Better support for user accounts (#349)

* Better support for user accounts

* Nits

* Check for invalid ids

25 files changed, 314 insertions, 136 deletions

diff --git a/Ryujinx.HLE/OsHle/Horizon.cs b/Ryujinx.HLE/OsHle/Horizon.cs
index f12bf37d..b4c7d36e 100644
--- a/Ryujinx.HLE/OsHle/Horizon.cs
+++ b/Ryujinx.HLE/OsHle/Horizon.cs
@@ -2,6 +2,7 @@ using Ryujinx.HLE.Loaders.Executables;
 using Ryujinx.HLE.Loaders.Npdm;
 using Ryujinx.HLE.Logging;
 using Ryujinx.HLE.OsHle.Handles;
+using Ryujinx.HLE.OsHle.SystemState;
 using System;
 using System.Collections.Concurrent;
 using System.IO;
diff --git a/Ryujinx.HLE/OsHle/Kernel/SvcSystem.cs b/Ryujinx.HLE/OsHle/Kernel/SvcSystem.cs
index a968a1db..08305522 100644
--- a/Ryujinx.HLE/OsHle/Kernel/SvcSystem.cs
+++ b/Ryujinx.HLE/OsHle/Kernel/SvcSystem.cs
@@ -242,6 +242,7 @@ namespace Ryujinx.HLE.OsHle.Kernel
                 Process.Scheduler.Suspend(CurrThread);
 
                 IpcMessage Cmd = new IpcMessage(CmdData, CmdPtr);
+
                 long Result = IpcHandler.IpcCall(Ns, Process, Memory, Session, Cmd, CmdPtr);
 
                 Thread.Yield();
diff --git a/Ryujinx.HLE/OsHle/Process.cs b/Ryujinx.HLE/OsHle/Process.cs
index ac5ed456..6cbc0860 100644
--- a/Ryujinx.HLE/OsHle/Process.cs
+++ b/Ryujinx.HLE/OsHle/Process.cs
@@ -11,6 +11,7 @@ using Ryujinx.HLE.OsHle.Exceptions;
 using Ryujinx.HLE.OsHle.Handles;
 using Ryujinx.HLE.OsHle.Kernel;
 using Ryujinx.HLE.OsHle.Services.Nv;
+using Ryujinx.HLE.OsHle.SystemState;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
diff --git a/Ryujinx.HLE/OsHle/Profile.cs b/Ryujinx.HLE/OsHle/Profile.cs
deleted file mode 100644
index 80b4487b..00000000
--- a/Ryujinx.HLE/OsHle/Profile.cs
+++ /dev/null
@@ -1,8 +0,0 @@
-namespace Ryujinx.HLE.OsHle
-{
-    public struct Profile
-    {
-        public string Username;
-        public string UserId;
-    }
-}
diff --git a/Ryujinx.HLE/OsHle/Services/Acc/AccErr.cs b/Ryujinx.HLE/OsHle/Services/Acc/AccErr.cs
new file mode 100644
index 00000000..5daef1aa
--- /dev/null
+++ b/Ryujinx.HLE/OsHle/Services/Acc/AccErr.cs
@@ -0,0 +1,7 @@
+namespace Ryujinx.HLE.OsHle.Services.Acc
+{
+    static class AccErr
+    {
+        public const int UserNotFound = 100;
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/OsHle/Services/Acc/IAccountServiceForApplication.cs b/Ryujinx.HLE/OsHle/Services/Acc/IAccountServiceForApplication.cs
index 35c4cd82..34376a7b 100644
--- a/Ryujinx.HLE/OsHle/Services/Acc/IAccountServiceForApplication.cs
+++ b/Ryujinx.HLE/OsHle/Services/Acc/IAccountServiceForApplication.cs
@@ -1,7 +1,11 @@
+using ChocolArm64.Memory;
 using Ryujinx.HLE.Logging;
 using Ryujinx.HLE.OsHle.Ipc;
+using Ryujinx.HLE.OsHle.SystemState;
 using System.Collections.Generic;
 
+using static Ryujinx.HLE.OsHle.ErrorCode;
+
 namespace Ryujinx.HLE.OsHle.Services.Acc
 {
     class IAccountServiceForApplication : IpcService
@@ -27,49 +31,80 @@ namespace Ryujinx.HLE.OsHle.Services.Acc
 
         public long GetUserCount(ServiceCtx Context)
         {
-            Context.ResponseData.Write(0);
-
-            Context.Ns.Log.PrintStub(LogClass.ServiceAcc, "Stubbed.");
+            Context.ResponseData.Write(Context.Ns.Os.SystemState.GetUserCount());
 
             return 0;
         }
 
         public long GetUserExistence(ServiceCtx Context)
         {
-            Context.ResponseData.Write(1);
+            UserId Uuid = new UserId(
+                Context.RequestData.ReadInt64(),
+                Context.RequestData.ReadInt64());
 
