Outlook sync improvements.

Wino.Core/Synchronizers/Errors/Outlook/DeltaTokenExpiredHandler.cs

@@ -0,0 +1,71 @@
+using System.Threading.Tasks;
+using Microsoft.Graph.Models.ODataErrors;
+using Microsoft.Kiota.Abstractions;
+using Serilog;
+using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Errors;
+using Wino.Core.Integration.Processors;
+
+namespace Wino.Core.Synchronizers.Errors.Outlook;
+
+/// <summary>
+/// Handles 410 Gone errors for Outlook synchronization, which indicates that delta tokens have expired.
+/// When this occurs, all local mail cache should be deleted and initial synchronization should be reset.
+/// </summary>
+public class DeltaTokenExpiredHandler : ISynchronizerErrorHandler
+{
+    private readonly ILogger _logger = Log.ForContext<DeltaTokenExpiredHandler>();
+    private readonly IOutlookChangeProcessor _outlookChangeProcessor;
+
+    public DeltaTokenExpiredHandler(IOutlookChangeProcessor outlookChangeProcessor)
+    {
+        _outlookChangeProcessor = outlookChangeProcessor;
+    }
+
+    public bool CanHandle(SynchronizerErrorContext error)
+    {
+        // Handle 410 Gone responses which indicate delta token expiration
+        return error.ErrorCode == 410 || 
+               (error.Exception is ODataError oDataError && oDataError.ResponseStatusCode == 410) ||
+               (error.Exception is ApiException apiException && apiException.ResponseStatusCode == 410);
+    }
+
+    public async Task<bool> HandleAsync(SynchronizerErrorContext error)
+    {
+        _logger.Warning("Delta token has expired for account {AccountName} ({AccountId}). Deleting all local mail cache and resetting synchronization.", 
+            error.Account.Name, error.Account.Id);
+
+        try
+        {
+            // Delete all local mail cache for the account
+            await _outlookChangeProcessor.DeleteUserMailCacheAsync(error.Account.Id).ConfigureAwait(false);
+
+            // Reset the account's delta synchronization identifier
+            await _outlookChangeProcessor.UpdateAccountDeltaSynchronizationIdentifierAsync(error.Account.Id, string.Empty).ConfigureAwait(false);
+
+            // Get all folders for the account and reset their delta tokens and initial sync status
+            var folders = await _outlookChangeProcessor.GetLocalFoldersAsync(error.Account.Id).ConfigureAwait(false);
+            
+            foreach (var folder in folders)
+            {
+                // Reset folder delta token
+                await _outlookChangeProcessor.UpdateFolderDeltaSynchronizationIdentifierAsync(folder.Id, string.Empty).ConfigureAwait(false);
+                
+                // Reset initial sync completion status to force full re-sync
+                await _outlookChangeProcessor.UpdateFolderInitialSyncCompletedAsync(folder.Id, false).ConfigureAwait(false);
+            }
+
+            _logger.Information("Successfully reset synchronization state for account {AccountName} ({AccountId}). Next sync will be a full re-sync.", 
+                error.Account.Name, error.Account.Id);
+
+            return true;
+        }
+        catch (System.Exception ex)
+        {
+            _logger.Error(ex, "Failed to handle delta token expiration for account {AccountName} ({AccountId})", 
+                error.Account.Name, error.Account.Id);
+            
+            return false;
+        }
+    }
+}