using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace NtApiDotNet.Win32
{
    // From https://pinvoke.net/default.aspx/Structures/KEYBDINPUT.html.
    [Flags]
    internal enum MOUSEEVENTF
    {
        ABSOLUTE = 0x8000,
        HWHEEL = 0x01000,
        MOVE = 0x0001,
        MOVE_NOCOALESCE = 0x2000,
        LEFTDOWN = 0x0002,
        LEFTUP = 0x0004,
        RIGHTDOWN = 0x0008,
        RIGHTUP = 0x0010,
        MIDDLEDOWN = 0x0020,
        MIDDLEUP = 0x0040,
        VIRTUALDESK = 0x4000,
        WHEEL = 0x0800,
        XDOWN = 0x0080,
        XUP = 0x0100
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct MOUSEINPUT
    {
        internal int dx;
        internal int dy;
        internal int mouseData;
        internal MOUSEEVENTF dwFlags;
        internal uint time;
        internal UIntPtr dwExtraInfo;
    }

    [Flags]
    internal enum KEYEVENTF : uint
    {
        EXTENDEDKEY = 0x0001,
        KEYUP = 0x0002,
        SCANCODE = 0x0008,
        UNICODE = 0x0004
    }

    /// <summary>
    /// Virtual Key enumeration.
    /// </summary>
    public enum VirtualKey : short
    {
        ///<summary>
        ///Left mouse button
        ///</summary>
        LBUTTON = 0x01,
        ///<summary>
        ///Right mouse button
        ///</summary>
        RBUTTON = 0x02,
        ///<summary>
        ///Control-break processing
        ///</summary>
        CANCEL = 0x03,
        ///<summary>
        ///Middle mouse button (three-button mouse)
        ///</summary>
        MBUTTON = 0x04,
        ///<summary>
        ///Windows 2000/XP: X1 mouse button
        ///</summary>
        XBUTTON1 = 0x05,
        ///<summary>
        ///Windows 2000/XP: X2 mouse button
        ///</summary>
        XBUTTON2 = 0x06,
        ///<summary>
        ///BACKSPACE key
        ///</summary>
        BACK = 0x08,
        ///<summary>
        ///TAB key
        ///</summary>
        TAB = 0x09,
        ///<summary>
        ///CLEAR key
        ///</summary>
        CLEAR = 0x0C,
        ///<summary>
        ///ENTER key
        ///</summary>
        RETURN = 0x0D,
        ///<summary>
        ///SHIFT key
        ///</summary>
        SHIFT = 0x10,
        ///<summary>
        ///CTRL key
        ///</summary>
        CONTROL = 0x11,
        ///<summary>
        ///ALT key
        ///</summary>
        MENU = 0x12,
        ///<summary>
        ///PAUSE key
        ///</summary>
        PAUSE = 0x13,
        ///<summary>
        ///CAPS LOCK key
        ///</summary>
        CAPITAL = 0x14,
        ///<summary>
        ///Input Method Editor (IME) Kana mode
        ///</summary>
        KANA = 0x15,
        ///<summary>
        ///IME Hangul mode
        ///</summary>
        HANGUL = 0x15,
        ///<summary>
        ///IME Junja mode
        ///</summary>
        JUNJA = 0x17,
        ///<summary>
        ///IME final mode
        ///</summary>
        FINAL = 0x18,
        ///<summary>
        ///IME Hanja mode
        ///</summary>
        HANJA = 0x19,
        ///<summary>
        ///IME Kanji mode
        ///</summary>
        KANJI = 0x19,
        ///<summary>
        ///ESC key
        ///</summary>
        ESCAPE = 0x1B,
        ///<summary>
        ///IME convert
        ///</summary>
        CONVERT = 0x1C,
        ///<summary>
        ///IME nonconvert
        ///</summary>
        NONCONVERT = 0x1D,
        ///<summary>
        ///IME accept
        ///</summary>
        ACCEPT = 0x1E,
        ///<summary>
        ///IME mode change request
        ///</summary>
        MODECHANGE = 0x1F,
        ///<summary>
        ///SPACEBAR
        ///</summary>
        SPACE = 0x20,
        ///<summary>
        ///PAGE UP key
        ///</summary>
        PRIOR = 0x21,
        ///<summary>
        ///PAGE DOWN key
        ///</summary>
        NEXT = 0x22,
        ///<summary>
        ///END key
        ///</summary>