-            Context.Ns.Log.PrintStub(LogClass.ServiceAcc, "Stubbed.");
+            Context.ResponseData.Write(Context.Ns.Os.SystemState.TryGetUser(Uuid, out _) ? 1 : 0);
 
             return 0;
         }
 
         public long ListAllUsers(ServiceCtx Context)
         {
-            Context.Ns.Log.PrintStub(LogClass.ServiceAcc, "Stubbed.");
-
-            return 0;
+            return WriteUserList(Context, Context.Ns.Os.SystemState.GetAllUsers());
         }
 
         public long ListOpenUsers(ServiceCtx Context)
         {
-            Context.Ns.Log.PrintStub(LogClass.ServiceAcc, "Stubbed.");
+            return WriteUserList(Context, Context.Ns.Os.SystemState.GetOpenUsers());
+        }
+
+        private long WriteUserList(ServiceCtx Context, IEnumerable<UserProfile> Profiles)
+        {
+            long OutputPosition = Context.Request.RecvListBuff[0].Position;
+            long OutputSize     = Context.Request.RecvListBuff[0].Size;
+
+            long Offset = 0;
+
+            foreach (UserProfile Profile in Profiles)
+            {
+                if ((ulong)Offset + 16 > (ulong)OutputSize)
+                {
+                    break;
+                }
+
+                byte[] Uuid = Profile.Uuid.Bytes;
+
+                for (int Index = Uuid.Length - 1; Index >= 0; Index--)
+                {
+                    Context.Memory.WriteByte(OutputPosition + Offset++, Uuid[Index]);
+                }
+            }
 
             return 0;
         }
 
         public long GetLastOpenedUser(ServiceCtx Context)
         {
-            Context.ResponseData.Write(1L);
-            Context.ResponseData.Write(0L);
+            UserProfile LastOpened = Context.Ns.Os.SystemState.LastOpenUser;
 
-            Context.Ns.Log.PrintStub(LogClass.ServiceAcc, "Stubbed.");
+            LastOpened.Uuid.Write(Context.ResponseData);
 
             return 0;
         }
 
         public long GetProfile(ServiceCtx Context)
         {
-            MakeObject(Context, new IProfile());
+            UserId Uuid = new UserId(
+                Context.RequestData.ReadInt64(),
+                Context.RequestData.ReadInt64());
+
+            if (!Context.Ns.Os.SystemState.TryGetUser(Uuid, out UserProfile Profile))
+            {
+                Context.Ns.Log.PrintWarning(LogClass.ServiceAcc, $"User 0x{Uuid} not found!");
+
+                return MakeError(ErrorModule.Account, AccErr.UserNotFound);
+            }
+
+            MakeObject(Context, new IProfile(Profile));
 
             return 0;
         }
diff --git a/Ryujinx.HLE/OsHle/Services/Acc/IProfile.cs b/Ryujinx.HLE/OsHle/Services/Acc/IProfile.cs
index 0639b09c..bb1e885e 100644
--- a/Ryujinx.HLE/OsHle/Services/Acc/IProfile.cs
+++ b/Ryujinx.HLE/OsHle/Services/Acc/IProfile.cs
@@ -1,6 +1,7 @@
 using ChocolArm64.Memory;
 using Ryujinx.HLE.Logging;
 using Ryujinx.HLE.OsHle.Ipc;
+using Ryujinx.HLE.OsHle.SystemState;
 using Ryujinx.HLE.OsHle.Utilities;
 using System.Collections.Generic;
 using System.Text;
@@ -13,13 +14,17 @@ namespace Ryujinx.HLE.OsHle.Services.Acc
 
         public override IReadOnlyDictionary<int, ServiceProcessRequest> Commands => m_Commands;
 
-        public IProfile()
+        private UserProfile Profile;
+
+        public IProfile(UserProfile Profile)
         {
             m_Commands = new Dictionary<int, ServiceProcessRequest>()
             {
                 { 0, Get     },
                 { 1, GetBase }
             };
+
+            this.Profile = Profile;
         }
 
         public long Get(ServiceCtx Context)
@@ -32,20 +37,18 @@ namespace Ryujinx.HLE.OsHle.Services.Acc
 
