[Core] Support sending with group reaction (#659)

Co-authored-by: Decrabbityyy <[email protected]>

Lagrange.Core/Common/Entity/BotGroupReaction.cs

@@ -0,0 +1,20 @@
+namespace Lagrange.Core.Common.Entity;
+
+public class BotGroupReaction
+{
+    public string FaceId { get; set; }
+
+    public uint Type { get; set; }
+
+    public uint Count { get; set; }
+
+    public bool IsAdded { get; set; }
+
+    public BotGroupReaction(string faceId, uint type, uint count, bool isAdded)
+    {
+        FaceId = faceId;
+        Type = type;
+        Count = count;
+        IsAdded = isAdded;
+    }
+}

Lagrange.Core/Internal/Packets/Message/Element/Implementation/Extra/GroupReactionExtra.cs

@@ -0,0 +1,41 @@
+#pragma warning disable CS8618
+
+using ProtoBuf;
+
+namespace Lagrange.Core.Internal.Packets.Message.Element.Implementation.Extra;
+
+[ProtoContract]
+internal class GroupReactionExtra
+{
+    [ProtoMember(1)] public GroupReactionExtraBody Body { get; set; }
+}
+
+[ProtoContract]
+internal class GroupReactionExtraBody
+{
+    [ProtoMember(1)] public GroupReactionExtraBodyField1 Field1 { get; set; }
+
+    [ProtoMember(2)] public GroupReactionExtraFaceInfo[] FaceInfos { get; set; }
+}
+
+[ProtoContract]
+internal class GroupReactionExtraBodyField1
+{
+    [ProtoMember(1)] public uint Field1 { get; set; }
+
+    [ProtoMember(2)] public uint Field2 { get; set; }
+}
+
+[ProtoContract]
+internal class GroupReactionExtraFaceInfo
+{
+    // See Lagrange.Core/Internal/Service/System/FetchFullSysFacesService.cs
+    [ProtoMember(1)] public string FaceId { get; set; }
+
+    // See Lagrange.Core/Internal/Service/System/FetchFullSysFacesService.cs
+    [ProtoMember(2)] public uint Type { get; set; }
+
+    [ProtoMember(3)] public uint Count { get; set; }
+
+    [ProtoMember(4)] public uint IsAdded { get; set; }
+}

Lagrange.Core/Message/Entity/GroupReactionEntity.cs

@@ -0,0 +1,67 @@
+using Lagrange.Core.Common.Entity;
+using Lagrange.Core.Internal.Packets.Message.Element;
+using Lagrange.Core.Internal.Packets.Message.Element.Implementation;
+using Lagrange.Core.Internal.Packets.Message.Element.Implementation.Extra;
+using ProtoBuf;
+
+namespace Lagrange.Core.Message.Entity;
+
+[MessageElement(typeof(CommonElem))]
+public class GroupReactionEntity : IMessageEntity
+{
+    private readonly IEnumerable<BotGroupReaction> _reactions;
+
+    public GroupReactionEntity() { _reactions = Array.Empty<BotGroupReaction>(); }
+
+    public GroupReactionEntity(IEnumerable<BotGroupReaction> reactions)
+    {
+        _reactions = reactions;
+    }
+
+    IEnumerable<Elem> IMessageEntity.PackElement()
+    {
+        var infos = _reactions
+            .Select(reaction => new GroupReactionExtraFaceInfo()
+            {
+                FaceId = reaction.FaceId,
+                Type = reaction.Type,
+                Count = reaction.Count,
+                IsAdded = reaction.IsAdded ? 1u : 0u,
+            })
+            .ToArray();
+
+        var extra = new GroupReactionExtra
+        {
+            Body = new()
+            {
+                Field1 = new()
+                {
+                    Field1 = 0,
+                    Field2 = 7240
+                },
+                FaceInfos = infos,
+            }
+        };
+        using var stream = new MemoryStream();
+        Serializer.Serialize(stream, extra);
+
+        return new Elem[] {
+            new() { CommonElem = new() {
+                ServiceType = 38,
+                PbElem = stream.ToArray(),
+                BusinessType = 1
+            } }
+        };
+    }
+
+    string IMessageEntity.ToPreviewString()
+    {
+        return "";
+    }
+
+    IMessageEntity? IMessageEntity.UnpackElement(Elem elem)
+    {
+        // TODO Parase
+        return null;
+    }
+}