Refactoring HOS folder structure (#771)

* Refactoring HOS folder structure

Refactoring HOS folder structure:

- Added some subfolders when needed (Following structure decided in private).
- Added some `Types` folders when needed.
- Little cleanup here and there.
- Add services placeholders for every HOS services (close #766 and #753).

* Remove Types namespaces

12 files changed, 582 insertions, 0 deletions

diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/Friend.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/Friend.cs
new file mode 100644
index 00000000..4947a5ce
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/Friend.cs
@@ -0,0 +1,29 @@
+using Ryujinx.HLE.Utilities;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.FriendService
+{
+    [StructLayout(LayoutKind.Sequential, Pack = 0x8, Size = 0x200, CharSet = CharSet.Ansi)]
+    struct Friend
+    {
+        public UInt128 UserId;
+        public long    NetworkUserId;
+
+        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 0x21)]
+        public string Nickname;
+
+        public UserPresence presence;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsFavourite;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsNew;
+
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x6)]
+        char[] Unknown;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsValid;
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/FriendFilter.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/FriendFilter.cs
new file mode 100644
index 00000000..261bf7bf
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/FriendFilter.cs
@@ -0,0 +1,24 @@
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.FriendService
+{
+    [StructLayout(LayoutKind.Sequential)]
+    struct FriendFilter
+    {
+        public PresenceStatusFilter PresenceStatus;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsFavoriteOnly;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsSameAppPresenceOnly;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsSameAppPlayedOnly;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool IsArbitraryAppPlayedOnly;
+
+        public long PresenceGroupId;
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatus.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatus.cs
new file mode 100644
index 00000000..df2e6525
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatus.cs
@@ -0,0 +1,9 @@
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.FriendService
+{
+    enum PresenceStatus : uint
+    {
+        Offline,
+        Online,
+        OnlinePlay
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatusFilter.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatusFilter.cs
new file mode 100644
index 00000000..24da7fd3
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatusFilter.cs
@@ -0,0 +1,10 @@
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.FriendService
+{
+    enum PresenceStatusFilter : uint
+    {
+        None,
+        Online,
+        OnlinePlay,
+        OnlineOrOnlinePlay
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/UserPresence.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/UserPresence.cs
new file mode 100644
index 00000000..5fe8bfd7
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/UserPresence.cs
@@ -0,0 +1,27 @@
+using Ryujinx.HLE.Utilities;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.FriendService
+{
+    [StructLayout(LayoutKind.Sequential, Pack = 0x8, CharSet = CharSet.Ansi)]
+    struct UserPresence
+    {
+        public UInt128        UserId;
+        public long           LastTimeOnlineTimestamp;
+        public PresenceStatus Status;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool SamePresenceGroupApplication;
+
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x3)]
+        public char[] Unknown;
+
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0xC0)]
+        public char[] AppKeyValueStorage;
+
+        public override string ToString()
+        {
+            return $"UserPresence {{ UserId: {UserId}, LastTimeOnlineTimestamp: {LastTimeOnlineTimestamp}, Status: {Status}, AppKeyValueStorage: {AppKeyValueStorage} }}";
+        }
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IDaemonSuspendSessionService.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IDaemonSuspendSessionService.cs
new file mode 100644
index 00000000..42b34312
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IDaemonSuspendSessionService.cs
@@ -0,0 +1,12 @@
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator
+{
+    class IDaemonSuspendSessionService : IpcService
+    {
+        private FriendServicePermissionLevel PermissionLevel;
+
+        public IDaemonSuspendSessionService(FriendServicePermissionLevel permissionLevel)
+        {
+            PermissionLevel = permissionLevel;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IFriendService.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IFriendService.cs
new file mode 100644
index 00000000..7492c5a7
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IFriendService.cs
@@ -0,0 +1,170 @@
+using Ryujinx.Common;
+using Ryujinx.Common.Logging;
+using Ryujinx.HLE.HOS.Services.Account.Acc;
+using Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.FriendService;
+using Ryujinx.HLE.Utilities;
+using System.IO;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator
+{
+    class IFriendService : IpcService
+    {
+        private FriendServicePermissionLevel _permissionLevel;
+
+        public IFriendService(FriendServicePermissionLevel permissionLevel)
+        {
+            _permissionLevel = permissionLevel;
+        }
+
+        [Command(10100)]
+        // nn::friends::GetFriendListIds(int offset, nn::account::Uid userUUID, nn::friends::detail::ipc::SizedFriendFilter friendFilter, ulong pidPlaceHolder, pid) 
+        // -> int outCount, array<nn::account::NetworkServiceAccountId, 0xa>
+        public ResultCode GetFriendListIds(ServiceCtx context)
+        {
+            int offset = context.RequestData.ReadInt32();
+
+            // Padding
+            context.RequestData.ReadInt32();
+
+            UInt128      uuid   = context.RequestData.ReadStruct<UInt128>();
+            FriendFilter filter = context.RequestData.ReadStruct<FriendFilter>();
+
+            // Pid placeholder
+            context.RequestData.ReadInt64();
+
+            if (uuid.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            // There are no friends online, so we return 0 because the nn::account::NetworkServiceAccountId array is empty.
