Files
Wino-Mail/Wino.Core/Synchronizers/ImapSynchronizer.cs
2024-08-13 14:12:54 +02:00

1068 lines
46 KiB
C#

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using CommunityToolkit.Mvvm.Messaging;
using MailKit;
using MailKit.Net.Imap;
using MailKit.Search;
using MimeKit;
using MoreLinq;
using Serilog;
using Wino.Core.Domain.Entities;
using Wino.Core.Domain.Enums;
using Wino.Core.Domain.Exceptions;
using Wino.Core.Domain.Interfaces;
using Wino.Core.Domain.Models.MailItem;
using Wino.Core.Domain.Models.Synchronization;
using Wino.Core.Extensions;
using Wino.Core.Integration;
using Wino.Core.Integration.Processors;
using Wino.Core.Mime;
using Wino.Core.Requests;
using Wino.Core.Requests.Bundles;
using Wino.Messaging.Server;
namespace Wino.Core.Synchronizers
{
public class ImapSynchronizer : BaseSynchronizer<ImapRequest, ImapMessageCreationPackage>
{
private CancellationTokenSource idleDoneToken;
private CancellationTokenSource cancelInboxListeningToken;
private IMailFolder inboxFolder;
private readonly ILogger _logger = Log.ForContext<ImapSynchronizer>();
private readonly ImapClientPool _clientPool;
private readonly IImapChangeProcessor _imapChangeProcessor;
public bool IsChangeListeningActive { get; set; }
// Minimum summary items to Fetch for mail synchronization from IMAP.
private readonly MessageSummaryItems mailSynchronizationFlags =
MessageSummaryItems.Flags |
MessageSummaryItems.UniqueId |
MessageSummaryItems.ThreadId |
MessageSummaryItems.EmailId |
MessageSummaryItems.Headers |
MessageSummaryItems.PreviewText |
MessageSummaryItems.GMailThreadId |
MessageSummaryItems.References |
MessageSummaryItems.ModSeq;
/// <summary>
/// ImapClient that keeps the Inbox folder opened all the time for listening notifications.
/// </summary>
private ImapClient _inboxIdleClient;
public override uint BatchModificationSize => 1000;
public override uint InitialMessageDownloadCountPerFolder => 250;
public ImapSynchronizer(MailAccount account, IImapChangeProcessor imapChangeProcessor) : base(account)
{
_clientPool = new ImapClientPool(Account.ServerInformation);
_imapChangeProcessor = imapChangeProcessor;
}
private async Task AwaitInboxIdleAsync()
{
if (_inboxIdleClient == null)
{
_logger.Warning("InboxClient is null. Cannot send IDLE command.");
return;
}
if (inboxFolder == null)
{
_logger.Warning("Inbox folder is null. Cannot listen for changes.");
return;
}
idleDoneToken ??= new CancellationTokenSource();
cancelInboxListeningToken ??= new CancellationTokenSource();
await _clientPool.EnsureConnectedAsync(_inboxIdleClient);
await _clientPool.EnsureAuthenticatedAsync(_inboxIdleClient);
try
{
if (!inboxFolder.IsOpen)
{
await inboxFolder.OpenAsync(FolderAccess.ReadOnly, cancelInboxListeningToken.Token);
}
if (!_inboxIdleClient.IsIdle)
{
idleDoneToken = new CancellationTokenSource();
IsChangeListeningActive = true;
await _inboxIdleClient.IdleAsync(idleDoneToken.Token, cancelInboxListeningToken.Token);
}
}
catch (ImapProtocolException)
{
await ReconnectAsync();
}
catch (IOException)
{
await ReconnectAsync();
}
catch (Exception exception)
{
Logger.Error(exception, "Error occured while listening for Inbox changes.");
}
finally
{
IsChangeListeningActive = false;
}
}
private async Task ReconnectAsync()
{
await _clientPool.EnsureConnectedAsync(_inboxIdleClient);
await _clientPool.EnsureAuthenticatedAsync(_inboxIdleClient);
}
public async Task StopInboxListeningAsync()
{
if (inboxFolder != null)
{
inboxFolder.CountChanged -= InboxFolderCountChanged;
inboxFolder.MessageExpunged -= InboxFolderMessageExpunged;
inboxFolder.MessageFlagsChanged -= InboxFolderMessageFlagsChanged;
}
if (idleDoneToken != null)
{
idleDoneToken.Cancel();
idleDoneToken.Dispose();
idleDoneToken = null;
}
if (cancelInboxListeningToken != null)
{
cancelInboxListeningToken.Cancel();
cancelInboxListeningToken.Dispose();
cancelInboxListeningToken = null;
}
IsChangeListeningActive = false;
if (_inboxIdleClient != null)
{
await _inboxIdleClient.DisconnectAsync(true);
_inboxIdleClient.Dispose();
_inboxIdleClient = null;
}
}
/// <summary>
/// Tries to connect & authenticate with the given credentials.
