refactor to use ModelPropertySegment, instead of itemName/itemSeriali…

…zedNmae/itemType

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/mapper/ClientMethodMapper.java

@@ -35,14 +35,14 @@
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.MethodParameter;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.MethodPollingDetails;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.MethodTransformationDetail;
+import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ModelPropertySegment;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ParameterMapping;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.PrimitiveType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ProxyMethod;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ProxyMethodParameter;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ReturnValue;
 import com.microsoft.typespec.http.client.generator.core.model.javamodel.JavaVisibility;
 import com.microsoft.typespec.http.client.generator.core.util.ClientModelUtil;
-import com.microsoft.typespec.http.client.generator.core.util.CodeNamer;
 import com.microsoft.typespec.http.client.generator.core.util.MethodNamer;
 import com.microsoft.typespec.http.client.generator.core.util.MethodUtil;
 import com.microsoft.typespec.http.client.generator.core.util.ReturnTypeDescriptionAssembler;
@@ -327,31 +327,32 @@ private List<ClientMethod> createClientMethods(Operation operation, boolean isPr
                     .methodPageDetails(null);
 
                 if (isPageable) {
-                    String pageableItemName = getPageableItemName(operation.getExtensions().getXmsPageable(),
-                        proxyMethod.getRawResponseBodyType() != null
-                            ? proxyMethod.getRawResponseBodyType()
-                            : proxyMethod.getResponseBodyType());
-                    if (pageableItemName == null) {
+                    IType responseType = proxyMethod.getRawResponseBodyType() != null
+                        ? proxyMethod.getRawResponseBodyType()
+                        : proxyMethod.getResponseBodyType();
+                    ModelPropertySegment itemPropertyReference
+                        = getPageableItem(operation.getExtensions().getXmsPageable(), responseType);
+                    if (itemPropertyReference == null) {
                         // There is no pageable item name for this operation, skip it.
                         continue;
                     }
 
                     // If the ProxyMethod is synchronous perform a complete generation of synchronous pageable APIs.
                     if (proxyMethod.isSync()) {
                         createSyncPageableClientMethods(operation, isProtocolMethod, settings, methods, builder,
-                            returnTypeHolder, proxyMethod, parameters, pageableItemName, generateOnlyRequiredParameters,
-                            defaultOverloadType);
+                            returnTypeHolder, proxyMethod, parameters, itemPropertyReference,
+                            generateOnlyRequiredParameters, defaultOverloadType);
                     } else {
                         // Otherwise, perform a complete generation of asynchronous pageable APIs.
                         // Then if SyncMethodsGeneration is enabled and Sync Stack is not perform synchronous pageable
                         // API generation based on SyncMethodsGeneration configuration.
                         createAsyncPageableClientMethods(operation, isProtocolMethod, settings, methods, builder,
-                            returnTypeHolder, proxyMethod, parameters, pageableItemName, generateOnlyRequiredParameters,
-                            defaultOverloadType);
+                            returnTypeHolder, proxyMethod, parameters, itemPropertyReference,
+                            generateOnlyRequiredParameters, defaultOverloadType);
 
                         if (settings.isGenerateSyncMethods() && !settings.isSyncStackEnabled()) {
                             createSyncPageableClientMethods(operation, isProtocolMethod, settings, methods, builder,
-                                returnTypeHolder, proxyMethod, parameters, pageableItemName,
+                                returnTypeHolder, proxyMethod, parameters, itemPropertyReference,
                                 generateOnlyRequiredParameters, defaultOverloadType);
                         }
                     }
@@ -698,7 +699,7 @@ private static List<Parameter> getCodeModelParameters(Request request, boolean i
 
     private void createAsyncPageableClientMethods(Operation operation, boolean isProtocolMethod, JavaSettings settings,
         List<ClientMethod> methods, ClientMethod.Builder builder, ReturnTypeHolder returnTypeHolder,
-        ProxyMethod proxyMethod, List<ClientMethodParameter> parameters, String pageableItemName,
+        ProxyMethod proxyMethod, List<ClientMethodParameter> parameters, ModelPropertySegment itemPropertyReference,
         boolean generateClientMethodWithOnlyRequiredParameters, MethodOverloadType defaultOverloadType) {
 