+            context.ResponseData.Write(0);
+
+            Logger.PrintStub(LogClass.ServiceFriend, new
+            {
+                UserId = uuid.ToString(),
+                offset,
+                filter.PresenceStatus,
+                filter.IsFavoriteOnly,
+                filter.IsSameAppPresenceOnly,
+                filter.IsSameAppPlayedOnly,
+                filter.IsArbitraryAppPlayedOnly,
+                filter.PresenceGroupId,
+            });
+
+            return ResultCode.Success;
+        }
+
+        [Command(10101)]
+        // nn::friends::GetFriendList(int offset, nn::account::Uid userUUID, nn::friends::detail::ipc::SizedFriendFilter friendFilter, ulong pidPlaceHolder, pid) 
+        // -> int outCount, array<nn::friends::detail::FriendImpl, 0x6>
+        public ResultCode GetFriendList(ServiceCtx context)
+        {
+            int offset = context.RequestData.ReadInt32();
+
+            // Padding
+            context.RequestData.ReadInt32();
+
+            UInt128      uuid   = context.RequestData.ReadStruct<UInt128>();
+            FriendFilter filter = context.RequestData.ReadStruct<FriendFilter>();
+
+            // Pid placeholder
+            context.RequestData.ReadInt64();
+
+            if (uuid.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            // There are no friends online, so we return 0 because the nn::account::NetworkServiceAccountId array is empty.
+            context.ResponseData.Write(0);
+
+            Logger.PrintStub(LogClass.ServiceFriend, new {
+                UserId = uuid.ToString(),
+                offset,
+                filter.PresenceStatus,
+                filter.IsFavoriteOnly,
+                filter.IsSameAppPresenceOnly,
+                filter.IsSameAppPlayedOnly,
+                filter.IsArbitraryAppPlayedOnly,
+                filter.PresenceGroupId,
+            });
+
+            return ResultCode.Success;
+        }
+
+        [Command(10600)]
+        // nn::friends::DeclareOpenOnlinePlaySession(nn::account::Uid)
+        public ResultCode DeclareOpenOnlinePlaySession(ServiceCtx context)
+        {
+            UInt128 uuid = context.RequestData.ReadStruct<UInt128>();
+
+            if (uuid.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            if (context.Device.System.State.Account.TryGetUser(uuid, out UserProfile profile))
+            {
+                profile.OnlinePlayState = AccountState.Open;
+            }
+
+            Logger.PrintStub(LogClass.ServiceFriend, new { UserId = uuid.ToString(), profile.OnlinePlayState });
+
+            return ResultCode.Success;
+        }
+
+        [Command(10601)]
+        // nn::friends::DeclareCloseOnlinePlaySession(nn::account::Uid)
+        public ResultCode DeclareCloseOnlinePlaySession(ServiceCtx context)
+        {
+            UInt128 uuid = context.RequestData.ReadStruct<UInt128>();
+
+            if (uuid.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            if (context.Device.System.State.Account.TryGetUser(uuid, out UserProfile profile))
+            {
+                profile.OnlinePlayState = AccountState.Closed;
+            }
+
+            Logger.PrintStub(LogClass.ServiceFriend, new { UserId = uuid.ToString(), profile.OnlinePlayState });
+
+            return ResultCode.Success;
+        }
+
+        [Command(10610)]
+        // nn::friends::UpdateUserPresence(nn::account::Uid, u64, pid, buffer<nn::friends::detail::UserPresenceImpl, 0x19>)
+        public ResultCode UpdateUserPresence(ServiceCtx context)
+        {
+            UInt128 uuid = context.RequestData.ReadStruct<UInt128>();
+
+            // Pid placeholder
+            context.RequestData.ReadInt64();
+
+            long position = context.Request.PtrBuff[0].Position;
+            long size     = context.Request.PtrBuff[0].Size;
+
+            byte[] bufferContent = context.Memory.ReadBytes(position, size);
+
+            if (uuid.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            int elementCount = bufferContent.Length / Marshal.SizeOf<UserPresence>();
+
+            using (BinaryReader bufferReader = new BinaryReader(new MemoryStream(bufferContent)))
+            {
+                UserPresence[] userPresenceInputArray = bufferReader.ReadStructArray<UserPresence>(elementCount);
+
+                Logger.PrintStub(LogClass.ServiceFriend, new { UserId = uuid.ToString(), userPresenceInputArray });
+            }
+
+            return ResultCode.Success;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/INotificationService.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/INotificationService.cs
new file mode 100644
index 00000000..1ff37442
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/INotificationService.cs
@@ -0,0 +1,175 @@
+using Ryujinx.Common;
+using Ryujinx.HLE.HOS.Ipc;
+using Ryujinx.HLE.HOS.Kernel.Common;
+using Ryujinx.HLE.HOS.Kernel.Threading;
