[http-client-csharp-mgmt] code refactoring (Azure#50205)

* refine method BuildOperationMethodTryStatement.

* address remaining unresolved review comments from ealier PR.

* remove useless comments.

* fix typo.

* new tspCodeModel.json.

* regen tspCodeModel.json.

* fix rebase issue.

* address review comments.

* fix.

* address code review comments.

* create new class ResourceOperationMethodProvider.

* add two extension methods to CSharpType.

* address new review comments from copilot.

* further refine.

* more refine.

* Apply WrapAsync everywhere possible.

* Replace SkipMethodParameter with ImplicitParameterNames property

* introduce GetAllResourceOperationMethodProvider.

* address new review comments.

* rename GetAllResourceOperationMethodProvider to GetAllOperationMethodProvider

* small refine.

* address review comments.

* add one TODO item inline in the code.

Author: haiyuazhang

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/Providers/OperationMethodProviders/ExistsOperationMethodProvider.cs

@@ -0,0 +1,56 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using Azure.Generator.Management.Utilities;
+using Microsoft.TypeSpec.Generator.Expressions;
+using Microsoft.TypeSpec.Generator.Input;
+using Microsoft.TypeSpec.Generator.Primitives;
+using Microsoft.TypeSpec.Generator.Providers;
+using Microsoft.TypeSpec.Generator.Statements;
+using System.Collections.Generic;
+using static Microsoft.TypeSpec.Generator.Snippets.Snippet;
+
+namespace Azure.Generator.Management.Providers.OperationMethodProviders
+{
+    internal class ExistsOperationMethodProvider(
+        ResourceClientProvider resourceClientProvider,
+        InputServiceMethod method,
+        MethodProvider convenienceMethod,
+        bool isAsync) : ResourceOperationMethodProvider(resourceClientProvider, method, convenienceMethod, isAsync)
+    {
+        protected override MethodSignature CreateSignature()
+        {
+            var returnType = new CSharpType(typeof(Response<>), typeof(bool))
+                .WrapAsync(_isAsync);
+
+            return new MethodSignature(
+                _isAsync ? "ExistsAsync" : "Exists",
+                $"Checks to see if the resource exists in azure.",
+                _convenienceMethod.Signature.Modifiers,
+                returnType,
+                _convenienceMethod.Signature.ReturnDescription,
+                GetOperationMethodParameters(),
+                _convenienceMethod.Signature.Attributes,
+                _convenienceMethod.Signature.GenericArguments,
+                _convenienceMethod.Signature.GenericParameterConstraints,
+                _convenienceMethod.Signature.ExplicitInterface,
+                _convenienceMethod.Signature.NonDocumentComment);
+        }
+
+        protected override IReadOnlyList<MethodBodyStatement> BuildReturnStatements(ValueExpression responseVariable, MethodSignature signature)
+        {
+            // For Exists methods, we check if Value is not null and return a boolean
+            var returnValueExpression = responseVariable.Property("Value").NotEqual(Null);
+
+            return [
+                Return(
+                    Static(typeof(Response)).Invoke(
+                        nameof(Response.FromValue),
+                        returnValueExpression,
+                        responseVariable.Invoke("GetRawResponse")
+                    )
+                )
+            ];
+        }
+    }
+}

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/Providers/OperationMethodProviders/GetAllOperationMethodProvider.cs

