using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;

namespace Mesen.GUI
{
	public class InputApi
	{
		private const string DllPath = "MesenSCore.dll";
		
		[DllImport(DllPath)] public static extern void SetKeyState(Int32 scanCode, [MarshalAs(UnmanagedType.I1)]bool pressed);
		[DllImport(DllPath)] public static extern void ResetKeyState();

		[DllImport(DllPath)] public static extern void SetMouseMovement(Int16 x, Int16 y);
		[DllImport(DllPath)] public static extern void SetMousePosition(double x, double y);
		[DllImport(DllPath)] public static extern void DisableAllKeys([MarshalAs(UnmanagedType.I1)]bool disabled);
		[DllImport(DllPath)] public static extern void UpdateInputDevices();

		[DllImport(DllPath)] public static extern UInt32 GetKeyCode([MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(Utf8Marshaler))]string keyName);

		[DllImport(DllPath, EntryPoint = "GetKeyName")] private static extern IntPtr GetKeyNameWrapper(UInt32 key);
		public static string GetKeyName(UInt32 key) { return Utf8Marshaler.PtrToStringUtf8(InputApi.GetKeyNameWrapper(key)); }

		[DllImport(DllPath, EntryPoint = "GetPressedKeys")] private static extern void GetPressedKeysWrapper(IntPtr keyBuffer);
		public static List<UInt32> GetPressedKeys()
		{
			UInt32[] keyBuffer = new UInt32[3];
			GCHandle handle = GCHandle.Alloc(keyBuffer, GCHandleType.Pinned);
			try {
				InputApi.GetPressedKeysWrapper(handle.AddrOfPinnedObject());
			} finally {
				handle.Free();
			}

			List<UInt32> keys = new List<UInt32>();
			for(int i = 0; i < 3; i++) {
				if(keyBuffer[i] != 0) {
					keys.Add(keyBuffer[i]);
				}
			}
			return keys;
		}
	}
}