using Microsoft.OpenApi;
using Microsoft.OpenApi.Reader;
using System.Text.Json.Nodes;

namespace Dasfn
{
    internal class Program
    {
        static async Task Main(string[] args)
        {
            Uri baseUrl = new("https://www.bcb.gov.br/htms/dasfn/catalogo/1.0.10/");

            HttpClient httpClient = new()
            {
                BaseAddress = baseUrl,
            };

            OpenApiReaderSettings settings = new()
            {
                BaseUrl = baseUrl,
                HttpClient = httpClient,
                LoadExternalRefs = true,
            };

            (OpenApiDocument? document, OpenApiDiagnostic? diagnostic) = await OpenApiDocument.LoadAsync(new Uri(baseUrl, "openapi.json").AbsoluteUri, settings);

            if (diagnostic?.Errors is IList<OpenApiError> errors)
            {
                foreach (OpenApiError error in errors)
                { 
                    Console.WriteLine(error); 
                }
            }

            OpenApiMediaType mediaType = document!
                .Paths["/catalogo"]
                .Operations![HttpMethod.Get]
                .Responses!["200"]
                .Content!["application/json"]
                ;

            if (mediaType.Schema is OpenApiSchemaReference schemaReference && schemaReference.UnresolvedReference)
            {
                using MemoryStream stream = new(await httpClient.GetByteArrayAsync(schemaReference.Reference.ExternalResource, CancellationToken.None));

                mediaType.Schema = settings.Readers["json"]
                    .ReadFragment<OpenApiSchema>(stream, diagnostic!.SpecificationVersion, document, out OpenApiDiagnostic schemaDiagnostic);
            }
        }
    }
}