#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright 2014 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.
"""Windows Registry plugin related functions and classes for testing."""

from dfvfs.lib import definitions
from dfvfs.path import factory as path_spec_factory
from dfvfs.resolver import resolver as path_spec_resolver

from plaso.engine import single_process
from plaso.parsers import test_lib
from plaso.winreg import winregistry


class RegistryPluginTestCase(test_lib.ParserTestCase):
  """The unit test case for a Windows Registry plugin."""

  def _GetKeyFromFile(self, path, key_path):
    """Retrieves a Windows Registry key from a file.

    Args:
      path: The path to the file, as a string.
      key_path: The path of the key to parse.

    Returns:
      A Windows Registry key (instance of WinRegKey).
    """
    path_spec = path_spec_factory.Factory.NewPathSpec(
        definitions.TYPE_INDICATOR_OS, location=path)
    file_entry = path_spec_resolver.Resolver.OpenFileEntry(path_spec)
    return self._GetKeyFromFileEntry(file_entry, key_path)

  def _GetKeyFromFileEntry(self, file_entry, key_path):
    """Retrieves a Windows Registry key from a file.

    Args:
      file_entry: A dfVFS file_entry object that references a test file.
      key_path: The path of the key to parse.

    Returns:
      A Windows Registry key (instance of WinRegKey).
    """
    registry = winregistry.WinRegistry(winregistry.WinRegistry.BACKEND_PYREGF)
    winreg_file = registry.OpenFile(file_entry, codepage='cp1252')
    return winreg_file.GetKeyByPath(key_path)

  def _ParseKeyWithPlugin(
      self, plugin_object, winreg_key, knowledge_base_values=None,
      file_entry=None, parser_chain=None):
    """Parses a key within a Windows Registry file using the plugin object.

    Args:
      plugin_object: The plugin object.
      winreg_key: The Windows Registry Key.
      knowledge_base_values: Optional dict containing the knowledge base
                             values. The default is None.
      file_entry: Optional file entry object (instance of dfvfs.FileEntry).
                  The default is None.
      parser_chain: Optional string containing the parsing chain up to this
                    point. The default is None.

    Returns:
      An event object queue consumer object (instance of
      TestEventObjectQueueConsumer).
    """
    self.assertNotEquals(winreg_key, None)

    event_queue = single_process.SingleProcessQueue()
    event_queue_consumer = test_lib.TestEventObjectQueueConsumer(event_queue)

    parse_error_queue = single_process.SingleProcessQueue()

    parser_context = self._GetParserContext(
        event_queue, parse_error_queue,
        knowledge_base_values=knowledge_base_values)
    plugin_object.Process(
        parser_context, key=winreg_key, parser_chain=parser_chain,
        file_entry=file_entry)

    return event_queue_consumer

  def _TestRegvalue(self, event_object, identifier, expected_value):
    """Tests a specific 'regvalue' attribute within the event object.

    Args:
      event_object: the event object (instance of EventObject).
      identifier: the identifier of the 'regvalue' attribute.
      expected_value: the expected value of the 'regvalue' attribute.
    """
    self.assertTrue(hasattr(event_object, 'regvalue'))
    self.assertIn(identifier, event_object.regvalue)
    self.assertEquals(event_object.regvalue[identifier], expected_value)