# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

from twisted.trial.unittest import TestCase
from twisted.python.failure import Failure

try:
import syslog as stdsyslog
except ImportError:
stdsyslog = None
else:
from twisted.python import syslog



class SyslogObserverTests(TestCase):
"""
Tests for L{SyslogObserver} which sends Twisted log events to the syslog.
"""
events = None

if stdsyslog is None:
skip = "syslog is not supported on this platform"

def setUp(self):
self.patch(syslog.SyslogObserver, 'openlog', self.openlog)
self.patch(syslog.SyslogObserver, 'syslog', self.syslog)
self.observer = syslog.SyslogObserver('SyslogObserverTests')


def openlog(self, prefix, options, facility):
self.logOpened = (prefix, options, facility)
self.events = []


def syslog(self, options, message):
self.events.append((options, message))


def test_emitWithoutMessage(self):
"""
L{SyslogObserver.emit} ignores events with an empty value for the
C{'message'} key.
"""
self.observer.emit({'message': (), 'isError': False, 'system': '-'})
self.assertEqual(self.events, [])


def test_emitCustomPriority(self):
"""
L{SyslogObserver.emit} uses the value of the C{'syslogPriority'} as the
syslog priority, if that key is present in the event dictionary.
"""
self.observer.emit({
'message': ('hello, world',), 'isError': False, 'system': '-',
'syslogPriority': stdsyslog.LOG_DEBUG})
self.assertEqual(
self.events,
[(stdsyslog.LOG_DEBUG, '[-] hello, world')])


def test_emitErrorPriority(self):
"""
L{SyslogObserver.emit} uses C{LOG_ALERT} if the event represents an
error.
"""
self.observer.emit({
'message': ('hello, world',), 'isError': True, 'system': '-',
'failure': Failure(Exception("foo"))})
self.assertEqual(
self.events,
[(stdsyslog.LOG_ALERT, '[-] hello, world')])


def test_emitCustomPriorityOverridesError(self):
"""
L{SyslogObserver.emit} uses the value of the C{'syslogPriority'} key if
it is specified even if the event dictionary represents an error.
"""
self.observer.emit({
'message': ('hello, world',), 'isError': True, 'system': '-',
'syslogPriority': stdsyslog.LOG_NOTICE,
'failure': Failure(Exception("bar"))})
self.assertEqual(
self.events,
[(stdsyslog.LOG_NOTICE, '[-] hello, world')])


def test_emitCustomFacility(self):
"""
L{SyslogObserver.emit} uses the value of the C{'syslogPriority'} as the
syslog priority, if that key is present in the event dictionary.
"""
self.observer.emit({
'message': ('hello, world',), 'isError': False, 'system': '-',
'syslogFacility': stdsyslog.LOG_CRON})
self.assertEqual(
self.events,
[(stdsyslog.LOG_INFO | stdsyslog.LOG_CRON, '[-] hello, world')])


def test_emitCustomSystem(self):
"""
L{SyslogObserver.emit} uses the value of the C{'system'} key to prefix
the logged message.
"""
self.observer.emit({'message': ('hello, world',), 'isError': False,
'system': 'nonDefaultSystem'})
self.assertEqual(
self.events,
[(stdsyslog.LOG_INFO, "[nonDefaultSystem] hello, world")])


def test_emitMessage(self):
"""
L{SyslogObserver.emit} logs the value of the C{'message'} key of the
event dictionary it is passed to the syslog.
"""
self.observer.emit({
'message': ('hello, world',), 'isError': False,
'system': '-'})
self.assertEqual(
self.events,
[(stdsyslog.LOG_INFO, "[-] hello, world")])


def test_emitMultilineMessage(self):
"""
Each line of a multiline message is emitted separately to the syslog.
"""
self.observer.emit({
'message': ('hello,\nworld',), 'isError': False,
'system': '-'})
self.assertEqual(
self.events,
[(stdsyslog.LOG_INFO, '[-] hello,'),
(stdsyslog.LOG_INFO, '[-] \tworld')])


def test_emitStripsTrailingEmptyLines(self):
"""
Trailing empty lines of a multiline message are omitted from the
messages sent to the syslog.
"""
self.observer.emit({
'message': ('hello,\nworld\n\n',), 'isError': False,
'system': '-'})
self.assertEqual(
self.events,
[(stdsyslog.LOG_INFO, '[-] hello,'),
(stdsyslog.LOG_INFO, '[-] \tworld')])