         ReturnValue singlePageReturnValue = createPagingAsyncSinglePageReturnValue(operation,
@@ -710,13 +711,13 @@ private void createAsyncPageableClientMethods(Operation operation, boolean isPro
             includesContext, isProtocolMethod);
 
         createPageableClientMethods(operation, isProtocolMethod, settings, methods, builder, proxyMethod, parameters,
-            pageableItemName, false, singlePageReturnValue, nextPageReturnValue, visibilityFunction,
+            itemPropertyReference, false, singlePageReturnValue, nextPageReturnValue, visibilityFunction,
             getContextParameter(isProtocolMethod), generateClientMethodWithOnlyRequiredParameters, defaultOverloadType);
     }
 
     private void createSyncPageableClientMethods(Operation operation, boolean isProtocolMethod, JavaSettings settings,
         List<ClientMethod> methods, Builder builder, ReturnTypeHolder returnTypeHolder, ProxyMethod proxyMethod,
-        List<ClientMethodParameter> parameters, String pageableItemName,
+        List<ClientMethodParameter> parameters, ModelPropertySegment itemPropertyReference,
         boolean generateClientMethodWithOnlyRequiredParameters, MethodOverloadType defaultOverloadType) {
 
         ReturnValue singlePageReturnValue = createPagingSyncSinglePageReturnValue(operation,
@@ -727,22 +728,20 @@ private void createSyncPageableClientMethods(Operation operation, boolean isProt
             includesContext, isProtocolMethod);
 
         createPageableClientMethods(operation, isProtocolMethod, settings, methods, builder, proxyMethod, parameters,
-            pageableItemName, true, singlePageReturnValue, nextPageReturnValue, visibilityFunction,
+            itemPropertyReference, true, singlePageReturnValue, nextPageReturnValue, visibilityFunction,
             getContextParameter(isProtocolMethod), generateClientMethodWithOnlyRequiredParameters, defaultOverloadType);
     }
 
     private static void createPageableClientMethods(Operation operation, boolean isProtocolMethod,
         JavaSettings settings, List<ClientMethod> methods, Builder builder, ProxyMethod proxyMethod,
-        List<ClientMethodParameter> parameters, String pageableItemName, boolean isSync,
+        List<ClientMethodParameter> parameters, ModelPropertySegment itemPropertyReference, boolean isSync,
         ReturnValue singlePageReturnValue, ReturnValue nextPageReturnValue, MethodVisibilityFunction visibilityFunction,
         ClientMethodParameter contextParameter, boolean generateClientMethodWithOnlyRequiredParameters,
         MethodOverloadType defaultOverloadType) {
 
         MethodNamer methodNamer = resolveMethodNamer(proxyMethod, operation.getConvenienceApi(), isProtocolMethod);
 
         Operation nextOperation = operation.getExtensions().getXmsPageable().getNextOperation();
-        String nextLinkName = operation.getExtensions().getXmsPageable().getNextLinkName();
-        String itemName = operation.getExtensions().getXmsPageable().getItemName();
         ClientMethodType nextMethodType
             = isSync ? ClientMethodType.PagingSyncSinglePage : ClientMethodType.PagingAsyncSinglePage;
 
@@ -760,14 +759,15 @@ private static void createPageableClientMethods(Operation operation, boolean isP
             ? null
             : nextMethods.stream().filter(m -> m.getType() == nextMethodType).findFirst().orElse(null);
 
-        IType nextLinkType = getPageableNextLinkType(operation.getExtensions().getXmsPageable(),
-            (proxyMethod.getRawResponseBodyType() != null
-                ? proxyMethod.getRawResponseBodyType()
-                : proxyMethod.getResponseBodyType()).toString());
+        IType responseType = proxyMethod.getRawResponseBodyType() != null
+            ? proxyMethod.getRawResponseBodyType()
+            : proxyMethod.getResponseBodyType();
+        ModelPropertySegment nextLinkPropertyReference
+            = getPageableNextLink(operation.getExtensions().getXmsPageable(), responseType);
 
-        MethodPageDetails details = new MethodPageDetails(CodeNamer.getPropertyName(nextLinkName), nextLinkType,
-            pageableItemName, nextMethod, lroIntermediateType, nextLinkName, itemName,
-            operation.getExtensions().getXmsPageable().getContinuationToken());
+        MethodPageDetails details = new MethodPageDetails(itemPropertyReference, nextLinkPropertyReference, nextMethod,
+            lroIntermediateType, MethodPageDetails.ContinuationToken.fromContinuationToken(
+                operation.getExtensions().getXmsPageable().getContinuationToken(), responseType));
         builder.methodPageDetails(details);
 
         String pageMethodName
@@ -836,9 +836,9 @@ private static void createPageableClientMethods(Operation operation, boolean isP
                 .orElse(null);
 
             if (nextMethod != null) {
-                detailsWithContext = new MethodPageDetails(CodeNamer.getPropertyName(nextLinkName), nextLinkType,
-                    pageableItemName, nextMethod, lroIntermediateType, nextLinkName, itemName,
-                    operation.getExtensions().getXmsPageable().getContinuationToken());
+                detailsWithContext = new MethodPageDetails(itemPropertyReference, nextLinkPropertyReference, nextMethod,
+                    lroIntermediateType, MethodPageDetails.ContinuationToken.fromContinuationToken(
+                        operation.getExtensions().getXmsPageable().getContinuationToken(), responseType));
             }
         }
 
