#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright 2013 The Plaso Project Authors.
# Please see the AUTHORS file for details on individual authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""The unit tests for the generic collector object."""

import logging
import os
import shutil
import tempfile
import unittest

from dfvfs.helpers import file_system_searcher
from dfvfs.lib import definitions as dfvfs_definitions
from dfvfs.path import factory as path_spec_factory
from dfvfs.resolver import context
from dfvfs.resolver import resolver as path_spec_resolver

from plaso.engine import collector
from plaso.engine import queue
from plaso.engine import single_process
from plaso.engine import utils as engine_utils


class TempDirectory(object):
  """A self cleaning temporary directory."""

  def __init__(self):
    """Initializes the temporary directory."""
    super(TempDirectory, self).__init__()
    self.name = u''

  def __enter__(self):
    """Make this work with the 'with' statement."""
    self.name = tempfile.mkdtemp()
    return self.name

  def __exit__(self, unused_type, unused_value, unused_traceback):
    """Make this work with the 'with' statement."""
    shutil.rmtree(self.name, True)


class TestCollectorQueueConsumer(queue.ItemQueueConsumer):
  """Class that implements a test collector queue consumer."""

  def __init__(self, queue_object):
    """Initializes the queue consumer.

    Args:
      queue_object: the queue object (instance of Queue).
    """
    super(TestCollectorQueueConsumer, self).__init__(queue_object)
    self.path_specs = []

  def _ConsumeItem(self, path_spec):
    """Consumes an item callback for ConsumeItems.

    Args:
      path_spec: a path specification (instance of dfvfs.PathSpec).
    """
    self.path_specs.append(path_spec)

  @property
  def number_of_path_specs(self):
    """The number of path specifications."""
    return len(self.path_specs)

  def GetFilePaths(self):
    """Retrieves a list of file paths from the path specifications."""
    file_paths = []
    for path_spec in self.path_specs:
      location = getattr(path_spec, 'location', None)
      if location is not None:
        file_paths.append(location)
    return file_paths


class CollectorTestCase(unittest.TestCase):
  """The collector test case."""

  _TEST_DATA_PATH = os.path.join(os.getcwd(), u'test_data')

  # Show full diff results, part of TestCase so does not follow our naming
  # conventions.
  maxDiff = None

  def _GetTestFilePath(self, path_segments):
    """Retrieves the path of a test file relative to the test data directory.

    Args:
      path_segments: the path segments inside the test data directory.

    Returns:
      A path of the test file.
    """
    # Note that we need to pass the individual path segments to os.path.join
    # and not a list.
    return os.path.join(self._TEST_DATA_PATH, *path_segments)


class CollectorTest(CollectorTestCase):
  """Tests for the collector."""

  def testFileSystemCollection(self):
    """Test collection on the file system."""
    test_files = [
        self._GetTestFilePath([u'syslog.tgz']),
        self._GetTestFilePath([u'syslog.zip']),
        self._GetTestFilePath([u'syslog.bz2']),
        self._GetTestFilePath([u'wtmp.1'])]

    with TempDirectory() as dirname:
      for a_file in test_files:
        shutil.copy(a_file, dirname)

      path_spec = path_spec_factory.Factory.NewPathSpec(
          dfvfs_definitions.TYPE_INDICATOR_OS, location=dirname)

      test_collection_queue = single_process.SingleProcessQueue()
      resolver_context = context.Context()
      test_collector = collector.Collector(
          test_collection_queue, dirname, path_spec,
          resolver_context=resolver_context)
      test_collector.Collect()

      test_collector_queue_consumer = TestCollectorQueueConsumer(
          test_collection_queue)
      test_collector_queue_consumer.ConsumeItems()

      self.assertEquals(test_collector_queue_consumer.number_of_path_specs, 4)

  def testFileSystemWithFilterCollection(self):
    """Test collection on the file system with a filter."""
    dirname = u'.'
    path_spec = path_spec_factory.Factory.NewPathSpec(
        dfvfs_definitions.TYPE_INDICATOR_OS, location=dirname)