/// Prepares synchronizer for active listening of Inbox folder.
/// </summary>
public async Task<bool> StartInboxListeningAsync()
{
_inboxIdleClient = await _clientPool.GetClientAsync();
if (!_inboxIdleClient.Capabilities.HasFlag(ImapCapabilities.Idle))
{
_logger.Information("Imap server does not support IDLE command. Listening live changes is not supported for {Name}", Account.Name);
return false;
}
inboxFolder = _inboxIdleClient.Inbox;
if (inboxFolder == null)
{
_logger.Information("Inbox folder is null. Cannot listen for changes.");
return false;
}
inboxFolder.CountChanged += InboxFolderCountChanged;
inboxFolder.MessageExpunged += InboxFolderMessageExpunged;
inboxFolder.MessageFlagsChanged += InboxFolderMessageFlagsChanged;
try
{
while (true)
{
await AwaitInboxIdleAsync();
}
}
catch (OperationCanceledException)
{
Log.Information("Listening Inbox changes for IMAP is canceled.");
}
catch (Exception ex)
{
Log.Error(ex, "Error occured while listening for Inbox changes.");
return false;
}
return true;
}
/// <summary>
/// When a change occurs in the Inbox folder, this method is called to force synchronization.
/// Quueing new sync is ignored if the synchronizer is already in a synchronization process.
/// </summary>
private void ForceInboxIdleSynchronization()
{
// Do not try to synchronize if we're already in a synchronization process.
if (State == AccountSynchronizerState.Idle)
{
var options = new SynchronizationOptions()
{
Type = SynchronizationType.Inbox,
AccountId = Account.Id
};
WeakReferenceMessenger.Default.Send(new NewSynchronizationRequested(options, SynchronizationSource.Server));
}
}
private void InboxFolderMessageFlagsChanged(object sender, MessageFlagsChangedEventArgs e)
=> ForceInboxIdleSynchronization();
private void InboxFolderMessageExpunged(object sender, MessageEventArgs e)
=> ForceInboxIdleSynchronization();
private void InboxFolderCountChanged(object sender, EventArgs e)
=> ForceInboxIdleSynchronization();
/// <summary>
/// Parses List of string of mail copy ids and return valid uIds.
/// Follow the rules for creating arbitrary unique id for mail copies.
/// </summary>
private UniqueIdSet GetUniqueIds(IEnumerable<string> mailCopyIds)
=> new(mailCopyIds.Select(a => new UniqueId(MailkitClientExtensions.ResolveUid(a))));
#region Mail Integrations
// Items are grouped before being passed to this method.
// Meaning that all items will come from and to the same folder.
// It's fine to assume that here.
public override IEnumerable<IRequestBundle<ImapRequest>> Move(BatchMoveRequest request)
{
return CreateTaskBundle(async (ImapClient client) =>
{
var uniqueIds = GetUniqueIds(request.Items.Select(a => a.Item.Id));
var sourceFolder = await client.GetFolderAsync(request.FromFolder.RemoteFolderId);
var destinationFolder = await client.GetFolderAsync(request.ToFolder.RemoteFolderId);
// Only opening source folder is enough.
await sourceFolder.OpenAsync(FolderAccess.ReadWrite).ConfigureAwait(false);
await sourceFolder.MoveToAsync(uniqueIds, destinationFolder).ConfigureAwait(false);
await sourceFolder.CloseAsync().ConfigureAwait(false);
}, request);
}
public override IEnumerable<IRequestBundle<ImapRequest>> ChangeFlag(BatchChangeFlagRequest request)
{
return CreateTaskBundle(async (ImapClient client) =>
{
var folder = request.Items.First().Item.AssignedFolder;
var remoteFolder = await client.GetFolderAsync(folder.RemoteFolderId);
var uniqueIds = GetUniqueIds(request.Items.Select(a => a.Item.Id));
await remoteFolder.OpenAsync(FolderAccess.ReadWrite).ConfigureAwait(false);
await remoteFolder.StoreAsync(uniqueIds, new StoreFlagsRequest(request.IsFlagged ? StoreAction.Add : StoreAction.Remove, MessageFlags.Flagged) { Silent = true }).ConfigureAwait(false);
await remoteFolder.CloseAsync().ConfigureAwait(false);
}, request);
}
public override IEnumerable<IRequestBundle<ImapRequest>> Delete(BatchDeleteRequest request)
{
return CreateTaskBundle(async (ImapClient client) =>
{
var folder = request.Items.First().Item.AssignedFolder;
