text: # Copyright: (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
  # Copyright: (c) 2017, Ansible Project
  # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
  
  from __future__ import (absolute_import, division, print_function)
  __metaclass__ = type
  
  import itertools
  import operator
  import os
  
  from copy import copy as shallowcopy
  from functools import partial
  
  from jinja2.exceptions import UndefinedError
  
  from ansible import constants as C
  from ansible import context
  from ansible.errors import AnsibleError
  from ansible.module_utils.six import iteritems, string_types, with_metaclass
  from ansible.module_utils.parsing.convert_bool import boolean
  from ansible.errors import AnsibleParserError, AnsibleUndefinedVariable, AnsibleAssertionError
  from ansible.module_utils._text import to_text, to_native
  from ansible.parsing.dataloader import DataLoader
  from ansible.playbook.attribute import Attribute, FieldAttribute
  from ansible.plugins.loader import module_loader, action_loader
  from ansible.utils.collection_loader._collection_finder import _get_collection_metadata, AnsibleCollectionRef
  from ansible.utils.display import Display
  from ansible.utils.sentinel import Sentinel
  from ansible.utils.vars import combine_vars, isidentifier, get_unique_id
  
  display = Display()
  
  
  def _generic_g(prop_name, self):
      try:
          value = self._attributes[prop_name]
      except KeyError:
          raise AttributeError("'%s' object has no attribute '%s'" % (self.__class__.__name__, prop_name))
  
      if value is Sentinel:
          value = self._attr_defaults[prop_name]
  
      return value
  
  
  def _generic_g_method(prop_name, self):
      try:
          if self._squashed:
              return self._attributes[prop_name]
          method = "_get_attr_%s" % prop_name
          return getattr(self, method)()
      except KeyError:
          raise AttributeError("'%s' object has no attribute '%s'" % (self.__class__.__name__, prop_name))
  
  
  def _generic_g_parent(prop_name, self):
      try:
          if self._squashed or self._finalized:
              value = self._attributes[prop_name]
          else:
              try:
                  value = self._get_parent_attribute(prop_name)
              except AttributeError:
                  value = self._attributes[prop_name]
      except KeyError:
          raise AttributeError("'%s' object has no attribute '%s'" % (self.__class__.__name__, prop_name))
  
      if value is Sentinel:
          value = self._attr_defaults[prop_name]
  
      return value
  
  
  def _generic_s(prop_name, self, value):
      self._attributes[prop_name] = value
  
  
  def _generic_d(prop_name, self):
      del self._attributes[prop_name]
  
  
  def _validate_action_group_metadata(action, found_group_metadata, fq_group_name):
      valid_metadata = {
          'extend_group': {
              'types': (list, string_types,),
              'errortype': 'list',
          },
      }
  
      metadata_warnings = []
  
      validate = C.VALIDATE_ACTION_GROUP_METADATA
      metadata_only = isinstance(action, dict) and 'metadata' in action and len(action) == 1
  
      if validate and not metadata_only:
          found_keys = ', '.join(sorted(list(action)))
          metadata_warnings.append("The only expected key is metadata, but got keys: {keys}".format(keys=found_keys))
      elif validate:
          if found_group_metadata:
              metadata_warnings.append("The group contains multiple metadata entries.")
          if not isinstance(action['metadata'], dict):
              metadata_warnings.append("The metadata is not a dictionary. Got {metadata}".format(metadata=action['metadata']))
          else:
              unexpected_keys = set(action['metadata'].keys()) - set(valid_metadata.keys())
              if unexpected_keys:
                  metadata_warnings.append("The metadata contains unexpected keys: {0}".format(', '.join(unexpected_keys)))
              unexpected_types = []
              for field, requirement in valid_metadata.items():
                  if field not in action['metadata']:
                      continue
                  value = action['metadata'][field]
                  if not isinstance(value, requirement['types']):
                      unexpected_types.append("%s is %s (expected type %s)" % (field, value, requirement['errortype']))
              if unexpected_types:
                  metadata_warnings.append("The metadata contains unexpected key types: {0}".format(', '.join(unexpected_types)))
      if metadata_warnings:
          metadata_warnings.insert(0, "Invalid metadata was found for action_group {0} while loading module_defaults.".format(fq_group_name))
          display.warning(" ".join(metadata_warnings))
  
  
  class BaseMeta(type):
  