             Context.Memory.WriteInt32(Position, 0);
             Context.Memory.WriteInt32(Position + 4, 1);
-            Context.Memory.WriteByte(Position + 8, 1);
+            Context.Memory.WriteInt64(Position + 8, 1);
 
             return GetBase(Context);
         }
 
         public long GetBase(ServiceCtx Context)
         {
-            ProfileBase ProfileBase = new ProfileBase(Context.Ns.Settings.User);
+            Profile.Uuid.Write(Context.ResponseData);
 
-            Context.ResponseData.Write(ProfileBase.UserId.ToBytes());
-            Context.ResponseData.Write(ProfileBase.Timestamp);
+            Context.ResponseData.Write(Profile.LastModifiedTimestamp);
 
-            int    ByteCount = Encoding.UTF8.GetByteCount(ProfileBase.Username);
-            byte[] Username  = StringUtils.GetFixedLengthBytes(ProfileBase.Username, 0x20, Encoding.UTF8);
+            byte[] Username = StringUtils.GetFixedLengthBytes(Profile.Name, 0x20, Encoding.UTF8);
 
             Context.ResponseData.Write(Username);
 
diff --git a/Ryujinx.HLE/OsHle/Services/Acc/ProfileBase.cs b/Ryujinx.HLE/OsHle/Services/Acc/ProfileBase.cs
deleted file mode 100644
index 69914a86..00000000
--- a/Ryujinx.HLE/OsHle/Services/Acc/ProfileBase.cs
+++ /dev/null
@@ -1,52 +0,0 @@
-using Ryujinx.HLE.OsHle.Utilities;
-using System;
-using System.Linq;
-
-namespace Ryujinx.HLE.OsHle.Services.Acc
-{
-    struct ProfileBase
-    {
-        public UserId UserId;
-        public long   Timestamp;
-        public string Username;
-
-        public ProfileBase(Profile User)
-        {
-            UserId    = new UserId(User.UserId);
-            Username  = User.Username;
-            Timestamp = ((DateTimeOffset)DateTime.Today).ToUnixTimeSeconds();
-        }
-    }
-
-    struct UserId
-    {
-        private readonly ulong LowBytes;
-        private readonly ulong HighBytes;
-
-        public UserId(string UserIdHex)
-        {
-            if (UserIdHex == null || UserIdHex.Length != 32 || !UserIdHex.All("0123456789abcdefABCDEF".Contains))
-            {
-                throw new ArgumentException("UserId is not a valid Hex string", "UserIdHex");
-            }
-
-            byte[] HexBytes = StringUtils.HexToBytes(UserIdHex);
-
-            LowBytes = BitConverter.ToUInt64(HexBytes, 8);
-
-            Array.Resize(ref HexBytes, 8);
-
-            HighBytes = BitConverter.ToUInt64(HexBytes, 0);
-        }
-
-        public byte[] ToBytes()
-        {
-            return BitConverter.GetBytes(HighBytes).Concat(BitConverter.GetBytes(LowBytes)).ToArray();
-        }
-
-        public override string ToString()
-        {
-            return BitConverter.ToString(ToBytes()).ToLower().Replace("-", string.Empty);
-        }
-    }
-}
diff --git a/Ryujinx.HLE/OsHle/Services/Am/ICommonStateGetter.cs b/Ryujinx.HLE/OsHle/Services/Am/ICommonStateGetter.cs
index 3276f066..2d04151c 100644
--- a/Ryujinx.HLE/OsHle/Services/Am/ICommonStateGetter.cs
+++ b/Ryujinx.HLE/OsHle/Services/Am/ICommonStateGetter.cs
@@ -3,7 +3,6 @@ using Ryujinx.HLE.OsHle.Handles;
 using Ryujinx.HLE.OsHle.Ipc;
 using System.Collections.Generic;
 
-using static Ryujinx.HLE.OsHle.SystemStateMgr;
 using static Ryujinx.HLE.OsHle.ErrorCode;
 
 namespace Ryujinx.HLE.OsHle.Services.Am
@@ -58,7 +57,9 @@ namespace Ryujinx.HLE.OsHle.Services.Am
 
         public long GetOperationMode(ServiceCtx Context)
         {
-            OperationMode Mode = DockedMode ? OperationMode.Docked : OperationMode.Handheld;
+            OperationMode Mode = Context.Ns.Os.SystemState.DockedMode
+                ? OperationMode.Docked
+                : OperationMode.Handheld;
 
             Context.ResponseData.Write((byte)Mode);
 