var remoteFolder = await client.GetFolderAsync(folder.RemoteFolderId).ConfigureAwait(false);
var uniqueIds = GetUniqueIds(request.Items.Select(a => a.Item.Id));
await remoteFolder.OpenAsync(FolderAccess.ReadWrite).ConfigureAwait(false);
await remoteFolder.StoreAsync(uniqueIds, new StoreFlagsRequest(StoreAction.Add, MessageFlags.Deleted) { Silent = true }).ConfigureAwait(false);
await remoteFolder.ExpungeAsync().ConfigureAwait(false);
await remoteFolder.CloseAsync().ConfigureAwait(false);
}, request);
}
public override IEnumerable<IRequestBundle<ImapRequest>> MarkRead(BatchMarkReadRequest request)
{
return CreateTaskBundle(async (ImapClient client) =>
{
var folder = request.Items.First().Item.AssignedFolder;
var remoteFolder = await client.GetFolderAsync(folder.RemoteFolderId);
var uniqueIds = GetUniqueIds(request.Items.Select(a => a.Item.Id));
await remoteFolder.OpenAsync(FolderAccess.ReadWrite).ConfigureAwait(false);
await remoteFolder.StoreAsync(uniqueIds, new StoreFlagsRequest(request.IsRead ? StoreAction.Add : StoreAction.Remove, MessageFlags.Seen) { Silent = true }).ConfigureAwait(false);
await remoteFolder.CloseAsync().ConfigureAwait(false);
}, request);
}
public override IEnumerable<IRequestBundle<ImapRequest>> CreateDraft(BatchCreateDraftRequest request)
{
return CreateTaskBundle(async (ImapClient client) =>
{
var remoteDraftFolder = await client.GetFolderAsync(request.DraftPreperationRequest.CreatedLocalDraftCopy.AssignedFolder.RemoteFolderId).ConfigureAwait(false);
await remoteDraftFolder.OpenAsync(FolderAccess.ReadWrite).ConfigureAwait(false);
await remoteDraftFolder.AppendAsync(request.DraftPreperationRequest.CreatedLocalDraftMimeMessage, MessageFlags.Draft).ConfigureAwait(false);
await remoteDraftFolder.CloseAsync().ConfigureAwait(false);
}, request);
}
public override IEnumerable<IRequestBundle<ImapRequest>> Archive(BatchArchiveRequest request)
=> Move(new BatchMoveRequest(request.Items, request.FromFolder, request.ToFolder));
public override IEnumerable<IRequestBundle<ImapRequest>> EmptyFolder(EmptyFolderRequest request)
=> Delete(new BatchDeleteRequest(request.MailsToDelete.Select(a => new DeleteRequest(a))));
public override IEnumerable<IRequestBundle<ImapRequest>> MarkFolderAsRead(MarkFolderAsReadRequest request)
=> MarkRead(new BatchMarkReadRequest(request.MailsToMarkRead.Select(a => new MarkReadRequest(a, true)), true));
public override IEnumerable<IRequestBundle<ImapRequest>> SendDraft(BatchSendDraftRequestRequest request)
{
return CreateTaskBundle(async (ImapClient client) =>
{
// Batch sending is not supported. It will always be a single request therefore no need for a loop here.
var singleRequest = request.Request;
singleRequest.Mime.Prepare(EncodingConstraint.None);
using var smtpClient = new MailKit.Net.Smtp.SmtpClient();
if (smtpClient.IsConnected && client.IsAuthenticated) return;
if (!smtpClient.IsConnected)
await smtpClient.ConnectAsync(Account.ServerInformation.OutgoingServer, int.Parse(Account.ServerInformation.OutgoingServerPort), MailKit.Security.SecureSocketOptions.Auto);
if (!smtpClient.IsAuthenticated)
await smtpClient.AuthenticateAsync(Account.ServerInformation.OutgoingServerUsername, Account.ServerInformation.OutgoingServerPassword);
// TODO: Transfer progress implementation as popup in the UI.
await smtpClient.SendAsync(singleRequest.Mime, default);
await smtpClient.DisconnectAsync(true);
// SMTP sent the message, but we need to remove it from the Draft folder.
var draftFolder = singleRequest.MailItem.AssignedFolder;
var folder = await client.GetFolderAsync(draftFolder.RemoteFolderId);
await folder.OpenAsync(FolderAccess.ReadWrite);
var notUpdatedIds = await folder.StoreAsync(new UniqueId(MailkitClientExtensions.ResolveUid(singleRequest.MailItem.Id)), new StoreFlagsRequest(StoreAction.Add, MessageFlags.Deleted) { Silent = true });
await folder.ExpungeAsync();
await folder.CloseAsync();
// Check whether we need to create a copy of the message to Sent folder.
