#!/usr/bin/python
#

# Copyright (C) 2011 Google Inc.
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"""Script for testing ganeti.utils.log"""

import os
import unittest
import logging
import tempfile
import shutil
import threading
from cStringIO import StringIO

from ganeti import constants
from ganeti import errors
from ganeti import compat
from ganeti import utils

import testutils


class TestLogHandler(unittest.TestCase):
  def testNormal(self):
    tmpfile = tempfile.NamedTemporaryFile()

    handler = utils.log._ReopenableLogHandler(tmpfile.name)
    handler.setFormatter(logging.Formatter("%(asctime)s: %(message)s"))

    logger = logging.Logger("TestLogger")
    logger.addHandler(handler)
    self.assertEqual(len(logger.handlers), 1)

    logger.error("Test message ERROR")
    logger.info("Test message INFO")

    logger.removeHandler(handler)
    self.assertFalse(logger.handlers)
    handler.close()

    self.assertEqual(len(utils.ReadFile(tmpfile.name).splitlines()), 2)

  def testReopen(self):
    tmpfile = tempfile.NamedTemporaryFile()
    tmpfile2 = tempfile.NamedTemporaryFile()

    handler = utils.log._ReopenableLogHandler(tmpfile.name)

    self.assertFalse(utils.ReadFile(tmpfile.name))
    self.assertFalse(utils.ReadFile(tmpfile2.name))

    logger = logging.Logger("TestLoggerReopen")
    logger.addHandler(handler)

    for _ in range(3):
      logger.error("Test message ERROR")
    handler.flush()
    self.assertEqual(len(utils.ReadFile(tmpfile.name).splitlines()), 3)
    before_id = utils.GetFileID(tmpfile.name)

    handler.RequestReopen()
    self.assertTrue(handler._reopen)
    self.assertTrue(utils.VerifyFileID(utils.GetFileID(tmpfile.name),
                                       before_id))

    # Rename only after requesting reopen
    os.rename(tmpfile.name, tmpfile2.name)
    assert not os.path.exists(tmpfile.name)

    # Write another message, should reopen
    for _ in range(4):
      logger.info("Test message INFO")

      # Flag must be reset
      self.assertFalse(handler._reopen)

      self.assertFalse(utils.VerifyFileID(utils.GetFileID(tmpfile.name),
                                          before_id))

    logger.removeHandler(handler)
    self.assertFalse(logger.handlers)
    handler.close()

    self.assertEqual(len(utils.ReadFile(tmpfile.name).splitlines()), 4)
    self.assertEqual(len(utils.ReadFile(tmpfile2.name).splitlines()), 3)

  def testConsole(self):
    for (console, check) in [(None, False),
                             (tempfile.NamedTemporaryFile(), True),
                             (self._FailingFile(os.devnull), False)]:
      # Create a handler which will fail when handling errors
      cls = utils.log._LogErrorsToConsole(self._FailingHandler)

      # Instantiate handler with file which will fail when writing,
      # provoking a write to the console
      handler = cls(console, self._FailingFile(os.devnull))

      logger = logging.Logger("TestLogger")
      logger.addHandler(handler)
      self.assertEqual(len(logger.handlers), 1)

      # Provoke write
      logger.error("Test message ERROR")

      # Take everything apart
      logger.removeHandler(handler)
      self.assertFalse(logger.handlers)
      handler.close()

      if console and check:
        console.flush()

        # Check console output
        consout = utils.ReadFile(console.name)
        self.assertTrue("Cannot log message" in consout)
        self.assertTrue("Test message ERROR" in consout)

  class _FailingFile(file):
    def write(self, _):
      raise Exception

  class _FailingHandler(logging.StreamHandler):
    def handleError(self, _):
      raise Exception


class TestSetupLogging(unittest.TestCase):
  def setUp(self):
    self.tmpdir = tempfile.mkdtemp()

  def tearDown(self):
    shutil.rmtree(self.tmpdir)

  def testSimple(self):
    logfile = utils.PathJoin(self.tmpdir, "basic.log")
    logger = logging.Logger("TestLogger")
    self.assertTrue(callable(utils.SetupLogging(logfile, "test",
                                                console_logging=False,
                                                syslog=constants.SYSLOG_NO,
                                                stderr_logging=False,
                                                multithreaded=False,
                                                root_logger=logger)))
    self.assertEqual(utils.ReadFile(logfile), "")
    logger.error("This is a test")

    # Ensure SetupLogging used custom logger
    logging.error("This message should not show up in the test log file")

    self.assertTrue(utils.ReadFile(logfile).endswith("This is a test\n"))

  def testReopen(self):
    logfile = utils.PathJoin(self.tmpdir, "reopen.log")
    logfile2 = utils.PathJoin(self.tmpdir, "reopen.log.OLD")
    logger = logging.Logger("TestLogger")
    reopen_fn = utils.SetupLogging(logfile, "test",
                                   console_logging=False,
                                   syslog=constants.SYSLOG_NO,
                                   stderr_logging=False,
                                   multithreaded=False,
                                   root_logger=logger)
    self.assertTrue(callable(reopen_fn))

    self.assertEqual(utils.ReadFile(logfile), "")
    logger.error("This is a test")
    self.assertTrue(utils.ReadFile(logfile).endswith("This is a test\n"))

    os.rename(logfile, logfile2)
    assert not os.path.exists(logfile)

    # Notify logger to reopen on the next message
    reopen_fn()
    assert not os.path.exists(logfile)

    # Provoke actual reopen
    logger.error("First message")

    self.assertTrue(utils.ReadFile(logfile).endswith("First message\n"))
    self.assertTrue(utils.ReadFile(logfile2).endswith("This is a test\n"))


if __name__ == "__main__":
  testutils.GanetiTestProgram()