        END = 0x23,
        ///<summary>
        ///HOME key
        ///</summary>
        HOME = 0x24,
        ///<summary>
        ///LEFT ARROW key
        ///</summary>
        LEFT = 0x25,
        ///<summary>
        ///UP ARROW key
        ///</summary>
        UP = 0x26,
        ///<summary>
        ///RIGHT ARROW key
        ///</summary>
        RIGHT = 0x27,
        ///<summary>
        ///DOWN ARROW key
        ///</summary>
        DOWN = 0x28,
        ///<summary>
        ///SELECT key
        ///</summary>
        SELECT = 0x29,
        ///<summary>
        ///PRINT key
        ///</summary>
        PRINT = 0x2A,
        ///<summary>
        ///EXECUTE key
        ///</summary>
        EXECUTE = 0x2B,
        ///<summary>
        ///PRINT SCREEN key
        ///</summary>
        SNAPSHOT = 0x2C,
        ///<summary>
        ///INS key
        ///</summary>
        INSERT = 0x2D,
        ///<summary>
        ///DEL key
        ///</summary>
        DELETE = 0x2E,
        ///<summary>
        ///HELP key
        ///</summary>
        HELP = 0x2F,
        ///<summary>
        ///0 key
        ///</summary>
        KEY_0 = 0x30,
        ///<summary>
        ///1 key
        ///</summary>
        KEY_1 = 0x31,
        ///<summary>
        ///2 key
        ///</summary>
        KEY_2 = 0x32,
        ///<summary>
        ///3 key
        ///</summary>
        KEY_3 = 0x33,
        ///<summary>
        ///4 key
        ///</summary>
        KEY_4 = 0x34,
        ///<summary>
        ///5 key
        ///</summary>
        KEY_5 = 0x35,
        ///<summary>
        ///6 key
        ///</summary>
        KEY_6 = 0x36,
        ///<summary>
        ///7 key
        ///</summary>
        KEY_7 = 0x37,
        ///<summary>
        ///8 key
        ///</summary>
        KEY_8 = 0x38,
        ///<summary>
        ///9 key
        ///</summary>
        KEY_9 = 0x39,
        ///<summary>
        ///A key
        ///</summary>
        KEY_A = 0x41,
        ///<summary>
        ///B key
        ///</summary>
        KEY_B = 0x42,
        ///<summary>
        ///C key
        ///</summary>
        KEY_C = 0x43,
        ///<summary>
        ///D key
        ///</summary>
        KEY_D = 0x44,
        ///<summary>
        ///E key
        ///</summary>
        KEY_E = 0x45,
        ///<summary>
        ///F key
        ///</summary>
        KEY_F = 0x46,
        ///<summary>
        ///G key
        ///</summary>
        KEY_G = 0x47,
        ///<summary>
        ///H key
        ///</summary>
        KEY_H = 0x48,
        ///<summary>
        ///I key
        ///</summary>
        KEY_I = 0x49,
        ///<summary>
        ///J key
        ///</summary>
        KEY_J = 0x4A,
        ///<summary>
        ///K key
        ///</summary>
        KEY_K = 0x4B,
        ///<summary>
        ///L key
        ///</summary>
        KEY_L = 0x4C,
        ///<summary>
        ///M key
        ///</summary>
        KEY_M = 0x4D,
        ///<summary>
        ///N key
        ///</summary>
        KEY_N = 0x4E,
        ///<summary>
        ///O key
        ///</summary>
        KEY_O = 0x4F,
        ///<summary>
        ///P key
        ///</summary>
        KEY_P = 0x50,
        ///<summary>
        ///Q key
        ///</summary>
        KEY_Q = 0x51,
        ///<summary>
        ///R key
        ///</summary>
        KEY_R = 0x52,
        ///<summary>
        ///S key
        ///</summary>
        KEY_S = 0x53,
        ///<summary>
        ///T key
        ///</summary>
        KEY_T = 0x54,
        ///<summary>
        ///U key
        ///</summary>
        KEY_U = 0x55,
        ///<summary>
        ///V key
        ///</summary>
        KEY_V = 0x56,
        ///<summary>
        ///W key
        ///</summary>
        KEY_W = 0x57,
        ///<summary>
        ///X key
        ///</summary>
        KEY_X = 0x58,
        ///<summary>
        ///Y key
