#!/usr/bin/env python3
"""Capture one frame through the Jarvis GNOME Shell helper, then the Screenshot portal."""
import sys
from gi.repository import Gio, GLib

target = sys.argv[1]
bus = Gio.bus_get_sync(Gio.BusType.SESSION, None)


def jarvis_shell_screenshot():
    proxy = Gio.DBusProxy.new_sync(
        bus, Gio.DBusProxyFlags.NONE, None,
        'io.qvac.Jarvis.Shell', '/io/qvac/Jarvis/Shell',
        'io.qvac.Jarvis.Shell', None,
    )
    path = proxy.call_sync(
        'Screenshot',
        GLib.Variant('(s)', (target,)),
        Gio.DBusCallFlags.NONE,
        5000,
        None,
    ).unpack()[0]
    if not path:
        raise RuntimeError('Jarvis Shell screenshot returned no path')
    return path


def portal_screenshot():
    proxy = Gio.DBusProxy.new_sync(
        bus, Gio.DBusProxyFlags.NONE, None,
        'org.freedesktop.portal.Desktop', '/org/freedesktop/portal/desktop',
        'org.freedesktop.portal.Screenshot', None,
    )
    options = {'interactive': GLib.Variant('b', False)}
    try:
        request = proxy.call_sync('Screenshot', GLib.Variant('(a{sv})', (options,)), Gio.DBusCallFlags.NONE, 8000, None).unpack()[0]
    except Exception:
        request = proxy.call_sync('Screenshot', GLib.Variant('(sa{sv})', ('', options)), Gio.DBusCallFlags.NONE, 8000, None).unpack()[0]
    loop = GLib.MainLoop()
    result = {'uri': None}

    def response(_conn, _sender, _path, _interface, _member, params):
        code, values = params.unpack()
        if code == 0:
            result['uri'] = values.get('uri')
        loop.quit()

    sub = bus.signal_subscribe(None, 'org.freedesktop.portal.Request', 'Response', request, None, Gio.DBusSignalFlags.NONE, response)
    GLib.timeout_add(4000, loop.quit)
    loop.run()
    bus.signal_unsubscribe(sub)
    if not result['uri']:
        raise RuntimeError('Screenshot portal returned no image URI')
    ok, contents, _etag = Gio.File.new_for_uri(result['uri']).load_contents(None)
    if not ok:
        raise RuntimeError('could not read screenshot portal URI')
    Gio.File.new_for_path(target).replace_contents(contents, None, False, Gio.FileCreateFlags.REPLACE_DESTINATION, None)
    return target


errors = []
for capture in (jarvis_shell_screenshot, portal_screenshot):
    try:
        print(capture())
        raise SystemExit(0)
    except Exception as exc:
        errors.append(f'{capture.__name__}: {exc}')
raise SystemExit('; '.join(errors) or 'screenshot unavailable')