[Core] Implement Fetch Group Extra

Author: NoirHare

Lagrange.Core/Common/Entity/BotGroupExtra.cs

@@ -0,0 +1,6 @@
+namespace Lagrange.Core.Common.Entity;
+
+public class BotGroupExtra
+{
+    public required long LatestMessageSequence { get; set; }
+}

Lagrange.Core/Common/Interface/OperationExt.cs

@@ -24,6 +24,9 @@ public static Task<List<BotFriend>> FetchFriends(this BotContext context, bool r
     public static Task<List<BotGroup>> FetchGroups(this BotContext context, bool refresh = false) =>
         context.CacheContext.GetGroupList(refresh);
 
+    public static Task<BotGroupExtra> FetchGroupExtra(this BotContext context, long groupUin) =>
+        context.EventContext.GetLogic<OperationLogic>().FetchGroupExtra(groupUin);
+
     public static Task<List<BotGroupMember>> FetchMembers(this BotContext context, long groupUin, bool refresh = false) =>
         context.CacheContext.GetMemberList(groupUin, refresh);
 

Lagrange.Core/Internal/Events/System/FetchGroupExtraEvent.cs

@@ -0,0 +1,13 @@
+using Lagrange.Core.Common.Entity;
+
+namespace Lagrange.Core.Internal.Events.System;
+
+internal class FetchGroupExtraEventReq(long groupUin) : ProtocolEvent
+{
+    public long GroupUin { get; } = groupUin;
+}
+
+internal class FetchGroupExtraEventResp(BotGroupExtra extra) : ProtocolEvent
+{
+    public BotGroupExtra Extra { get; } = extra;
+}

Lagrange.Core/Internal/Logic/OperationLogic.cs

@@ -22,7 +22,7 @@ internal class OperationLogic(BotContext context) : ILogic
     private const string Tag = nameof(OperationLogic);
 
     public async Task<Dictionary<string, string>> FetchCookies(List<string> domains) => (await context.EventContext.SendEvent<FetchCookiesEventResp>(new FetchCookiesEventReq(domains))).Cookies;
-    
+
     public ValueTask<BotSsoPacket> SendPacket(BotSsoPacket packet, RequestType requestType, EncryptType encryptType)
     {
         int sequence = packet.Sequence != 0 ? packet.Sequence : context.ServiceContext.GetNewSequence();
@@ -88,17 +88,17 @@ public async Task<string> GroupFSDownload(long groupUin, string fileId)
         fileName = ResolveFileName(fileStream, fileName);
 
         var friend = await context.CacheContext.ResolveFriend(targetUin) ?? throw new InvalidTargetException(targetUin);
-        
+
         var buffer = ArrayPool<byte>.Shared.Rent(10002432);
         int payload = await fileStream.ReadAsync(buffer.AsMemory(0, 10002432));
         var md510m = MD5.HashData(buffer[..payload]);
         ArrayPool<byte>.Shared.Return(buffer);
         fileStream.Seek(0, SeekOrigin.Begin);
-        
+
         var request = new FileUploadEventReq(friend.Uid, fileStream, fileName, md510m);
         var result = await context.EventContext.SendEvent<FileUploadEventResp>(request);
 
-        
+
         if (!result.IsExist)
         {
             var ext = new FileUploadExt
@@ -241,6 +241,13 @@ public async Task<string> SendGroupFile(long groupUin, Stream fileStream, string
         return uploadResp.FileId;
     }
 
+    public async Task<BotGroupExtra> FetchGroupExtra(long groupUin)
+    {
+        var req = new FetchGroupExtraEventReq(groupUin);
+        var resp = await context.EventContext.SendEvent<FetchGroupExtraEventResp>(req);
+        return resp.Extra;
+    }
+
     public async Task<List<BotGroupNotificationBase>> FetchGroupNotifications(ulong count, ulong start)
     {
         var req = new FetchGroupNotificationsEventReq(count, start);

Lagrange.Core/Internal/Packets/Service/FetchGroupExtra.cs

@@ -0,0 +1,56 @@
+using Lagrange.Proto;
+
+namespace Lagrange.Core.Internal.Packets.Service;
+
+#pragma warning disable CS8618
+
+[ProtoPackable]
+internal partial class FetchGroupExtraRequest
+{
+    [ProtoMember(1)]
+    public long Random { get; set; }
+
+    [ProtoMember(2)]
+    public FetchGroupExtraRequestConfig Config { get; set; }
+}
+
+[ProtoPackable]
+internal partial class FetchGroupExtraRequestConfig
+{
+    [ProtoMember(1)]
+    public long GroupUin { get; set; }
+
+    [ProtoMember(2)]
+    public FetchGroupExtraRequestConfigFlags Flags { get; set; }
+}
+
+[ProtoPackable]
+internal partial class FetchGroupExtraRequestConfigFlags
+{
+    [ProtoMember(22)]
+    public bool LatestMessageSequence { get; set; }
+}
+
+[ProtoPackable]
+internal partial class FetchGroupExtraResponse
+{
+    [ProtoMember(1)]
+    public FetchGroupExtraResponseInfo Info { get; set; }
+}
+
+[ProtoPackable]
+internal partial class FetchGroupExtraResponseInfo
+{
+    [ProtoMember(1)]
+    public long GroupUin { get; set; }
+
+    [ProtoMember(3)]
+    public FetchGroupExtraResponseInfoResult Result { get; set; }
+}
+
+[ProtoPackable]
+internal partial class FetchGroupExtraResponseInfoResult
+{
+    [ProtoMember(22)]
+    public long LatestMessageSequence { get; set; }
+}

Lagrange.Core/Internal/Services/System/FetchGroupExtraService.cs

@@ -0,0 +1,36 @@
+using Lagrange.Core.Common;
+using Lagrange.Core.Common.Entity;
+using Lagrange.Core.Internal.Events;
+using Lagrange.Core.Internal.Events.System;
+using Lagrange.Core.Internal.Packets.Service;
+
+namespace Lagrange.Core.Internal.Services.System;
+
+[EventSubscribe<FetchGroupExtraEventReq>(Protocols.All)]
+[Service("OidbSvcTrpcTcp.0x88d_0")]
+internal class FetchGroupExtraService : OidbService<FetchGroupExtraEventReq, FetchGroupExtraEventResp, FetchGroupExtraRequest, FetchGroupExtraResponse>
+{
+    private protected override uint Command => 0x88d;
+
+    private protected override uint Service => 0;
+
+    private protected override Task<FetchGroupExtraRequest> ProcessRequest(FetchGroupExtraEventReq request, BotContext context)
+        => Task.FromResult(new FetchGroupExtraRequest
+        {
+            Random = Random.Shared.NextInt64(),
+            Config = new FetchGroupExtraRequestConfig
+            {
+                GroupUin = request.GroupUin,
+                Flags = new FetchGroupExtraRequestConfigFlags
+                {
+                    LatestMessageSequence = true,
+                }
+            }
+        });
+
+    private protected override Task<FetchGroupExtraEventResp> ProcessResponse(FetchGroupExtraResponse response, BotContext context)
+        => Task.FromResult(new FetchGroupExtraEventResp(new BotGroupExtra
+        {
+            LatestMessageSequence = response.Info.Result.LatestMessageSequence
+        }));
+}