Move solution and projects to src

13 files changed, 788 insertions, 0 deletions

diff --git a/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/Friend.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/Friend.cs
new file mode 100644
index 00000000..87f54bf3
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/Friend.cs
@@ -0,0 +1,29 @@
+using Ryujinx.HLE.HOS.Services.Account.Acc;
+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 UserId  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/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/FriendFilter.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/FriendFilter.cs
new file mode 100644
index 00000000..261bf7bf
--- /dev/null
+++ b/src/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/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatus.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatus.cs
new file mode 100644
index 00000000..df2e6525
--- /dev/null
+++ b/src/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/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatusFilter.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/PresenceStatusFilter.cs
new file mode 100644
index 00000000..24da7fd3
--- /dev/null
+++ b/src/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/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/UserPresence.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/UserPresence.cs
new file mode 100644
index 00000000..d36b3f31
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/FriendService/Types/UserPresence.cs
@@ -0,0 +1,34 @@
+using Ryujinx.Common.Memory;
+using Ryujinx.HLE.HOS.Services.Account.Acc;
+using System;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.FriendService
+{
+    [StructLayout(LayoutKind.Sequential, Pack = 0x8)]
+    struct UserPresence
+    {
+        public UserId         UserId;
+        public long           LastTimeOnlineTimestamp;
+        public PresenceStatus Status;
+
+        [MarshalAs(UnmanagedType.I1)]
+        public bool SamePresenceGroupApplication;
+
+        public Array3<byte> Unknown;
+        private AppKeyValueStorageHolder _appKeyValueStorage;
+
+        public Span<byte> AppKeyValueStorage => MemoryMarshal.Cast<AppKeyValueStorageHolder, byte>(MemoryMarshal.CreateSpan(ref _appKeyValueStorage, AppKeyValueStorageHolder.Size));
+
+        [StructLayout(LayoutKind.Sequential, Pack = 0x1, Size = Size)]
+        private struct AppKeyValueStorageHolder
+        {
+            public const int Size = 0xC0;
+        }
+
+        public override string ToString()
+        {
+            return $"UserPresence {{ UserId: {UserId}, LastTimeOnlineTimestamp: {LastTimeOnlineTimestamp}, Status: {Status} }}";
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IDaemonSuspendSessionService.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IDaemonSuspendSessionService.cs
new file mode 100644
index 00000000..42b34312
--- /dev/null
+++ b/src/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/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IFriendService.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IFriendService.cs
new file mode 100644
index 00000000..2858aa46
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/IFriendService.cs
@@ -0,0 +1,352 @@
+using LibHac.Ns;
+using Ryujinx.Common;
+using Ryujinx.Common.Logging;
+using Ryujinx.Common.Memory;
+using Ryujinx.Common.Utilities;
+using Ryujinx.HLE.HOS.Ipc;
+using Ryujinx.HLE.HOS.Kernel.Threading;
+using Ryujinx.HLE.HOS.Services.Account.Acc;
+using Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.FriendService;
+using Ryujinx.Horizon.Common;
+using System;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator
+{
+    class IFriendService : IpcService
+    {
+        private FriendServicePermissionLevel _permissionLevel;
+        private KEvent                       _completionEvent;
+
+        public IFriendService(FriendServicePermissionLevel permissionLevel)
+        {
+            _permissionLevel = permissionLevel;
+        }
+
+        [CommandCmif(0)]
+        // GetCompletionEvent() -> handle<copy>
+        public ResultCode GetCompletionEvent(ServiceCtx context)
+        {
+            if (_completionEvent == null)
+            {
+                _completionEvent = new KEvent(context.Device.System.KernelContext);
+            }
+
+            if (context.Process.HandleTable.GenerateHandle(_completionEvent.ReadableEvent, out int completionEventHandle) != Result.Success)
+            {
+                throw new InvalidOperationException("Out of handles!");
+            }
+
+            context.Response.HandleDesc = IpcHandleDesc.MakeCopy(completionEventHandle);
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(1)]
+        // nn::friends::Cancel()
+        public ResultCode Cancel(ServiceCtx context)
+        {
+            // TODO: Original service sets an internal field to 1 here. Determine usage.
