IDLE implementation, imap synchronization strategies basics and condstore synchronization.

Wino.Core.Domain/Interfaces/ICustomFolderSynchronizationRequest.cs

@@ -13,5 +13,10 @@ namespace Wino.Core.Domain.Interfaces
         /// Which folders to sync after this operation?
         /// </summary>
         List<Guid> SynchronizationFolderIds { get; }
+
+        /// <summary>
+        /// If true, additional folders like Sent, Drafts and Deleted will not be synchronized
+        /// </summary>
+        bool ExcludeMustHaveFolders { get; }
     }
 }

Wino.Core.Domain/Interfaces/IImapSynchronizationStrategyProvider.cs

@@ -0,0 +1,12 @@
+using MailKit.Net.Imap;
+
+namespace Wino.Core.Domain.Interfaces
+{
+    /// <summary>
+    /// Provides a synchronization strategy for synchronizing IMAP folders based on the server capabilities.
+    /// </summary>
+    public interface IImapSynchronizationStrategyProvider
+    {
+        IImapSynchronizerStrategy GetSynchronizationStrategy(IImapClient client);
+    }
+}

Wino.Core.Domain/Interfaces/IImapSynchronizer.cs

@@ -0,0 +1,15 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Wino.Core.Domain.Entities.Mail;
+using Wino.Core.Domain.Models.MailItem;
+
+namespace Wino.Core.Domain.Interfaces
+{
+    public interface IImapSynchronizer
+    {
+        Task<List<NewMailItemPackage>> CreateNewMailPackagesAsync(ImapMessageCreationPackage message, MailItemFolder assignedFolder, CancellationToken cancellationToken = default);
+        Task StartIdleClientAsync();
+        Task StopIdleClientAsync();
+    }
+}

Wino.Core.Domain/Interfaces/IImapSynchronizerStrategy.cs

@@ -0,0 +1,22 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using MailKit.Net.Imap;
+using Wino.Core.Domain.Entities.Mail;
+
+namespace Wino.Core.Domain.Interfaces
+{
+    public interface IImapSynchronizerStrategy
+    {
+        /// <summary>
+        /// Synchronizes given folder with the ImapClient client from the client pool.
+        /// </summary>
+        /// <param name="client">Client to perform sync with. I love Mira and Jasminka</param>
+        /// <param name="folder">Folder to synchronize.</param>
+        /// <param name="synchronizer">Imap synchronizer that downloads messages.</param>
+        /// <param name="cancellationToken">Cancellation token.</param>
+        /// <returns>List of new downloaded message ids that don't exist locally.</returns>
+        Task<List<string>> HandleSynchronizationAsync(IImapClient client, MailItemFolder folder, IImapSynchronizer synchronizer, CancellationToken cancellationToken = default);
+    }
+}
+

Wino.Core.Domain/Interfaces/IMailService.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
+using MailKit;
 using Wino.Core.Domain.Entities.Mail;
 using Wino.Core.Domain.Entities.Shared;
 using Wino.Core.Domain.Models.MailItem;
@@ -108,5 +109,13 @@ namespace Wino.Core.Domain.Interfaces
         /// <param name="draftCreationOptions">Options like new email/forward/draft.</param>
         /// <returns>Draft MailCopy and Draft MimeMessage as base64.</returns>
         Task<(MailCopy draftMailCopy, string draftBase64MimeMessage)> CreateDraftAsync(Guid accountId, DraftCreationOptions draftCreationOptions);
+
+        /// <summary>
+        /// Returns ids 
+        /// </summary>
+        /// <param name="folderId"></param>
+        /// <param name="uniqueIds"></param>
+        /// <returns></returns>
+        Task<List<MailCopy>> GetExistingMailsAsync(Guid folderId, IEnumerable<UniqueId> uniqueIds);
     }
 }