/// <summary>
/// Publish requested mail content to the stream.
/// </summary>
/// <param name="cancel"></param>
/// <param name="uid"></param>
/// <returns></returns>
private async Task PublishRequestedByUidMailContent(CancellationToken cancel, string uid)
{
try
{
using (IMailStorage <MailContentEntity> storage = _mailContentStorageFactory())
{
// 1. Check if content already exists in the database.
if (storage.Exists(x => x.Uid == uid))
{
var mailContentEntity = storage.FindOne(x => x.Uid == uid);
if (mailContentEntity == null || !mailContentEntity.IsComplete)
{
// 2. If content is not yet downloaded of any reason, download it and publish afterwards.
await RunDownloadContentAsyncLoop(cancel, new List <string>() { uid });
}
else
{
_mailContentStream.OnNext(new MailContent(mailContentEntity));
}
}
}
}
catch (Exception e)
{
Logger.Error(e, "PublishRequestedByUidMailContent");
}
}
/// <summary>
/// Download MailContent for given uids.
/// </summary>
/// <param name="cancel"></param>
/// <param name="uids"></param>
/// <returns></returns>
private async Task RunDownloadContentAsyncLoop(CancellationToken cancel, List <string> uids)
{
if (uids == null || uids.Count == 0)
{
return;
}
// Create mail client.
IMailClient client = (new TrivialMailDllFactory()).Build(_serverType);
try
{
await Task.Factory.StartNew(() =>
{
client.Connect(_serverEncryption, _host);
client.Login(_user, _password);
// If is not connected or encrypted (if req) then will break and try to reconnect.
if (client.IsConnected && (_serverEncryption == MailServerEncryption.Unencrypted || client.IsEncrypted))
{
using (IMailStorage <MailContentEntity> storage = _mailContentStorageFactory())
{
foreach (var uid in uids)
{
if (string.IsNullOrWhiteSpace(uid))
{
continue;
}
if (cancel.IsCancellationRequested)
{
break;
}
var downloadRequired = true;
MailContentEntity mailContentEntity = null;
if (storage.Exists(x => x.Uid == uid))
{
mailContentEntity = storage.FindOne(x => x.Uid == uid);
if (mailContentEntity != null && mailContentEntity.IsComplete)
{
downloadRequired = false;
}
}
if (downloadRequired)
{
// 1. Insert empty MailContent with only uid set to prevent other concurrent method to download same content.
mailContentEntity = new MailContentEntity()
{
Uid = uid,
IsComplete = false
};
storage.Insert(new List <MailContentEntity>()
{
mailContentEntity
});
// 2. Download complete email.
var message = client.GetMessageByUid(uid);
// Note: MailDll documentation states that message can be null.
if (message != null)
{
IMail email = new MailBuilder().CreateFromEml(message);
if (email != null)
{
// 3. Update database with downloaded email content.
mailContentEntity = new MailContentEntity()
{
Uid = uid,
Date = email?.Date == null ? DateTime.MinValue : email.Date.Value,
Html = email.Html,
MessageId = email.MessageID,
Text = email.Text,
CustomHeader = email?.Document.Root.Headers["x-spam"],
IsComplete = true
};
storage.Update(new List <MailContentEntity>()
{
mailContentEntity
});
// Publish MailContent.
_mailContentStream.OnNext(new MailContent(mailContentEntity));
}
}
}
}
}
}
}, cancel, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);
}
catch (Exception e)
{
Logger.Error(e, $"RunDownloadContentAsync");
}
finally
{
client?.Close();
}
}