    filter_name = ''
    with tempfile.NamedTemporaryFile(delete=False) as temp_file:
      filter_name = temp_file.name
      temp_file.write('/test_data/testdir/filter_.+.txt\n')
      temp_file.write('/test_data/.+evtx\n')
      temp_file.write('/AUTHORS\n')
      temp_file.write('/does_not_exist/some_file_[0-9]+txt\n')

    test_collection_queue = single_process.SingleProcessQueue()
    resolver_context = context.Context()
    test_collector = collector.Collector(
        test_collection_queue, dirname, path_spec,
        resolver_context=resolver_context)

    find_specs = engine_utils.BuildFindSpecsFromFile(filter_name)
    test_collector.SetFilter(find_specs)

    test_collector.Collect()

    test_collector_queue_consumer = TestCollectorQueueConsumer(
        test_collection_queue)
    test_collector_queue_consumer.ConsumeItems()

    try:
      os.remove(filter_name)
    except (OSError, IOError) as exception:
      logging.warning((
          u'Unable to remove temporary file: {0:s} with error: {1:s}').format(
              filter_name, exception))

    # Two files with test_data/testdir/filter_*.txt, AUTHORS
    # and test_data/System.evtx.
    self.assertEquals(test_collector_queue_consumer.number_of_path_specs, 4)

    paths = test_collector_queue_consumer.GetFilePaths()

    current_directory = os.getcwd()

    expected_path = os.path.join(
        current_directory, u'test_data', u'testdir', u'filter_1.txt')
    self.assertTrue(expected_path in paths)

    expected_path = os.path.join(
        current_directory, u'test_data', u'testdir', u'filter_2.txt')
    self.assertFalse(expected_path in paths)

    expected_path = os.path.join(
        current_directory, u'test_data', u'testdir', u'filter_3.txt')
    self.assertTrue(expected_path in paths)

    expected_path = os.path.join(
        current_directory, u'AUTHORS')
    self.assertTrue(expected_path in paths)

  def testImageCollection(self):
    """Test collection on a storage media image file.

    This images has two files:
      + logs/hidden.zip
      + logs/sys.tgz

    The hidden.zip file contains one file, syslog, which is the
    same for sys.tgz.

    The end results should therefore be:
      + logs/hidden.zip (unchanged)
      + logs/hidden.zip:syslog (the text file extracted out)
      + logs/sys.tgz (unchanged)
      + logs/sys.tgz (read as a GZIP file, so not compressed)
      + logs/sys.tgz:syslog.gz (A GZIP file from the TAR container)
      + logs/sys.tgz:syslog.gz:syslog (the extracted syslog file)

    This means that the collection script should collect 6 files in total.
    """
    test_file = self._GetTestFilePath([u'syslog_image.dd'])

    volume_path_spec = path_spec_factory.Factory.NewPathSpec(
        dfvfs_definitions.TYPE_INDICATOR_OS, location=test_file)
    path_spec = path_spec_factory.Factory.NewPathSpec(
        dfvfs_definitions.TYPE_INDICATOR_TSK, location=u'/',
        parent=volume_path_spec)

    test_collection_queue = single_process.SingleProcessQueue()
    resolver_context = context.Context()
    test_collector = collector.Collector(
        test_collection_queue, test_file, path_spec,
        resolver_context=resolver_context)
    test_collector.Collect()

    test_collector_queue_consumer = TestCollectorQueueConsumer(
        test_collection_queue)
    test_collector_queue_consumer.ConsumeItems()

    self.assertEquals(test_collector_queue_consumer.number_of_path_specs, 3)

  def testImageWithFilterCollection(self):
    """Test collection on a storage media image file with a filter."""
    test_file = self._GetTestFilePath([u'ímynd.dd'])

