#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import unicode_literals, print_function

import argparse
parser = argparse.ArgumentParser(
	description='Tool to compare the set of enabled'
		' systemd services against currently running ones.\n'
	'If started without parameters, it\'ll just show all the enabled services'
		' that should be running (Type != oneshot) yet for some reason they aren\'t.')
parser.add_argument('-s', '--status',
	action='store_true', help='Show status report on found services.')
parser.add_argument('-u', '--unknown',
	action='store_true', help='Show enabled but unknown (not loaded) services.')
parser.add_argument('-n', '--not-enabled',
	action='store_true', help='Show list of services that are running but are not enabled directly.')
parser.add_argument('-x', '--systemd-internals',
	action='store_true', help='Dont exclude systemd internal services from the output.')
optz = parser.parse_args()


import itertools as it, operator as op, functools as ft
import os, sys


from glob import iglob

class Service(object):

	_cache = dict()

	def __new__(cls, unit=None, id=None):
		if unit: id = unicode(unit[0])
		try: self = cls._cache[id]
		except KeyError:
			self = super(Service, cls).__new__(cls)
			self.id = id
			cls._cache[id] = self
		if unit:
			self.obj = unit[6]
			self.state = tuple(it.imap(unicode, unit[3:5]))
		return self

	def __repr__(self): return self.id
	def __eq__(self, other): return hash(self) == hash(other)
	def __hash__(self):
		if self.id is None: raise ValueError
		return hash(self.id)

	@property
	def type(self):
		return unicode(bus.get_object('org.freedesktop.systemd1', self.obj)\
			.Get( 'org.freedesktop.systemd1.Service', 'Type',
				dbus_interface='org.freedesktop.DBus.Properties' ))

class ServiceLink(object):

	def __init__(self, path):
		self.path = path
		self.eid = unicode(self.path).split('/', 4)[-1]
		self.id = self.eid.split('/', 1)[-1]
		self.masked = os.readlink(self.path) == '/dev/null'

	def __hash__(self):
		if self.eid is None: raise ValueError
		return hash(self.eid)

	def to_service(self): return Service(id=self.id)


svc_links_list = set(it.imap(ServiceLink, it.chain.from_iterable(it.imap( iglob,
	('/etc/systemd/system/*/*.service', '/lib/systemd/system/*/*.service') ))))

svc_links_masked = set(it.ifilter(op.attrgetter('masked'), svc_links_list))
svc_links_enabled = svc_links_list - svc_links_masked

svc_enabled = set(it.imap(op.methodcaller('to_service'), svc_links_enabled))


import dbus

bus = dbus.SystemBus()
svc_known = set( Service(unit)
	for unit in bus.get_object(
		'org.freedesktop.systemd1',
		'/org/freedesktop/systemd1' ).ListUnits()
	if unit[0].endswith('.service') )

if optz.unknown:
	for svc in svc_enabled.difference(svc_known): print('{}'.format(svc))

elif optz.not_enabled:
	for svc in svc_known.difference(svc_enabled):
		if not optz.systemd_internals and svc.id.startswith('systemd-'): continue
		if svc.state == ('active', 'running'): print(svc)

else:
	for svc in svc_enabled.intersection(svc_known):
		if svc.state[0] == 'active' or svc.type == 'oneshot': continue
		if not optz.systemd_internals and svc.id.startswith('systemd-'): continue
		if optz.status:
			from subprocess import Popen, STDOUT
			print()
			Popen(['systemctl', 'status', unicode(svc)], stdout=sys.stderr, stderr=STDOUT).wait()
		else: print(svc)
	if optz.status: print()