Merged in feature/download-pdf (pull request #216)

retrieve document by id and tests

* working

* missing files

api/queryAPI/documents.go

@@ -15,6 +15,23 @@ import (
 	openapi_types "github.com/oapi-codegen/runtime/types"
 )
 
+// DownloadDocument streams the original uploaded document file to the client.
+func (s *Controllers) DownloadDocument(ctx echo.Context, id DocumentID) error {
+	result, err := s.svc.DocumentDownload.GetDownload(ctx.Request().Context(), uuid.UUID(id))
+	if err != nil {
+		slog.Error("unable to download document", "error", err, "document_id", id)
+		return echo.NewHTTPError(http.StatusNotFound, fmt.Sprintf("Unable to download document: %s", err))
+	}
+	defer result.Body.Close()
+
+	ctx.Response().Header().Set("Content-Disposition",
+		fmt.Sprintf(`attachment; filename="%s"`, result.Filename))
+	ctx.Response().Header().Set("Content-Length",
+		fmt.Sprintf("%d", result.Size))
+
+	return ctx.Stream(http.StatusOK, result.ContentType, result.Body)
+}
+
 func (s *Controllers) UploadDocument(ctx echo.Context, clientId ClientID) error {
 	form, err := ctx.MultipartForm()
 	if err != nil {