    volume_path_spec = path_spec_factory.Factory.NewPathSpec(
        dfvfs_definitions.TYPE_INDICATOR_OS, location=test_file)
    path_spec = path_spec_factory.Factory.NewPathSpec(
        dfvfs_definitions.TYPE_INDICATOR_TSK, location=u'/',
        parent=volume_path_spec)

    filter_name = ''
    with tempfile.NamedTemporaryFile(delete=False) as temp_file:
      filter_name = temp_file.name
      temp_file.write('/a_directory/.+zip\n')
      temp_file.write('/a_directory/another.+\n')
      temp_file.write('/passwords.txt\n')

    test_collection_queue = single_process.SingleProcessQueue()
    resolver_context = context.Context()
    test_collector = collector.Collector(
        test_collection_queue, test_file, path_spec,
        resolver_context=resolver_context)

    find_specs = engine_utils.BuildFindSpecsFromFile(filter_name)
    test_collector.SetFilter(find_specs)

    test_collector.Collect()

    test_collector_queue_consumer = TestCollectorQueueConsumer(
        test_collection_queue)
    test_collector_queue_consumer.ConsumeItems()

    try:
      os.remove(filter_name)
    except (OSError, IOError) as exception:
      logging.warning((
          u'Unable to remove temporary file: {0:s} with error: {1:s}').format(
              filter_name, exception))

    self.assertEquals(test_collector_queue_consumer.number_of_path_specs, 2)

    paths = test_collector_queue_consumer.GetFilePaths()

    # path_specs[0]
    # type: TSK
    # file_path: '/a_directory/another_file'
    # container_path: 'test_data/ímynd.dd'
    # image_offset: 0
    self.assertEquals(paths[0], u'/a_directory/another_file')

    # path_specs[1]
    # type: TSK
    # file_path: '/passwords.txt'
    # container_path: 'test_data/ímynd.dd'
    # image_offset: 0
    self.assertEquals(paths[1], u'/passwords.txt')


class BuildFindSpecsFromFileTest(unittest.TestCase):
  """Tests for the BuildFindSpecsFromFile function."""

  def testBuildFindSpecsFromFile(self):
    """Tests the BuildFindSpecsFromFile function."""
    filter_name = ''
    with tempfile.NamedTemporaryFile(delete=False) as temp_file:
      filter_name = temp_file.name
      # 2 hits.
      temp_file.write('/test_data/testdir/filter_.+.txt\n')
      # A single hit.
      temp_file.write('/test_data/.+evtx\n')
      # A single hit.
      temp_file.write('/AUTHORS\n')
      temp_file.write('/does_not_exist/some_file_[0-9]+txt\n')
      # This should not compile properly, missing file information.
      temp_file.write('failing/\n')
      # This should not fail during initial loading, but fail later on.
      temp_file.write('bad re (no close on that parenthesis/file\n')

    find_specs = engine_utils.BuildFindSpecsFromFile(filter_name)

    try:
      os.remove(filter_name)
    except (OSError, IOError) as exception:
      logging.warning(
          u'Unable to remove temporary file: {0:s} with error: {1:s}'.format(
              filter_name, exception))

    self.assertEquals(len(find_specs), 4)

    dirname = u'.'
    path_spec = path_spec_factory.Factory.NewPathSpec(
        dfvfs_definitions.TYPE_INDICATOR_OS, location=dirname)
    file_system = path_spec_resolver.Resolver.OpenFileSystem(path_spec)
    searcher = file_system_searcher.FileSystemSearcher(
        file_system, path_spec)

    path_spec_generator = searcher.Find(find_specs=find_specs)
    self.assertNotEquals(path_spec_generator, None)

    path_specs = list(path_spec_generator)
    # One evtx, one AUTHORS, two filter_*.txt files, total 4 files.
    self.assertEquals(len(path_specs), 4)

    with self.assertRaises(IOError):
      _ = engine_utils.BuildFindSpecsFromFile('thisfiledoesnotexist')


if __name__ == '__main__':
  unittest.main()