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using Microsoft.TypeSpec.Generator.Expressions;
+using Microsoft.TypeSpec.Generator.Input;
+using Microsoft.TypeSpec.Generator.Primitives;
+using Microsoft.TypeSpec.Generator.Providers;
+using Microsoft.TypeSpec.Generator.Statements;
+using System;
+using static Microsoft.TypeSpec.Generator.Snippets.Snippet;
+
+namespace Azure.Generator.Management.Providers.OperationMethodProviders
+{
+    internal class GetAllOperationMethodProvider(
+        ResourceCollectionClientProvider resourceCollectionClientProvider,
+        InputServiceMethod method,
+        MethodProvider convenienceMethod,
+        bool isAsync) : ResourceOperationMethodProvider(resourceCollectionClientProvider, method, convenienceMethod, isAsync)
+    {
+        private readonly ResourceCollectionClientProvider _resourceCollectionClientProvider = resourceCollectionClientProvider;
+
+        protected override MethodSignature CreateSignature()
+        {
+            var resourceType = _resourceCollectionClientProvider.ResourceClientCSharpType;
+            var returnType = _isAsync
+                ? new CSharpType(typeof(AsyncPageable<>), resourceType)
+                : new CSharpType(typeof(Pageable<>), resourceType);
+
+            return new MethodSignature(
+            _isAsync ? "GetAllAsync" : "GetAll",
+            _convenienceMethod.Signature.Description,
+            _convenienceMethod.Signature.Modifiers,
+            returnType,
+            _convenienceMethod.Signature.ReturnDescription,
+            GetOperationMethodParameters(),
+            _convenienceMethod.Signature.Attributes,
+            _convenienceMethod.Signature.GenericArguments,
+            _convenienceMethod.Signature.GenericParameterConstraints,
+            _convenienceMethod.Signature.ExplicitInterface,
+            _convenienceMethod.Signature.NonDocumentComment);
+        }
+
+        protected override MethodBodyStatement[] BuildBodyStatements()
+        {
+            // TODO: implement paging method properly
+            return [((KeywordExpression)ThrowExpression(New.Instance(typeof(NotImplementedException)))).Terminate()];
+        }
+    }
+}

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/Providers/OperationMethodProviders/GetIfExistsOperationMethodProvider.cs

@@ -0,0 +1,71 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using Azure.Generator.Management.Utilities;
+using Microsoft.TypeSpec.Generator.Expressions;
+using Microsoft.TypeSpec.Generator.Input;
+using Microsoft.TypeSpec.Generator.Primitives;
+using Microsoft.TypeSpec.Generator.Providers;
+using Microsoft.TypeSpec.Generator.Statements;
+using System.Collections.Generic;
+using static Microsoft.TypeSpec.Generator.Snippets.Snippet;
+
+namespace Azure.Generator.Management.Providers.OperationMethodProviders
+{
+    internal class GetIfExistsOperationMethodProvider(
+        ResourceClientProvider resourceClientProvider,
+        InputServiceMethod method,
+        MethodProvider convenienceMethod,
+        bool isAsync) : ResourceOperationMethodProvider(resourceClientProvider, method, convenienceMethod, isAsync)
+    {
+        protected override MethodSignature CreateSignature()
+        {
+            var returnType = new CSharpType(typeof(NullableResponse<>), _resourceClientProvider.ResourceClientCSharpType)
+                .WrapAsync(_isAsync);
+
+            return new MethodSignature(
+                _isAsync ? "GetIfExistsAsync" : "GetIfExists",
+                $"Tries to get details for this resource from the service.",
+                _convenienceMethod.Signature.Modifiers,
+                returnType,
+                _convenienceMethod.Signature.ReturnDescription,
+                GetOperationMethodParameters(),
+                _convenienceMethod.Signature.Attributes,
+                _convenienceMethod.Signature.GenericArguments,
+                _convenienceMethod.Signature.GenericParameterConstraints,
+                _convenienceMethod.Signature.ExplicitInterface,
+                _convenienceMethod.Signature.NonDocumentComment);
+        }
+
+        protected override IReadOnlyList<MethodBodyStatement> BuildReturnStatements(ValueExpression responseVariable, MethodSignature signature)
+        {
+            var resourceClientCSharpType = _resourceClientProvider.ResourceClientCSharpType;
+
+            List<MethodBodyStatement> statements =
+            [
+                new IfStatement(responseVariable.Property("Value").Equal(Null))
+                {
+                    Return(
+                        New.Instance(
+                            new CSharpType(typeof(NoValueResponse<>), resourceClientCSharpType),
+                            responseVariable.Invoke("GetRawResponse")
+                        )
+                    )
+                }
+            ];
+
+            var returnValueExpression = New.Instance(resourceClientCSharpType, This.Property("Client"), responseVariable.Property("Value"));
+            statements.Add(
+                Return(
+                    Static(typeof(Response)).Invoke(
+                        nameof(Response.FromValue),
+                        returnValueExpression,
+                        responseVariable.Invoke("GetRawResponse")
+                    )
+                )
+            );
+
+            return statements;
+        }
+    }
+}