@@ -67,7 +68,9 @@ namespace Ryujinx.HLE.OsHle.Services.Am
 
         public long GetPerformanceMode(ServiceCtx Context)
         {
-            Apm.PerformanceMode Mode = DockedMode ? Apm.PerformanceMode.Docked : Apm.PerformanceMode.Handheld;
+            Apm.PerformanceMode Mode = Context.Ns.Os.SystemState.DockedMode
+                ? Apm.PerformanceMode.Docked
+                : Apm.PerformanceMode.Handheld;
 
             Context.ResponseData.Write((int)Mode);
 
diff --git a/Ryujinx.HLE/OsHle/Services/Aud/IAudioDevice.cs b/Ryujinx.HLE/OsHle/Services/Aud/IAudioDevice.cs
index 67c0d837..cc5fc244 100644
--- a/Ryujinx.HLE/OsHle/Services/Aud/IAudioDevice.cs
+++ b/Ryujinx.HLE/OsHle/Services/Aud/IAudioDevice.cs
@@ -1,6 +1,7 @@
 using Ryujinx.HLE.Logging;
 using Ryujinx.HLE.OsHle.Handles;
 using Ryujinx.HLE.OsHle.Ipc;
+using Ryujinx.HLE.OsHle.SystemState;
 using System.Collections.Generic;
 using System.Text;
 
diff --git a/Ryujinx.HLE/OsHle/Services/Friend/IFriendService.cs b/Ryujinx.HLE/OsHle/Services/Friend/IFriendService.cs
index d5843ffb..e241138f 100644
--- a/Ryujinx.HLE/OsHle/Services/Friend/IFriendService.cs
+++ b/Ryujinx.HLE/OsHle/Services/Friend/IFriendService.cs
@@ -1,4 +1,6 @@
+using Ryujinx.HLE.Logging;
 using Ryujinx.HLE.OsHle.Ipc;
+using Ryujinx.HLE.OsHle.SystemState;
 using System.Collections.Generic;
 
 namespace Ryujinx.HLE.OsHle.Services.Friend
@@ -13,8 +15,35 @@ namespace Ryujinx.HLE.OsHle.Services.Friend
         {
             m_Commands = new Dictionary<int, ServiceProcessRequest>()
             {
-                //...
+                { 10601, DeclareCloseOnlinePlaySession },
+                { 10610, UpdateUserPresence            }
             };
         }
+
+        public long DeclareCloseOnlinePlaySession(ServiceCtx Context)
+        {
+            UserId Uuid = new UserId(
+                Context.RequestData.ReadInt64(),
+                Context.RequestData.ReadInt64());
+
+            if (Context.Ns.Os.SystemState.TryGetUser(Uuid, out UserProfile Profile))
+            {
+                Profile.OnlinePlayState = OpenCloseState.Closed;
+            }
+
+            return 0;
+        }
+
+        public long UpdateUserPresence(ServiceCtx Context)
+        {
+            UserId Uuid = new UserId(
+                Context.RequestData.ReadInt64(),
+                Context.RequestData.ReadInt64());
+
+            //TODO.
+            Context.Ns.Log.PrintStub(LogClass.ServiceFriend, "Stubbed.");
+
+            return 0;
+        }
     }
 }
\ No newline at end of file
diff --git a/Ryujinx.HLE/OsHle/Services/Set/ISettingsServer.cs b/Ryujinx.HLE/OsHle/Services/Set/ISettingsServer.cs
index 5c4f8267..0feccfa2 100644
--- a/Ryujinx.HLE/OsHle/Services/Set/ISettingsServer.cs
+++ b/Ryujinx.HLE/OsHle/Services/Set/ISettingsServer.cs
@@ -1,4 +1,5 @@
 using Ryujinx.HLE.OsHle.Ipc;
+using Ryujinx.HLE.OsHle.SystemState;
 using System.Collections.Generic;
 
 namespace Ryujinx.HLE.OsHle.Services.Set
diff --git a/Ryujinx.HLE/OsHle/Services/Set/ISystemSettingsServer.cs b/Ryujinx.HLE/OsHle/Services/Set/ISystemSettingsServer.cs
index 6a3ea537..ef083e4c 100644
--- a/Ryujinx.HLE/OsHle/Services/Set/ISystemSettingsServer.cs
+++ b/Ryujinx.HLE/OsHle/Services/Set/ISystemSettingsServer.cs
@@ -1,5 +1,5 @@
 using Ryujinx.HLE.OsHle.Ipc;
-using Ryujinx.HLE.Settings;
+using Ryujinx.HLE.OsHle.SystemState;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -75,7 +75,7 @@ namespace Ryujinx.HLE.OsHle.Services.Set
 
         public static long GetColorSetId(ServiceCtx Context)
         {
-            Context.ResponseData.Write((int)Context.Ns.Settings.ThemeColor);
+            Context.ResponseData.Write((int)Context.Ns.Os.SystemState.ThemeColor);
 
             return 0;
         }
@@ -84,7 +84,8 @@ namespace Ryujinx.HLE.OsHle.Services.Set
         {
             int ColorSetId = Context.RequestData.ReadInt32();
 