        ///</summary>
        KEY_Y = 0x59,
        ///<summary>
        ///Z key
        ///</summary>
        KEY_Z = 0x5A,
        ///<summary>
        ///Left Windows key (Microsoft Natural keyboard)
        ///</summary>
        LWIN = 0x5B,
        ///<summary>
        ///Right Windows key (Natural keyboard)
        ///</summary>
        RWIN = 0x5C,
        ///<summary>
        ///Applications key (Natural keyboard)
        ///</summary>
        APPS = 0x5D,
        ///<summary>
        ///Computer Sleep key
        ///</summary>
        SLEEP = 0x5F,
        ///<summary>
        ///Numeric keypad 0 key
        ///</summary>
        NUMPAD0 = 0x60,
        ///<summary>
        ///Numeric keypad 1 key
        ///</summary>
        NUMPAD1 = 0x61,
        ///<summary>
        ///Numeric keypad 2 key
        ///</summary>
        NUMPAD2 = 0x62,
        ///<summary>
        ///Numeric keypad 3 key
        ///</summary>
        NUMPAD3 = 0x63,
        ///<summary>
        ///Numeric keypad 4 key
        ///</summary>
        NUMPAD4 = 0x64,
        ///<summary>
        ///Numeric keypad 5 key
        ///</summary>
        NUMPAD5 = 0x65,
        ///<summary>
        ///Numeric keypad 6 key
        ///</summary>
        NUMPAD6 = 0x66,
        ///<summary>
        ///Numeric keypad 7 key
        ///</summary>
        NUMPAD7 = 0x67,
        ///<summary>
        ///Numeric keypad 8 key
        ///</summary>
        NUMPAD8 = 0x68,
        ///<summary>
        ///Numeric keypad 9 key
        ///</summary>
        NUMPAD9 = 0x69,
        ///<summary>
        ///Multiply key
        ///</summary>
        MULTIPLY = 0x6A,
        ///<summary>
        ///Add key
        ///</summary>
        ADD = 0x6B,
        ///<summary>
        ///Separator key
        ///</summary>
        SEPARATOR = 0x6C,
        ///<summary>
        ///Subtract key
        ///</summary>
        SUBTRACT = 0x6D,
        ///<summary>
        ///Decimal key
        ///</summary>
        DECIMAL = 0x6E,
        ///<summary>
        ///Divide key
        ///</summary>
        DIVIDE = 0x6F,
        ///<summary>
        ///F1 key
        ///</summary>
        F1 = 0x70,
        ///<summary>
        ///F2 key
        ///</summary>
        F2 = 0x71,
        ///<summary>
        ///F3 key
        ///</summary>
        F3 = 0x72,
        ///<summary>
        ///F4 key
        ///</summary>
        F4 = 0x73,
        ///<summary>
        ///F5 key
        ///</summary>
        F5 = 0x74,
        ///<summary>
        ///F6 key
        ///</summary>
        F6 = 0x75,
        ///<summary>
        ///F7 key
        ///</summary>
        F7 = 0x76,
        ///<summary>
        ///F8 key
        ///</summary>
        F8 = 0x77,
        ///<summary>
        ///F9 key
        ///</summary>
        F9 = 0x78,
        ///<summary>
        ///F10 key
        ///</summary>
        F10 = 0x79,
        ///<summary>
        ///F11 key
        ///</summary>
        F11 = 0x7A,
        ///<summary>
        ///F12 key
        ///</summary>
        F12 = 0x7B,
        ///<summary>
        ///F13 key
        ///</summary>
        F13 = 0x7C,
        ///<summary>
        ///F14 key
        ///</summary>
        F14 = 0x7D,
        ///<summary>
        ///F15 key
        ///</summary>
        F15 = 0x7E,
        ///<summary>
        ///F16 key
        ///</summary>
        F16 = 0x7F,
        ///<summary>
        ///F17 key  
        ///</summary>
        F17 = 0x80,
        ///<summary>
        ///F18 key  
        ///</summary>
        F18 = 0x81,
        ///<summary>
        ///F19 key  
        ///</summary>
        F19 = 0x82,
        ///<summary>
        ///F20 key  
        ///</summary>
        F20 = 0x83,
        ///<summary>
        ///F21 key  
        ///</summary>
        F21 = 0x84,
        ///<summary>
        ///F22 key, (PPC only) Key used to lock device.
