in a path and calls a corresponding delegate verifier on each segment.
        /// Do not overuse this method: most test cases don't need to over-baseline what the expected segments are.
        /// </summary>
        public static void VerifyPath(ODataPath path, Action<ODataPathSegment>[] segmentVerifiers)
        {
            path.Count().Should().Be(segmentVerifiers.Count());

            var i = 0;
            foreach (var segment in path)
            {
                segmentVerifiers[i++](segment);
            }
        }

        /// <summary>
        /// Creates a <see cref="RangeVariable"/> for an implicit parameter ($it) from an <see cref="ODataPath"/>.
        /// </summary>
        /// <param name="path"><see cref="ODataPath"/> that the range variable is iterating over.</param>
        /// <returns>A new <see cref="RangeVariable"/>.</returns>
        internal static RangeVariable CreateImplicitRangeVariable(ODataPath path)
        {
            ExceptionUtils.CheckArgumentNotNull(path, "path");
            IEdmTypeReference elementType = path.EdmType();

            if (elementType == null)
            {
                // This case if for something like a void service operation
                // This is pretty ugly; if pratice we shouldn't be creating a parameter node for this case I think
                return null;
            }

            if (elementType.IsCollection())
            {
                elementType = elementType.AsCollection().ElementType();
            }

            if (elementType.IsEntity())
            {
                IEdmEntityTypeReference entityTypeReference = elementType as IEdmEntityTypeReference;
                return new EntityRangeVariable(ExpressionConstants.It, entityTypeReference, path.NavigationSource());
            }

            return new NonentityRangeVariable(ExpressionConstants.It, elementType, null);
        }

 /// <summary>
 /// Create a new ODataUri. This contains the semantic meaning of the 
 /// entire uri.
 /// </summary>
 /// <param name="parameterAliasValueAccessor">The ParameterAliasValueAccessor.</param>
 /// <param name="path">The top level path for this uri.</param>
 /// <param name="customQueryOptions">Any custom query options for this uri. Can be null.</param>
 /// <param name="selectAndExpand">Any $select or $expand option for this uri. Can be null.</param>
 /// <param name="filter">Any $filter option for this uri. Can be null.</param>
 /// <param name="orderby">Any $orderby option for this uri. Can be null</param>
 /// <param name="search">Any $search option for this uri. Can be null</param>
 /// <param name="apply">Any $apply option for this uri. Can be null</param>
 /// <param name="skip">Any $skip option for this uri. Can be null.</param>
 /// <param name="top">Any $top option for this uri. Can be null.</param>
 /// <param name="queryCount">Any query $count option for this uri. Can be null.</param>
 internal ODataUri(
     ParameterAliasValueAccessor parameterAliasValueAccessor,
     ODataPath path,
     IEnumerable<QueryNode> customQueryOptions,
     SelectExpandClause selectAndExpand,
     FilterClause filter,
     OrderByClause orderby,
     SearchClause search,
     ApplyClause apply,
     long? skip,
     long? top,
     bool? queryCount)
 {
     this.ParameterAliasValueAccessor = parameterAliasValueAccessor;
     this.Path = path;
     this.CustomQueryOptions = new ReadOnlyCollection<QueryNode>(customQueryOptions.ToList());
     this.SelectAndExpand = selectAndExpand;
     this.Filter = filter;
     this.OrderBy = orderby;
     this.Search = search;
     this.Apply = apply;
     this.Skip = skip;
     this.Top = top;
     this.QueryCount = queryCount;
 }

 /// <summary>
 /// Build a segment representing a navigation property.
 /// </summary>
 /// <param name="path">Path to perform the computation on.</param>
 /// <param name="navigationProperty">The navigation property this segment represents.</param>
 /// <param name="navigationSource">The navigation source of the entities targetted by this navigation property. This can be null.</param>
 /// <returns>The ODataPath with navigation property appended in the end in the end</returns>
 public static ODataPath AppendNavigationPropertySegment(this ODataPath path, IEdmNavigationProperty navigationProperty, IEdmNavigationSource navigationSource)
 {
     var newPath = new ODataPath(path);
     NavigationPropertySegment np = new NavigationPropertySegment(navigationProperty, navigationSource);
     newPath.Add(np);
     return newPath;
 }

        public void SelectAction_Returns_ExpectedMethodOnBaseType(string method, string[] methodsInController,
            string expectedSelectedAction)
        {
            // Arrange
            string key = "42";
            CustomersModelWithInheritance model = new CustomersModelWithInheritance();
            var ordersProperty = model.Customer.FindProperty("Orders") as IEdmNavigationProperty;

