using System;
using System.Runtime.InteropServices;

namespace WeldingCommon.Views.DoorInterlock
{
    public class KeyboardHook
    {
        private const int WH_KEYBOARD_LL = 13;
        private const int WM_KEYDOWN = 0x0100;
        private const int WM_SYSKEYDOWN = 0x0104;
        private const int VK_TAB = 0x09;
        private const int VK_MENU = 0x12;
        private const int VK_ALT = 0xA4;

        private const int VK_LWIN = 0x5B;
        private const int VK_RWIN = 0x5C;

        private readonly LowLevelKeyboardProc _proc;
        private IntPtr _hookID = IntPtr.Zero;

        public KeyboardHook()
        {
            _proc = HookCallback;
        }

        public void HookKeyboard()
        {
            _hookID = SetHook(_proc);
        }

        public void UnhookKeyboard()
        {
            UnhookWindowsHookEx(_hookID);
        }

        private IntPtr SetHook(LowLevelKeyboardProc proc)
        {
            using (var curProcess = System.Diagnostics.Process.GetCurrentProcess())
            using (var curModule = curProcess.MainModule) {
                return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
                    GetModuleHandle(curModule.ModuleName), 0);
            }
        }

        private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
        {
            // Alt 키 막음 
            if (nCode >= 0 && wParam == (IntPtr)WM_SYSKEYDOWN) {
                int vkCode = Marshal.ReadInt32(lParam);
                if (vkCode == VK_ALT) {
                    return (IntPtr)1; // 키 입력 무시
                }
            }

            if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN) {
                int vkCode = Marshal.ReadInt32(lParam);
                if (vkCode == VK_LWIN || vkCode == VK_RWIN) {
                    return (IntPtr)1; // 키 입력 무시
                }
            }

            return CallNextHookEx(_hookID, nCode, wParam, lParam);
        }

        private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool UnhookWindowsHookEx(IntPtr hhk);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr GetModuleHandle(string lpModuleName);
    }
}