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from typing import Optional
import logging

import Xlib
import Xlib.display
from Xlib.xobject.drawable import Window
from Xlib import X, Xatom

logger = logging.getLogger(__name__)

display = Xlib.display.Display()
screen = display.screen()

NET_WM_NAME = display.intern_atom("_NET_WM_NAME")
UTF8_STRING = display.intern_atom("UTF8_STRING")

def _get_current_window_id() -> Optional[int]:
    atom = display.get_atom("_NET_ACTIVE_WINDOW")
    window_prop = screen.root.get_full_property(atom, X.AnyPropertyType)

    if window_prop is None:
        logger.warning("window_prop was None")
        return None

    # window_prop may contain more than one value, but it seems that it's always the first we want.
    # The second has in my attempts always been 0 or rubbish.
    window_id = window_prop.value[0]
    return window_id if window_id != 0 else None

def _get_window(window_id: int) -> Window:
    return display.create_resource_object('window', window_id)

def get_current_window() -> Optional[Window]:
    window_id = _get_current_window_id()
    if window_id is None:
        return None
        return _get_window(window_id)

# Things that can lead to unknown cls/name:
#  - (cls+name) Empty desktop in xfce (no window focused)
#  - (name) Chrome (fixed, didn't support when WM_NAME was UTF8_STRING)

def get_window_name(window: Window) -> str:
    """ After some annoying debugging I resorted to pretty much copying selfspy.
        Source: """
        d = window.get_full_property(NET_WM_NAME, UTF8_STRING)
    except Xlib.error.XError as e:
        logger.warning("Unable to get window property NET_WM_NAME, got a {} exception from Xlib".format(type(e).__name__))
        # I strongly suspect window.get_wm_name() will also fail and we should return "unknown" right away.
        # But I don't know, so I pass the thing on, for now.
        d = None
    if d is None or d.format != 8:
        # Fallback.
        r = window.get_wm_name()
        if type(r) == str:
            return r
            logger.warning("I don't think this case will ever happen, but not sure so leaving this message here just in case.")
            return r.decode('latin1')  # WM_NAME with type=STRING.
        # Fixing utf8 issue on Ubuntu (
        # Thanks to
            return d.value.decode('utf8')
        except UnicodeError:
            logger.warning("Failed to decode one or more characters which will be skipped, bytes are: {}".format(d.value))
            if isinstance(d.value, bytes):
                return d.value.decode('utf8', 'ignore')
                return d.value.encode('utf8').decode('utf8', 'ignore')

def get_window_class(window: Window) -> str:
    cls = None

        cls = window.get_wm_class()
    except Xlib.error.BadWindow:
        logger.warning("Unable to get window class, got a BadWindow exception.")

    # TODO: Is this needed?
    # nikanar: Indeed, it seems that it is. But it would be interesting to see how often this succeeds, and if it is low, maybe fail earlier.
    if not cls:
        logger.warning("Code made an unclear branch")
            window = window.query_tree().parent
        except Xlib.error.XError as e:
            logger.warning("Unable to get window query_tree().parent, got a {} exception from Xlib".format(type(e).__name__))
            return "unknown"
        if window:
            return get_window_class(window)
            return "unknown"

    cls = cls[1]
    return cls

def get_window_pid(window: Window) -> str:
    atom = display.get_atom("_NET_WM_PID")
    pid_property = window.get_full_property(atom, X.AnyPropertyType)
    if pid_property:
        pid = pid_property.value[-1]
        return pid
        # TODO: Needed?
        raise Exception("pid_property was None")

if __name__ == "__main__":
    from time import sleep

    while True:
        print("-" * 20)
        window = get_current_window()
        if window is None:
            print("unable to get active window")
            name, cls = "unknown", "unknown"
            cls = get_window_class(window)
            name = get_window_name(window)
        print("name:", name)
        print("class:", cls)