      """
      Metaclass for the Base object, which is used to construct the class
      attributes based on the FieldAttributes available.
      """
  
      def __new__(cls, name, parents, dct):
          def _create_attrs(src_dict, dst_dict):
              '''
              Helper method which creates the attributes based on those in the
              source dictionary of attributes. This also populates the other
              attributes used to keep track of these attributes and via the
              getter/setter/deleter methods.
              '''
              keys = list(src_dict.keys())
              for attr_name in keys:
                  value = src_dict[attr_name]
                  if isinstance(value, Attribute):
                      if attr_name.startswith('_'):
                          attr_name = attr_name[1:]
  
                      # here we selectively assign the getter based on a few
                      # things, such as whether we have a _get_attr_<name>
                      # method, or if the attribute is marked as not inheriting
                      # its value from a parent object
                      method = "_get_attr_%s" % attr_name
                      if method in src_dict or method in dst_dict:
                          getter = partial(_generic_g_method, attr_name)
                      elif ('_get_parent_attribute' in dst_dict or '_get_parent_attribute' in src_dict) and value.inherit:
                          getter = partial(_generic_g_parent, attr_name)
                      else:
                          getter = partial(_generic_g, attr_name)
  
                      setter = partial(_generic_s, attr_name)
                      deleter = partial(_generic_d, attr_name)
  
                      dst_dict[attr_name] = property(getter, setter, deleter)
                      dst_dict['_valid_attrs'][attr_name] = value
                      dst_dict['_attributes'][attr_name] = Sentinel
                      dst_dict['_attr_defaults'][attr_name] = value.default
  
                      if value.alias is not None:
                          dst_dict[value.alias] = property(getter, setter, deleter)
                          dst_dict['_valid_attrs'][value.alias] = value
                          dst_dict['_alias_attrs'][value.alias] = attr_name
  
          def _process_parents(parents, dst_dict):
              '''
              Helper method which creates attributes from all parent objects
              recursively on through grandparent objects
              '''
              for parent in parents:
                  if hasattr(parent, '__dict__'):
                      _create_attrs(parent.__dict__, dst_dict)
                      new_dst_dict = parent.__dict__.copy()
                      new_dst_dict.update(dst_dict)
                      _process_parents(parent.__bases__, new_dst_dict)
  
          # create some additional class attributes
          dct['_attributes'] = {}
          dct['_attr_defaults'] = {}
          dct['_valid_attrs'] = {}
          dct['_alias_attrs'] = {}
  
          # now create the attributes based on the FieldAttributes
          # available, including from parent (and grandparent) objects
          _create_attrs(dct, dct)
          _process_parents(parents, dct)
  
          return super(BaseMeta, cls).__new__(cls, name, parents, dct)
  
  
  class FieldAttributeBase(with_metaclass(BaseMeta, object)):
  
      def __init__(self):
  
          # initialize the data loader and variable manager, which will be provided
          # later when the object is actually loaded
          self._loader = None
          self._variable_manager = None
  
          # other internal params
          self._validated = False
          self._squashed = False
          self._finalized = False
  
          # every object gets a random uuid:
          self._uuid = get_unique_id()
  
          # we create a copy of the attributes here due to the fact that
          # it was initialized as a class param in the meta class, so we
          # need a unique object here (all members contained within are
          # unique already).
          self._attributes = self.__class__._attributes.copy()
          self._attr_defaults = self.__class__._attr_defaults.copy()
          for key, value in self._attr_defaults.items():
              if callable(value):
                  self._attr_defaults[key] = value()
  
