# This file is part of cloud-init. See LICENSE file for license information.

"""Tests for cloudinit.log """

import datetime

import io

import logging

import time

from cloudinit import log as ci_logging

from cloudinit.analyze.dump import CLOUD_INIT_ASCTIME_FMT

from cloudinit.tests.helpers import CiTestCase

class TestCloudInitLogger(CiTestCase):

    def setUp(self):

        # set up a logger like cloud-init does in setupLogging, but instead

        # of sys.stderr, we'll plug in a StringIO() object so we can see

        # what gets logged

        logging.Formatter.converter = time.gmtime

        self.ci_logs = io.StringIO()

        self.ci_root = logging.getLogger()

        console = logging.StreamHandler(self.ci_logs)

        console.setFormatter(logging.Formatter(ci_logging.DEF_CON_FORMAT))

        console.setLevel(ci_logging.DEBUG)

        self.ci_root.addHandler(console)

        self.ci_root.setLevel(ci_logging.DEBUG)

        self.LOG = logging.getLogger('test_cloudinit_logger')

    def test_logger_uses_gmtime(self):

        """Test that log message have timestamp in UTC (gmtime)"""

        # Log a message, extract the timestamp from the log entry

        # convert to datetime, and compare to a utc timestamp before

        # and after the logged message.

        # Due to loss of precision in the LOG timestamp, subtract and add

        # time to the utc stamps for comparison

        #

        # utc_before: 2017-08-23 14:19:42.569299

        # parsed dt : 2017-08-23 14:19:43.069000

        # utc_after : 2017-08-23 14:19:43.570064

        utc_before = datetime.datetime.utcnow() - datetime.timedelta(0, 0.5)

        self.LOG.error('Test message')

        utc_after = datetime.datetime.utcnow() + datetime.timedelta(0, 0.5)

        # extract timestamp from log:

        # 2017-08-23 14:19:43,069 - test_log.py[ERROR]: Test message

        logstr = self.ci_logs.getvalue().splitlines()[0]

        timestampstr = logstr.split(' - ')[0]

        parsed_dt = datetime.datetime.strptime(timestampstr,

                                               CLOUD_INIT_ASCTIME_FMT)

        self.assertLess(utc_before, parsed_dt)

        self.assertLess(parsed_dt, utc_after)

        self.assertLess(utc_before, utc_after)

        self.assertGreater(utc_after, parsed_dt)