+using Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.NotificationService;
+using Ryujinx.HLE.Utilities;
+using System;
+using System.Collections.Generic;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator
+{
+    class INotificationService : IpcService, IDisposable
+    {
+        private readonly UInt128                      _userId;
+        private readonly FriendServicePermissionLevel _permissionLevel;
+
+        private readonly object _lock = new object();
+
+        private KEvent _notificationEvent;
+        private int    _notificationEventHandle = 0;
+
+        private LinkedList<NotificationInfo> _notifications;
+
+        private bool _hasNewFriendRequest;
+        private bool _hasFriendListUpdate;
+
+        public INotificationService(ServiceCtx context, UInt128 userId, FriendServicePermissionLevel permissionLevel)
+        {
+            _userId            = userId;
+            _permissionLevel   = permissionLevel;
+            _notifications     = new LinkedList<NotificationInfo>();
+            _notificationEvent = new KEvent(context.Device.System);
+
+            _hasNewFriendRequest = false;
+            _hasFriendListUpdate = false;
+
+            NotificationEventHandler.Instance.RegisterNotificationService(this);
+        }
+
+        [Command(0)] //2.0.0+
+        // nn::friends::detail::ipc::INotificationService::GetEvent() -> handle<copy>
+        public ResultCode GetEvent(ServiceCtx context)
+        {
+            if (_notificationEventHandle == 0)
+            {
+                if (context.Process.HandleTable.GenerateHandle(_notificationEvent.ReadableEvent, out _notificationEventHandle) != KernelResult.Success)
+                {
+                    throw new InvalidOperationException("Out of handles!");
+                }
+            }
+
+            context.Response.HandleDesc = IpcHandleDesc.MakeCopy(_notificationEventHandle);
+
+            return ResultCode.Success;
+        }
+
+        [Command(1)] //2.0.0+
+        // nn::friends::detail::ipc::INotificationService::Clear()
+        public ResultCode Clear(ServiceCtx context)
+        {
+            lock (_lock)
+            {
+                _hasNewFriendRequest = false;
+                _hasFriendListUpdate = false;
+
+                _notifications.Clear();
+            }
+
+            return ResultCode.Success;
+        }
+
+        [Command(2)] // 2.0.0+
+        // nn::friends::detail::ipc::INotificationService::Pop() -> nn::friends::detail::ipc::SizedNotificationInfo
+        public ResultCode Pop(ServiceCtx context)
+        {
+            lock (_lock)
+            {
+                if (_notifications.Count >= 1)
+                {
+                    NotificationInfo notificationInfo = _notifications.First.Value;
+                    _notifications.RemoveFirst();
+
+                    if (notificationInfo.Type == NotificationEventType.FriendListUpdate)
+                    {
+                        _hasFriendListUpdate = false;
+                    }
+                    else if (notificationInfo.Type == NotificationEventType.NewFriendRequest)
+                    {
+                        _hasNewFriendRequest = false;
+                    }
+
+                    context.ResponseData.WriteStruct(notificationInfo);
+
+                    return ResultCode.Success;
+                }
+            }
+
+            return ResultCode.NotificationQueueEmpty;
+        }
+
+        public void SignalFriendListUpdate(UInt128 targetId)
+        {
+            lock (_lock)
+            {
+                if (_userId == targetId)
+                {
+                    if (!_hasFriendListUpdate)
+                    {
+                        NotificationInfo friendListNotification = new NotificationInfo();
+
+                        if (_notifications.Count != 0)
+                        {
+                            friendListNotification = _notifications.First.Value;
+                            _notifications.RemoveFirst();
+                        }
+
+                        friendListNotification.Type = NotificationEventType.FriendListUpdate;
+                        _hasFriendListUpdate = true;
+
+                        if (_hasNewFriendRequest)
+                        {
+                            NotificationInfo newFriendRequestNotification = new NotificationInfo();
+
+                            if (_notifications.Count != 0)
+                            {
+                                newFriendRequestNotification = _notifications.First.Value;
+                                _notifications.RemoveFirst();
+                            }
+
+                            newFriendRequestNotification.Type = NotificationEventType.NewFriendRequest;
+                            _notifications.AddFirst(newFriendRequestNotification);
+                        }
+
+                        // We defer this to make sure we are on top of the queue.
