#!/usr/bin/env python3

import dbus
import sys
import os
import fcntl
import subprocess
import getpass
import argparse
from collections import OrderedDict
from dbusmock import DBusTestCase
from dbus.mainloop.glib import DBusGMainLoop
from pathlib import Path


def get_subprocess_stdout():
    if os.getenv('META_DBUS_RUNNER_VERBOSE') == '1':
        return sys.stderr
    else:
        return subprocess.DEVNULL;


class MutterDBusRunner(DBusTestCase):
    @classmethod
    def __get_templates_dir(klass):
            return os.path.join(os.path.dirname(__file__), 'dbusmock-templates')

    @classmethod
    def setUpClass(klass, enable_kvm):
        klass.templates_dirs = [klass.__get_templates_dir()]

        klass.mocks = OrderedDict()

        print('Starting D-Bus daemons (session & system)...', file=sys.stderr)
        DBusTestCase.setUpClass()
        klass.start_session_bus()
        klass.start_system_bus()

        print('Starting mocked services...', file=sys.stderr)
        (klass.mocks_manager, klass.mock_obj) = klass.start_from_local_template(
            'meta-mocks-manager', {'templates-dir': klass.__get_templates_dir()})

        klass.start_from_local_template('localed')
        klass.start_from_local_template('colord')
        klass.start_from_local_template('gsd-color')

        klass.system_bus_con = klass.get_dbus(system_bus=True)
        klass.session_bus_con = klass.get_dbus(system_bus=False)

        klass.init_logind(enable_kvm)

        if klass.session_bus_con.name_has_owner('org.gnome.Mutter.DisplayConfig'):
            raise Exception(
                'org.gnome.Mutter.DisplayConfig already has owner on the session bus, bailing')

    @classmethod
    def tearDownClass(klass):
        klass.mock_obj.Cleanup()

        for (mock_server, mock_obj) in reversed(klass.mocks.values()):
            mock_server.terminate()
            mock_server.wait()

        DBusTestCase.tearDownClass()

    @classmethod
    def start_from_template(klass, template, params={}, system_bus=None):
        mock_server, mock_obj = \
            klass.spawn_server_template(template,
                                        params,
                                        get_subprocess_stdout(),
                                        system_bus=system_bus)

        mocks = (mock_server, mock_obj)
        return mocks

    @classmethod
    def start_from_local_template(klass, template_file_name, params={}, system_bus=None):
        template = klass.find_template(template_file_name)
        return klass.start_from_template(template, params, system_bus=system_bus)

    @classmethod
    def start_from_template_managed(klass, template):
        klass.mock_obj.StartFromTemplate(template)

    @classmethod
    def start_from_local_template_managed(klass, template_file_name):
        template = klass.find_template(template_file_name)
        klass.mock_obj.StartFromLocalTemplate(template)

    @classmethod
    def start_from_class(klass, mock_class, params={}):
        mock_server = \
            klass.spawn_server(mock_class.BUS_NAME,
                               mock_class.MAIN_OBJ,
                               mock_class.MAIN_IFACE,
                               mock_class.SYSTEM_BUS,
                               stdout=get_subprocess_stdout())

        bus = klass.get_dbus(system_bus=mock_class.SYSTEM_BUS)
        mock_obj = bus.get_object(mock_class.BUS_NAME, mock_class.MAIN_OBJ)
        mock_class.load(mock_obj, params)

        mocks = (mock_server, mock_obj)
        return mocks

    @classmethod
    def init_logind_kvm(klass, session_path):
        session_obj = klass.system_bus_con.get_object('org.freedesktop.login1', session_path)
        session_obj.AddMethod('org.freedesktop.login1.Session',
                              'TakeDevice',
                              'uu', 'hb',
'''
import re

major = args[0]
minor = args[1]

sysfs_uevent_path = '/sys/dev/char/{}:{}/uevent'.format(major, minor)
sysfs_uevent = open(sysfs_uevent_path, 'r')
devname = None
for line in sysfs_uevent.readlines():
    match = re.match('DEVNAME=(.*)', line)
    if match:
        devname = match[1]
        break
sysfs_uevent.close()
if not devname:
    raise dbus.exceptions.DBusException(f'Device file {major}:{minor} doesn\\\'t exist',
                                        major=major, minor=minor)
fd = os.open('/dev/' + devname, os.O_RDWR | os.O_CLOEXEC)
unix_fd = dbus.types.UnixFd(fd)
os.close(fd)
ret = (unix_fd, False)
''')
        session_obj.AddMethods('org.freedesktop.login1.Session', [
            ('ReleaseDevice', 'uu', '', ''),
            ('TakeControl', 'b', '', ''),
        ])

    @classmethod
    def init_logind(klass, enable_kvm):
        logind = klass.start_from_template('logind')

        [p_mock, obj] = logind

        mock_iface = 'org.freedesktop.DBus.Mock'
        obj.AddSeat('seat0', dbus_interface=mock_iface)
        session_path = obj.AddSession('dummy', 'seat0',
                                      dbus.types.UInt32(os.getuid()),
                                      getpass.getuser(),
                                      True,
                                      dbus_interface=mock_iface)

        if enable_kvm:
            klass.init_logind_kvm(session_path)

    @classmethod
    def add_template_dir(klass, templates_dir):
        klass.templates_dirs += [templates_dir]

    @classmethod
    def find_template(klass, template_name):
        for templates_dir in klass.templates_dirs:
            template_path = os.path.join(templates_dir, template_name + '.py')
            template_file = Path(template_path)
            if template_file.is_file():
                return template_path
        raise FileNotFoundError(f'Couldnt find a {template_name} template')

    def wrap_call(self, args):
        env = {}
        env.update(os.environ)
        env['NO_AT_BRIDGE'] = '1'
        env['GSETTINGS_BACKEND'] = 'memory'

        wrapper = env.get('META_DBUS_RUNNER_WRAPPER')
        if wrapper == 'gdb':
            args = ['gdb', '-ex', 'r', '-ex', 'bt full', '--args'] + args
        elif wrapper:
            args = wrapper.split(' ') + args

        p = subprocess.Popen(args, env=env)
        return p.wait()


def meta_run(klass):
    DBusGMainLoop(set_as_default=True)

    parser = argparse.ArgumentParser()
    parser.add_argument('--kvm', action='store_true', default=False)
    (args, rest) = parser.parse_known_args(sys.argv)

    rest.pop(0)
    if rest[0] == '--':
      rest.pop(0)

    klass.setUpClass(args.kvm)
    runner = klass()
    runner.assertGreater(len(rest), 0)
    result = 1

    try:
        print('Running test case...', file=sys.stderr)
        result = runner.wrap_call(rest)
    finally:
        MutterDBusRunner.tearDownClass()
    return result