Node.JS FFI (WinAPI) utility for keyboard

keyboard.js

const ffi = require('node-ffi');
const FFIStruct = require('ref-struct');

const arch = require('os').arch();
const INPUT_KEYBOARD = 0x1;
const KEYEVENTF_KEYUP = 0x2;
const KEYEVENTF_SCANCODE = 0x8;
const InputStruct = FFIStruct({
    type: 'int',
    '???': 'int',
    wVK: 'short',
    wScan: 'short',
    dwFlags: 'int',
    time: 'int',
    dwExtraInfo: 'int64'
});

const SCANCODES = {
	ESC: 0x1,
	F1: 0x3b,
	F2: 0x3c,
	F3: 0x3d,
	F4: 0x3e,
	F5: 0x3f,
	F6: 0x40,
	F7: 0x41,
	F8: 0x42,
	F9: 0x43,
	F10: 0x44,

	Tilde: 0x29,
	Num1: 0x2,
	Num2: 0x3,
	Num3: 0x4,
	Num4: 0x5,
	Num5: 0x6,
	Num6: 0x7,
	Num7: 0x8,
	Num8: 0x9,
	Num9: 0xa,
	Num0: 0xb,
	Minus: 0xc,
	Equal: 0xd,
	Backspace: 0xe,

	Tab: 0xf,
	Q: 0x10,
	W: 0x11,
	E: 0x12,
	R: 0x13,
	T: 0x14,
	Y: 0x15,
	U: 0x16,
	I: 0x17,
	O: 0x18,
	P: 0x19,
	BracketOpen: 0x1a,
	BracketClose: 0x1b,
	Enter: 0x1c,

	CapsLock: 0x3a,
	A: 0x1e,
	S: 0x1f,
	D: 0x20,
	F: 0x21,
	G: 0x22,
	H: 0x23,
	J: 0x24,
	K: 0x25,
	L: 0x26,
	Colon: 0x27,
	Quote: 0x28,
	Slash: 0x2b,

	LShift: 0x2a,
	Z: 0x2c,
	X: 0x2d,
	C: 0x2e,
	V: 0x2f,
	B: 0x30,
	N: 0x31,
	M: 0x32,
	LT: 0x33,
	GT: 0x34,
	Question: 0x35,
	RShift: 0x36,

	LCtrl: 0x1d,
	LAlt: 0x38,
	Space: 0x39,
	ScrollLock: 0x46,

	NumLock: 0x45,
	NumpadAsterisk: 0x37,
	NumpadMinus: 0x4a,
	NumpadPlus: 0x4e,
	Numpad1: 0x4f,
	Numpad2: 0x50,
	Numpad3: 0x51,
	Numpad4: 0x4b,
	Numpad5: 0x4c,
	Numpad6: 0x4d,
	Numpad7: 0x47,
	Numpad8: 0x48,
	Numpad9: 0x49,
	Numpad0: 0x52,
	NumpadDot: 0x53
};

const user32 = ffi.Library('user32', {
    SendInput: ['int', ['int', InputStruct, 'int']]
});

function toggle (key, status) {
    const entry = new InputStruct();
    entry.type = INPUT_KEYBOARD;
    entry.time = 0;
    entry.dwExtraInfo = 0;
	entry.dwFlags = status ? KEYEVENTF_SCANCODE : (KEYEVENTF_SCANCODE | KEYEVENTF_KEYUP);
	entry.wVK = 0;
	entry.wScan = SCANCODES[key];

    user32.SendInput(1, entry, arch == 'x64' ? 40 : 28);
}

function press (key) {
    toggle(key, 'down');
    toggle(key, 'up');
}

module.exports = {
	toggle,
	press
};