feat: input type updates for multiservice support (#9399)

This PR adds emitter updates and fixes in preparation for generating
multiservice clients.
contributes to: #9032

Author: jorgerangel-msft

packages/http-client-csharp/emitter/src/lib/client-converter.ts

@@ -24,7 +24,7 @@ import {
   getParameterDefaultValue,
 } from "./operation-converter.js";
 import { fromSdkType } from "./type-converter.js";
-import { isReadOnly } from "./utils.js";
+import { isMultiServiceClient, isReadOnly } from "./utils.js";
 
 type SdkClientType = SdkClientTypeOfT<SdkHttpOperation>;
 
@@ -79,6 +79,7 @@ function fromSdkClient(
     apiVersions: client.apiVersions,
     parent: undefined,
     children: undefined,
+    isMultiServiceClient: isMultiServiceClient(client),
   };
 
   sdkContext.__typeCache.updateSdkClientReferences(client, inputClient);

packages/http-client-csharp/emitter/src/lib/client-model-builder.ts

@@ -1,15 +1,24 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
-import { UsageFlags } from "@azure-tools/typespec-client-generator-core";
+import {
+  SdkClientType,
+  SdkEnumType,
+  SdkHttpOperation,
+  UsageFlags,
+} from "@azure-tools/typespec-client-generator-core";
 import { CSharpEmitterContext } from "../sdk-context.js";
 import { CodeModel } from "../type/code-model.js";
 import { InputEnumType, InputLiteralType, InputModelType } from "../type/input-type.js";
 import { fromSdkClients } from "./client-converter.js";
 import { fromSdkNamespaces } from "./namespace-converter.js";
 import { processServiceAuthentication } from "./service-authentication.js";
 import { fromSdkType } from "./type-converter.js";
-import { firstLetterToUpperCase, getClientNamespaceString } from "./utils.js";
+import {
+  containsMultiServiceClient,
+  firstLetterToUpperCase,
+  getClientNamespaceString,
+} from "./utils.js";
 
 /**
  * Creates the code model from the SDK context.
@@ -31,13 +40,8 @@ export function createModel(sdkContext: CSharpEmitterContext): CodeModel {
     types.filter((type) => type.kind === "enum") as InputEnumType[],
   ];
 
-  const sdkApiVersionEnums = sdkPackage.enums.filter((e) => e.usage === UsageFlags.ApiVersionEnum);
   const rootClients = sdkPackage.clients;
-  const rootApiVersions =
-    sdkApiVersionEnums.length > 0
-      ? sdkApiVersionEnums[0].values.map((v) => v.value as string).flat()
-      : (rootClients[0]?.apiVersions ?? []);
-
+  const rootApiVersions = parseApiVersions(sdkPackage.enums, rootClients);
   const inputClients = fromSdkClients(sdkContext, rootClients, rootApiVersions);
 
   // TODO -- TCGC now does not have constants field in its sdkPackage, they might add it in the future.
@@ -61,6 +65,30 @@ export function createModel(sdkContext: CSharpEmitterContext): CodeModel {
   return clientModel;
 }
 
+/**
+ * Parses and returns the correct API versions for the library.
+ * Handles both regular and multiservice client libraries.
+ *
+ * @param enums - Array of enums from the SDK package
+ * @param rootClients - Array of root clients from the SDK package
+ * @returns Array of API version strings
+ */
+function parseApiVersions(
+  enums: SdkEnumType[],
+  rootClients: SdkClientType<SdkHttpOperation>[],
+): string[] {
+  if (containsMultiServiceClient(rootClients)) {
+    return rootClients[0]?.apiVersions ?? [];
+  }
+
+  const apiVersionEnum = enums.find((e) => (e.usage & UsageFlags.ApiVersionEnum) !== 0);
+  if (apiVersionEnum) {
+    return apiVersionEnum.values.map((v) => v.value as string);
+  }
+
+  return rootClients[0]?.apiVersions ?? [];
+}
+
 /**
  * Fixes naming conflicts for constants, enums, and models.
  *

packages/http-client-csharp/emitter/src/lib/utils.ts

@@ -1,5 +1,7 @@
 import {
   listAllServiceNamespaces,
+  SdkClientType,
+  SdkHttpOperation,
   SdkHttpParameter,
   SdkMethodParameter,
   SdkModelPropertyType,
@@ -139,10 +141,19 @@ export async function execAsync(
 }
 
 export function getClientNamespaceString(context: CSharpEmitterContext): string | undefined {
-  return getClientNamespaceStringHelper(
-    context.emitContext.options["package-name"],
-    listAllServiceNamespaces(context)[0],
-  );
+  const packageName = context.emitContext.options["package-name"];
+  const serviceNamespaces = listAllServiceNamespaces(context);
+  const firstNamespace = serviceNamespaces.length > 0 ? serviceNamespaces[0] : undefined;
+
+  if (packageName) {
+    return getClientNamespaceStringHelper(packageName, firstNamespace);
+  }
+
+  if (containsMultiServiceClient(context.sdkPackage.clients)) {
+    return getClientNamespaceStringHelper(context.sdkPackage.clients[0].namespace);
+  }
+
+  return getClientNamespaceStringHelper(undefined, firstNamespace);
 }
 
 export function getClientNamespaceStringHelper(
@@ -186,3 +197,33 @@ export function isReadOnly(
     return false;
   }
 }
+
+/**
+ * Determines if the library contains a multiservice client.
+ *
+ * @param rootClients - Array of root clients from the SDK package
+ * @returns True if this is a multiservice client library, false otherwise
+ * @beta
+ */
+export function containsMultiServiceClient(
+  rootClients: SdkClientType<SdkHttpOperation>[],
+): boolean {
+  if (rootClients.length === 0) {
+    return false;
+  }
+
+  return isMultiServiceClient(rootClients[0]);
+}
+
+/**
+ * Determines if a client is a multiservice client.
+ * A multiservice client is one where the underlying service is an array of services
+ * with more than one element.
+ *
+ * @param client - The SDK client to check
+ * @returns True if this is a multiservice client, false otherwise
+ * @beta
+ */
+export function isMultiServiceClient(client: SdkClientType<SdkHttpOperation>): boolean {
+  return Array.isArray(client.__raw.service) && client.__raw.service.length > 1;
+}

packages/http-client-csharp/emitter/src/type/input-type.ts

@@ -43,6 +43,7 @@ export interface InputClient extends DecoratedType {
   crossLanguageDefinitionId: string;
   parent?: InputClient;
   children?: InputClient[];
+  isMultiServiceClient: boolean;
 }
 
 /**