text: #
  # Copyright 2012 New Dream Network, LLC (DreamHost)
  # Copyright 2013 IBM Corp.
  # Copyright 2013 eNovance <licensing@enovance.com>
  # Copyright Ericsson AB 2013. All rights reserved
  #
  # Authors: Doug Hellmann <doug.hellmann@dreamhost.com>
  #          Angus Salkeld <asalkeld@redhat.com>
  #          Eoghan Glynn <eglynn@redhat.com>
  #          Julien Danjou <julien@danjou.info>
  #          Ildiko Vancsa <ildiko.vancsa@ericsson.com>
  #          Balazs Gibizer <balazs.gibizer@ericsson.com>
  #
  # 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.
  """Version 2 of the API.
  """
  import ast
  import base64
  import copy
  import croniter
  import datetime
  import functools
  import inspect
  import json
  import jsonschema
  import pytz
  import uuid
  
  from oslo.config import cfg
  from oslo.utils import strutils
  from oslo.utils import timeutils
  import pecan
  from pecan import rest
  import six
  import wsme
  from wsme import types as wtypes
  import wsmeext.pecan as wsme_pecan
  
  from ceilometer.alarm.storage import models as alarm_models
  from ceilometer.api import acl
  from ceilometer import messaging
  from ceilometer.openstack.common import context
  from ceilometer.openstack.common.gettextutils import _
  from ceilometer.openstack.common import log
  from ceilometer import sample
  from ceilometer import storage
  from ceilometer import utils
  
  LOG = log.getLogger(__name__)
  
  
  ALARM_API_OPTS = [
      cfg.BoolOpt('record_history',
                  default=True,
                  help='Record alarm change events.'
                  ),
      cfg.IntOpt('user_alarm_quota',
                 default=None,
                 help='Maximum number of alarms defined for a user.'
                 ),
      cfg.IntOpt('project_alarm_quota',
                 default=None,
                 help='Maximum number of alarms defined for a project.'
                 ),
  ]
  
  cfg.CONF.register_opts(ALARM_API_OPTS, group='alarm')
  
  state_kind = ["ok", "alarm", "insufficient data"]
  state_kind_enum = wtypes.Enum(str, *state_kind)
  operation_kind = ('lt', 'le', 'eq', 'ne', 'ge', 'gt')
  operation_kind_enum = wtypes.Enum(str, *operation_kind)
  
  
  class ClientSideError(wsme.exc.ClientSideError):
      def __init__(self, error, status_code=400):
          pecan.response.translatable_error = error
          super(ClientSideError, self).__init__(error, status_code)
  
  
  class EntityNotFound(ClientSideError):
      def __init__(self, entity, id):
          super(EntityNotFound, self).__init__(
              _("%(entity)s %(id)s Not Found") % {'entity': entity,
                                                  'id': id},
              status_code=404)
  
  
  class AlarmNotFound(ClientSideError):
      def __init__(self, alarm, auth_project):
          if not auth_project:
              msg = _('Alarm %s not found') % alarm
          else:
              msg = _('Alarm %(alarm_id)s not found in project %'
                      '(project)s') % {
                          'alarm_id': alarm, 'project': auth_project}
          super(AlarmNotFound, self).__init__(msg, status_code=404)
  
  
  class OverQuota(ClientSideError):
      def __init__(self, data):
          d = {
              'u': data.user_id,
              'p': data.project_id
          }
          super(OverQuota, self).__init__(
              _("Alarm quota exceeded for user %(u)s on project %(p)s") % d,
              status_code=403)
  
  
  def is_over_quota(conn, project_id, user_id):
      """Returns False if an alarm is within the set quotas, True otherwise.
  
      :param conn: a backend connection object
      :param project_id: the ID of the project setting the alarm
      :param user_id: the ID of the user setting the alarm
      """
  
      over_quota = False
  
      # Start by checking for user quota
      user_alarm_quota = cfg.CONF.alarm.user_alarm_quota
      if user_alarm_quota is not None:
          user_alarms = list(conn.get_alarms(user=user_id))
          over_quota = len(user_alarms) >= user_alarm_quota
  