          # and init vars, avoid using defaults in field declaration as it lives across plays
          self.vars = dict()
  
      @property
      def finalized(self):
          return self._finalized
  
      def dump_me(self, depth=0):
          ''' this is never called from production code, it is here to be used when debugging as a 'complex print' '''
          if depth == 0:
              display.debug("DUMPING OBJECT ------------------------------------------------------")
          display.debug("%s- %s (%s, id=%s)" % (" " * depth, self.__class__.__name__, self, id(self)))
          if hasattr(self, '_parent') and self._parent:
              self._parent.dump_me(depth + 2)
              dep_chain = self._parent.get_dep_chain()
              if dep_chain:
                  for dep in dep_chain:
                      dep.dump_me(depth + 2)
          if hasattr(self, '_play') and self._play:
              self._play.dump_me(depth + 2)
  
      def preprocess_data(self, ds):
          ''' infrequently used method to do some pre-processing of legacy terms '''
          return ds
  
      def load_data(self, ds, variable_manager=None, loader=None):
          ''' walk the input datastructure and assign any values '''
  
          if ds is None:
              raise AnsibleAssertionError('ds (%s) should not be None but it is.' % ds)
  
          # cache the datastructure internally
          setattr(self, '_ds', ds)
  
          # the variable manager class is used to manage and merge variables
          # down to a single dictionary for reference in templating, etc.
          self._variable_manager = variable_manager
  
          # the data loader class is used to parse data from strings and files
          if loader is not None:
              self._loader = loader
          else:
              self._loader = DataLoader()
  
          # call the preprocess_data() function to massage the data into
          # something we can more easily parse, and then call the validation
          # function on it to ensure there are no incorrect key values
          ds = self.preprocess_data(ds)
          self._validate_attributes(ds)
  
          # Walk all attributes in the class. We sort them based on their priority
          # so that certain fields can be loaded before others, if they are dependent.
          for name, attr in sorted(iteritems(self._valid_attrs), key=operator.itemgetter(1)):
              # copy the value over unless a _load_field method is defined
              target_name = name
              if name in self._alias_attrs:
                  target_name = self._alias_attrs[name]
              if name in ds:
                  method = getattr(self, '_load_%s' % name, None)
                  if method:
                      self._attributes[target_name] = method(name, ds[name])
                  else:
                      self._attributes[target_name] = ds[name]
  
          # run early, non-critical validation
          self.validate()
  
          # return the constructed object
          return self
  
      def get_ds(self):
          try:
              return getattr(self, '_ds')
          except AttributeError:
              return None
  
      def get_loader(self):
          return self._loader
  
      def get_variable_manager(self):
          return self._variable_manager
  
      def _post_validate_debugger(self, attr, value, templar):
          value = templar.template(value)
          valid_values = frozenset(('always', 'on_failed', 'on_unreachable', 'on_skipped', 'never'))
          if value and isinstance(value, string_types) and value not in valid_values:
              raise AnsibleParserError("'%s' is not a valid value for debugger. Must be one of %s" % (value, ', '.join(valid_values)), obj=self.get_ds())
          return value
  
      def _validate_attributes(self, ds):
          '''
          Ensures that there are no keys in the datastructure which do
          not map to attributes for this object.
          '''
  
          valid_attrs = frozenset(self._valid_attrs.keys())
          for key in ds:
              if key not in valid_attrs:
                  raise AnsibleParserError("'%s' is not a valid attribute for a %s" % (key, self.__class__.__name__), obj=ds)
  
      def validate(self, all_vars=None):
          ''' validation that is done at parse time, not load time '''
          all_vars = {} if all_vars is None else all_vars
  
          if not self._validated:
              # walk all fields in the object
              for (name, attribute) in iteritems(self._valid_attrs):
  
                  if name in self._alias_attrs:
                      name = self._alias_attrs[name]
  
