private CodeTypeDeclaration GenerateEnumStruct()

in telemetry/csharp/AwsToolkit.Telemetry.Events.Generator.Core/DefinitionsBuilder.cs [189:252]
47 lines of code
2 McCabe index (conditional complexity)

        private CodeTypeDeclaration GenerateEnumStruct(MetricType type)
        {
            var typeDeclaration = new CodeTypeDeclaration(type.GetGeneratedTypeName())
            {
                IsStruct = true,
                TypeAttributes = TypeAttributes.Public | TypeAttributes.Sealed
            };

            typeDeclaration.Comments.Add(new CodeCommentStatement("Metric field type", true));
            if (!string.IsNullOrWhiteSpace(type.description))
            {
                typeDeclaration.Comments.Add(new CodeCommentStatement(type.description, true));
            }

            var valueField = new CodeMemberField(typeof(string), "_value");
            valueField.Attributes = MemberAttributes.Private;
            typeDeclaration.Members.Add(valueField);

            // Generate the constructor (stores provided value in _value)
            var typeConstructor = new CodeConstructor();
            typeConstructor.Attributes = MemberAttributes.Public;
            typeConstructor.Parameters.Add(new CodeParameterDeclarationExpression("System.string", "value"));

            // this._value = value;
            var valueFieldRef = new CodeFieldReferenceExpression(new CodeThisReferenceExpression(), valueField.Name);
            typeConstructor.Statements.Add(new CodeAssignStatement(valueFieldRef, new CodeArgumentReferenceExpression("value")));

            typeDeclaration.Members.Add(typeConstructor);

            // Generate static fields for each allowed value
            type.allowedValues?
                .ToList()
                .ForEach(allowedValue =>
            {
                // eg: public static readonly Runtime Dotnetcore21 = new Runtime("dotnetcore2.1")
                CodeMemberField field = new CodeMemberField($"readonly {type.GetGeneratedTypeName()}",
                    allowedValue.Replace(" ", "_").ToPascalCase().Replace(".", "").Replace("-", ""))
                {
                    InitExpression = new CodeObjectCreateExpression(type.GetGeneratedTypeName(),
                        new CodeExpression[] {new CodePrimitiveExpression(allowedValue)}),
                    Attributes = MemberAttributes.Static | MemberAttributes.Public
                };
                field.Comments.Add(new CodeCommentStatement(allowedValue, true));

                typeDeclaration.Members.Add(field);
            });

            // Generate a ToString method, which returns this._value
            // ToString is used by the AddMetadata method
            var toString = new CodeMemberMethod()
            {
                Name = "ToString",
                Attributes = MemberAttributes.Public | MemberAttributes.Override,
                ReturnType = new CodeTypeReference(typeof(string))
            };
            
            toString.Statements.Add(
                new CodeMethodReturnStatement(new CodeFieldReferenceExpression(new CodeThisReferenceExpression(),
                    valueField.Name)));

            typeDeclaration.Members.Add(toString);

            return typeDeclaration;
        }