            ODataPath odataPath = new ODataPath(new EntitySetPathSegment(model.Customers), new KeyValuePathSegment(key),
                new LinksPathSegment(), new NavigationPathSegment(ordersProperty));

            HttpControllerContext controllerContext = CreateControllerContext(method);
            var actionMap = GetMockActionMap(methodsInController);

            // Act
            string selectedAction = new LinksRoutingConvention().SelectAction(odataPath, controllerContext, actionMap);

            // Assert
            Assert.Equal(expectedSelectedAction, selectedAction);
            if (expectedSelectedAction == null)
            {
                Assert.Empty(controllerContext.RouteData.Values);
            }
            else
            {
                Assert.Equal(2, controllerContext.RouteData.Values.Count);
                Assert.Equal(key, controllerContext.RouteData.Values["key"]);
                Assert.Equal(ordersProperty.Name, controllerContext.RouteData.Values["navigationProperty"]);
            }
        }

        /// <summary>
        /// Selects the controller for OData requests.
        /// </summary>
        /// <param name="odataPath">The OData path.</param>
        /// <param name="request">The request.</param>
        /// <returns>
        ///   <c>null</c> if the request isn't handled by this convention; otherwise, the name of the selected controller
        /// </returns>
        public virtual string SelectController(ODataPath odataPath, HttpRequestMessage request)
        {
            if (odataPath == null)
            {
                throw Error.ArgumentNull("odataPath");
            }

            if (request == null)
            {
                throw Error.ArgumentNull("request");
            }

            // entity set
            EntitySetPathSegment entitySetSegment = odataPath.Segments.FirstOrDefault() as EntitySetPathSegment;
            if (entitySetSegment != null)
            {
                return entitySetSegment.EntitySetName;
            }

            // singleton
            SingletonPathSegment singletonSegment = odataPath.Segments.FirstOrDefault() as SingletonPathSegment;
            if (singletonSegment != null)
            {
                return singletonSegment.SingletonName;
            }

            return null;
        }

        /// <summary>
        /// Selects the action for OData requests.
        /// </summary>
        /// <param name="odataPath">The OData path.</param>
        /// <param name="controllerContext">The controller context.</param>
        /// <param name="actionMap">The action map.</param>
        /// <returns>
        ///   <c>null</c> if the request isn't handled by this convention; otherwise, the name of the selected action
        /// </returns>
        public string SelectAction(ODataPath odataPath, HttpControllerContext controllerContext, ILookup<string, HttpActionDescriptor> actionMap)
        {
            if (odataPath == null)
            {
                throw Error.ArgumentNull("odataPath");
            }

            if (controllerContext == null)
            {
                throw Error.ArgumentNull("controllerContext");
            }

            if (actionMap == null)
            {
                throw Error.ArgumentNull("actionMap");
            }

            if (odataPath.PathTemplate == "~")
            {
                return "GetServiceDocument";
            }

            if (odataPath.PathTemplate == "~/$metadata")
            {
                return "GetMetadata";
            }

            return null;
        }

 private static void AddLinkInfoToRouteData(IHttpRouteData routeData, ODataPath odataPath)
 {
     KeyValuePathSegment keyValueSegment = odataPath.Segments[1] as KeyValuePathSegment;
     routeData.Values[ODataRouteConstants.Key] = keyValueSegment.Value;
     NavigationPathSegment navigationSegment = odataPath.Segments[3] as NavigationPathSegment;
     routeData.Values[ODataRouteConstants.NavigationProperty] = navigationSegment.NavigationProperty.Name;
 }

        private void ProcessUpdateEntityReference(IODataRequestMessage requestMessage, IODataResponseMessage responseMessage, ODataPath odataPath)
        {
            // This is for change the reference in single-valued navigation property
            // PUT ~/Person(0)/Parent/$ref
            // {
            //     "@odata.context": "http://host/service/$metadata#$ref",
            //     "@odata.id": "Orders(10643)"
            // }

            if (this.HttpMethod == HttpMethod.PATCH)
            {
                throw Utility.BuildException(HttpStatusCode.MethodNotAllowed, "PATCH on a reference link is not supported.", null);
            }

            // Get the parent first
            var level = this.QueryContext.QueryPath.Count - 2;
            var parent = this.QueryContext.ResolveQuery(this.DataSource, level);

            var navigationPropertyName = ((NavigationPropertyLinkSegment)odataPath.LastSegment).NavigationProperty.Name;

            using (var messageReader = new ODataMessageReader(requestMessage, this.GetReaderSettings(), this.DataSource.Model))
            {
                var referenceLink = messageReader.ReadEntityReferenceLink();
                var queryContext = new QueryContext(this.ServiceRootUri, referenceLink.Url, this.DataSource.Model);
                var target = queryContext.ResolveQuery(this.DataSource);

                this.DataSource.UpdateProvider.UpdateLink(parent, navigationPropertyName, target);
                this.DataSource.UpdateProvider.SaveChanges();
            }