// This comes from the account preferences.
if (singleRequest.AccountPreferences.ShouldAppendMessagesToSentFolder && singleRequest.SentFolder != null)
{
var sentFolder = await client.GetFolderAsync(singleRequest.SentFolder.RemoteFolderId);
await sentFolder.OpenAsync(FolderAccess.ReadWrite);
// Delete local Wino draft header. Otherwise mapping will be applied on re-sync.
singleRequest.Mime.Headers.Remove(Domain.Constants.WinoLocalDraftHeader);
await sentFolder.AppendAsync(singleRequest.Mime, MessageFlags.Seen);
await sentFolder.CloseAsync();
}
}, request);
}
public override async Task DownloadMissingMimeMessageAsync(IMailItem mailItem,
ITransferProgress transferProgress = null,
CancellationToken cancellationToken = default)
{
var folder = mailItem.AssignedFolder;
var remoteFolderId = folder.RemoteFolderId;
var client = await _clientPool.GetClientAsync().ConfigureAwait(false);
var remoteFolder = await client.GetFolderAsync(remoteFolderId, cancellationToken).ConfigureAwait(false);
var uniqueId = new UniqueId(MailkitClientExtensions.ResolveUid(mailItem.Id));
await remoteFolder.OpenAsync(FolderAccess.ReadOnly, cancellationToken).ConfigureAwait(false);
var message = await remoteFolder.GetMessageAsync(uniqueId, cancellationToken, transferProgress).ConfigureAwait(false);
await _imapChangeProcessor.SaveMimeFileAsync(mailItem.FileId, message, Account.Id).ConfigureAwait(false);
await remoteFolder.CloseAsync(false, cancellationToken).ConfigureAwait(false);
_clientPool.Release(client);
}
public override IEnumerable<IRequestBundle<ImapRequest>> RenameFolder(RenameFolderRequest request)
{
return CreateTaskBundle(async (ImapClient client) =>
{
var folder = await client.GetFolderAsync(request.Folder.RemoteFolderId).ConfigureAwait(false);
await folder.RenameAsync(folder.ParentFolder, request.NewFolderName).ConfigureAwait(false);
}, request);
}
#endregion
public override async Task<List<NewMailItemPackage>> CreateNewMailPackagesAsync(ImapMessageCreationPackage message, MailItemFolder assignedFolder, CancellationToken cancellationToken = default)
{
var imapFolder = message.MailFolder;
var summary = message.MessageSummary;
var mimeMessage = await imapFolder.GetMessageAsync(summary.UniqueId, cancellationToken).ConfigureAwait(false);
var mailCopy = summary.GetMailDetails(assignedFolder, mimeMessage);
// Draft folder message updates must be updated as IsDraft.
// I couldn't find it in MimeMessage...
mailCopy.IsDraft = assignedFolder.SpecialFolderType == SpecialFolderType.Draft;
// Check draft mapping.
// This is the same implementation as in the OutlookSynchronizer.
if (mimeMessage.Headers.Contains(Domain.Constants.WinoLocalDraftHeader)
&& Guid.TryParse(mimeMessage.Headers[Domain.Constants.WinoLocalDraftHeader], out Guid localDraftCopyUniqueId))
{
// This message belongs to existing local draft copy.
// We don't need to create a new mail copy for this message, just update the existing one.
bool isMappingSuccessful = await _imapChangeProcessor.MapLocalDraftAsync(Account.Id, localDraftCopyUniqueId, mailCopy.Id, mailCopy.DraftId, mailCopy.ThreadId);
if (isMappingSuccessful) return null;
// Local copy doesn't exists. Continue execution to insert mail copy.
}
var package = new NewMailItemPackage(mailCopy, mimeMessage, assignedFolder.RemoteFolderId);
return
[
package
];
}
public override async Task<SynchronizationResult> SynchronizeInternalAsync(SynchronizationOptions options, CancellationToken cancellationToken = default)
{
var downloadedMessageIds = new List<string>();
_logger.Information("Internal synchronization started for {Name}", Account.Name);
_logger.Information("Options: {Options}", options);
PublishSynchronizationProgress(1);
bool shouldDoFolderSync = options.Type == SynchronizationType.Full || options.Type == SynchronizationType.FoldersOnly;
if (shouldDoFolderSync)
{
await SynchronizeFoldersAsync(cancellationToken).ConfigureAwait(false);
}
if (options.Type != SynchronizationType.FoldersOnly)
{
var synchronizationFolders = await _imapChangeProcessor.GetSynchronizationFoldersAsync(options).ConfigureAwait(false);
for (int i = 0; i < synchronizationFolders.Count; i++)
{
var folder = synchronizationFolders[i];
var progress = (int)Math.Round((double)(i + 1) / synchronizationFolders.Count * 100);
PublishSynchronizationProgress(progress);
var folderDownloadedMessageIds = await SynchronizeFolderInternalAsync(folder, cancellationToken).ConfigureAwait(false);
downloadedMessageIds.AddRange(folderDownloadedMessageIds);
}
}
PublishSynchronizationProgress(100);
// Get all unread new downloaded items and return in the result.
// This is primarily used in notifications.
var unreadNewItems = await _imapChangeProcessor.GetDownloadedUnreadMailsAsync(Account.Id, downloadedMessageIds).ConfigureAwait(false);
return SynchronizationResult.Completed(unreadNewItems);
}
public override async Task ExecuteNativeRequestsAsync(IEnumerable<IRequestBundle<ImapRequest>> batchedRequests, CancellationToken cancellationToken = default)
{
// First apply the UI changes for each bundle.
