ReboundEmulator/Core/Rooms/IGameRoom.cs

namespace NotPogo.Core.Rooms
{
    public interface IGameRoom
    {
        Task OnPlayerJoinedAsync(Room room, Player player);
        Task OnPlayerLeftAsync(Room room, Player player);
        Task<bool> OnMessageAsync(Room room, Player player, string op, Dictionary<string, string> msg);
        Task OnGameJoinAsync(Room room, Player player);
    }

    public sealed class ChatOnlyRoom : IGameRoom
    {
        public Task<bool> OnMessageAsync(Room room, Player player, string op, Dictionary<string, string> msg) => Task.FromResult(false);
        public Task OnPlayerJoinedAsync(Room room, Player player) => Task.CompletedTask;
        public Task OnPlayerLeftAsync(Room room, Player player) => Task.CompletedTask;
        public Task OnGameJoinAsync(Room room, Player player) => Task.CompletedTask;
    }
}