                  # run validator only if present
                  method = getattr(self, '_validate_%s' % name, None)
                  if method:
                      method(attribute, name, getattr(self, name))
                  else:
                      # and make sure the attribute is of the type it should be
                      value = self._attributes[name]
                      if value is not None:
                          if attribute.isa == 'string' and isinstance(value, (list, dict)):
                              raise AnsibleParserError(
                                  "The field '%s' is supposed to be a string type,"
                                  " however the incoming data structure is a %s" % (name, type(value)), obj=self.get_ds()
                              )
  
          self._validated = True
  
      def _load_module_defaults(self, name, value):
          if value is None:
              return
  
          if not isinstance(value, list):
              value = [value]
  
          validated_module_defaults = []
          for defaults_dict in value:
              if not isinstance(defaults_dict, dict):
                  raise AnsibleParserError(
                      "The field 'module_defaults' is supposed to be a dictionary or list of dictionaries, "
                      "the keys of which must be static action, module, or group names. Only the values may contain "
                      "templates. For example: {'ping': \"{{ ping_defaults }}\"}"
                  )
  
              validated_defaults_dict = {}
              for defaults_entry, defaults in defaults_dict.items():
                  # module_defaults do not use the 'collections' keyword, so actions and
                  # action_groups that are not fully qualified are part of the 'ansible.legacy'
                  # collection. Update those entries here, so module_defaults contains
                  # fully qualified entries.
                  if defaults_entry.startswith('group/'):
                      group_name = defaults_entry.split('group/')[-1]
  
                      # The resolved action_groups cache is associated saved on the current Play
                      if self.play is not None:
                          group_name, dummy = self._resolve_group(group_name)
  
                      defaults_entry = 'group/' + group_name
                      validated_defaults_dict[defaults_entry] = defaults
  
                  else:
                      if len(defaults_entry.split('.')) < 3:
                          defaults_entry = 'ansible.legacy.' + defaults_entry
  
                      resolved_action = self._resolve_action(defaults_entry)
                      if resolved_action:
                          validated_defaults_dict[resolved_action] = defaults
  
                      # If the defaults_entry is an ansible.legacy plugin, these defaults
                      # are inheritable by the 'ansible.builtin' subset, but are not
                      # required to exist.
                      if defaults_entry.startswith('ansible.legacy.'):
                          resolved_action = self._resolve_action(
                              defaults_entry.replace('ansible.legacy.', 'ansible.builtin.'),
                              mandatory=False
                          )
                          if resolved_action:
                              validated_defaults_dict[resolved_action] = defaults
  
              validated_module_defaults.append(validated_defaults_dict)
  
          return validated_module_defaults
  
      @property
      def play(self):
          if hasattr(self, '_play'):
              play = self._play
          elif hasattr(self, '_parent') and hasattr(self._parent, '_play'):
              play = self._parent._play
          else:
              play = self
  
          if play.__class__.__name__ != 'Play':
              # Should never happen, but handle gracefully by returning None, just in case
              return None
  
          return play
  
      def _resolve_group(self, fq_group_name, mandatory=True):
          if not AnsibleCollectionRef.is_valid_fqcr(fq_group_name):
              collection_name = 'ansible.builtin'
              fq_group_name = collection_name + '.' + fq_group_name
          else:
              collection_name = '.'.join(fq_group_name.split('.')[0:2])
  
          # Check if the group has already been resolved and cached
          if fq_group_name in self.play._group_actions:
              return fq_group_name, self.play._group_actions[fq_group_name]
  
          try:
              action_groups = _get_collection_metadata(collection_name).get('action_groups', {})
          except ValueError:
              if not mandatory:
                  display.vvvvv("Error loading module_defaults: could not resolve the module_defaults group %s" % fq_group_name)
                  return fq_group_name, []
  
              raise AnsibleParserError("Error loading module_defaults: could not resolve the module_defaults group %s" % fq_group_name)
  