// This is important to reflect changes to the UI before the network call is done.
foreach (var item in batchedRequests)
{
item.Request.ApplyUIChanges();
}
// All task bundles will execute on the same client.
// Tasks themselves don't pull the client from the pool
// because exception handling is easier this way.
// Also we might parallelize these bundles later on for additional performance.
foreach (var item in batchedRequests)
{
// At this point this client is ready to execute async commands.
// Each task bundle will await and execution will continue in case of error.
ImapClient executorClient = null;
bool isCrashed = false;
try
{
executorClient = await _clientPool.GetClientAsync();
}
catch (ImapClientPoolException)
{
// Client pool failed to get a client.
// Requests may not be executed at this point.
item.Request.RevertUIChanges();
isCrashed = true;
throw;
}
finally
{
// Make sure that the client is released from the pool for next usages if error occurs.
if (isCrashed && executorClient != null)
{
_clientPool.Release(executorClient);
}
}
// TODO: Retry pattern.
// TODO: Error handling.
try
{
await item.NativeRequest.IntegratorTask(executorClient).ConfigureAwait(false);
}
catch (Exception)
{
item.Request.RevertUIChanges();
throw;
}
finally
{
_clientPool.Release(executorClient);
}
}
}
/// <summary>
/// Assigns special folder type for the given local folder.
/// If server doesn't support special folders, we can't determine the type. MailKit will throw for GetFolder.
/// Default type is Other.
/// </summary>
/// <param name="executorClient">ImapClient from the pool</param>
/// <param name="remoteFolder">Assigning remote folder.</param>
/// <param name="localFolder">Assigning local folder.</param>
private void AssignSpecialFolderType(ImapClient executorClient, IMailFolder remoteFolder, MailItemFolder localFolder)
{
// Inbox is awlawys available. Don't miss it for assignment even though XList or SpecialUser is not supported.
if (executorClient.Inbox == remoteFolder)
{
localFolder.SpecialFolderType = SpecialFolderType.Inbox;
return;
}
bool isSpecialFoldersSupported = executorClient.Capabilities.HasFlag(ImapCapabilities.SpecialUse) || executorClient.Capabilities.HasFlag(ImapCapabilities.XList);
if (!isSpecialFoldersSupported)
{
localFolder.SpecialFolderType = SpecialFolderType.Other;
return;
}
if (remoteFolder == executorClient.Inbox)
localFolder.SpecialFolderType = SpecialFolderType.Inbox;
else if (remoteFolder == executorClient.GetFolder(SpecialFolder.Drafts))
localFolder.SpecialFolderType = SpecialFolderType.Draft;
else if (remoteFolder == executorClient.GetFolder(SpecialFolder.Junk))
localFolder.SpecialFolderType = SpecialFolderType.Junk;
else if (remoteFolder == executorClient.GetFolder(SpecialFolder.Trash))
localFolder.SpecialFolderType = SpecialFolderType.Deleted;
else if (remoteFolder == executorClient.GetFolder(SpecialFolder.Sent))
localFolder.SpecialFolderType = SpecialFolderType.Sent;
else if (remoteFolder == executorClient.GetFolder(SpecialFolder.Archive))
localFolder.SpecialFolderType = SpecialFolderType.Archive;
else if (remoteFolder == executorClient.GetFolder(SpecialFolder.Important))
localFolder.SpecialFolderType = SpecialFolderType.Important;
else if (remoteFolder == executorClient.GetFolder(SpecialFolder.Flagged))
localFolder.SpecialFolderType = SpecialFolderType.Starred;
}
private async Task SynchronizeFoldersAsync(CancellationToken cancellationToken = default)
{
// https://www.rfc-editor.org/rfc/rfc4549#section-1.1
var localFolders = await _imapChangeProcessor.GetLocalFoldersAsync(Account.Id).ConfigureAwait(false);
ImapClient executorClient = null;
try
{
List<MailItemFolder> insertedFolders = new();
List<MailItemFolder> updatedFolders = new();
List<MailItemFolder> deletedFolders = new();
executorClient = await _clientPool.GetClientAsync().ConfigureAwait(false);
var remoteFolders = (await executorClient.GetFoldersAsync(executorClient.PersonalNamespaces[0], cancellationToken: cancellationToken)).ToList();
// 1. First check deleted folders.
// 1.a If local folder doesn't exists remotely, delete it.