        ///</summary>
        F22 = 0x85,
        ///<summary>
        ///F23 key  
        ///</summary>
        F23 = 0x86,
        ///<summary>
        ///F24 key  
        ///</summary>
        F24 = 0x87,
        ///<summary>
        ///NUM LOCK key
        ///</summary>
        NUMLOCK = 0x90,
        ///<summary>
        ///SCROLL LOCK key
        ///</summary>
        SCROLL = 0x91,
        ///<summary>
        ///Left SHIFT key
        ///</summary>
        LSHIFT = 0xA0,
        ///<summary>
        ///Right SHIFT key
        ///</summary>
        RSHIFT = 0xA1,
        ///<summary>
        ///Left CONTROL key
        ///</summary>
        LCONTROL = 0xA2,
        ///<summary>
        ///Right CONTROL key
        ///</summary>
        RCONTROL = 0xA3,
        ///<summary>
        ///Left MENU key
        ///</summary>
        LMENU = 0xA4,
        ///<summary>
        ///Right MENU key
        ///</summary>
        RMENU = 0xA5,
        ///<summary>
        ///Windows 2000/XP: Browser Back key
        ///</summary>
        BROWSER_BACK = 0xA6,
        ///<summary>
        ///Windows 2000/XP: Browser Forward key
        ///</summary>
        BROWSER_FORWARD = 0xA7,
        ///<summary>
        ///Windows 2000/XP: Browser Refresh key
        ///</summary>
        BROWSER_REFRESH = 0xA8,
        ///<summary>
        ///Windows 2000/XP: Browser Stop key
        ///</summary>
        BROWSER_STOP = 0xA9,
        ///<summary>
        ///Windows 2000/XP: Browser Search key
        ///</summary>
        BROWSER_SEARCH = 0xAA,
        ///<summary>
        ///Windows 2000/XP: Browser Favorites key
        ///</summary>
        BROWSER_FAVORITES = 0xAB,
        ///<summary>
        ///Windows 2000/XP: Browser Start and Home key
        ///</summary>
        BROWSER_HOME = 0xAC,
        ///<summary>
        ///Windows 2000/XP: Volume Mute key
        ///</summary>
        VOLUME_MUTE = 0xAD,
        ///<summary>
        ///Windows 2000/XP: Volume Down key
        ///</summary>
        VOLUME_DOWN = 0xAE,
        ///<summary>
        ///Windows 2000/XP: Volume Up key
        ///</summary>
        VOLUME_UP = 0xAF,
        ///<summary>
        ///Windows 2000/XP: Next Track key
        ///</summary>
        MEDIA_NEXT_TRACK = 0xB0,
        ///<summary>
        ///Windows 2000/XP: Previous Track key
        ///</summary>
        MEDIA_PREV_TRACK = 0xB1,
        ///<summary>
        ///Windows 2000/XP: Stop Media key
        ///</summary>
        MEDIA_STOP = 0xB2,
        ///<summary>
        ///Windows 2000/XP: Play/Pause Media key
        ///</summary>
        MEDIA_PLAY_PAUSE = 0xB3,
        ///<summary>
        ///Windows 2000/XP: Start Mail key
        ///</summary>
        LAUNCH_MAIL = 0xB4,
        ///<summary>
        ///Windows 2000/XP: Select Media key
        ///</summary>
        LAUNCH_MEDIA_SELECT = 0xB5,
        ///<summary>
        ///Windows 2000/XP: Start Application 1 key
        ///</summary>
        LAUNCH_APP1 = 0xB6,
        ///<summary>
        ///Windows 2000/XP: Start Application 2 key
        ///</summary>
        LAUNCH_APP2 = 0xB7,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_1 = 0xBA,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '+' key
        ///</summary>
        OEM_PLUS = 0xBB,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the ',' key
        ///</summary>
        OEM_COMMA = 0xBC,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '-' key
        ///</summary>
        OEM_MINUS = 0xBD,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '.' key
        ///</summary>
        OEM_PERIOD = 0xBE,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_2 = 0xBF,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_3 = 0xC0,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_4 = 0xDB,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_5 = 0xDC,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_6 = 0xDD,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_7 = 0xDE,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_8 = 0xDF,
        ///<summary>
        ///Windows 2000/XP: Either the angle bracket key or the backslash key on the RT 102-key keyboard
        ///</summary>
        OEM_102 = 0xE2,
        ///<summary>
        ///Windows 95/98/Me, Windows NT 4.0, Windows 2000/XP: IME PROCESS key
        ///</summary>
        PROCESSKEY = 0xE5,
        ///<summary>
        ///Windows 2000/XP: Used to pass Unicode characters as if they were keystrokes.