      # If the user quota isn't reached, we check for the project quota
      if not over_quota:
          project_alarm_quota = cfg.CONF.alarm.project_alarm_quota
          if project_alarm_quota is not None:
              project_alarms = list(conn.get_alarms(project=project_id))
              over_quota = len(project_alarms) >= project_alarm_quota
  
      return over_quota
  
  
  class AdvEnum(wtypes.wsproperty):
      """Handle default and mandatory for wtypes.Enum."""
      def __init__(self, name, *args, **kwargs):
          self._name = '_advenum_%s' % name
          self._default = kwargs.pop('default', None)
          mandatory = kwargs.pop('mandatory', False)
          enum = wtypes.Enum(*args, **kwargs)
          super(AdvEnum, self).__init__(datatype=enum, fget=self._get,
                                        fset=self._set, mandatory=mandatory)
  
      def _get(self, parent):
          if hasattr(parent, self._name):
              value = getattr(parent, self._name)
              return value or self._default
          return self._default
  
      def _set(self, parent, value):
          if self.datatype.validate(value):
              setattr(parent, self._name, value)
  
  
  class CronType(wtypes.UserType):
      """A user type that represents a cron format."""
      basetype = six.string_types
      name = 'cron'
  
      @staticmethod
      def validate(value):
          # raises ValueError if invalid
          croniter.croniter(value)
          return value
  
  
  class _Base(wtypes.Base):
  
      @classmethod
      def from_db_model(cls, m):
          return cls(**(m.as_dict()))
  
      @classmethod
      def from_db_and_links(cls, m, links):
          return cls(links=links, **(m.as_dict()))
  
      def as_dict(self, db_model):
          valid_keys = inspect.getargspec(db_model.__init__)[0]
          if 'self' in valid_keys:
              valid_keys.remove('self')
          return self.as_dict_from_keys(valid_keys)
  
      def as_dict_from_keys(self, keys):
          return dict((k, getattr(self, k))
                      for k in keys
                      if hasattr(self, k) and
                      getattr(self, k) != wsme.Unset)
  
  
  class Link(_Base):
      """A link representation."""
  
      href = wtypes.text
      "The url of a link"
  
      rel = wtypes.text
      "The name of a link"
  
      @classmethod
      def sample(cls):
          return cls(href=('http://localhost:8777/v2/meters/volume?'
                           'q.field=resource_id&'
                           'q.value=bd9431c1-8d69-4ad3-803a-8d4a6b89fd36'),
                     rel='volume'
                     )
  
  
  class Query(_Base):
      """Query filter."""
  
      # The data types supported by the query.
      _supported_types = ['integer', 'float', 'string', 'boolean']
  
      # Functions to convert the data field to the correct type.
      _type_converters = {'integer': int,
                          'float': float,
                          'boolean': functools.partial(
                              strutils.bool_from_string, strict=True),
                          'string': six.text_type,
                          'datetime': timeutils.parse_isotime}
  
      _op = None  # provide a default
  
      def get_op(self):
          return self._op or 'eq'
  
      def set_op(self, value):
          self._op = value
  
      field = wtypes.text
      "The name of the field to test"
  
      # op = wsme.wsattr(operation_kind, default='eq')
      # this ^ doesn't seem to work.
      op = wsme.wsproperty(operation_kind_enum, get_op, set_op)
      "The comparison operator. Defaults to 'eq'."
  
      value = wtypes.text
      "The value to compare against the stored data"
  
      type = wtypes.text
      "The data type of value to compare against the stored data"
  
      def __repr__(self):
          # for logging calls
          return '<Query %r %s %r %s>' % (self.field,
                                          self.op,
                                          self.value,
                                          self.type)
  
      @classmethod
      def sample(cls):
          return cls(field='resource_id',
                     op='eq',
                     value='bd9431c1-8d69-4ad3-803a-8d4a6b89fd36',
                     type='string'
                     )
  
      def as_dict(self):
          return self.as_dict_from_keys(['field', 'op', 'type', 'value'])
  
      def _get_value_as_type(self, forced_type=None):
          """Convert metadata value to the specified data type.
  
          This method is called during metadata query to help convert the
          querying metadata to the data type specified by user. If there is no
          data type given, the metadata will be parsed by ast.literal_eval to
          try to do a smart converting.
  
          NOTE (flwang) Using "_" as prefix to avoid an InvocationError raised
          from wsmeext/sphinxext.py. It's OK to call it outside the Query class.
          Because the "public" side of that class is actually the outside of the
          API, and the "private" side is the API implementation. The method is
          only used in the API implementation, so it's OK.
  