          # The collection may or may not use the fully qualified name
          # Don't fail if the group doesn't exist in the collection
          resource_name = fq_group_name.split(collection_name + '.')[-1]
          action_group = action_groups.get(
              fq_group_name,
              action_groups.get(resource_name)
          )
          if action_group is None:
              if not mandatory:
                  display.vvvvv("Error loading module_defaults: could not resolve the module_defaults group %s" % fq_group_name)
                  return fq_group_name, []
              raise AnsibleParserError("Error loading module_defaults: could not resolve the module_defaults group %s" % fq_group_name)
  
          resolved_actions = []
          include_groups = []
  
          found_group_metadata = False
          for action in action_group:
              # Everything should be a string except the metadata entry
              if not isinstance(action, string_types):
                  _validate_action_group_metadata(action, found_group_metadata, fq_group_name)
  
                  if isinstance(action['metadata'], dict):
                      found_group_metadata = True
  
                      include_groups = action['metadata'].get('extend_group', [])
                      if isinstance(include_groups, string_types):
                          include_groups = [include_groups]
                      if not isinstance(include_groups, list):
                          # Bad entries may be a warning above, but prevent tracebacks by setting it back to the acceptable type.
                          include_groups = []
                  continue
  
              # The collection may or may not use the fully qualified name.
              # If not, it's part of the current collection.
              if not AnsibleCollectionRef.is_valid_fqcr(action):
                  action = collection_name + '.' + action
              resolved_action = self._resolve_action(action, mandatory=False)
              if resolved_action:
                  resolved_actions.append(resolved_action)
  
          for action in resolved_actions:
              if action not in self.play._action_groups:
                  self.play._action_groups[action] = []
              self.play._action_groups[action].append(fq_group_name)
  
          self.play._group_actions[fq_group_name] = resolved_actions
  
          # Resolve extended groups last, after caching the group in case they recursively refer to each other
          for include_group in include_groups:
              if not AnsibleCollectionRef.is_valid_fqcr(include_group):
                  include_group_collection = collection_name
                  include_group = collection_name + '.' + include_group
              else:
                  include_group_collection = '.'.join(include_group.split('.')[0:2])
  
              dummy, group_actions = self._resolve_group(include_group, mandatory=False)
  
              for action in group_actions:
                  if action not in self.play._action_groups:
                      self.play._action_groups[action] = []
                  self.play._action_groups[action].append(fq_group_name)
  
              self.play._group_actions[fq_group_name].extend(group_actions)
              resolved_actions.extend(group_actions)
  
          return fq_group_name, resolved_actions
  
      def _resolve_action(self, action_name, mandatory=True):
          context = action_loader.find_plugin_with_context(action_name)
          if not context.resolved:
              context = module_loader.find_plugin_with_context(action_name)
  
          if context.resolved:
              return context.resolved_fqcn
          if mandatory:
              raise AnsibleParserError("Could not resolve action %s in module_defaults" % action_name)
          display.vvvvv("Could not resolve action %s in module_defaults" % action_name)
  
      def squash(self):
          '''
          Evaluates all attributes and sets them to the evaluated version,
          so that all future accesses of attributes do not need to evaluate
          parent attributes.
          '''
          if not self._squashed:
              for name in self._valid_attrs.keys():
                  self._attributes[name] = getattr(self, name)
              self._squashed = True
  
      def copy(self):
          '''
          Create a copy of this object and return it.
          '''
  
          try:
              new_me = self.__class__()
          except RuntimeError as e:
              raise AnsibleError("Exceeded maximum object depth. This may have been caused by excessive role recursion", orig_exc=e)
  
          for name in self._valid_attrs.keys():
              if name in self._alias_attrs:
                  continue
              new_me._attributes[name] = shallowcopy(self._attributes[name])
              new_me._attr_defaults[name] = shallowcopy(self._attr_defaults[name])
  
          new_me._loader = self._loader
          new_me._variable_manager = self._variable_manager
          new_me._validated = self._validated
          new_me._finalized = self._finalized
          new_me._uuid = self._uuid
  