        ///The VK_PACKET key is the low word of a 32-bit Virtual Key value used for non-keyboard input methods. For more information,
        ///see Remark in KEYBDINPUT, SendInput, WM_KEYDOWN, and WM_KEYUP
        ///</summary>
        PACKET = 0xE7,
        ///<summary>
        ///Attn key
        ///</summary>
        ATTN = 0xF6,
        ///<summary>
        ///CrSel key
        ///</summary>
        CRSEL = 0xF7,
        ///<summary>
        ///ExSel key
        ///</summary>
        EXSEL = 0xF8,
        ///<summary>
        ///Erase EOF key
        ///</summary>
        EREOF = 0xF9,
        ///<summary>
        ///Play key
        ///</summary>
        PLAY = 0xFA,
        ///<summary>
        ///Zoom key
        ///</summary>
        ZOOM = 0xFB,
        ///<summary>
        ///Reserved
        ///</summary>
        NONAME = 0xFC,
        ///<summary>
        ///PA1 key
        ///</summary>
        PA1 = 0xFD,
        ///<summary>
        ///Clear key
        ///</summary>
        OEM_CLEAR = 0xFE
    }
    internal enum ScanCodeShort : short
    {
        LBUTTON = 0,
        RBUTTON = 0,
        CANCEL = 70,
        MBUTTON = 0,
        XBUTTON1 = 0,
        XBUTTON2 = 0,
        BACK = 14,
        TAB = 15,
        CLEAR = 76,
        RETURN = 28,
        SHIFT = 42,
        CONTROL = 29,
        MENU = 56,
        PAUSE = 0,
        CAPITAL = 58,
        KANA = 0,
        HANGUL = 0,
        JUNJA = 0,
        FINAL = 0,
        HANJA = 0,
        KANJI = 0,
        ESCAPE = 1,
        CONVERT = 0,
        NONCONVERT = 0,
        ACCEPT = 0,
        MODECHANGE = 0,
        SPACE = 57,
        PRIOR = 73,
        NEXT = 81,
        END = 79,
        HOME = 71,
        LEFT = 75,
        UP = 72,
        RIGHT = 77,
        DOWN = 80,
        SELECT = 0,
        PRINT = 0,
        EXECUTE = 0,
        SNAPSHOT = 84,
        INSERT = 82,
        DELETE = 83,
        HELP = 99,
        KEY_0 = 11,
        KEY_1 = 2,
        KEY_2 = 3,
        KEY_3 = 4,
        KEY_4 = 5,
        KEY_5 = 6,
        KEY_6 = 7,
        KEY_7 = 8,
        KEY_8 = 9,
        KEY_9 = 10,
        KEY_A = 30,
        KEY_B = 48,
        KEY_C = 46,
        KEY_D = 32,
        KEY_E = 18,
        KEY_F = 33,
        KEY_G = 34,
        KEY_H = 35,
        KEY_I = 23,
        KEY_J = 36,
        KEY_K = 37,
        KEY_L = 38,
        KEY_M = 50,
        KEY_N = 49,
        KEY_O = 24,
        KEY_P = 25,
        KEY_Q = 16,
        KEY_R = 19,
        KEY_S = 31,
        KEY_T = 20,
        KEY_U = 22,
        KEY_V = 47,
        KEY_W = 17,
        KEY_X = 45,
        KEY_Y = 21,
        KEY_Z = 44,
        LWIN = 91,
        RWIN = 92,
        APPS = 93,
        SLEEP = 95,
        NUMPAD0 = 82,
        NUMPAD1 = 79,
        NUMPAD2 = 80,
        NUMPAD3 = 81,
        NUMPAD4 = 75,
        NUMPAD5 = 76,
        NUMPAD6 = 77,
        NUMPAD7 = 71,
        NUMPAD8 = 72,
        NUMPAD9 = 73,