@@ -1589,30 +1589,12 @@ protected static void addClientMethodWithContext(List<ClientMethod> methods, Bui
         builder.parameters(parameters);
     }
 
-    private static String getPageableItemName(XmsPageable xmsPageable, IType responseBodyType) {
-        ClientModel responseBodyModel = ClientModelUtil.getClientModel(responseBodyType.toString());
-        return Stream
-            .concat(responseBodyModel.getProperties().stream(),
-                ClientModelUtil.getParentProperties(responseBodyModel).stream())
-            .filter(p -> p.getSerializedName().equals(xmsPageable.getItemName()))
-            .map(ClientModelProperty::getName)
-            .findAny()
-            .orElse(null);
+    private static ModelPropertySegment getPageableItem(XmsPageable xmsPageable, IType responseBodyType) {
+        return ClientModelUtil.getModelPropertySegment(responseBodyType, xmsPageable.getItemName());
     }
 
-    private static IType getPageableNextLinkType(XmsPageable xmsPageable, String clientModelName) {
-        ClientModel responseBodyModel = ClientModelUtil.getClientModel(clientModelName);
-        IType nextLinkType = responseBodyModel.getProperties()
-            .stream()
-            .filter(p -> p.getSerializedName().equals(xmsPageable.getNextLinkName()))
-            .map(ClientModelProperty::getClientType)
-            .findAny()
-            .orElse(null);
-        if (nextLinkType == null && !CoreUtils.isNullOrEmpty(responseBodyModel.getParentModelName())) {
-            // try find nextLink property in parent model
-            nextLinkType = getPageableNextLinkType(xmsPageable, responseBodyModel.getParentModelName());
-        }
-        return nextLinkType;
+    private static ModelPropertySegment getPageableNextLink(XmsPageable xmsPageable, IType responseBodyType) {
+        return ClientModelUtil.getModelPropertySegment(responseBodyType, xmsPageable.getNextLinkName());
     }
 
     private IType getPollingIntermediateType(JavaSettings.PollingDetails details, IType syncReturnType) {

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/MethodPageDetails.java

@@ -3,68 +3,108 @@
 
 package com.microsoft.typespec.http.client.generator.core.model.clientmodel;
 
+import com.microsoft.typespec.http.client.generator.core.extension.model.codemodel.Property;
 import com.microsoft.typespec.http.client.generator.core.extension.model.extensionmodel.PageableContinuationToken;
+import com.microsoft.typespec.http.client.generator.core.mapper.ProxyParameterMapper;
+import com.microsoft.typespec.http.client.generator.core.util.ClientModelUtil;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * A page class that contains results that are received from a service request.
  */
-public class MethodPageDetails {
+public final class MethodPageDetails {
     /**
      * Get whether or not this method is a request to get the next page of a sequence of pages.
      */
-    private final String nextLinkName;
-    private final IType nextLinkType;
-
-    private final String itemName;
-
-    /**
-     * Serialized nextLink name. It is the name in swagger and in response.
-     */
-    private final String serializedNextLinkName;
-    /**
-     * Serialized item name. It is the name in swagger and in response.
-     */
-    private final String serializedItemName;
+    private final ModelPropertySegment nextLinkPropertyReference;
+    private final ModelPropertySegment itemPropertyReference;
 
     private final ClientMethod nextMethod;
 
     // Proxy method return type is Flux<ByteBuffer>. Client method return type is PagedResponse<>.
     // This intermediate type is the type of pagination response (the type with values and nextLink).
     private final IType lroIntermediateType;
 
