//public async Task<string> ResolveAsync(string name,
// bool recursive = false,
// CancellationToken cancel = default(CancellationToken))
//{
// // Find the TXT dnslink in either <name> or _dnslink.<name>.
// string link = null;
// using (var cts = CancellationTokenSource.CreateLinkedTokenSource(cancel))
// {
// try
// {
// var attempts = new Task<string>[]
// {
// FindAsync(name, cts.Token),
// FindAsync("_dnslink." + name, cts.Token)
// };
// link = await TaskHelper.WhenAnyResultAsync(attempts, cancel).ConfigureAwait(false);
// cts.Cancel();
// }
// catch (Exception e)
// {
// throw new NotSupportedException($"Cannot resolve '{name}'.", e);
// }
// }
// if (!recursive || link.StartsWith("/ipfs/"))
// {
// return link;
// }
// // if (link.StartsWith("/ipns/"))
// // {
// // return await _nameApi.ResolveAsync(link, recursive, false, cancel).ConfigureAwait(false);
// // }
// throw new NotSupportedException($"Cannot resolve '{link}'.");
//}
private async Task <string> FindAsync(string name, CancellationToken cancel)
{
var response = await _dnsClient.QueryAsync(name, DnsType.TXT, cancel).ConfigureAwait(false);
var link = response.Answers.OfType <TXTRecord>().SelectMany(txt => txt.Strings)
.Where(s => s.StartsWith("dnslink=")).Select(s => s.Substring(8)).FirstOrDefault();
if (link == null)
{
throw new Exception($"'{name}' is missing a TXT record with a dnslink.");
}
return(link);
}