// 1.b If local folder exists remotely, check if it is still a valid folder. If UidValidity is changed, delete it.
foreach (var localFolder in localFolders)
{
IMailFolder remoteFolder = null;
try
{
remoteFolder = remoteFolders.FirstOrDefault(a => a.FullName == localFolder.RemoteFolderId);
bool shouldDeleteLocalFolder = false;
// Check UidValidity of the remote folder if exists.
if (remoteFolder != null)
{
// UidValidity won't be available until it's opened.
await remoteFolder.OpenAsync(FolderAccess.ReadOnly, cancellationToken).ConfigureAwait(false);
shouldDeleteLocalFolder = remoteFolder.UidValidity != localFolder.UidValidity;
}
else
{
// Remote folder doesn't exist. Delete it.
shouldDeleteLocalFolder = true;
}
if (shouldDeleteLocalFolder)
{
await _imapChangeProcessor.DeleteFolderAsync(Account.Id, localFolder.RemoteFolderId).ConfigureAwait(false);
deletedFolders.Add(localFolder);
}
}
catch (Exception)
{
throw;
}
finally
{
if (remoteFolder != null)
{
await remoteFolder.CloseAsync().ConfigureAwait(false);
}
}
}
deletedFolders.ForEach(a => localFolders.Remove(a));
// 2. Get all remote folders and insert/update each of them.
var nameSpace = executorClient.PersonalNamespaces[0];
IMailFolder inbox = executorClient.Inbox;
// Sometimes Inbox is the root namespace. We need to check for that.
if (inbox != null && !remoteFolders.Contains(inbox))
remoteFolders.Add(inbox);
foreach (var remoteFolder in remoteFolders)
{
// Namespaces are not needed as folders.
// Non-existed folders don't need to be synchronized.
if ((remoteFolder.IsNamespace && !remoteFolder.Attributes.HasFlag(FolderAttributes.Inbox)) || !remoteFolder.Exists)
continue;
var existingLocalFolder = localFolders.FirstOrDefault(a => a.RemoteFolderId == remoteFolder.FullName);
if (existingLocalFolder == null)
{
// Folder doesn't exist locally. Insert it.
var localFolder = remoteFolder.GetLocalFolder();
// Check whether this is a special folder.
AssignSpecialFolderType(executorClient, remoteFolder, localFolder);
bool isSystemFolder = localFolder.SpecialFolderType != SpecialFolderType.Other;
localFolder.IsSynchronizationEnabled = isSystemFolder;
localFolder.IsSticky = isSystemFolder;
// By default, all special folders update unread count in the UI except Trash.
localFolder.ShowUnreadCount = localFolder.SpecialFolderType != SpecialFolderType.Deleted || localFolder.SpecialFolderType != SpecialFolderType.Other;
localFolder.MailAccountId = Account.Id;
// Sometimes sub folders are parented under Inbox.
// Even though this makes sense in server level, in the client it sucks.
// That will make sub folders to be parented under Inbox in the client.
// Instead, we will mark them as non-parented folders.
// This is better. Model allows personalized folder structure anyways
// even though we don't have the page/control to adjust it.
if (remoteFolder.ParentFolder == executorClient.Inbox)
localFolder.ParentRemoteFolderId = string.Empty;
// Set UidValidity for cache expiration.
// Folder must be opened for this.
await remoteFolder.OpenAsync(FolderAccess.ReadOnly, cancellationToken);
localFolder.UidValidity = remoteFolder.UidValidity;
await remoteFolder.CloseAsync(cancellationToken: cancellationToken);
insertedFolders.Add(localFolder);
}
else
{
// Update existing folder. Right now we only update the name.
// TODO: Moving folders around different parents. This is not supported right now.
// We will need more comphrensive folder update mechanism to support this.
if (ShouldUpdateFolder(remoteFolder, existingLocalFolder))
{
existingLocalFolder.FolderName = remoteFolder.Name;
updatedFolders.Add(existingLocalFolder);
}
else
{
// Remove it from the local folder list to skip additional folder updates.
localFolders.Remove(existingLocalFolder);
}
}
}
// Process changes in order-> Insert, Update. Deleted ones are already processed.
foreach (var folder in insertedFolders)
{
await _imapChangeProcessor.InsertFolderAsync(folder).ConfigureAwait(false);
}
foreach (var folder in updatedFolders)
{
await _imapChangeProcessor.UpdateFolderAsync(folder).ConfigureAwait(false);
}
}
catch (Exception ex)
{
_logger.Error(ex, "Synchronizing IMAP folders failed.");
throw;
}
finally
{
if (executorClient != null)
{
_clientPool.Release(executorClient);
}
}
}
private async Task<IEnumerable<string>> SynchronizeFolderInternalAsync(MailItemFolder folder, CancellationToken cancellationToken = default)
{
if (!folder.IsSynchronizationEnabled) return default;
var downloadedMessageIds = new List<string>();
// STEP1: Ask for flag changes for older mails.
// STEP2: Get new mail changes.
