Перепиливание под чистый DDD

backend/src/Modules/Conversations/Application/Messages/Read/ReadMessagesCommandHandler.cs

@@ -0,0 +1,36 @@
+using MediatR;
+using Knot.Modules.Conversations.Domain;
+using Knot.Shared.Kernel;
+using Knot.Modules.Conversations.Application.Abstractions;
+
+namespace Knot.Modules.Conversations.Application.Messages.Read;
+
+public sealed record ReadMessagesCommand(Guid ChatId, Guid UserId, Guid LastReadMessageId, long LastReadSequenceId) : ICommand;
+
+public sealed class ReadMessagesCommandHandler : ICommandHandler<ReadMessagesCommand>
+{
+    private readonly IChatRepository _chatRepository;
+    private readonly IChatsUnitOfWork _unitOfWork;
+
+    public ReadMessagesCommandHandler(IChatRepository chatRepository, IChatsUnitOfWork unitOfWork)
+    {
+        _chatRepository = chatRepository;
+        _unitOfWork = unitOfWork;
+    }
+
+    public async Task<Result> Handle(ReadMessagesCommand request, CancellationToken cancellationToken)
+    {
+        var chat = await _chatRepository.GetByIdAsync(request.ChatId, cancellationToken);
+        if (chat == null) return Result.Failure(ChatErrors.NotFound);
+
+        var member = chat.Members.FirstOrDefault(m => m.UserId == request.UserId);
+        if (member == null) return Result.Failure(ChatErrors.NotMember);
+
+        member.UpdateReadCursor(request.LastReadMessageId, request.LastReadSequenceId);
+
+        await _unitOfWork.SaveChangesAsync(cancellationToken);
+
+        return Result.Success();
+    }
+}
+