          # if the ds value was set on the object, copy it to the new copy too
          if hasattr(self, '_ds'):
              new_me._ds = self._ds
  
          return new_me
  
      def get_validated_value(self, name, attribute, value, templar):
          if attribute.isa == 'string':
              value = to_text(value)
          elif attribute.isa == 'int':
              value = int(value)
          elif attribute.isa == 'float':
              value = float(value)
          elif attribute.isa == 'bool':
              value = boolean(value, strict=True)
          elif attribute.isa == 'percent':
              # special value, which may be an integer or float
              # with an optional '%' at the end
              if isinstance(value, string_types) and '%' in value:
                  value = value.replace('%', '')
              value = float(value)
          elif attribute.isa == 'list':
              if value is None:
                  value = []
              elif not isinstance(value, list):
                  value = [value]
              if attribute.listof is not None:
                  for item in value:
                      if not isinstance(item, attribute.listof):
                          raise AnsibleParserError("the field '%s' should be a list of %s, "
                                                   "but the item '%s' is a %s" % (name, attribute.listof, item, type(item)), obj=self.get_ds())
                      elif attribute.required and attribute.listof == string_types:
                          if item is None or item.strip() == "":
                              raise AnsibleParserError("the field '%s' is required, and cannot have empty values" % (name,), obj=self.get_ds())
          elif attribute.isa == 'set':
              if value is None:
                  value = set()
              elif not isinstance(value, (list, set)):
                  if isinstance(value, string_types):
                      value = value.split(',')
                  else:
                      # Making a list like this handles strings of
                      # text and bytes properly
                      value = [value]
              if not isinstance(value, set):
                  value = set(value)
          elif attribute.isa == 'dict':
              if value is None:
                  value = dict()
              elif not isinstance(value, dict):
                  raise TypeError("%s is not a dictionary" % value)
          elif attribute.isa == 'class':
              if not isinstance(value, attribute.class_type):
                  raise TypeError("%s is not a valid %s (got a %s instead)" % (name, attribute.class_type, type(value)))
              value.post_validate(templar=templar)
          return value
  
      def post_validate(self, templar):
          '''
          we can't tell that everything is of the right type until we have
          all the variables.  Run basic types (from isa) as well as
          any _post_validate_<foo> functions.
          '''
  
          # save the omit value for later checking
          omit_value = templar.available_variables.get('omit')
  
          for (name, attribute) in iteritems(self._valid_attrs):
  
              if attribute.static:
                  value = getattr(self, name)
  
                  # we don't template 'vars' but allow template as values for later use
                  if name not in ('vars',) and templar.is_template(value):
                      display.warning('"%s" is not templatable, but we found: %s, '
                                      'it will not be templated and will be used "as is".' % (name, value))
                  continue
  
              if getattr(self, name) is None:
                  if not attribute.required:
                      continue
                  else:
                      raise AnsibleParserError("the field '%s' is required but was not set" % name)
              elif not attribute.always_post_validate and self.__class__.__name__ not in ('Task', 'Handler', 'PlayContext'):
                  # Intermediate objects like Play() won't have their fields validated by
                  # default, as their values are often inherited by other objects and validated
                  # later, so we don't want them to fail out early
                  continue
  
              try:
                  # Run the post-validator if present. These methods are responsible for
                  # using the given templar to template the values, if required.
                  method = getattr(self, '_post_validate_%s' % name, None)
                  if method:
                      value = method(attribute, getattr(self, name), templar)
                  elif attribute.isa == 'class':
                      value = getattr(self, name)
                  else:
                      # if the attribute contains a variable, template it now
                      value = templar.template(getattr(self, name))
  
                  # if this evaluated to the omit value, set the value back to
                  # the default specified in the FieldAttribute and move on
                  if omit_value is not None and value == omit_value:
                      if callable(attribute.default):
                          setattr(self, name, attribute.default())
                      else:
                          setattr(self, name, attribute.default)
                      continue
  
                  # and make sure the attribute is of the type it should be
                  if value is not None:
                      value = self.get_validated_value(name, attribute, value, templar)
  