// https://www.rfc-editor.org/rfc/rfc4549 - Section 4.3
var _synchronizationClient = await _clientPool.GetClientAsync();
IMailFolder imapFolder = null;
var knownMailIds = new UniqueIdSet();
var locallyKnownMailUids = await _imapChangeProcessor.GetKnownUidsForFolderAsync(folder.Id);
knownMailIds.AddRange(locallyKnownMailUids.Select(a => new UniqueId(a)));
var highestUniqueId = Math.Max(0, locallyKnownMailUids.Count == 0 ? 0 : locallyKnownMailUids.Max());
var missingMailIds = new UniqueIdSet();
var uidValidity = folder.UidValidity;
var highestModeSeq = folder.HighestModeSeq;
var logger = Log.ForContext("FolderName", folder.FolderName);
logger.Verbose("HighestModeSeq: {HighestModeSeq}, HighestUniqueId: {HighestUniqueId}, UIDValidity: {UIDValidity}", highestModeSeq, highestUniqueId, uidValidity);
// Event handlers are placed here to handle existing MailItemFolder and IIMailFolder from MailKit.
// MailKit doesn't expose folder data when these events are emitted.
// Use local folder's UidValidty because cache might've been expired for remote IMAP folder.
// That will make our mail copy id invalid.
EventHandler<MessagesVanishedEventArgs> MessageVanishedHandler = async (s, e) =>
{
if (imapFolder == null) return;
foreach (var uniqueId in e.UniqueIds)
{
var localMailCopyId = MailkitClientExtensions.CreateUid(folder.Id, uniqueId.Id);
await _imapChangeProcessor.DeleteMailAsync(Account.Id, localMailCopyId);
}
};
EventHandler<MessageFlagsChangedEventArgs> MessageFlagsChangedHandler = async (s, e) =>
{
if (imapFolder == null) return;
var localMailCopyId = MailkitClientExtensions.CreateUid(folder.Id, e.UniqueId.Value.Id);
var isFlagged = MailkitClientExtensions.GetIsFlagged(e.Flags);
var isRead = MailkitClientExtensions.GetIsRead(e.Flags);
await _imapChangeProcessor.ChangeMailReadStatusAsync(localMailCopyId, isRead);
await _imapChangeProcessor.ChangeFlagStatusAsync(localMailCopyId, isFlagged);
};
EventHandler<MessageEventArgs> MessageExpungedHandler = async (s, e) =>
{
if (imapFolder == null) return;
if (e.UniqueId == null) return;
var localMailCopyId = MailkitClientExtensions.CreateUid(folder.Id, e.UniqueId.Value.Id);
await _imapChangeProcessor.DeleteMailAsync(Account.Id, localMailCopyId);
};
try
{
imapFolder = await _synchronizationClient.GetFolderAsync(folder.RemoteFolderId, cancellationToken);
imapFolder.MessageFlagsChanged += MessageFlagsChangedHandler;
// TODO: Bug: Enabling quick re-sync actually doesn't enable it.
var qsyncEnabled = false; // _synchronizationClient.Capabilities.HasFlag(ImapCapabilities.QuickResync);
var condStoreEnabled = _synchronizationClient.Capabilities.HasFlag(ImapCapabilities.CondStore);
if (qsyncEnabled)
{
imapFolder.MessagesVanished += MessageVanishedHandler;
await imapFolder.OpenAsync(FolderAccess.ReadWrite, uidValidity, (ulong)highestModeSeq, knownMailIds, cancellationToken);
// Check the folder validity.
// We'll delete our existing cache if it's not.
// Get all messages after the last successful synchronization date.
// This is fine for Wino synchronization because we're not really looking to
// synchronize all folder.
var allMessageIds = await imapFolder.SearchAsync(SearchQuery.All, cancellationToken);
if (uidValidity != imapFolder.UidValidity)
{
// TODO: Cache is invalid. Delete all local cache.
//await ChangeProcessor.FolderService.ClearImapFolderCacheAsync(folder.Id);
folder.UidValidity = imapFolder.UidValidity;
missingMailIds.AddRange(allMessageIds);
}
else
{
// Cache is valid.
// Add missing mails only.
missingMailIds.AddRange(allMessageIds.Except(knownMailIds).Where(a => a.Id > highestUniqueId));
}
}
else
{
// QSYNC extension is not enabled for the server.
// We rely on ConditionalStore.
imapFolder.MessageExpunged += MessageExpungedHandler;
await imapFolder.OpenAsync(FolderAccess.ReadWrite, cancellationToken);
// Get all messages after the last succesful synchronization date.
// This is fine for Wino synchronization because we're not really looking to
// synchronize all folder.
var allMessageIds = await imapFolder.SearchAsync(SearchQuery.All, cancellationToken);
if (uidValidity != imapFolder.UidValidity)
{
// TODO: Cache is invalid. Delete all local cache.