+            Logger.Stub?.PrintStub(LogClass.ServiceFriend);
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10100)]
+        // nn::friends::GetFriendListIds(int offset, nn::account::Uid userId, 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();
+
+            UserId       userId = context.RequestData.ReadStruct<UserId>();
+            FriendFilter filter = context.RequestData.ReadStruct<FriendFilter>();
+
+            // Pid placeholder
+            context.RequestData.ReadInt64();
+
+            if (userId.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.Stub?.PrintStub(LogClass.ServiceFriend, new
+            {
+                UserId = userId.ToString(),
+                offset,
+                filter.PresenceStatus,
+                filter.IsFavoriteOnly,
+                filter.IsSameAppPresenceOnly,
+                filter.IsSameAppPlayedOnly,
+                filter.IsArbitraryAppPlayedOnly,
+                filter.PresenceGroupId,
+            });
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10101)]
+        // nn::friends::GetFriendList(int offset, nn::account::Uid userId, 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();
+
+            UserId       userId = context.RequestData.ReadStruct<UserId>();
+            FriendFilter filter = context.RequestData.ReadStruct<FriendFilter>();
+
+            // Pid placeholder
+            context.RequestData.ReadInt64();
+
+            if (userId.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.Stub?.PrintStub(LogClass.ServiceFriend, new {
+                UserId = userId.ToString(),
+                offset,
+                filter.PresenceStatus,
+                filter.IsFavoriteOnly,
+                filter.IsSameAppPresenceOnly,
+                filter.IsSameAppPlayedOnly,
+                filter.IsArbitraryAppPlayedOnly,
+                filter.PresenceGroupId,
+            });
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10120)] // 10.0.0+
+        // nn::friends::IsFriendListCacheAvailable(nn::account::Uid userId) -> bool
+        public ResultCode IsFriendListCacheAvailable(ServiceCtx context)
+        {
+            UserId userId = context.RequestData.ReadStruct<UserId>();
+
+            if (userId.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            // TODO: Service mount the friends:/ system savedata and try to load friend.cache file, returns true if exists, false otherwise.
+            // NOTE: If no cache is available, guest then calls nn::friends::EnsureFriendListAvailable, we can avoid that by faking the cache check.
+            context.ResponseData.Write(true);
+
+            // TODO: Since we don't support friend features, it's fine to stub it for now.
+            Logger.Stub?.PrintStub(LogClass.ServiceFriend, new { UserId = userId.ToString() });
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10121)] // 10.0.0+
+        // nn::friends::EnsureFriendListAvailable(nn::account::Uid userId)
+        public ResultCode EnsureFriendListAvailable(ServiceCtx context)
+        {
+            UserId userId = context.RequestData.ReadStruct<UserId>();
+
+            if (userId.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            // TODO: Service mount the friends:/ system savedata and create a friend.cache file for the given user id.
+            //       Since we don't support friend features, it's fine to stub it for now.
+            Logger.Stub?.PrintStub(LogClass.ServiceFriend, new { UserId = userId.ToString() });
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10400)]
+        // nn::friends::GetBlockedUserListIds(int offset, nn::account::Uid userId) -> (u32, buffer<nn::account::NetworkServiceAccountId, 0xa>)
+        public ResultCode GetBlockedUserListIds(ServiceCtx context)
+        {
+            int offset = context.RequestData.ReadInt32();
+
+            // Padding
+            context.RequestData.ReadInt32();
+
+            UserId userId = context.RequestData.ReadStruct<UserId>();
+
+            // There are no friends blocked, so we return 0 because the nn::account::NetworkServiceAccountId array is empty.
+            context.ResponseData.Write(0);
+
+            Logger.Stub?.PrintStub(LogClass.ServiceFriend, new { offset, UserId = userId.ToString() });
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10600)]
+        // nn::friends::DeclareOpenOnlinePlaySession(nn::account::Uid userId)
+        public ResultCode DeclareOpenOnlinePlaySession(ServiceCtx context)
+        {
+            UserId userId = context.RequestData.ReadStruct<UserId>();
+
+            if (userId.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            context.Device.System.AccountManager.OpenUserOnlinePlay(userId);
+
+            Logger.Stub?.PrintStub(LogClass.ServiceFriend, new { UserId = userId.ToString() });
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10601)]
+        // nn::friends::DeclareCloseOnlinePlaySession(nn::account::Uid userId)
+        public ResultCode DeclareCloseOnlinePlaySession(ServiceCtx context)
+        {
+            UserId userId = context.RequestData.ReadStruct<UserId>();
+
+            if (userId.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            context.Device.System.AccountManager.CloseUserOnlinePlay(userId);
+
+            Logger.Stub?.PrintStub(LogClass.ServiceFriend, new { UserId = userId.ToString() });
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10610)]
+        // nn::friends::UpdateUserPresence(nn::account::Uid, u64, pid, buffer<nn::friends::detail::UserPresenceImpl, 0x19>)
+        public ResultCode UpdateUserPresence(ServiceCtx context)
+        {
+            UserId uuid = context.RequestData.ReadStruct<UserId>();
+
+            // Pid placeholder
+            context.RequestData.ReadInt64();
+
+            ulong position = context.Request.PtrBuff[0].Position;
+            ulong size     = context.Request.PtrBuff[0].Size;
+
+            ReadOnlySpan<UserPresence> userPresenceInputArray = MemoryMarshal.Cast<byte, UserPresence>(context.Memory.GetSpan(position, (int)size));
+
+            if (uuid.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            Logger.Stub?.PrintStub(LogClass.ServiceFriend, new { UserId = uuid.ToString(), userPresenceInputArray = userPresenceInputArray.ToArray() });
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10700)]
+        // nn::friends::GetPlayHistoryRegistrationKey(b8 unknown, nn::account::Uid) -> buffer<nn::friends::PlayHistoryRegistrationKey, 0x1a>
+        public ResultCode GetPlayHistoryRegistrationKey(ServiceCtx context)
+        {
+            bool   unknownBool = context.RequestData.ReadBoolean();
+            UserId userId      = context.RequestData.ReadStruct<UserId>();
+
+            context.Response.PtrBuff[0] = context.Response.PtrBuff[0].WithSize(0x40UL);
+
+            ulong bufferPosition = context.Request.RecvListBuff[0].Position;
+
+            if (userId.IsNull)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            // NOTE: Calls nn::friends::detail::service::core::PlayHistoryManager::GetInstance and stores the instance.