          :returns: metadata value converted with the specified data type.
          """
          type = forced_type or self.type
          try:
              converted_value = self.value
              if not type:
                  try:
                      converted_value = ast.literal_eval(self.value)
                  except (ValueError, SyntaxError):
                      # Unable to convert the metadata value automatically
                      # let it default to self.value
                      pass
              else:
                  if type not in self._supported_types:
                      # Types must be explicitly declared so the
                      # correct type converter may be used. Subclasses
                      # of Query may define _supported_types and
                      # _type_converters to define their own types.
                      raise TypeError()
                  converted_value = self._type_converters[type](self.value)
          except ValueError:
              msg = (_('Unable to convert the value %(value)s'
                       ' to the expected data type %(type)s.') %
                     {'value': self.value, 'type': type})
              raise ClientSideError(msg)
          except TypeError:
              msg = (_('The data type %(type)s is not supported. The supported'
                       ' data type list is: %(supported)s') %
                     {'type': type, 'supported': self._supported_types})
              raise ClientSideError(msg)
          except Exception:
              msg = (_('Unexpected exception converting %(value)s to'
                       ' the expected data type %(type)s.') %
                     {'value': self.value, 'type': type})
              raise ClientSideError(msg)
          return converted_value
  
  
  class ProjectNotAuthorized(ClientSideError):
      def __init__(self, id, aspect='project'):
          params = dict(aspect=aspect, id=id)
          super(ProjectNotAuthorized, self).__init__(
              _("Not Authorized to access %(aspect)s %(id)s") % params,
              status_code=401)
  
  
  def _get_auth_project(on_behalf_of=None):
      # when an alarm is created by an admin on behalf of another tenant
      # we must ensure for:
      # - threshold alarm, that an implicit query constraint on project_id is
      #   added so that admin-level visibility on statistics is not leaked
      # - combination alarm, that alarm ids verification is scoped to
      #   alarms owned by the alarm project.
      # hence for null auth_project (indicating admin-ness) we check if
      # the creating tenant differs from the tenant on whose behalf the
      # alarm is being created
      auth_project = acl.get_limited_to_project(pecan.request.headers)
      created_by = pecan.request.headers.get('X-Project-Id')
      is_admin = auth_project is None
  
      if is_admin and on_behalf_of != created_by:
          auth_project = on_behalf_of
      return auth_project
  
  
  def _sanitize_query(query, db_func, on_behalf_of=None):
      """Check the query.
  
      See if:
      1) the request is coming from admin - then allow full visibility
      2) non-admin - make sure that the query includes the requester's project.
      """
      q = copy.copy(query)
  
      auth_project = _get_auth_project(on_behalf_of)
      if auth_project:
          _verify_query_segregation(q, auth_project)
  
          proj_q = [i for i in q if i.field == 'project_id']
          valid_keys = inspect.getargspec(db_func)[0]
          if not proj_q and 'on_behalf_of' not in valid_keys:
              # The user is restricted, but they didn't specify a project
              # so add it for them.
              q.append(Query(field='project_id',
                             op='eq',
                             value=auth_project))
      return q
  
  
  def _verify_query_segregation(query, auth_project=None):
      """Ensure non-admin queries are not constrained to another project."""
      auth_project = (auth_project or
                      acl.get_limited_to_project(pecan.request.headers))
  
      if not auth_project:
          return
  
      for q in query:
          if q.field in ('project', 'project_id') and auth_project != q.value:
              raise ProjectNotAuthorized(q.value)
  
  
  def _validate_query(query, db_func, internal_keys=None,
                      allow_timestamps=True):
      """Validates the syntax of the query and verifies the query.
  
