public async Task Start(StatusCb status, DataCb data, ProgressCb progress, bool compression=false)
{
try
{
status("Connecting...");
if (await connect.Connect() != ConnectStatus.Ok)
throw new ConnectionFailedException();
ImapCmd cmd = null;
if (await connect.ConnectTls() == ConnectStatus.Failed)
{
cmd = CreateImap(connect.stream);
if (await cmd.Run(new StarttlsCommand()) != ReturnCode.Ok)
throw new SslFailedException();
}
cmd = CreateImap(connect.stream);
// initial Capability
await cmd.Run(new NullCommand());
// login to the server
if (await cmd.Run(new LoginCommand(user, pswd)) != ReturnCode.Ok)
throw new FailedLoginException();
status("Logged in to the email server");
// check if compression is supported
if (compression && await cmd.Run(new CapabilityCommand(new String[] { "compress=deflate" })) == ReturnCode.Ok &&
await cmd.Run(new DeflateCommand()) == ReturnCode.Ok)
{
StreamReader reader = new StreamReader(new DeflateStream(connect.stream, CompressionMode.Decompress, true));
cmd = new ImapCmd(token, reader, connect.stream, true);
status("Compression enabled");
}
// get the list of mailboxes
status("Fetching mailbox list...");
mailboxes = await GetMailboxesList(cmd,status,progress);
status("Downloading ...");
progress(0);
int processed = 0;
Regex rx_msgid = new Regex("^message-id: ([^ \r\n]+)", RegexOptions.IgnoreCase | RegexOptions.Multiline);
Func<String, String> getMsgId = (String message) =>
{
int len = message.Length > 5000 ? 5000 : message.Length;
Match m = rx_msgid.Match(message, 0, len);
return (m.Success ? m.Groups[1].Value : "");
};
foreach (Mailbox mailbox in mailboxes)
{
if (token.IsCancellationRequested)
return;
status("{0} - {1} messages: ", mailbox.name, mailbox.cnt);
if (mailbox.start < mailbox.cnt)
{
if (await cmd.Run(new SelectCommand(mailbox.name)) != ReturnCode.Ok)
throw new FailedException();
if (!GmailSpecial(mailbox.name))
{
if (await cmd.Run(new FetchCommand(FetchCommand.Fetch.Body,
async delegate (String message, String msgn)
{
mailbox.start = int.Parse(msgn);
String msgid = "";
if (host == "imap.gmail.com")
{
msgid = getMsgId(message);
messageid[msgid] = "";
}
progress((100.0 * (processed + int.Parse(msgn))) / messagesInAccount);
await data(mailbox.name, message, msgid, msgn);
}, mailbox.start)) != ReturnCode.Ok)
{
status(token.IsCancellationRequested ? "Download cancelled" : "No messages downloaded");
}
}
else
{
List<String> unique = new List<string>();
progress(0);
if (await cmd.Run(new FetchCommand(FetchCommand.Fetch.MessageID,
async delegate (String message, String msgn)
{
mailbox.start = int.Parse(msgn);
String msgid = getMsgId(message);
if (msgid != "" && messageid.ContainsKey(msgid))
return;
else
{
messageid[msgid] = "";
unique.Add(msgn);
}
progress(100.0 * int.Parse(msgn) / mailbox.cnt);
await Task.Yield();
})) != ReturnCode.Ok)
{
progress(0);
status(token.IsCancellationRequested ? "Download cancelled" : "No messages downloaded, failed to get the list of unique messages");
}
else
{
progress(0);
status("Downloading {0} out of {1}", unique.Count, mailbox.cnt);
status("{0} - {1} messages: ", mailbox.name, unique.Count);
int downloaded = 0;
foreach (String n in unique)
{
int num = int.Parse(n);
if (await cmd.Run(new FetchCommand(FetchCommand.Fetch.Body,
async delegate (String message, String msgn)
{
progress((100.0 * (processed + int.Parse(msgn))) / messagesInAccount);
await data(mailbox.name, message, getMsgId(message), msgn);
downloaded++;
}, num, num)) != ReturnCode.Ok)
{
status("failed to download {0}", n);
continue;
}
}
if (token.IsCancellationRequested)
status("Download cancelled");
if (unique.Count != downloaded)
status("{0} out of {1} failed to download", unique.Count-downloaded, unique.Count);
}
}
}
processed += mailbox.cnt;
mailbox.start = mailbox.cnt;
}
status("Download complete");
}
finally
{
connect.Close();
}
}
async Task<List<Mailbox>> GetMailboxesList(ImapCmd cmd, StatusCb status, ProgressCb progress)
{
List<Mailbox> mailboxes = new List<Mailbox>();
if (await cmd.Run(new ListCommand(async delegate (String mailbox, String ctx)
{ await Task.Yield(); mailboxes.Add(new Mailbox(mailbox)); })) != ReturnCode.Ok)
throw new FailedException();
mailboxes.Sort((Mailbox m1, Mailbox m2) => {
bool g1 = GmailSpecial(m1.name);
bool g2 = GmailSpecial(m2.name);
if (g1 && g2)
return String.Compare(m2.name, m1.name); // reverse
else if (g1)
return 1;
else if (g2)
return -1;
else
return String.Compare(m1.name, m2.name);
});
for (int i = 0; i < mailboxes.Count; i++)
{
await cmd.Run(new StatusCommand(mailboxes[i].name, async delegate (String cnt, String ctx)
{
await Task.Yield();
status("{0} - {1}", mailboxes[i].name, cnt);
mailboxes[i].cnt = int.Parse(cnt);
messagesInAccount += int.Parse(cnt);
}));
}
status("Total messages: {0}", messagesInAccount);
Dictionary<String, int> downloaded = await CheckResume(status, progress);
foreach (String mbox in downloaded.Keys)
{
mailboxes.ForEach((Mailbox m) => {
if (m.name == mbox)
m.start = downloaded[mbox] > 0 ? downloaded[mbox] : 1;
});
}
return mailboxes;
}