+
+            byte[] randomBytes = new byte[8];
+
+            Random.Shared.NextBytes(randomBytes);
+
+            // NOTE: Calls nn::friends::detail::service::core::UuidManager::GetInstance and stores the instance.
+            //       Then call nn::friends::detail::service::core::AccountStorageManager::GetInstance and store the instance.
+            //       Then it checks if an Uuid is already stored for the UserId, if not it generates a random Uuid.
+            //       And store it in the savedata 8000000000000080 in the friends:/uid.bin file.
+
+            Array16<byte> randomGuid = new Array16<byte>();
+
+            Guid.NewGuid().ToByteArray().AsSpan().CopyTo(randomGuid.AsSpan());
+
+            PlayHistoryRegistrationKey playHistoryRegistrationKey = new PlayHistoryRegistrationKey
+            {
+                Type        = 0x101,
+                KeyIndex    = (byte)(randomBytes[0] & 7),
+                UserIdBool  = 0, // TODO: Find it.
+                UnknownBool = (byte)(unknownBool ? 1 : 0), // TODO: Find it.
+                Reserved    = new Array11<byte>(),
+                Uuid        = randomGuid
+            };
+
+            ReadOnlySpan<byte> playHistoryRegistrationKeyBuffer = SpanHelpers.AsByteSpan(ref playHistoryRegistrationKey);
+
+            /*
+
+            NOTE: The service uses the KeyIndex to get a random key from a keys buffer (since the key index is stored in the returned buffer).
+                  We currently don't support play history and online services so we can use a blank key for now.
+                  Code for reference:
+
+            byte[] hmacKey = new byte[0x20];
+
+            HMACSHA256 hmacSha256 = new HMACSHA256(hmacKey);
+            byte[]     hmacHash   = hmacSha256.ComputeHash(playHistoryRegistrationKeyBuffer);
+
+            */
+
+            context.Memory.Write(bufferPosition,        playHistoryRegistrationKeyBuffer);
+            context.Memory.Write(bufferPosition + 0x20, new byte[0x20]); // HmacHash
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(10702)]
+        // nn::friends::AddPlayHistory(nn::account::Uid, u64, pid, buffer<nn::friends::PlayHistoryRegistrationKey, 0x19>, buffer<nn::friends::InAppScreenName, 0x19>, buffer<nn::friends::InAppScreenName, 0x19>)
+        public ResultCode AddPlayHistory(ServiceCtx context)
+        {
+            UserId userId = context.RequestData.ReadStruct<UserId>();
+
+            // Pid placeholder
+            context.RequestData.ReadInt64();
+            ulong pid = context.Request.HandleDesc.PId;
+
+            ulong playHistoryRegistrationKeyPosition = context.Request.PtrBuff[0].Position;
+            ulong PlayHistoryRegistrationKeySize     = context.Request.PtrBuff[0].Size;
+
+            ulong inAppScreenName1Position = context.Request.PtrBuff[1].Position;
+            ulong inAppScreenName1Size     = context.Request.PtrBuff[1].Size;
+
+            ulong inAppScreenName2Position = context.Request.PtrBuff[2].Position;
+            ulong inAppScreenName2Size     = context.Request.PtrBuff[2].Size;
+
+            if (userId.IsNull || inAppScreenName1Size > 0x48 || inAppScreenName2Size > 0x48)
+            {
+                return ResultCode.InvalidArgument;
+            }
+
+            // TODO: Call nn::arp::GetApplicationControlProperty here when implemented.
+            ApplicationControlProperty controlProperty = context.Device.Processes.ActiveApplication.ApplicationControlProperties;
+
+            /*
+
+            NOTE: The service calls nn::friends::detail::service::core::PlayHistoryManager to store informations using the registration key computed in GetPlayHistoryRegistrationKey.
