// .NET 8+. Coloque em um projeto Console e execute somente no servidor.
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;
using System.Text.RegularExpressions;

var key = Environment.GetEnvironmentVariable("PIX_API_KEY");
var id = Environment.GetEnvironmentVariable("PIX_SALE_ID");
if (string.IsNullOrWhiteSpace(key) || id is null ||
    !Regex.IsMatch(id, @"\A[0123456789ABCDEFGHJKMNPQRSTVWXYZ]{21}\z"))
    throw new ArgumentException("Configure PIX_API_KEY e PIX_SALE_ID.");
if (args.Length != 1 || (args[0] != "create" && args[0] != "get"))
    throw new ArgumentException("Use: dotnet run -- create|get");

// Persista ID e corpo antes do POST; preserve ambos em toda retentativa.
var create = args[0] == "create";
var body = new { sale_id = id, amount_cents = 8990, reference = "Pedido 1042" };
var url = "https://pixlojista.com.br/v1/integration/sales" + (create ? "" : "/" + id);
using var handler = new HttpClientHandler { AllowAutoRedirect = false };
using var client = new HttpClient(handler) { Timeout = TimeSpan.FromSeconds(15) };
using var request = new HttpRequestMessage(create ? HttpMethod.Post : HttpMethod.Get, url);
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", key);
if (create) request.Content = new StringContent(JsonSerializer.Serialize(body), Encoding.UTF8, "application/json");
using var response = await client.SendAsync(request);
var json = await response.Content.ReadAsStringAsync();
if (!response.IsSuccessStatusCode) throw new HttpRequestException($"HTTP {(int)response.StatusCode}: {json}");
Console.WriteLine(json); // JSON: sale, brcode, qr_png_base64.