using System.Runtime.InteropServices;

namespace EC.Util.Platform;

public static class LinuxUtil
{
    #region const

    private const string libX11 = "libX11.so.6";
    private const string libX11Randr = "libXrandr.so.2";
    private const string libX11Ext = "libXext.so.6";
    private const string libXInput = "libXi.so.6";
    private const string libXCursor = "libXcursor.so.1";

    private enum PropertyMode
    {
        Replace = 0,
        Prepend = 1,
        Append = 2
    }

    [Flags]
    private enum MotifFlags
    {
        Functions = 1,
        Decorations = 2,
        InputMode = 4,
        Status = 8
    }

    [Flags]
    private enum MotifFunctions
    {
        All = 0x01,
        Resize = 0x02,
        Move = 0x04,
        Minimize = 0x08,
        Maximize = 0x10,
        Close = 0x20
    }

    [Flags]
    private enum MotifDecorations
    {
        All = 0x01,
        Border = 0x02,
        ResizeH = 0x04,
        Title = 0x08,
        Menu = 0x10,
        Minimize = 0x20,
        Maximize = 0x40,
    }

    [Flags]
    private enum MotifInputMode
    {
        Modeless = 0,
        ApplicationModal = 1,
        SystemModal = 2,
        FullApplicationModal = 3
    }

    #endregion const

    #region struct

    [StructLayout(LayoutKind.Sequential)]
    private struct MotifWmHints
    {
        public IntPtr flags;
        public IntPtr functions;
        public IntPtr decorations;
        public IntPtr input_mode;
        public IntPtr status;

        public override string ToString()
        {
            return string.Format("MotifWmHints <flags={0}, functions={1}, decorations={2}, input_mode={3}, status={4}", (MotifFlags)flags.ToInt32(), (MotifFunctions)functions.ToInt32(), (MotifDecorations)decorations.ToInt32(), (MotifInputMode)input_mode.ToInt32(), status.ToInt32());
        }
    }

    [StructLayout(LayoutKind.Sequential)]
    private struct XSizeHints
    {
        private IntPtr flags;
        private int x;
        private int y;
        private int width;
        private int height;
        private int min_width;
        private int min_height;
        private int max_width;
        private int max_height;
        private int width_inc;
        private int height_inc;
        private int min_aspect_x;
        private int min_aspect_y;
        private int max_aspect_x;
        private int max_aspect_y;
        private int base_width;
        private int base_height;
        private int win_gravity;
    }

    [Flags]
    private enum XSizeHintsFlags
    {
        USPosition = (1 << 0),
        USSize = (1 << 1),
        PPosition = (1 << 2),
        PSize = (1 << 3),
        PMinSize = (1 << 4),
        PMaxSize = (1 << 5),
        PResizeInc = (1 << 6),
        PAspect = (1 << 7),
        PAllHints = (PPosition | PSize | PMinSize | PMaxSize | PResizeInc | PAspect),
        PBaseSize = (1 << 8),
        PWinGravity = (1 << 9),
    }

    #endregion struct

    #region lib

    [DllImport(libX11, CharSet = CharSet.Unicode)]
    private static extern IntPtr XInternAtom(IntPtr display, string atom_name, bool only_if_exists);

    [DllImport(libX11)]
    private static extern int XChangeProperty(IntPtr display, IntPtr window, IntPtr property, IntPtr type,
        int format, PropertyMode mode, ref MotifWmHints data, int nelements);

    [DllImport(libX11)]
    private static extern void XSetWMNormalHints(IntPtr display, IntPtr window, ref XSizeHints hints);

    #endregion lib

    #region cmd

    public static void DisableMinMaximizeButton(IntPtr display, IntPtr handle, IntPtr atom)
    {
        MotifDecorations decorations = MotifDecorations.Title | MotifDecorations.Border;
        MotifFunctions functions = MotifFunctions.Move | MotifFunctions.Close;
        MotifWmHints hints = new()
        {
            flags = (nint)(MotifFlags.Decorations | MotifFlags.Functions),
            decorations = (nint)decorations,
            functions = (nint)functions,
            input_mode = 0,
            status = 0,
        };
        int result = XChangeProperty(display, handle, atom, atom, 32, PropertyMode.Replace, ref hints, 5);
    }

    #endregion cmd
}