-            Context.Ns.Settings.ThemeColor = (ColorSet)ColorSetId;
+            Context.Ns.Os.SystemState.ThemeColor = (ColorSet)ColorSetId;
+
             return 0;
         }
 
@@ -121,6 +122,7 @@ namespace Ryujinx.HLE.OsHle.Services.Set
                         SettingBuffer = Encoding.ASCII.GetBytes(StringValue + "\0");
                     }
                 }
+
                 if (NxSetting is int IntValue)
                 {
                     SettingBuffer = BitConverter.GetBytes(IntValue);
diff --git a/Ryujinx.HLE/OsHle/AppletStateMgr.cs b/Ryujinx.HLE/OsHle/SystemState/AppletStateMgr.cs
index 5fdb5343..a656d218 100644
--- a/Ryujinx.HLE/OsHle/AppletStateMgr.cs
+++ b/Ryujinx.HLE/OsHle/SystemState/AppletStateMgr.cs
@@ -3,7 +3,7 @@ using Ryujinx.HLE.OsHle.Services.Am;
 using System;
 using System.Collections.Concurrent;
 
-namespace Ryujinx.HLE.OsHle
+namespace Ryujinx.HLE.OsHle.SystemState
 {
     class AppletStateMgr : IDisposable
     {
diff --git a/Ryujinx.HLE/Settings/ColorSet.cs b/Ryujinx.HLE/OsHle/SystemState/ColorSet.cs
index 77485d22..adcdf00d 100644
--- a/Ryujinx.HLE/Settings/ColorSet.cs
+++ b/Ryujinx.HLE/OsHle/SystemState/ColorSet.cs
@@ -1,4 +1,4 @@
-namespace Ryujinx.HLE.Settings
+namespace Ryujinx.HLE.OsHle.SystemState
 {
     public enum ColorSet
     {
diff --git a/Ryujinx.HLE/OsHle/SystemState/OpenCloseState.cs b/Ryujinx.HLE/OsHle/SystemState/OpenCloseState.cs
new file mode 100644
index 00000000..c43a260f
--- /dev/null
+++ b/Ryujinx.HLE/OsHle/SystemState/OpenCloseState.cs
@@ -0,0 +1,8 @@
+namespace Ryujinx.HLE.OsHle.SystemState
+{
+    public enum OpenCloseState
+    {
+        Closed,
+        Open
+    }
+}
diff --git a/Ryujinx.HLE/OsHle/SystemLanguage.cs b/Ryujinx.HLE/OsHle/SystemState/SystemLanguage.cs
index 4f190876..946d0a3b 100644
--- a/Ryujinx.HLE/OsHle/SystemLanguage.cs
+++ b/Ryujinx.HLE/OsHle/SystemState/SystemLanguage.cs
@@ -1,4 +1,4 @@
-namespace Ryujinx.HLE.OsHle
+namespace Ryujinx.HLE.OsHle.SystemState
 {
     public enum SystemLanguage
     {
diff --git a/Ryujinx.HLE/OsHle/SystemStateMgr.cs b/Ryujinx.HLE/OsHle/SystemState/SystemStateMgr.cs
index 7d14f0a5..bf0c0efb 100644
--- a/Ryujinx.HLE/OsHle/SystemStateMgr.cs
+++ b/Ryujinx.HLE/OsHle/SystemState/SystemStateMgr.cs
@@ -1,7 +1,9 @@
-using Ryujinx.HLE.Loaders.Npdm;
 using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
 
-namespace Ryujinx.HLE.OsHle
+namespace Ryujinx.HLE.OsHle.SystemState
 {
     public class SystemStateMgr
     {
@@ -36,14 +38,27 @@ namespace Ryujinx.HLE.OsHle
         internal long DesiredLanguageCode { get; private set; }
 
         internal string ActiveAudioOutput { get; private set; }
-        
-        public static bool DockedMode { get; set; }
+
+        public bool DockedMode { get; set; }
+
+        public ColorSet ThemeColor { get; set; }
+
+        private ConcurrentDictionary<string, UserProfile> Profiles;
+
+        internal UserProfile LastOpenUser { get; private set; }
 
         public SystemStateMgr()
         {
             SetLanguage(SystemLanguage.AmericanEnglish);
 
