Refactoring mail collection class.

Wino.Mail.ViewModels/Collections/ThreadingManager.cs

@@ -0,0 +1,31 @@
+using Wino.Core.Domain.Entities.Mail;
+using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.MailItem;
+
+namespace Wino.Mail.ViewModels.Collections;
+
+internal class ThreadingManager
+{
+    private readonly IThreadingStrategyProvider _threadingStrategyProvider;
+
+    public ThreadingManager(IThreadingStrategyProvider threadingStrategyProvider)
+    {
+        _threadingStrategyProvider = threadingStrategyProvider;
+    }
+
+    public bool ShouldThread(MailCopy newItem, IMailItem existingItem)
+    {
+        if (_threadingStrategyProvider == null) return false;
+
+        var strategy = _threadingStrategyProvider.GetStrategy(newItem.AssignedAccount.ProviderType);
+        return strategy?.ShouldThreadWithItem(newItem, existingItem) ?? false;
+    }
+
+    public ThreadMailItem CreateNewThread(IMailItem existingItem, MailCopy newItem)
+    {
+        var thread = new ThreadMailItem();
+        thread.AddThreadItem(existingItem);
+        thread.AddThreadItem(newItem);
+        return thread;
+    }
+}