public static void ProcessOpenApiDocument()

in src/Microsoft.OpenApi.Hidi/OpenApiService.cs [23:116]
80 lines of code
14 McCabe index (conditional complexity)

        public static void ProcessOpenApiDocument(
            string input,
            FileInfo output,
            OpenApiSpecVersion? version,
            OpenApiFormat? format,
            string filterByOperationIds,
            string filterByTags,
            string filterByCollection,
            bool inline,
            bool resolveExternal)
        {
            if (string.IsNullOrEmpty(input))
            {
                throw new ArgumentNullException(nameof(input));
            }
            if(output == null)
            {
                throw new ArgumentException(nameof(output));
            }
            if (output.Exists)
            {
                throw new IOException("The file you're writing to already exists. Please input a new output path.");
            }

            var stream = GetStream(input);
            var result = new OpenApiStreamReader(new OpenApiReaderSettings
            {
                ReferenceResolution = resolveExternal ? ReferenceResolutionSetting.ResolveAllReferences : ReferenceResolutionSetting.ResolveLocalReferences,
                RuleSet = ValidationRuleSet.GetDefaultRuleSet()
            }
            ).ReadAsync(stream).GetAwaiter().GetResult();

            var document = result.OpenApiDocument;
            Func<string, OperationType?, OpenApiOperation, bool> predicate;

            // Check if filter options are provided, then execute
            if (!string.IsNullOrEmpty(filterByOperationIds) && !string.IsNullOrEmpty(filterByTags))
            {
                throw new InvalidOperationException("Cannot filter by operationIds and tags at the same time.");
            }
            if (!string.IsNullOrEmpty(filterByOperationIds))
            {
                predicate = OpenApiFilterService.CreatePredicate(operationIds: filterByOperationIds);
                document = OpenApiFilterService.CreateFilteredDocument(document, predicate);
            }
            if (!string.IsNullOrEmpty(filterByTags))
            {
                predicate = OpenApiFilterService.CreatePredicate(tags: filterByTags);
                document = OpenApiFilterService.CreateFilteredDocument(document, predicate);
            }

            if (!string.IsNullOrEmpty(filterByCollection))
            {
                var fileStream = GetStream(filterByCollection);
                var requestUrls = ParseJsonCollectionFile(fileStream);
                predicate = OpenApiFilterService.CreatePredicate(requestUrls: requestUrls, source:document);
                document = OpenApiFilterService.CreateFilteredDocument(document, predicate);
            }

            var context = result.OpenApiDiagnostic;

            if (context.Errors.Count > 0)
            {
                var errorReport = new StringBuilder();

                foreach (var error in context.Errors)
                {
                    errorReport.AppendLine(error.ToString());
                }

                throw new ArgumentException(string.Join(Environment.NewLine, context.Errors.Select(e => e.Message).ToArray()));
            }

            using var outputStream = output?.Create();

            var textWriter = outputStream != null ? new StreamWriter(outputStream) : Console.Out;

            var settings = new OpenApiWriterSettings()
            {
                ReferenceInline = inline ? ReferenceInlineSetting.InlineLocalReferences : ReferenceInlineSetting.DoNotInlineReferences
            };

            var openApiFormat = format ?? GetOpenApiFormat(input);
            var openApiVersion = version ?? result.OpenApiDiagnostic.SpecificationVersion;
            IOpenApiWriter writer = openApiFormat switch
            {
                OpenApiFormat.Json => new OpenApiJsonWriter(textWriter, settings),
                OpenApiFormat.Yaml => new OpenApiYamlWriter(textWriter, settings),
                _ => throw new ArgumentException("Unknown format"),
            };
            document.Serialize(writer, openApiVersion);

            textWriter.Flush();
        }