[Core] Fill in the tag and message of Offline

Lagrange.Core/Event/EventArg/BotOfflineEvent.cs

@@ -2,5 +2,13 @@ namespace Lagrange.Core.Event.EventArg;
 
 public class BotOfflineEvent : EventBase
 {
+    public string Tag { get; }
 
+    public string Message { get; }
+
+    public BotOfflineEvent(string tag, string message)
+    {
+        Tag = tag;
+        Message = message;
+    }
 }

Lagrange.Core/Internal/Context/Logic/Implementation/WtExchangeLogic.cs

@@ -44,7 +44,7 @@ public override async Task Incoming(ProtocolEvent e)
                 Collection.Log.LogFatal(Tag, "Bot will be offline in 5 seconds...");
                 await Task.Delay(5000);
 
-                Collection.Invoker.PostEvent(new BotOfflineEvent()); // TODO: Fill in the reason of offline
+                Collection.Invoker.PostEvent(new BotOfflineEvent(kick.Tag, kick.Message)); // TODO: Fill in the reason of offline
                 Collection.Scheduler.Dispose();
                 break;
         }

Lagrange.Core/Internal/Context/Uploader/FileUploader.cs

@@ -1,16 +1,23 @@
+using Lagrange.Core.Internal.Event.Message;
 using Lagrange.Core.Message;
+using Lagrange.Core.Message.Entity;
 
 namespace Lagrange.Core.Internal.Context.Uploader;
 
+[HighwayUploader(typeof(FileEntity))]
 internal class FileUploader : IHighwayUploader
 {
     public Task UploadPrivate(ContextCollection context, MessageChain chain, IMessageEntity entity)
     {
         throw new NotImplementedException();
     }
 
-    public Task UploadGroup(ContextCollection context, MessageChain chain, IMessageEntity entity)
+    public async Task UploadGroup(ContextCollection context, MessageChain chain, IMessageEntity entity)
     {
-        throw new NotImplementedException();
+        if (entity is FileEntity { FileStream: not null } file)
+        {
+            var uploadEvent = GroupFSUploadEvent.Create(chain.GroupUin ?? 0, file);
+            var result = await context.Business.SendEvent(uploadEvent);
+        }
     }
 }

Lagrange.Core/Internal/Context/Uploader/PttUploader.cs

@@ -1,9 +1,13 @@
 using Lagrange.Core.Message;
+using Lagrange.Core.Message.Entity;
 
 namespace Lagrange.Core.Internal.Context.Uploader;
 
+[HighwayUploader(typeof(RecordEntity))]
 internal class PttUploader : IHighwayUploader
 {
+    private const string Tag = nameof(PttUploader);
+
     public Task UploadPrivate(ContextCollection context, MessageChain chain, IMessageEntity entity)
     {
         throw new NotImplementedException();