[OneBot] Support get group requests (#787)

Author: DarkRRb

Lagrange.Core/Common/Entity/OperationResult.cs

@@ -0,0 +1,16 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace Lagrange.Core.Common.Entity;
+
+public class OperationResult<T>
+{
+    public int Retcode { get; init; }
+
+    public string? Message { get; init; }
+
+    public T? Data { get; init; }
+
+    [MemberNotNullWhen(true, nameof(Data))]
+    [MemberNotNullWhen(false, nameof(Message))]
+    public bool IsSuccess => Retcode == 0;
+}

Lagrange.Core/Common/Interface/Api/OperationExt.cs

@@ -107,6 +107,9 @@ public static Task<bool> RecallFriendMessage(this BotContext bot, MessageChain c
     public static Task<List<BotGroupRequest>?> FetchGroupRequests(this BotContext bot)
         => bot.ContextCollection.Business.OperationLogic.FetchGroupRequests();
 
+    public static Task<OperationResult<List<BotGroupRequest>>> FetchGroupRequestsWithResults(this BotContext bot)
+        => bot.ContextCollection.Business.OperationLogic.FetchGroupRequestsWithResult();
+
     /// <summary>
     ///
     /// </summary>

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

@@ -352,11 +352,15 @@ public async Task<bool> RecallFriendMessage(MessageChain chain)
         return events.Count != 0 && ((RecallFriendMessageEvent)events[0]).ResultCode == 0;
     }
 
-    public async Task<List<BotGroupRequest>?> FetchGroupRequests()
+    public async Task<OperationResult<List<BotGroupRequest>>> FetchGroupRequestsWithResult()
     {
         var fetchRequestsEvent = FetchGroupRequestsEvent.Create();
         var events = await Collection.Business.SendEvent(fetchRequestsEvent);
-        if (events.Count == 0) return null;
+        if (events.Count == 0) return new OperationResult<List<BotGroupRequest>>
+        {
+            Retcode = -1,
+            Message = "No Events"
+        };
 
         var resolved = events.Cast<FetchGroupRequestsEvent>().SelectMany(e => e.Events).ToList();
         var results = new List<BotGroupRequest>();
@@ -385,7 +389,11 @@ public async Task<bool> RecallFriendMessage(MessageChain chain)
             ));
         }
 
-        return results;
+        return new OperationResult<List<BotGroupRequest>>
+        {
+            Retcode = 0,
+            Data = results
+        };
 
         async Task<uint> ResolveUid(string? uid)
         {
@@ -397,6 +405,8 @@ async Task<uint> ResolveUid(string? uid)
         }
     }
 
+    public async Task<List<BotGroupRequest>?> FetchGroupRequests() => (await FetchGroupRequestsWithResult()).Data;
+
     public async Task<List<BotFriendRequest>?> FetchFriendRequests()
     {
         var fetchRequestsEvent = FetchFriendsRequestsEvent.Create();

Lagrange.Core/Internal/Event/System/FetchGroupRequestsEvent.cs

@@ -5,17 +5,22 @@ namespace Lagrange.Core.Internal.Event.System;
 internal class FetchGroupRequestsEvent : ProtocolEvent
 {
     public List<RawEvent> Events { get; }
-    
+
+    public string? Message { get; }
+
     private FetchGroupRequestsEvent() : base(true) { }
 
-    private FetchGroupRequestsEvent(int resultCode, List<RawEvent> events) : base(resultCode)
+    private FetchGroupRequestsEvent(int resultCode, string? message, List<RawEvent> events) : base(resultCode)
     {
+        Message = message;
         Events = events;
     }
 
     public static FetchGroupRequestsEvent Create() => new();
-    
-    public static FetchGroupRequestsEvent Result(int resultCode, List<RawEvent> events) => new(resultCode, events);
+
+    public static FetchGroupRequestsEvent Result(List<RawEvent> events) => new(0, null, events);
+
+    public static FetchGroupRequestsEvent Result(int resultCode, string message) => new(resultCode, message, new List<RawEvent>());
 
     public record RawEvent(
         uint GroupUin,

Lagrange.Core/Internal/Service/System/FetchFilteredGroupRequestsService.cs

@@ -45,8 +45,10 @@ protected override bool Parse(Span<byte> input, BotKeystore keystore, BotAppInfo
             x.Comment,
             true
         )).ToList() ?? new List<FetchGroupRequestsEvent.RawEvent>();
-        
-        output = FetchGroupRequestsEvent.Result((int)payload.ErrorCode, events);
+
+        output = payload.ErrorCode == 0
+            ? FetchGroupRequestsEvent.Result(events)
+            : FetchGroupRequestsEvent.Result((int)payload.ErrorCode, payload.ErrorMsg);
         extraEvents = null;
         return true;
     }

Lagrange.Core/Internal/Service/System/FetchGroupRequestsService.cs

@@ -45,8 +45,10 @@ protected override bool Parse(Span<byte> input, BotKeystore keystore, BotAppInfo
             x.Comment,
             false
         )).ToList() ?? new List<FetchGroupRequestsEvent.RawEvent>();
-        
-        output = FetchGroupRequestsEvent.Result((int)payload.ErrorCode, events);
+
+        output = (payload.ErrorCode == 0)
+            ? FetchGroupRequestsEvent.Result(events)
+            : FetchGroupRequestsEvent.Result((int)payload.ErrorCode, payload.ErrorMsg);
         extraEvents = null;
         return true;
     }

Lagrange.OneBot/Core/Operation/Request/GetGroupRequestsOperation.cs

@@ -0,0 +1,40 @@
+using System.Text.Json.Nodes;
+using Lagrange.Core;
+using Lagrange.Core.Common.Interface.Api;
+using Lagrange.OneBot.Core.Entity.Action;
+using Lagrange.OneBot.Core.Entity.Notify;
+
+namespace Lagrange.OneBot.Core.Operation.Request;
+
+[Operation("get_group_requests")]
+public class GetGroupRequestsOperation : IOperation
+{
+    public async Task<OneBotResult> HandleOperation(BotContext context, JsonNode? payload)
+    {
+        var result = await context.FetchGroupRequestsWithResults();
+        if (!result.IsSuccess) return new OneBotResult(null, result.Retcode, "failed");
+
+        var requests = result.Data.Select(r =>
+            {
+                string? type = r.EventType switch
+                {
+                    Lagrange.Core.Common.Entity.BotGroupRequest.Type.GroupRequest => "add",
+                    Lagrange.Core.Common.Entity.BotGroupRequest.Type.SelfInvitation or
+                    Lagrange.Core.Common.Entity.BotGroupRequest.Type.GroupInvitation => "invite",
+                    _ => null
+                };
+                if (type == null) return null;
+
+                return new OneBotGroupRequest(
+                    context.BotUin,
+                    r.TargetMemberUin,
+                    r.GroupUin,
+                    type,
+                    r.Comment,
+                    $"{r.Sequence}-{r.GroupUin}-{(uint)r.EventType}-{Convert.ToInt32(r.IsFiltered)}"
+                );
+            })
+            .Where(r => r != null);
+        return new OneBotResult(requests, 0, "ok");
+    }
+}