             SetAudioOutputAsBuiltInSpeaker();
+
+            Profiles = new ConcurrentDictionary<string, UserProfile>();
+
+            UserId DefaultUuid = new UserId("00000000000000000000000000000001");
+
+            AddUser(DefaultUuid, "Player");
+            OpenUser(DefaultUuid);
         }
 
         public void SetLanguage(SystemLanguage Language)
@@ -66,6 +81,49 @@ namespace Ryujinx.HLE.OsHle
             ActiveAudioOutput = AudioOutputs[2];
         }
 
+        public void AddUser(UserId Uuid, string Name)
+        {
+            UserProfile Profile = new UserProfile(Uuid, Name);
+
+            Profiles.AddOrUpdate(Uuid.UserIdHex, Profile, (Key, Old) => Profile);
+        }
+
+        public void OpenUser(UserId Uuid)
+        {
+            if (Profiles.TryGetValue(Uuid.UserIdHex, out UserProfile Profile))
+            {
+                (LastOpenUser = Profile).AccountState = OpenCloseState.Open;
+            }
+        }
+
+        public void CloseUser(UserId Uuid)
+        {
+            if (Profiles.TryGetValue(Uuid.UserIdHex, out UserProfile Profile))
+            {
+                Profile.AccountState = OpenCloseState.Closed;
+            }
+        }
+
+        public int GetUserCount()
+        {
+            return Profiles.Count;
+        }
+
+        internal bool TryGetUser(UserId Uuid, out UserProfile Profile)
+        {
+            return Profiles.TryGetValue(Uuid.UserIdHex, out Profile);
+        }
+
+        internal IEnumerable<UserProfile> GetAllUsers()
+        {
+            return Profiles.Values;
+        }
+
+        internal IEnumerable<UserProfile> GetOpenUsers()
+        {
+            return Profiles.Values.Where(x => x.AccountState == OpenCloseState.Open);
+        }
+
         internal static long GetLanguageCode(int Index)
         {
             if ((uint)Index >= LanguageCodes.Length)
diff --git a/Ryujinx.HLE/OsHle/SystemState/UserId.cs b/Ryujinx.HLE/OsHle/SystemState/UserId.cs
new file mode 100644
index 00000000..278ea9f7
--- /dev/null
+++ b/Ryujinx.HLE/OsHle/SystemState/UserId.cs
@@ -0,0 +1,76 @@
+using Ryujinx.HLE.OsHle.Utilities;
+using System;
+using System.IO;
+using System.Linq;
+
+namespace Ryujinx.HLE.OsHle.SystemState
+{
+    public struct UserId
+    {
+        public string UserIdHex { get; private set; }
+
+        public byte[] Bytes { get; private set; }
+
+        public UserId(long Low, long High)
+        {
+            if ((Low | High) == 0)
+            {
+                throw new ArgumentException("Zero is not a valid user id!");
+            }
+
+            byte[] Bytes = new byte[16];
+
+            int Index = Bytes.Length;
+
+            void WriteBytes(long Value)
+            {
+                for (int Byte = 0; Byte < 8; Byte++)
+                {
+                    Bytes[--Index] = (byte)(Value >> Byte * 8);
+                }
+            }
+
+            WriteBytes(Low);
+            WriteBytes(High);
+
+            UserIdHex = string.Empty;
+
+            foreach (byte Byte in Bytes)
+            {
+                UserIdHex += Byte.ToString("X2");
+            }
+
+            this.Bytes = Bytes;
+        }
+
+        public UserId(string UserIdHex)
+        {
+            if (UserIdHex == null || UserIdHex.Length != 32 || !UserIdHex.All("0123456789abcdefABCDEF".Contains))
+            {
+                throw new ArgumentException("Invalid user id!", nameof(UserIdHex));
+            }
+
+            if (UserIdHex == "00000000000000000000000000000000")
+            {
+                throw new ArgumentException("Zero is not a valid user id!", nameof(UserIdHex));
+            }
+
+            this.UserIdHex = UserIdHex.ToUpper();
+
+            Bytes = StringUtils.HexToBytes(UserIdHex);
+        }
+
+        internal void Write(BinaryWriter Writer)
+        {
+            for (int Index = Bytes.Length - 1; Index >= 0; Index--)
+            {
+                Writer.Write(Bytes[Index]);
+            }
+        }
+
+        public override string ToString()
+        {
+            return UserIdHex;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Ryujinx.HLE/OsHle/SystemState/UserProfile.cs b/Ryujinx.HLE/OsHle/SystemState/UserProfile.cs
new file mode 100644
index 00000000..b5b52339
--- /dev/null
+++ b/Ryujinx.HLE/OsHle/SystemState/UserProfile.cs
@@ -0,0 +1,36 @@
+using System;
+
+namespace Ryujinx.HLE.OsHle.SystemState
+{
+    class UserProfile
+    {
+        private static readonly DateTime Epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+
+        public UserId Uuid { get; private set; }
+
+        public string Name { get; private set; }
+
+        public long LastModifiedTimestamp { get; private set; }
+
+        public OpenCloseState AccountState    { get; set; }
+        public OpenCloseState OnlinePlayState { get; set; }
+
+        public UserProfile(UserId Uuid, string Name)
+        {
+            this.Uuid = Uuid;
+            this.Name = Name;
+
+            LastModifiedTimestamp = 0;
+
+            AccountState    = OpenCloseState.Closed;
+            OnlinePlayState = OpenCloseState.Closed;
+
+            UpdateTimestamp();
+        }
+
+        private void UpdateTimestamp()
+        {
+            LastModifiedTimestamp = (long)(DateTime.Now - Epoch).TotalSeconds;
+        }
+    }
+}
diff --git a/Ryujinx.HLE/OsHle/Utilities/StringUtils.cs b/Ryujinx.HLE/OsHle/Utilities/StringUtils.cs
index b0117f83..90f34695 100644
--- a/Ryujinx.HLE/OsHle/Utilities/StringUtils.cs
+++ b/Ryujinx.HLE/OsHle/Utilities/StringUtils.cs
@@ -11,13 +11,13 @@ namespace Ryujinx.HLE.OsHle.Utilities
         {
             InputString = InputString + "\0";
 
