From b1043dd3ff6c14f36df5c3e0eacdfe009a5f8dee Mon Sep 17 00:00:00 2001
From: SuuperW <SuuperW@gmail.com>
Date: Mon, 16 Dec 2019 10:37:39 -0600
Subject: [PATCH] MelonDS: ISettable

---
 .../BizHawk.Emulation.Cores.csproj            |  1 +
 .../Consoles/Nintendo/NDS/MelonDS_Settable.cs | 89 +++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS_Settable.cs

diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 8f97a3ffc5..9ab89952ea 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -989,6 +989,7 @@
     <Compile Include="Consoles\Nintendo\NDS\MelonDS.cs" />
     <Compile Include="Consoles\Nintendo\NDS\MelonDS_InputPollable.cs" />
     <Compile Include="Consoles\Nintendo\NDS\MelonDS_SaveRam.cs" />
+    <Compile Include="Consoles\Nintendo\NDS\MelonDS_Settable.cs" />
     <Compile Include="Consoles\Nintendo\NDS\MelonDS_SoundProvider.cs" />
     <Compile Include="Consoles\Nintendo\NDS\MelonDS_Statable.cs" />
     <Compile Include="Consoles\Nintendo\NDS\MelonDS_VideoProvider.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS_Settable.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS_Settable.cs
new file mode 100644
index 0000000000..939ba7a035
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/MelonDS_Settable.cs
@@ -0,0 +1,89 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Runtime.InteropServices;
+
+using BizHawk.Emulation.Common;
+
+namespace BizHawk.Emulation.Cores.Consoles.Nintendo.NDS
+{
+	unsafe partial class MelonDS : ISettable<object, MelonDS.MelonSyncSettings>
+	{
+		public object GetSettings()
+		{
+			return new object();
+		}
+
+		public MelonSyncSettings GetSyncSettings()
+		{
+			MelonSyncSettings ret = new MelonSyncSettings();
+			fixed (byte* ptr = ret.data)
+				GetUserSettings(ptr);
+			return ret;
+		}
+
+		public bool PutSettings(object o)
+		{
+			return false;
+		}
+
+		public bool PutSyncSettings(MelonSyncSettings o)
+		{
+			fixed (byte* ptr = o.data)
+				SetUserSettings(ptr);
+
+			return true;
+		}
+
+		[DllImport(dllPath)]
+		private static extern bool GetUserSettings(byte* dst);
+		[DllImport(dllPath)]
+		private static extern bool SetUserSettings(byte* src);
+
+		[DllImport(dllPath)]
+		private static extern int getUserSettingsLength();
+		static int userSettingsLength = getUserSettingsLength();
+
+		unsafe public class MelonSettings
+		{
+		}
+
+		public class MelonSyncSettings
+		{
+			public MelonSyncSettings()
+			{
+				data = new byte[userSettingsLength];
+			}
+
+			public byte[] data;
+
+			public byte favoriteColor => data[2];
+			public byte birthdayMonth => data[3];
+			public byte birthdayDay => data[4];
+			const int maxNicknameLength = 10;
+			public string nickname
+			{
+				get
+				{
+					fixed (byte* ptr = data)
+						return Encoding.Unicode.GetString(ptr + 6, nicknameLength * 2);
+				}
+				set
+				{
+					if (value.Length > maxNicknameLength) value = value.Substring(0, maxNicknameLength);
+					byte[] nick = new byte[maxNicknameLength * 2 + 2];
+					// I do not know how an actual NDS would handle characters that require more than 2 bytes to encode.
+					// They can't be input normally, so I will ignore attempts to set a nickname that uses them.
+					if (Encoding.Unicode.GetBytes(value, 0, value.Length, nick, 0) != value.Length * 2)
+						return;
+					// The extra 2 bytes on the end will overwrite nickname length, which is set immediately after
+					nick.CopyTo(data, 6);
+					data[0x1A] = (byte)value.Length;
+				}
+			}
+			public short nicknameLength { get => data[0x1A]; }
+		}
+	}
+}