WebApi + ClientApp, GraphQL, Reflection

Events-WebApi/Events.FilesAPI/Features/Certificates/DownloadCertificateController.cs

@@ -0,0 +1,30 @@
+using Microsoft.AspNetCore.Mvc;
+using Events.FilesAPI.Features.Certificates.Download;
+using MediatR;
+
+namespace Events.FilesAPI.Features.Certificates;
+
+[ApiController]
+[Route("Registrations")]
+public class DownloadCertificateController : ControllerBase
+{
+  private const string PdfContentType = "application/pdf";
+
+  [HttpGet("{id}/Certificate")]
+  [ProducesResponseType(typeof(PhysicalFileResult), StatusCodes.Status200OK)]
+  [ProducesResponseType(StatusCodes.Status404NotFound)]
+  public async Task<IActionResult> DownloadCertificate(
+    int id,
+    [FromServices] IMediator mediator,
+    CancellationToken cancellationToken)
+  {
+    DownloadCertificateResult result = await mediator.Send(new DownloadCertificateQuery(id), cancellationToken);
+    if (!result.RegistrationFound)
+      return Problem(statusCode: StatusCodes.Status404NotFound, detail: $"Invalid id = {id}");
+
+    if (result.File == null)
+      return Problem(statusCode: StatusCodes.Status404NotFound, detail: "Certificate could not be generated.");
+
+    return PhysicalFile(result.File.PhysicalPath, PdfContentType, result.File.FileName);
+  }
+}