                  # and assign the massaged value back to the attribute field
                  setattr(self, name, value)
              except (TypeError, ValueError) as e:
                  value = getattr(self, name)
                  raise AnsibleParserError("the field '%s' has an invalid value (%s), and could not be converted to an %s."
                                           "The error was: %s" % (name, value, attribute.isa, e), obj=self.get_ds(), orig_exc=e)
              except (AnsibleUndefinedVariable, UndefinedError) as e:
                  if templar._fail_on_undefined_errors and name != 'name':
                      if name == 'args':
                          msg = "The task includes an option with an undefined variable. The error was: %s" % (to_native(e))
                      else:
                          msg = "The field '%s' has an invalid value, which includes an undefined variable. The error was: %s" % (name, to_native(e))
                      raise AnsibleParserError(msg, obj=self.get_ds(), orig_exc=e)
  
          self._finalized = True
  
      def _load_vars(self, attr, ds):
          '''
          Vars in a play can be specified either as a dictionary directly, or
          as a list of dictionaries. If the later, this method will turn the
          list into a single dictionary.
          '''
  
          def _validate_variable_keys(ds):
              for key in ds:
                  if not isidentifier(key):
                      raise TypeError("'%s' is not a valid variable name" % key)
  
          try:
              if isinstance(ds, dict):
                  _validate_variable_keys(ds)
                  return combine_vars(self.vars, ds)
              elif isinstance(ds, list):
                  all_vars = self.vars
                  for item in ds:
                      if not isinstance(item, dict):
                          raise ValueError
                      _validate_variable_keys(item)
                      all_vars = combine_vars(all_vars, item)
                  return all_vars
              elif ds is None:
                  return {}
              else:
                  raise ValueError
          except ValueError as e:
              raise AnsibleParserError("Vars in a %s must be specified as a dictionary, or a list of dictionaries" % self.__class__.__name__,
                                       obj=ds, orig_exc=e)
          except TypeError as e:
              raise AnsibleParserError("Invalid variable name in vars specified for %s: %s" % (self.__class__.__name__, e), obj=ds, orig_exc=e)
  
      def _extend_value(self, value, new_value, prepend=False):
          '''
          Will extend the value given with new_value (and will turn both
          into lists if they are not so already). The values are run through
          a set to remove duplicate values.
          '''
  
          if not isinstance(value, list):
              value = [value]
          if not isinstance(new_value, list):
              new_value = [new_value]
  
          # Due to where _extend_value may run for some attributes
          # it is possible to end up with Sentinel in the list of values
          # ensure we strip them
          value = [v for v in value if v is not Sentinel]
          new_value = [v for v in new_value if v is not Sentinel]
  
          if prepend:
              combined = new_value + value
          else:
              combined = value + new_value
  
          return [i for i, _ in itertools.groupby(combined) if i is not None]
  
      def dump_attrs(self):
          '''
          Dumps all attributes to a dictionary
          '''
          attrs = {}
          for (name, attribute) in iteritems(self._valid_attrs):
              attr = getattr(self, name)
              if attribute.isa == 'class' and hasattr(attr, 'serialize'):
                  attrs[name] = attr.serialize()
              else:
                  attrs[name] = attr
          return attrs
  
      def from_attrs(self, attrs):
          '''
          Loads attributes from a dictionary
          '''
          for (attr, value) in iteritems(attrs):
              if attr in self._valid_attrs:
                  attribute = self._valid_attrs[attr]
                  if attribute.isa == 'class' and isinstance(value, dict):
                      obj = attribute.class_type()
                      obj.deserialize(value)
                      setattr(self, attr, obj)
                  else:
                      setattr(self, attr, value)
  
          # from_attrs is only used to create a finalized task
          # from attrs from the Worker/TaskExecutor
          # Those attrs are finalized and squashed in the TE
          # and controller side use needs to reflect that
          self._finalized = True
          self._squashed = True
  
      def serialize(self):
          '''
          Serializes the object derived from the base object into
          a dictionary of values. This only serializes the field
          attributes for the object, so this may need to be overridden
          for any classes which wish to add additional items not stored
          as field attributes.
          '''
  
          repr = self.dump_attrs()
  
