using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace GUI.Hook
{
    public class MouseHook : IHook
    {
        int hHook = 0;
        Win32Api.HookProc mouseHookDelegate;

        public event MouseEventHandler OnMouseMoveEvent;
        public event MouseEventHandler OnMouseDownEvent;
        public event MouseEventHandler OnMouseUpEvent;

        public MouseHook() { }

        public void SetHook()
        {
            mouseHookDelegate = new Win32Api.HookProc(MouseHookProc);
            hHook = Win32Api.SetWindowsHookEx(Win32Api.WH_MOUSE_LL, mouseHookDelegate, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);
        }

        public void UnHook()
        {
            Win32Api.UnhookWindowsHookEx(hHook);
        }

        int MouseHookProc(int nCode, int wParam, IntPtr lParam)
        {
            Win32Api.MouseHookStruct msg = (Win32Api.MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(Win32Api.MouseHookStruct));
            if (nCode >= 0)
            {
                switch (wParam)
                {
                    case 513: OnMouseDownEvent?.Invoke(this, new(MouseButtons.Left, 0, msg.pt.x, msg.pt.y, 0)); break;
                    case 514: OnMouseUpEvent?.Invoke(this, new(MouseButtons.Left, 0, msg.pt.x, msg.pt.y, 0)); break;
                    case 516: OnMouseDownEvent?.Invoke(this, new(MouseButtons.Right, 0, msg.pt.x, msg.pt.y, 0)); break;
                    case 517: OnMouseUpEvent?.Invoke(this, new(MouseButtons.Right, 0, msg.pt.x, msg.pt.y, 0)); break;
                    default: OnMouseMoveEvent?.Invoke(this, new(MouseButtons.None, 0, msg.pt.x, msg.pt.y, 0)); break;
                }
            }
            return Win32Api.CallNextHookEx(hHook, nCode, wParam, lParam);
        }
    }
}