            ResponseWriter.WriteEmptyResponse(responseMessage);
        }

        private static IEdmProperty GetProperty(ODataPath odataPath, HttpMethod method)
        {
            PropertyAccessPathSegment segment = null;
            if (method == HttpMethod.Get)
            {
                if (odataPath.PathTemplate == "~/entityset/key/property" ||
                    odataPath.PathTemplate == "~/entityset/key/cast/property" ||
                    odataPath.PathTemplate == "~/singleton/property" ||
                    odataPath.PathTemplate == "~/singleton/cast/property")
                {
                    segment = odataPath.Segments[odataPath.Segments.Count - 1] as PropertyAccessPathSegment;
                }
                else if (odataPath.PathTemplate == "~/entityset/key/property/$value" ||
                    odataPath.PathTemplate == "~/entityset/key/cast/property/$value" ||
                    odataPath.PathTemplate == "~/singleton/property/$value" ||
                    odataPath.PathTemplate == "~/singleton/cast/property/$value" ||
                    odataPath.PathTemplate == "~/entityset/key/property/$count" ||
                    odataPath.PathTemplate == "~/entityset/key/cast/property/$count" ||
                    odataPath.PathTemplate == "~/singleton/property/$count" ||
                    odataPath.PathTemplate == "~/singleton/cast/property/$count")
                {
                    segment = odataPath.Segments[odataPath.Segments.Count - 2] as PropertyAccessPathSegment;
                }
            }

            return segment == null ? null : segment.Property;
        }

 /// <summary>
 /// Binds a collection of <paramref name="segments"/> to metadata, creating a semantic ODataPath object.
 /// </summary>
 /// <param name="segments">Collection of path segments.</param>
 /// <param name="configuration">The configuration to use when binding the path.</param>
 /// <returns>A semantic <see cref="ODataPath"/> object to describe the path.</returns>
 internal static ODataPath BindPath(ICollection<string> segments, ODataUriParserConfiguration configuration)
 {
     ODataPathParser semanticPathParser = new ODataPathParser(configuration);
     var intermediateSegments = semanticPathParser.ParsePath(segments);
     ODataPath path = new ODataPath(intermediateSegments);
     return path;
 }

        /// <summary>
        /// Selects the action for OData requests.
        /// </summary>
        /// <param name="odataPath">The OData path.</param>
        /// <param name="controllerContext">The controller context.</param>
        /// <param name="actionMap">The action map.</param>
        /// <returns>
        ///   <c>null</c> if the request isn't handled by this convention; otherwise, the name of the selected action
        /// </returns>
        public override string SelectAction(ODataPath odataPath, HttpControllerContext controllerContext, ILookup<string, HttpActionDescriptor> actionMap)
        {
            if (odataPath == null)
            {
                throw Error.ArgumentNull("odataPath");
            }

            if (controllerContext == null)
            {
                throw Error.ArgumentNull("controllerContext");
            }

            if (actionMap == null)
            {
                throw Error.ArgumentNull("actionMap");
            }

            if (odataPath.PathTemplate == "~/entityset/key" ||
                odataPath.PathTemplate == "~/entityset/key/cast")
            {
                HttpMethod httpMethod = controllerContext.Request.Method;
                string httpMethodName;

                switch (httpMethod.ToString().ToUpperInvariant())
                {
                    case "GET":
                        httpMethodName = "Get";
                        break;
                    case "PUT":
                        httpMethodName = "Put";
                        break;
                    case "PATCH":
                    case "MERGE":
                        httpMethodName = "Patch";
                        break;
                    case "DELETE":
                        httpMethodName = "Delete";
                        break;
                    default:
                        return null;
                }

                Contract.Assert(httpMethodName != null);

                IEdmEntityType entityType = odataPath.EdmType as IEdmEntityType;

                // e.g. Try GetCustomer first, then fallback on Get action name
                string actionName = actionMap.FindMatchingAction(
                    httpMethodName + entityType.Name,
                    httpMethodName);

                if (actionName != null)
                {
                    KeyValuePathSegment keyValueSegment = odataPath.Segments[1] as KeyValuePathSegment;
                    controllerContext.RouteData.Values[ODataRouteConstants.Key] = keyValueSegment.Value;
                    return actionName;
                }
            }
            return null;
        }