      Verification check if the query request is authorized for the included
      project.
      :param query: Query expression that should be validated
      :param db_func: the function on the storage level, of which arguments
          will form the valid_keys list, which defines the valid fields for a
          query expression
      :param internal_keys: internally used field names, that should not be
          used for querying
      :param allow_timestamps: defines whether the timestamp-based constraint is
          applicable for this query or not
  
      :returns: None, if the query is valid
  
      :raises InvalidInput: if an operator is not supported for a given field
      :raises InvalidInput: if timestamp constraints are allowed, but
          search_offset was included without timestamp constraint
      :raises: UnknownArgument: if a field name is not a timestamp field, nor
          in the list of valid keys
      """
  
      internal_keys = internal_keys or []
      _verify_query_segregation(query)
  
      valid_keys = inspect.getargspec(db_func)[0]
      internal_keys.append('self')
      valid_keys = set(valid_keys) - set(internal_keys)
      translation = {'user_id': 'user',
                     'project_id': 'project',
                     'resource_id': 'resource'}
  
      has_timestamp_query = _validate_timestamp_fields(query,
                                                       'timestamp',
                                                       ('lt', 'le', 'gt', 'ge'),
                                                       allow_timestamps)
      has_search_offset_query = _validate_timestamp_fields(query,
                                                           'search_offset',
                                                           'eq',
                                                           allow_timestamps)
  
      if has_search_offset_query and not has_timestamp_query:
          raise wsme.exc.InvalidInput('field', 'search_offset',
                                      "search_offset cannot be used without " +
                                      "timestamp")
  
      def _is_field_metadata(field):
          return (field.startswith('metadata.') or
                  field.startswith('resource_metadata.'))
  
      for i in query:
          if i.field not in ('timestamp', 'search_offset'):
              key = translation.get(i.field, i.field)
              operator = i.op
              if key in valid_keys or _is_field_metadata(i.field):
                  if operator == 'eq':
                      if key == 'enabled':
                          i._get_value_as_type('boolean')
                      elif _is_field_metadata(key):
                          i._get_value_as_type()
                  else:
                      raise wsme.exc.InvalidInput('op', i.op,
                                                  'unimplemented operator for '
                                                  '%s' % i.field)
              else:
                  msg = ("unrecognized field in query: %s, "
                         "valid keys: %s") % (query, sorted(valid_keys))
                  raise wsme.exc.UnknownArgument(key, msg)
  
  
  def _validate_timestamp_fields(query, field_name, operator_list,
                                 allow_timestamps):
      """Validates the timestamp related constraints in a query if there are any.
  
      :param query: query expression that may contain the timestamp fields
      :param field_name: timestamp name, which should be checked (timestamp,
          search_offset)
      :param operator_list: list of operators that are supported for that
          timestamp, which was specified in the parameter field_name
      :param allow_timestamps: defines whether the timestamp-based constraint is
          applicable to this query or not
  
      :returns: True, if there was a timestamp constraint, containing
          a timestamp field named as defined in field_name, in the query and it
          was allowed and syntactically correct.
      :returns: False, if there wasn't timestamp constraint, containing a
          timestamp field named as defined in field_name, in the query
  
      :raises InvalidInput: if an operator is unsupported for a given timestamp
          field
      :raises UnknownArgument: if the timestamp constraint is not allowed in
          the query
      """
  
      for item in query:
          if item.field == field_name:
              # If *timestamp* or *search_offset* field was specified in the
              # query, but timestamp is not supported on that resource, on
              # which the query was invoked, then raise an exception.
              if not allow_timestamps:
                  raise wsme.exc.UnknownArgument(field_name,
                                                 "not valid for " +
                                                 "this resource")
              if item.op not in operator_list:
                  raise wsme.exc.InvalidInput('op', item.op,
                                              'unimplemented operator for %s' %
                                              item.field)
              return True
      return False
  
  
  def _query_to_kwargs(query, db_func, internal_keys=None,
                       allow_timestamps=True):
      internal_keys = internal_keys or []
      _validate_query(query, db_func, internal_keys=internal_keys,
                      allow_timestamps=allow_timestamps)
      query = _sanitize_query(query, db_func)
      internal_keys.append('self')
      valid_keys = set(inspect.getargspec(db_func)[0]) - set(internal_keys)
      translation = {'user_id': 'user',
                     'project_id': 'project',
                     'resource_id': 'resource'}
      stamp = {}
      metaquery = {}
      kwargs = {}
      for i in query:
          if i.field == 'timestamp':
              if i.op in ('lt', 'le'):
                  stamp['end_timestamp'] = i.value
                  stamp['end_timestamp_op'] = i.op
              elif i.op in ('gt', 'ge'):
                  stamp['start_timestamp'] = i.value
                  stamp['start_timestamp_op'] = i.op
          else:
              if i.op == 'eq':
                  if i.field == 'search_offset':
                      stamp['search_offset'] = i.value
                  elif i.field == 'enabled':
                      kwargs[i.field] = i._get_value_as_type('boolean')
                  elif i.field.startswith('metadata.'):
                      metaquery[i.field] = i._get_value_as_type()
                  elif i.field.startswith('resource_metadata.'):
                      metaquery[i.field[9:]] = i._get_value_as_type()
                  else:
                      key = translation.get(i.field, i.field)
                      kwargs[key] = i.value
  