+                        _notifications.AddFirst(friendListNotification);
+                    }
+
+                    _notificationEvent.ReadableEvent.Signal();
+                }
+            }
+        }
+
+        public void SignalNewFriendRequest(UInt128 targetId)
+        {
+            lock (_lock)
+            {
+                if ((_permissionLevel & FriendServicePermissionLevel.OverlayMask) != 0 && _userId == targetId)
+                {
+                    if (!_hasNewFriendRequest)
+                    {
+                        if (_notifications.Count == 100)
+                        {
+                            SignalFriendListUpdate(targetId);
+                        }
+
+                        NotificationInfo newFriendRequestNotification = new NotificationInfo
+                        {
+                            Type = NotificationEventType.NewFriendRequest
+                        };
+
+                        _notifications.AddLast(newFriendRequestNotification);
+                        _hasNewFriendRequest = true;
+                    }
+
+                    _notificationEvent.ReadableEvent.Signal();
+                }
+            }
+        }
+
+        public void Dispose()
+        {
+            NotificationEventHandler.Instance.UnregisterNotificationService(this);
+        }
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/NotificationEventHandler.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/NotificationEventHandler.cs
new file mode 100644
index 00000000..19b15416
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/NotificationEventHandler.cs
@@ -0,0 +1,83 @@
+using Ryujinx.HLE.Utilities;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.NotificationService
+{
+    public sealed class NotificationEventHandler
+    {
+        private static NotificationEventHandler instance;
+        private static object                   instanceLock = new object();
+
+        private INotificationService[] _registry;
+
+        public static NotificationEventHandler Instance
+        {
+            get
+            {
+                lock (instanceLock)
+                {
+                    if (instance == null)
+                    {
+                        instance = new NotificationEventHandler();
+                    }
+
+                    return instance;
+                }
+            }
+        }
+
+        NotificationEventHandler()
+        {
+            _registry = new INotificationService[0x20];
+        }
+
+        internal void RegisterNotificationService(INotificationService service)
+        {
+            // NOTE: in case there isn't space anymore in the registry array, Nintendo doesn't return any errors.
+            for (int i = 0; i < _registry.Length; i++)
+            {
+                if (_registry[i] == null)
+                {
+                    _registry[i] = service;
+                    break;
+                }
+            }
+        }
+
+        internal void UnregisterNotificationService(INotificationService service)
+        {
+            // NOTE: in case there isn't the entry in the registry array, Nintendo doesn't return any errors.
+            for (int i = 0; i < _registry.Length; i++)
+            {
+                if (_registry[i] == service)
+                {
+                    _registry[i] = null;
+                    break;
+                }
+            }
+        }
+
+        // TODO: Use this when we will have enough things to go online.
+        public void SignalFriendListUpdate(UInt128 targetId)
+        {
+            for (int i = 0; i < _registry.Length; i++)
+            {
+                if (_registry[i] != null)
+                {
+                    _registry[i].SignalFriendListUpdate(targetId);
+                }
+            }
+        }
+
+        // TODO: Use this when we will have enough things to go online.
+        public void SignalNewFriendRequest(UInt128 targetId)
+        {
+            for (int i = 0; i < _registry.Length; i++)
+            {
+                if (_registry[i] != null)
+                {
+                    _registry[i].SignalNewFriendRequest(targetId);
+                }
+            }
+        }
+    }
+}
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationEventType.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationEventType.cs
new file mode 100644
index 00000000..5136ae8a
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationEventType.cs
@@ -0,0 +1,9 @@
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.NotificationService
+{
+    enum NotificationEventType : uint
+    {
+        Invalid          = 0x0,
+        FriendListUpdate = 0x1,
+        NewFriendRequest = 0x65
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationInfo.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationInfo.cs
new file mode 100644
index 00000000..1bd6f011
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationInfo.cs
@@ -0,0 +1,15 @@
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.NotificationService
+{
+    [StructLayout(LayoutKind.Sequential, Pack = 0x8, Size = 0x10)]
+    struct NotificationInfo
+    {
+        public NotificationEventType Type;
+
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x4)]
+        public char[] Padding;
+
+        public long NetworkUserIdPlaceholder;
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/Types/FriendServicePermissionLevel.cs b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/Types/FriendServicePermissionLevel.cs
new file mode 100644
index 00000000..9c811365
--- /dev/null
+++ b/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/Types/FriendServicePermissionLevel.cs
@@ -0,0 +1,19 @@
+using System;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator
+{
+    [Flags]
+    enum FriendServicePermissionLevel
+    {
+        UserMask    = 1,
+        OverlayMask = 2,
+        ManagerMask = 4,
+        SystemMask  = 8,
+
+        Admin   = -1,
+        User    = UserMask,
+        Overlay = UserMask | OverlayMask,
+        Manager = UserMask | OverlayMask | ManagerMask,
+        System  = UserMask | SystemMask
+    }
+}
\ No newline at end of file