+                  Then calls nn::friends::detail::service::core::FriendListManager to update informations on the friend list.
+                  We currently don't support play history and online services so it's fine to do nothing.
+
+            */
+
+            Logger.Stub?.PrintStub(LogClass.ServiceFriend);
+
+            return ResultCode.Success;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/INotificationService.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/INotificationService.cs
new file mode 100644
index 00000000..063750c6
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/INotificationService.cs
@@ -0,0 +1,178 @@
+using Ryujinx.Common;
+using Ryujinx.HLE.HOS.Ipc;
+using Ryujinx.HLE.HOS.Kernel.Threading;
+using Ryujinx.HLE.HOS.Services.Account.Acc;
+using Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.NotificationService;
+using Ryujinx.Horizon.Common;
+using System;
+using System.Collections.Generic;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator
+{
+    class INotificationService : DisposableIpcService
+    {
+        private readonly UserId                       _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, UserId userId, FriendServicePermissionLevel permissionLevel)
+        {
+            _userId            = userId;
+            _permissionLevel   = permissionLevel;
+            _notifications     = new LinkedList<NotificationInfo>();
+            _notificationEvent = new KEvent(context.Device.System.KernelContext);
+
+            _hasNewFriendRequest = false;
+            _hasFriendListUpdate = false;
+
+            NotificationEventHandler.Instance.RegisterNotificationService(this);
+        }
+
+        [CommandCmif(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) != Result.Success)
+                {
+                    throw new InvalidOperationException("Out of handles!");
+                }
+            }
+
+            context.Response.HandleDesc = IpcHandleDesc.MakeCopy(_notificationEventHandle);
+
+            return ResultCode.Success;
+        }
+
+        [CommandCmif(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;
+        }
+
+        [CommandCmif(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(UserId 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(UserId targetId)
+        {
+            lock (_lock)
+            {
+                if ((_permissionLevel & FriendServicePermissionLevel.ViewerMask) != 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();
+                }
+            }
+        }
+
+        protected override void Dispose(bool isDisposing)
+        {
+            if (isDisposing)
+            {
+                NotificationEventHandler.Instance.UnregisterNotificationService(this);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/NotificationEventHandler.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/NotificationEventHandler.cs
new file mode 100644
index 00000000..383ad006
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/NotificationEventHandler.cs
@@ -0,0 +1,83 @@
+using Ryujinx.HLE.HOS.Services.Account.Acc;
+
+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(UserId 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(UserId targetId)
+        {
+            for (int i = 0; i < _registry.Length; i++)
+            {
+                if (_registry[i] != null)
+                {
+                    _registry[i].SignalNewFriendRequest(targetId);
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationEventType.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationEventType.cs
new file mode 100644
index 00000000..5136ae8a
--- /dev/null
+++ b/src/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/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationInfo.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationInfo.cs
new file mode 100644
index 00000000..e710bf06
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/NotificationService/Types/NotificationInfo.cs
@@ -0,0 +1,13 @@
+using Ryujinx.Common.Memory;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator.NotificationService
+{
+    [StructLayout(LayoutKind.Sequential, Size = 0x10)]
+    struct NotificationInfo
+    {
+        public NotificationEventType Type;
+        private Array4<byte> _padding;
+        public long NetworkUserIdPlaceholder;
+    }
+}
\ No newline at end of file
diff --git a/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/Types/FriendServicePermissionLevel.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/Types/FriendServicePermissionLevel.cs
new file mode 100644
index 00000000..12a3d42f
--- /dev/null
+++ b/src/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,
+        ViewerMask  = 2,
+        ManagerMask = 4,
+        SystemMask  = 8,
+
+        Administrator = -1,
+        User          = UserMask,
+        Viewer        = UserMask | ViewerMask,
+        Manager       = UserMask | ViewerMask | ManagerMask,
+        System        = UserMask | SystemMask
+    }
+}
\ No newline at end of file
diff --git a/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/Types/PlayHistoryRegistrationKey.cs b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/Types/PlayHistoryRegistrationKey.cs
new file mode 100644
index 00000000..32d962c1
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Services/Friend/ServiceCreator/Types/PlayHistoryRegistrationKey.cs
@@ -0,0 +1,16 @@
+using Ryujinx.Common.Memory;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.HLE.HOS.Services.Friend.ServiceCreator
+{
+    [StructLayout(LayoutKind.Sequential, Size = 0x20)]
+    struct PlayHistoryRegistrationKey
+    {
+        public ushort        Type;
+        public byte          KeyIndex;
+        public byte          UserIdBool;
+        public byte          UnknownBool;
+        public Array11<byte> Reserved;
+        public Array16<byte> Uuid;
+    }
+}