          # serialize the uuid field
          repr['uuid'] = self._uuid
          repr['finalized'] = self._finalized
          repr['squashed'] = self._squashed
  
          return repr
  
      def deserialize(self, data):
          '''
          Given a dictionary of values, load up the field attributes for
          this object. As with serialize(), if there are any non-field
          attribute data members, this method will need to be overridden
          and extended.
          '''
  
          if not isinstance(data, dict):
              raise AnsibleAssertionError('data (%s) should be a dict but is a %s' % (data, type(data)))
  
          for (name, attribute) in iteritems(self._valid_attrs):
              if name in data:
                  setattr(self, name, data[name])
              else:
                  if callable(attribute.default):
                      setattr(self, name, attribute.default())
                  else:
                      setattr(self, name, attribute.default)
  
          # restore the UUID field
          setattr(self, '_uuid', data.get('uuid'))
          self._finalized = data.get('finalized', False)
          self._squashed = data.get('squashed', False)
  
  
  class Base(FieldAttributeBase):
  
      _name = FieldAttribute(isa='string', default='', always_post_validate=True, inherit=False)
  
      # connection/transport
      _connection = FieldAttribute(isa='string', default=context.cliargs_deferred_get('connection'))
      _port = FieldAttribute(isa='int')
      _remote_user = FieldAttribute(isa='string', default=context.cliargs_deferred_get('remote_user'))
  
      # variables
      _vars = FieldAttribute(isa='dict', priority=100, inherit=False, static=True)
  
      # module default params
      _module_defaults = FieldAttribute(isa='list', extend=True, prepend=True)
  
      # flags and misc. settings
      _environment = FieldAttribute(isa='list', extend=True, prepend=True)
      _no_log = FieldAttribute(isa='bool')
      _run_once = FieldAttribute(isa='bool')
      _ignore_errors = FieldAttribute(isa='bool')
      _ignore_unreachable = FieldAttribute(isa='bool')
      _check_mode = FieldAttribute(isa='bool', default=context.cliargs_deferred_get('check'))
      _diff = FieldAttribute(isa='bool', default=context.cliargs_deferred_get('diff'))
      _any_errors_fatal = FieldAttribute(isa='bool', default=C.ANY_ERRORS_FATAL)
      _throttle = FieldAttribute(isa='int', default=0)
      _timeout = FieldAttribute(isa='int', default=C.TASK_TIMEOUT)
  
      # explicitly invoke a debugger on tasks
      _debugger = FieldAttribute(isa='string')
  
      # Privilege escalation
      _become = FieldAttribute(isa='bool', default=context.cliargs_deferred_get('become'))
      _become_method = FieldAttribute(isa='string', default=context.cliargs_deferred_get('become_method'))
      _become_user = FieldAttribute(isa='string', default=context.cliargs_deferred_get('become_user'))
      _become_flags = FieldAttribute(isa='string', default=context.cliargs_deferred_get('become_flags'))
      _become_exe = FieldAttribute(isa='string', default=context.cliargs_deferred_get('become_exe'))
  
      # used to hold sudo/su stuff
      DEPRECATED_ATTRIBUTES = []
  
      def get_path(self):
          ''' return the absolute path of the playbook object and its line number '''
  
          path = ""
          try:
              path = "%s:%s" % (self._ds._data_source, self._ds._line_number)
          except AttributeError:
              try:
                  path = "%s:%s" % (self._parent._play._ds._data_source, self._parent._play._ds._line_number)
              except AttributeError:
                  pass
          return path
  
      def get_dep_chain(self):
  
          if hasattr(self, '_parent') and self._parent:
              return self._parent.get_dep_chain()
          else:
              return None
  
      def get_search_path(self):
          '''
          Return the list of paths you should search for files, in order.
          This follows role/playbook dependency chain.
          '''
          path_stack = []
  
          dep_chain = self.get_dep_chain()
          # inside role: add the dependency chain from current to dependent
          if dep_chain:
              path_stack.extend(reversed([x._role_path for x in dep_chain if hasattr(x, '_role_path')]))
  
          # add path of task itself, unless it is already in the list
          task_dir = os.path.dirname(self.get_path())
          if task_dir not in path_stack:
              path_stack.append(task_dir)
  
          return path_stack
  