import ctypes
import ctypes.util

from gi.repository import GdkX11


class XScreenSaverInfo(ctypes.Structure):
    _fields_ = [
        ('window', ctypes.c_ulong),
        ('state', ctypes.c_int),
        ('kind', ctypes.c_int),
        ('til_or_since', ctypes.c_ulong),
        ('idle', ctypes.c_ulong),
        ('eventMask', ctypes.c_ulong)
        ]
XScreenSaverInfo_p = ctypes.POINTER(XScreenSaverInfo)

display_p = ctypes.c_void_p
xid = ctypes.c_ulong
c_int_p = ctypes.POINTER(ctypes.c_int)

libXsspath = ctypes.util.find_library('Xss')
if libXsspath == None:
    raise OSError('libXss could not be found.')
libXss = ctypes.cdll.LoadLibrary(libXsspath)
libXss.XScreenSaverQueryExtension.argtypes = display_p, c_int_p, c_int_p
libXss.XScreenSaverAllocInfo.restype = XScreenSaverInfo_p
libXss.XScreenSaverQueryInfo.argtypes = (display_p, xid, XScreenSaverInfo_p)

dpy_p = hash(GdkX11.x11_get_default_xdisplay())
rootwindow = GdkX11.x11_get_default_root_xwindow()

_event_basep = ctypes.c_int()
_error_basep = ctypes.c_int()
if libXss.XScreenSaverQueryExtension(ctypes.c_void_p(dpy_p), ctypes.byref(_event_basep),
                                     ctypes.byref(_error_basep)) == 0:
    raise OSError('XScreenSaver Extension not available on display.')

xss_info_p = libXss.XScreenSaverAllocInfo()
if xss_info_p == None:
    raise OSError('XScreenSaverAllocInfo: Out of Memory.')

def getIdleSec():
    if libXss.XScreenSaverQueryInfo(dpy_p, rootwindow, xss_info_p) == 0:
        return 0
    else:
        return int(xss_info_p.contents.idle) / 1000