      if metaquery and 'metaquery' in valid_keys:
          kwargs['metaquery'] = metaquery
      if stamp:
          q_ts = _get_query_timestamps(stamp)
          if 'start' in valid_keys:
              kwargs['start'] = q_ts['query_start']
              kwargs['end'] = q_ts['query_end']
          elif 'start_timestamp' in valid_keys:
              kwargs['start_timestamp'] = q_ts['query_start']
              kwargs['end_timestamp'] = q_ts['query_end']
          if 'start_timestamp_op' in stamp:
              kwargs['start_timestamp_op'] = stamp['start_timestamp_op']
          if 'end_timestamp_op' in stamp:
              kwargs['end_timestamp_op'] = stamp['end_timestamp_op']
  
      return kwargs
  
  
  def _validate_groupby_fields(groupby_fields):
      """Checks that the list of groupby fields from request is valid.
  
      If all fields are valid, returns fields with duplicates removed.
      """
      # NOTE(terriyu): Currently, metadata fields are not supported in our
      # group by statistics implementation
      valid_fields = set(['user_id', 'resource_id', 'project_id', 'source'])
  
      invalid_fields = set(groupby_fields) - valid_fields
      if invalid_fields:
          raise wsme.exc.UnknownArgument(invalid_fields,
                                         "Invalid groupby fields")
  
      # Remove duplicate fields
      # NOTE(terriyu): This assumes that we don't care about the order of the
      # group by fields.
      return list(set(groupby_fields))
  
  
  def _get_query_timestamps(args=None):
      """Return any optional timestamp information in the request.
  
      Determine the desired range, if any, from the GET arguments. Set
      up the query range using the specified offset.
  
      [query_start ... start_timestamp ... end_timestamp ... query_end]
  
      Returns a dictionary containing:
  
      query_start: First timestamp to use for query
      start_timestamp: start_timestamp parameter from request
      query_end: Final timestamp to use for query
      end_timestamp: end_timestamp parameter from request
      search_offset: search_offset parameter from request
  
      """
      if args is None:
          return {'query_start': None,
                  'query_end': None,
                  'start_timestamp': None,
                  'end_timestamp': None,
                  'search_offset': 0}
      search_offset = int(args.get('search_offset', 0))
  
      start_timestamp = args.get('start_timestamp')
      if start_timestamp:
          start_timestamp = timeutils.parse_isotime(start_timestamp)
          start_timestamp = start_timestamp.replace(tzinfo=None)
          query_start = (start_timestamp -
                         datetime.timedelta(minutes=search_offset))
      else:
          query_start = None
  
      end_timestamp = args.get('end_timestamp')
      if end_timestamp:
          end_timestamp = timeutils.parse_isotime(end_timestamp)
          end_timestamp = end_timestamp.replace(tzinfo=None)
          query_end = end_timestamp + datetime.timedelta(minutes=search_offset)
      else:
          query_end = None
  
      return {'query_start': query_start,
              'query_end': query_end,
              'start_timestamp': start_timestamp,
              'end_timestamp': end_timestamp,
              'search_offset': search_offset,
              }
  
  
  def _flatten_metadata(metadata):
      """Return flattened resource metadata.
  
      Metadata is returned with flattened nested structures (except nested sets)
      and with all values converted to unicode strings.
      """
      if metadata:
          # After changing recursive_keypairs` output we need to keep
          # flattening output unchanged.
          # Example: recursive_keypairs({'a': {'b':{'c':'d'}}}, '.')
          # output before: a.b:c=d
          # output now: a.b.c=d
          # So to keep the first variant just replace all dots except the first
          return dict((k.replace('.', ':').replace(':', '.', 1),
                       six.text_type(v))
                      for k, v in utils.recursive_keypairs(metadata,
                                                           separator='.')
                      if type(v) is not set)
      return {}
  