-            int ByteCount = Encoding.GetByteCount(InputString);
+            int BytesCount = Encoding.GetByteCount(InputString);
 
             byte[] Output = new byte[Size];
 
-            if (ByteCount < Size)
+            if (BytesCount < Size)
             {
-                Encoding.GetBytes(InputString, 0, InputString.Length, Output, Size - ByteCount);
+                Encoding.GetBytes(InputString, 0, InputString.Length, Output, 0);
             }
             else
             {
@@ -35,15 +35,14 @@ namespace Ryujinx.HLE.OsHle.Utilities
 
         public static byte[] HexToBytes(string HexString)
         {
-            //Ignore last charactor if HexLength % 2 != 0
+            //Ignore last charactor if HexLength % 2 != 0.
             int BytesInHex = HexString.Length / 2;
 
             byte[] Output = new byte[BytesInHex];
 
             for (int Index = 0; Index < BytesInHex; Index++)
             {
-                Output[Index] = byte.Parse(HexString.Substring(Index * 2, 2),
-                    NumberStyles.HexNumber);
+                Output[Index] = byte.Parse(HexString.Substring(Index * 2, 2), NumberStyles.HexNumber);
             }
 
             return Output;
diff --git a/Ryujinx.HLE/Settings/SystemSettings.cs b/Ryujinx.HLE/Settings/SystemSettings.cs
deleted file mode 100644
index fb94807e..00000000
--- a/Ryujinx.HLE/Settings/SystemSettings.cs
+++ /dev/null
@@ -1,11 +0,0 @@
-using System.Collections.Generic;
-using Ryujinx.HLE.OsHle;
-
-namespace Ryujinx.HLE.Settings
-{
-    public class SystemSettings
-    {
-        public Profile  User { get; set; }
-        public ColorSet ThemeColor { get; set; }
-    }
-}
diff --git a/Ryujinx.HLE/Switch.cs b/Ryujinx.HLE/Switch.cs
index b219d774..475e5116 100644
--- a/Ryujinx.HLE/Switch.cs
+++ b/Ryujinx.HLE/Switch.cs
@@ -5,7 +5,6 @@ using Ryujinx.HLE.Gpu;
 using Ryujinx.HLE.Input;
 using Ryujinx.HLE.Logging;
 using Ryujinx.HLE.OsHle;
-using Ryujinx.HLE.Settings;
 using System;
 
 namespace Ryujinx.HLE
@@ -22,8 +21,6 @@ namespace Ryujinx.HLE
 
         public Horizon Os { get; private set; }
 
-        public SystemSettings Settings { get; private set; }
-
         public PerformanceStatistics Statistics { get; private set; }
 
         public Hid Hid { get; private set; }
@@ -54,8 +51,6 @@ namespace Ryujinx.HLE
 
             Os = new Horizon(this);
 
-            Settings = new SystemSettings();
-
             Statistics = new PerformanceStatistics();
 