        MULTIPLY = 55,
        ADD = 78,
        SEPARATOR = 0,
        SUBTRACT = 74,
        DECIMAL = 83,
        DIVIDE = 53,
        F1 = 59,
        F2 = 60,
        F3 = 61,
        F4 = 62,
        F5 = 63,
        F6 = 64,
        F7 = 65,
        F8 = 66,
        F9 = 67,
        F10 = 68,
        F11 = 87,
        F12 = 88,
        F13 = 100,
        F14 = 101,
        F15 = 102,
        F16 = 103,
        F17 = 104,
        F18 = 105,
        F19 = 106,
        F20 = 107,
        F21 = 108,
        F22 = 109,
        F23 = 110,
        F24 = 118,
        NUMLOCK = 69,
        SCROLL = 70,
        LSHIFT = 42,
        RSHIFT = 54,
        LCONTROL = 29,
        RCONTROL = 29,
        LMENU = 56,
        RMENU = 56,
        BROWSER_BACK = 106,
        BROWSER_FORWARD = 105,
        BROWSER_REFRESH = 103,
        BROWSER_STOP = 104,
        BROWSER_SEARCH = 101,
        BROWSER_FAVORITES = 102,
        BROWSER_HOME = 50,
        VOLUME_MUTE = 32,
        VOLUME_DOWN = 46,
        VOLUME_UP = 48,
        MEDIA_NEXT_TRACK = 25,
        MEDIA_PREV_TRACK = 16,
        MEDIA_STOP = 36,
        MEDIA_PLAY_PAUSE = 34,
        LAUNCH_MAIL = 108,
        LAUNCH_MEDIA_SELECT = 109,
        LAUNCH_APP1 = 107,
        LAUNCH_APP2 = 33,
        OEM_1 = 39,
        OEM_PLUS = 13,
        OEM_COMMA = 51,
        OEM_MINUS = 12,
        OEM_PERIOD = 52,
        OEM_2 = 53,
        OEM_3 = 41,
        OEM_4 = 26,
        OEM_5 = 43,
        OEM_6 = 27,
        OEM_7 = 40,
        OEM_8 = 0,
        OEM_102 = 86,
        PROCESSKEY = 0,
        PACKET = 0,
        ATTN = 0,
        CRSEL = 0,
        EXSEL = 0,
        EREOF = 93,
        PLAY = 0,
        ZOOM = 98,
        NONAME = 0,
        PA1 = 0,
        OEM_CLEAR = 0,
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct KEYBDINPUT
    {
        internal VirtualKey wVk;
        internal ScanCodeShort wScan;
        internal KEYEVENTF dwFlags;
        internal int time;
        internal IntPtr dwExtraInfo;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct HARDWAREINPUT
    {
        internal int uMsg;
        internal short wParamL;
        internal short wParamH;
    }

    internal enum INPUT_TYPE
    {
        MOUSE = 0,
        KEYBOARD = 1,
        HARDWARE = 2
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct INPUT
    {
        internal INPUT_TYPE type;
        internal InputUnion U;

        public INPUT(VirtualKey vk, bool key_up)
        {
            type = INPUT_TYPE.KEYBOARD;
            U = new InputUnion();
            U.ki = new KEYBDINPUT()
            {
                wVk = vk,
                dwFlags = key_up ? KEYEVENTF.KEYUP : 0
            };
        }
    }

    [StructLayout(LayoutKind.Explicit)]
    internal struct InputUnion
    {
        [FieldOffset(0)]
        internal MOUSEINPUT mi;
        [FieldOffset(0)]
        internal KEYBDINPUT ki;
        [FieldOffset(0)]
        internal HARDWAREINPUT hi;
    }
}
