protected override async Task <HttpResponseMessage> SendAsync(
HttpRequestMessage request,
CancellationToken cancellationToken)
{
if (request.Headers.Authorization != null)
{
return(await base.SendAsync(request, cancellationToken));
}
// When the token is not fetched or it is expired, re-fetch a service account token.
if (_token == null || _tokenExpiryDate < DateTime.UtcNow)
{
_token = await _account.AuthenticateAsync(_options);
_tokenExpiryDate = DateTime.UtcNow + ServiceTokenLifetime;
}
request.Headers.Authorization = new("Bearer", _token);
return(await base.SendAsync(request, cancellationToken));
}