-    private PageableContinuationToken continuationToken;
+    public static final class ContinuationToken {
+        private final ProxyMethodParameter requestParameter;
+        private final List<ModelPropertySegment> responsePropertyReference;
+        private final String responseHeaderSerializedName;
+
+        private ContinuationToken(PageableContinuationToken continuationToken, IType responseBodyType) {
+            this.requestParameter = ProxyParameterMapper.getInstance().map(continuationToken.getParameter());
+            this.responseHeaderSerializedName = continuationToken.getResponseHeader() == null
+                ? null
+                : continuationToken.getResponseHeader().getHeader();
+
+            List<ModelPropertySegment> responsePropertyReference = null;
+            if (continuationToken.getResponseProperty() != null) {
+                responsePropertyReference = new ArrayList<>();
+                IType modelType = responseBodyType;
+                for (Property p : continuationToken.getResponseProperty()) {
+                    ModelPropertySegment segment
+                        = ClientModelUtil.getModelPropertySegment(modelType, p.getSerializedName());
+                    if (segment != null) {
+                        responsePropertyReference.add(segment);
+                    } else {
+                        throw new RuntimeException(
+                            String.format("Property of serialized name '%s' is not found in model '%s'.",
+                                p.getSerializedName(), modelType.toString()));
+                    }
+
+                    modelType = segment.getProperty().getClientType();
+                }
+            }
+            this.responsePropertyReference = responsePropertyReference;
+        }
+
+        public static ContinuationToken fromContinuationToken(PageableContinuationToken continuationToken,
+            IType responseBodyType) {
+            return continuationToken == null ? null : new ContinuationToken(continuationToken, responseBodyType);
+        }
+
+        public ProxyMethodParameter getRequestParameter() {
+            return requestParameter;
+        }
+
+        public List<ModelPropertySegment> getResponsePropertyReference() {
+            return responsePropertyReference;
+        }
+
+        public String getResponseHeaderSerializedName() {
+            return responseHeaderSerializedName;
+        }
+    }
+
+    private ContinuationToken continuationToken;
 
-    public MethodPageDetails(String nextLinkName, IType nextLinkType, String itemName, ClientMethod nextMethod,
-        IType lroIntermediateType, String serializedNextLinkName, String serializedItemName,
-        PageableContinuationToken continuationToken) {
-        this.nextLinkName = nextLinkName;
-        this.nextLinkType = nextLinkType;
-        this.itemName = itemName;
+    public MethodPageDetails(ModelPropertySegment itemPropertyReference, ModelPropertySegment nextLinkPropertyReference,
+        ClientMethod nextMethod, IType lroIntermediateType, ContinuationToken continuationToken) {
+        this.itemPropertyReference = itemPropertyReference;
+        this.nextLinkPropertyReference = nextLinkPropertyReference;
         this.nextMethod = nextMethod;
         this.lroIntermediateType = lroIntermediateType;
-        this.serializedNextLinkName = serializedNextLinkName;
-        this.serializedItemName = serializedItemName;
         this.continuationToken = continuationToken;
     }
 
     public String getNextLinkName() {
-        return nextLinkName;
+        return nextLinkPropertyReference == null ? null : nextLinkPropertyReference.getProperty().getName();
     }
 
     public IType getNextLinkType() {
-        return nextLinkType;
+        return nextLinkPropertyReference == null ? null : nextLinkPropertyReference.getProperty().getClientType();
     }
 
     public String getSerializedNextLinkName() {
-        return serializedNextLinkName;
+        return nextLinkPropertyReference.getProperty().getSerializedName();
     }
 
     public String getItemName() {
-        return itemName;
+        return itemPropertyReference == null ? null : itemPropertyReference.getProperty().getName();
     }
 
     public String getSerializedItemName() {
-        return serializedItemName;
+        return itemPropertyReference == null ? null : itemPropertyReference.getProperty().getSerializedName();
     }
 
     public ClientMethod getNextMethod() {
@@ -76,10 +116,10 @@ public IType getLroIntermediateType() {
     }
 
     public boolean nonNullNextLink() {
-        return nextLinkName != null && !nextLinkName.isEmpty();
+        return getNextLinkName() != null && !getNextLinkName().isEmpty();
     }
 
-    public PageableContinuationToken getContinuationToken() {
+    public ContinuationToken getContinuationToken() {
         return continuationToken;
     }
 }

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ModelPropertySegment.java

@@ -0,0 +1,38 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.microsoft.typespec.http.client.generator.core.model.clientmodel;
+
+/**
+ * A segment in property reference. It can be chained as a List, if the reference contains multiple model/property.
+ * <p>
+ * E.g. a reference to "links", "nextLink" in response body would be a List of 2 ModelPropertySegment.
+ */
+public class ModelPropertySegment {
+
+    private final ClientModel model;
+    private final ClientModelProperty property;
+
+    public ModelPropertySegment(ClientModel model, ClientModelProperty property) {
+        this.model = model;
+        this.property = property;
+    }
+
+    /**
+     * Gets the model of the property. It is possible that the property is actually specified in its parent model.
+     *
+     * @return the model of the property
+     */
+    public ClientModel getModel() {
+        return model;
+    }
+
+    /**
+     * Gets the property.
+     *
+     * @return the property
+     */
+    public ClientModelProperty getProperty() {
+        return property;
+    }
+}