        /// <inheritdoc/>
        public override string SelectAction(ODataPath odataPath, HttpControllerContext controllerContext, ILookup<string, HttpActionDescriptor> actionMap)
        {
            if (odataPath == null)
            {
                throw Error.ArgumentNull("odataPath");
            }

            if (controllerContext == null)
            {
                throw Error.ArgumentNull("controllerContext");
            }

            if (actionMap == null)
            {
                throw Error.ArgumentNull("actionMap");
            }

            string prefix;
            ComplexCastPathSegment cast;
            IEdmProperty property = GetProperty(odataPath, controllerContext.Request.Method, out prefix, out cast);
            IEdmEntityType declaringType = property == null ? null : property.DeclaringType as IEdmEntityType;

            if (declaringType != null)
            {
                string actionName;
                if (cast == null)
                {
                    actionName = actionMap.FindMatchingAction(
                        prefix + property.Name + "From" + declaringType.Name,
                        prefix + property.Name);
                }
                else
                {
                    // for example: GetCityOfSubAddressFromVipCustomer or GetCityOfSubAddress
                    actionName = actionMap.FindMatchingAction(
                        prefix + property.Name + "Of" + cast.CastType.Name + "From" + declaringType.Name,
                        prefix + property.Name + "Of" + cast.CastType.Name);
                }

                if (actionName != null)
                {
                    if (odataPath.PathTemplate.StartsWith("~/entityset/key", StringComparison.Ordinal))
                    {
                        EntitySetPathSegment entitySetPathSegment = (EntitySetPathSegment)odataPath.Segments.First();
                        IEdmEntityType edmEntityType = entitySetPathSegment.EntitySetBase.EntityType();
                        KeyValuePathSegment keyValueSegment = (KeyValuePathSegment)odataPath.Segments[1];

                        controllerContext.AddKeyValueToRouteData(keyValueSegment, edmEntityType, ODataRouteConstants.Key);
                    }

                    return actionName;
                }
            }

            return null;
        }

        public void EntitySetComputedForEntitySetSegment()
        {
            var entitySet = mbh.BuildValidEntitySet();
            var path = new ODataPath(new ODataPathSegment[]
            {
                new EntitySetSegment(entitySet)
            });

            path.NavigationSource().Should().BeSameAs(entitySet);
        }

        public void TypeComputedForEntitySetSegment()
        {
            var entitySet = mbh.BuildValidEntitySet();
            var path = new ODataPath(new ODataPathSegment[]
            {
                new EntitySetSegment(entitySet)
            });

            path.EdmType().Should().BeSameAs(entitySet);
        }

        public void SelectController_ThrowsArgmentNull_IfMissRequest()
        {
            // Arrange
            ODataPath odataPath = new ODataPath(new ODataPathSegment[] { new EntitySetPathSegment("Customers") });

            // Act & Assert
            Assert.ThrowsArgumentNull(
                () => new MockNavigationSourceRoutingConvention().SelectController(odataPath, null),
                "request");
        }

        public void SelectAction_ThrowsArgumentNull_IfControllerContextIsNull()
        {
            // Arrange
            ODataPath odataPath = new ODataPath();

            // Act & Assert
            Assert.ThrowsArgumentNull(
                () => new ActionRoutingConvention().SelectAction(odataPath, controllerContext: null, actionMap: null),
                "controllerContext");
        }

        /// <summary>
        /// Selects the action.
        /// </summary>
        /// <param name="odataPath">The odata path.</param>
        /// <param name="controllerContext">The controller context.</param>
        /// <param name="actionMap">The action map.</param>
        /// <returns></returns>
        public override string SelectAction(ODataPath odataPath, HttpControllerContext controllerContext, ILookup<string, HttpActionDescriptor> actionMap)
        {
            if (odataPath == null)
            {
                throw Error.ArgumentNull("odataPath");
            }

            if (controllerContext == null)
            {
                throw Error.ArgumentNull("controllerContext");
            }

            if (actionMap == null)
            {
                throw Error.ArgumentNull("actionMap");
            }