             Hid = new Hid(Log);
@@ -67,12 +62,6 @@ namespace Ryujinx.HLE
 
             Os.FontSharedMem.MemoryMapped   += Font.ShMemMap;
             Os.FontSharedMem.MemoryUnmapped += Font.ShMemUnmap;
-
-            Settings.User = new Profile()
-            {
-                Username = "Ryujinx",
-                UserId   = "000123456789abcdef09876543210000"
-            };
         }
 
         public void LoadCart(string ExeFsDir, string RomFsFile = null)
diff --git a/Ryujinx/Config.cs b/Ryujinx/Config.cs
index 09568217..14542706 100644
--- a/Ryujinx/Config.cs
+++ b/Ryujinx/Config.cs
@@ -1,5 +1,6 @@
-using Ryujinx.UI.Input;
+using Ryujinx.HLE;
 using Ryujinx.HLE.Logging;
+using Ryujinx.UI.Input;
 using System;
 using System.Globalization;
 using System.Collections.Generic;
@@ -7,8 +8,6 @@ using System.IO;
 using System.Linq;
 using System.Reflection;
 
-using static Ryujinx.HLE.OsHle.SystemStateMgr;
-
 namespace Ryujinx
 {
     public static class Config
@@ -16,7 +15,7 @@ namespace Ryujinx
         public static JoyConKeyboard   JoyConKeyboard   { get; private set; }
         public static JoyConController JoyConController { get; private set; }
 
-        public static void Read(Logger Log)
+        public static void Read(Switch Device)
         {
             string IniFolder = Path.GetDirectoryName(Assembly.GetEntryAssembly().Location);
 
@@ -28,13 +27,13 @@ namespace Ryujinx
 
             GraphicsConfig.ShadersDumpPath = Parser.Value("Graphics_Shaders_Dump_Path");
 
-            Log.SetEnable(LogLevel.Debug,   Convert.ToBoolean(Parser.Value("Logging_Enable_Debug")));
-            Log.SetEnable(LogLevel.Stub,    Convert.ToBoolean(Parser.Value("Logging_Enable_Stub")));
-            Log.SetEnable(LogLevel.Info,    Convert.ToBoolean(Parser.Value("Logging_Enable_Info")));
-            Log.SetEnable(LogLevel.Warning, Convert.ToBoolean(Parser.Value("Logging_Enable_Warn")));
-            Log.SetEnable(LogLevel.Error,   Convert.ToBoolean(Parser.Value("Logging_Enable_Error")));
-            
-            DockedMode = Convert.ToBoolean(Parser.Value("Docked_Mode"));
+            Device.Log.SetEnable(LogLevel.Debug,   Convert.ToBoolean(Parser.Value("Logging_Enable_Debug")));
+            Device.Log.SetEnable(LogLevel.Stub,    Convert.ToBoolean(Parser.Value("Logging_Enable_Stub")));
+            Device.Log.SetEnable(LogLevel.Info,    Convert.ToBoolean(Parser.Value("Logging_Enable_Info")));
+            Device.Log.SetEnable(LogLevel.Warning, Convert.ToBoolean(Parser.Value("Logging_Enable_Warn")));
+            Device.Log.SetEnable(LogLevel.Error,   Convert.ToBoolean(Parser.Value("Logging_Enable_Error")));
+
+            Device.Os.SystemState.DockedMode = Convert.ToBoolean(Parser.Value("Docked_Mode"));
 
             string[] FilteredLogClasses = Parser.Value("Logging_Filtered_Classes").Split(',', StringSplitOptions.RemoveEmptyEntries);
 
@@ -46,7 +45,7 @@ namespace Ryujinx
             {
                 foreach (LogClass Class in Enum.GetValues(typeof(LogClass)))
                 {
-                    Log.SetEnable(Class, false);
+                    Device.Log.SetEnable(Class, false);
                 }
             }
 
@@ -58,7 +57,7 @@ namespace Ryujinx
                     {
                         if (Class.ToString().ToLower().Contains(LogClass.Trim().ToLower()))
                         {
-                            Log.SetEnable(Class, true);
+                            Device.Log.SetEnable(Class, true);
                         }
                     }
                 }
diff --git a/Ryujinx/Ui/Program.cs b/Ryujinx/Ui/Program.cs
index 879b9c20..a0de2e9f 100644
--- a/Ryujinx/Ui/Program.cs
+++ b/Ryujinx/Ui/Program.cs
@@ -20,7 +20,7 @@ namespace Ryujinx
 
             Switch Ns = new Switch(Renderer, AudioOut);
 
-            Config.Read(Ns.Log);
+            Config.Read(Ns);
 
             Ns.Log.Updated += ConsoleLog.PrintLog;