// await ChangeProcessor.FolderService.ClearImapFolderCacheAsync(folder.Id);
folder.UidValidity = imapFolder.UidValidity;
missingMailIds.AddRange(allMessageIds);
}
else
{
// Cache is valid.
var purgedMessages = knownMailIds.Except(allMessageIds);
foreach (var purgedMessage in purgedMessages)
{
var mailId = MailkitClientExtensions.CreateUid(folder.Id, purgedMessage.Id);
await _imapChangeProcessor.DeleteMailAsync(Account.Id, mailId);
}
IList<IMessageSummary> changed;
if (knownMailIds.Count > 0)
{
// CONDSTORE enabled. Fetch items with highest mode seq for known items
// to track flag changes. Otherwise just get changes without the mode seq.
if (condStoreEnabled)
changed = await imapFolder.FetchAsync(knownMailIds, (ulong)highestModeSeq, MessageSummaryItems.Flags | MessageSummaryItems.ModSeq | MessageSummaryItems.UniqueId);
else
changed = await imapFolder.FetchAsync(knownMailIds, MessageSummaryItems.Flags | MessageSummaryItems.UniqueId);
foreach (var changedItem in changed)
{
var localMailCopyId = MailkitClientExtensions.CreateUid(folder.Id, changedItem.UniqueId.Id);
var isFlagged = MailkitClientExtensions.GetIsFlagged(changedItem.Flags);
var isRead = MailkitClientExtensions.GetIsRead(changedItem.Flags);
await _imapChangeProcessor.ChangeMailReadStatusAsync(localMailCopyId, isRead);
await _imapChangeProcessor.ChangeFlagStatusAsync(localMailCopyId, isFlagged);
}
}
// We're only interested in items that has highier known uid than we fetched before.
// Others are just older messages.
missingMailIds.AddRange(allMessageIds.Except(knownMailIds).Where(a => a.Id > highestUniqueId));
}
}
// Fetch completely missing new items in the end.
// Limit check.
if (missingMailIds.Count > InitialMessageDownloadCountPerFolder)
{
missingMailIds = new UniqueIdSet(missingMailIds.TakeLast((int)InitialMessageDownloadCountPerFolder));
}
// In case of the high input, we'll batch them by 50 to reflect changes quickly.
var batchedMissingMailIds = missingMailIds.Batch(50).Select(a => new UniqueIdSet(a, SortOrder.Descending));
foreach (var batchMissingMailIds in batchedMissingMailIds)
{
var summaries = await imapFolder.FetchAsync(batchMissingMailIds, mailSynchronizationFlags, cancellationToken).ConfigureAwait(false);
foreach (var summary in summaries)
{
// We pass the opened folder and summary to retrieve raw MimeMessage.
var creationPackage = new ImapMessageCreationPackage(summary, imapFolder);
var createdMailPackages = await CreateNewMailPackagesAsync(creationPackage, folder, cancellationToken).ConfigureAwait(false);
// Local draft is mapped. We don't need to create a new mail copy.
if (createdMailPackages == null)
continue;
foreach (var mailPackage in createdMailPackages)
{
bool isCreated = await _imapChangeProcessor.CreateMailAsync(Account.Id, mailPackage).ConfigureAwait(false);
if (isCreated)
{
downloadedMessageIds.Add(mailPackage.Copy.Id);
}
}
}
}
if (folder.HighestModeSeq != (long)imapFolder.HighestModSeq)
{
folder.HighestModeSeq = (long)imapFolder.HighestModSeq;
await _imapChangeProcessor.UpdateFolderAsync(folder).ConfigureAwait(false);
}
// Update last synchronization date for the folder..
await _imapChangeProcessor.UpdateFolderLastSyncDateAsync(folder.Id).ConfigureAwait(false);
return downloadedMessageIds;
}
catch (FolderNotFoundException)
{
await _imapChangeProcessor.DeleteFolderAsync(Account.Id, folder.RemoteFolderId).ConfigureAwait(false);
return default;
}
catch (Exception)
{
throw;
}
finally
{
if (imapFolder != null)
{
imapFolder.MessageFlagsChanged -= MessageFlagsChangedHandler;
imapFolder.MessageExpunged -= MessageExpungedHandler;
imapFolder.MessagesVanished -= MessageVanishedHandler;
if (imapFolder.IsOpen)
await imapFolder.CloseAsync();
}
_clientPool.Release(_synchronizationClient);
}
}
/// <summary>
/// Whether the local folder should be updated with the remote folder.
/// IMAP only compares folder name for now.
/// </summary>
/// <param name="remoteFolder">Remote folder</param>
/// <param name="localFolder">Local folder.</param>
public bool ShouldUpdateFolder(IMailFolder remoteFolder, MailItemFolder localFolder) => remoteFolder.Name != localFolder.FolderName;
/// <summary>
/// 1. Stops active inbox listening.
/// 2. Disconnects client pool with all clients.
/// 3. Disposes everything gracefully.
///
/// Usefull for killing server scenario where nothing is needed to be connected to IMAP server anymore.
/// </summary>
public async Task KillAsync()
{
Log.Debug("Killing ImapSynchronizer for {Name}", Account.Name);
await StopInboxListeningAsync();
_clientPool.Dispose();
}
}
}