            HttpMethod requestMethod = controllerContext.Request.Method;
            IHttpRouteData routeData = controllerContext.RouteData;

            if (odataPath.PathTemplate == "~/entityset/key/$links/navigation" ||
                odataPath.PathTemplate == "~/entityset/key/cast/$links/navigation")
            {
                NavigationPathSegment navigationSegment = odataPath.Segments.Last() as NavigationPathSegment;
                IEdmNavigationProperty navigationProperty = navigationSegment.NavigationProperty;
                IEdmEntityType declaringType = navigationProperty.DeclaringType as IEdmEntityType;

                string linksActionName = FindLinksActionName(actionMap, navigationProperty, declaringType, requestMethod);
                if (linksActionName != null)
                {
                    routeData.Values[ODataRouteConstants.Key] = (odataPath.Segments[1] as KeyValuePathSegment).Value;
                    routeData.Values[ODataRouteConstants.NavigationProperty] = navigationSegment.NavigationProperty.Name;
                    return linksActionName;
                }
            }
            else if ((odataPath.PathTemplate == "~/entityset/key/$links/navigation/key" ||
                odataPath.PathTemplate == "~/entityset/key/cast/$links/navigation/key") && requestMethod == HttpMethod.Delete)
            {
                NavigationPathSegment navigationSegment = odataPath.Segments[odataPath.Segments.Count - 2] as NavigationPathSegment;
                IEdmNavigationProperty navigationProperty = navigationSegment.NavigationProperty;
                IEdmEntityType declaringType = navigationProperty.DeclaringType as IEdmEntityType;

                string linksActionName = FindLinksActionName(actionMap, navigationProperty, declaringType, requestMethod);
                if (linksActionName != null)
                {
                    routeData.Values[ODataRouteConstants.Key] = (odataPath.Segments[1] as KeyValuePathSegment).Value;
                    routeData.Values[ODataRouteConstants.NavigationProperty] = navigationSegment.NavigationProperty.Name;
                    routeData.Values[ODataRouteConstants.RelatedKey] = (odataPath.Segments.Last() as KeyValuePathSegment).Value;
                    return linksActionName;
                }
            }

            return null;
        }

        /// <inheritdoc/>
        public override string SelectAction(ODataPath odataPath, HttpControllerContext controllerContext, ILookup<string, HttpActionDescriptor> actionMap)
        {
            if (odataPath == null)
            {
                throw Error.ArgumentNull("odataPath");
            }

            if (controllerContext == null)
            {
                throw Error.ArgumentNull("controllerContext");
            }

            if (actionMap == null)
            {
                throw Error.ArgumentNull("actionMap");
            }

            HttpMethod requestMethod = controllerContext.Request.Method;
            IHttpRouteData routeData = controllerContext.RouteData;

            if (odataPath.PathTemplate == EntitysetKeyNavigationRef ||
                odataPath.PathTemplate == EntitysetKeyCastNavigationRef)
            {
                NavigationPathSegment navigationSegment = (NavigationPathSegment)odataPath.Segments[odataPath.Segments.Count - 2];
                IEdmNavigationProperty navigationProperty = navigationSegment.NavigationProperty;
                IEdmEntityType declaringType = navigationProperty.DeclaringEntityType();

                string refActionName = FindRefActionName(actionMap, navigationProperty, declaringType, requestMethod);
                if (refActionName != null)
                {
                    routeData.Values[ODataRouteConstants.Key] = ((KeyValuePathSegment)odataPath.Segments[1]).Value;
                    routeData.Values[ODataRouteConstants.NavigationProperty] = navigationSegment.NavigationProperty.Name;
                    return refActionName;
                }
            }
            else if ((odataPath.PathTemplate == EntitysetKeyNavigationKeyRef ||
                odataPath.PathTemplate == EntitysetKeyCastNavigationKeyRef) && requestMethod == HttpMethod.Delete)
            {
                NavigationPathSegment navigationSegment = (NavigationPathSegment)odataPath.Segments[odataPath.Segments.Count - 3];
                IEdmNavigationProperty navigationProperty = navigationSegment.NavigationProperty;
                IEdmEntityType declaringType = navigationProperty.DeclaringEntityType();

                string refActionName = FindRefActionName(actionMap, navigationProperty, declaringType, requestMethod);
                if (refActionName != null)
                {
                    routeData.Values[ODataRouteConstants.Key] = ((KeyValuePathSegment)odataPath.Segments[1]).Value;
                    routeData.Values[ODataRouteConstants.NavigationProperty] = navigationSegment.NavigationProperty.Name;
                    routeData.Values[ODataRouteConstants.RelatedKey] = ((KeyValuePathSegment)odataPath.Segments[odataPath.Segments.Count - 2]).Value;
                    return refActionName;
                }
            }

            return null;
        }

        public void SelectAction_ThrowsArgumentNull_IfActionMapIsNull()
        {
            // Arrange
            ODataPath odataPath = new ODataPath();
            var controllerContext = new Mock<HttpControllerContext>().Object;

            // Act & Assert
            Assert.ThrowsArgumentNull(
                () => new ActionRoutingConvention().SelectAction(odataPath, controllerContext, actionMap: null),
                "actionMap");
        }