public async IAsyncEnumerable <IMailMessage> GetMessagesAsync(EmailConfig.IncomingConfig cfg, MailQuery?query = null,
[EnumeratorCancellation] CancellationToken cancellationToken = default)
{
if (!new[] { MailProtocol.Imap, MailProtocol.Pop3 }.Contains(cfg.Protocol))
{
throw new InvalidOperationException($"Invalid email protocol: {cfg.Protocol}");
}
var container = await Policy
.Handle <SocketException>().Or <System.IO.IOException>().Or <SslHandshakeException>()
.WaitAndRetryAsync(_retryConfig.Max, _ => _retryConfig.Delay,
(exc, delay, attempt, _) => _log.LogError(exc, Message.ConnError, attempt, cfg, delay))
.ExecuteAsync(token => InitContainerAsync(_client, cfg, token), cancellationToken);
if (container == null)
{
throw new InvalidOperationException("Message container must be initialized properly");
}
var ids = await GetMessageIdsAsync(container, query?.Limit, cancellationToken);
foreach (var id in ids)
{
var message = await TryOrNull(token => GetMessageAsync(container, id, token), cancellationToken,
Message.ReceiveError, _retryConfig.Max, id, cfg.Username);
if (message == null || (!query?.AutoDelete ?? false))
{
continue;
}
_ = await TryOrNull(token => DeleteMessageAsync(container, id, token), cancellationToken,
Message.DeleteError, _retryConfig.Max, id, cfg.Username);
yield return(message.ToPort());
}
await _client.DisconnectAsync(true, cancellationToken);
}
protected override async Task <IMailFolder?> InitContainerAsync(IImapClient client, EmailConfig.IncomingConfig config, CancellationToken cancellationToken)
{
_ = await base.InitContainerAsync(client, config, cancellationToken);
var mailbox = await client.GetFolderAsync(config.MailBox, cancellationToken);
if (mailbox == null)
{
throw new InvalidOperationException(
$"Email account {config.Username} doesn't have mailbox '{config.MailBox}'");
}
_ = await mailbox.OpenAsync(FolderAccess.ReadWrite, cancellationToken);
return(mailbox);
}