  
  def _make_link(rel_name, url, type, type_arg, query=None):
      query_str = ''
      if query:
          query_str = '?q.field=%s&q.value=%s' % (query['field'],
                                                  query['value'])
      return Link(href='%s/v2/%s/%s%s' % (url, type, type_arg, query_str),
                  rel=rel_name)
  
  
  def _send_notification(event, payload):
      notification = event.replace(" ", "_")
      notification = "alarm.%s" % notification
      transport = messaging.get_transport()
      notifier = messaging.get_notifier(transport, publisher_id="ceilometer.api")
      # FIXME(sileht): perhaps we need to copy some infos from the
      # pecan request headers like nova does
      notifier.info(context.RequestContext(), notification, payload)
  
  
  class OldSample(_Base):
      """A single measurement for a given meter and resource.
  
      This class is deprecated in favor of Sample.
      """
  
      source = wtypes.text
      "The ID of the source that identifies where the sample comes from"
  
      counter_name = wsme.wsattr(wtypes.text, mandatory=True)
      "The name of the meter"
      # FIXME(dhellmann): Make this meter_name?
  
      counter_type = wsme.wsattr(wtypes.text, mandatory=True)
      "The type of the meter (see :ref:`measurements`)"
      # FIXME(dhellmann): Make this meter_type?
  
      counter_unit = wsme.wsattr(wtypes.text, mandatory=True)
      "The unit of measure for the value in counter_volume"
      # FIXME(dhellmann): Make this meter_unit?
  
      counter_volume = wsme.wsattr(float, mandatory=True)
      "The actual measured value"
  
      user_id = wtypes.text
      "The ID of the user who last triggered an update to the resource"
  
      project_id = wtypes.text
      "The ID of the project or tenant that owns the resource"
  
      resource_id = wsme.wsattr(wtypes.text, mandatory=True)
      "The ID of the :class:`Resource` for which the measurements are taken"
  
      timestamp = datetime.datetime
      "UTC date and time when the measurement was made"
  
      recorded_at = datetime.datetime
      "When the sample has been recorded."
  
      resource_metadata = {wtypes.text: wtypes.text}
      "Arbitrary metadata associated with the resource"
  
      message_id = wtypes.text
      "A unique identifier for the sample"
  
      def __init__(self, counter_volume=None, resource_metadata=None,
                   timestamp=None, **kwds):
          resource_metadata = resource_metadata or {}
          if counter_volume is not None:
              counter_volume = float(counter_volume)
          resource_metadata = _flatten_metadata(resource_metadata)
          # this is to make it easier for clients to pass a timestamp in
          if timestamp and isinstance(timestamp, six.string_types):
              timestamp = timeutils.parse_isotime(timestamp)
  
          super(OldSample, self).__init__(counter_volume=counter_volume,
                                          resource_metadata=resource_metadata,
                                          timestamp=timestamp, **kwds)
  
          if self.resource_metadata in (wtypes.Unset, None):
              self.resource_metadata = {}
  
      @classmethod
      def sample(cls):
          return cls(source='openstack',
                     counter_name='instance',
                     counter_type='gauge',
                     counter_unit='instance',
                     counter_volume=1,
                     resource_id='bd9431c1-8d69-4ad3-803a-8d4a6b89fd36',
                     project_id='35b17138-b364-4e6a-a131-8f3099c5be68',
                     user_id='efd87807-12d2-4b38-9c70-5f5c2ac427ff',
                     recorded_at=datetime.datetime.utcnow(),
                     timestamp=datetime.datetime.utcnow(),
                     resource_metadata={'name1': 'value1',
                                        'name2': 'value2'},
                     message_id='5460acce-4fd6-480d-ab18-9735ec7b1996',
                     )
  
  
  class Statistics(_Base):
      """Computed statistics for a query."""
  
      groupby = {wtypes.text: wtypes.text}
      "Dictionary of field names for group, if groupby statistics are requested"
  
      unit = wtypes.text
      "The unit type of the data set"
  
      min = float
      "The minimum volume seen in the data"
  
      max = float
      "The maximum volume seen in the data"
  
      avg = float
      "The average of all of the volume values seen in the data"
  
      sum = float
      "The total of all of the volume values seen in the data"
  
      count = int
      "The number of samples seen"
  
      aggregate = {wtypes.text: float}
      "The selectable aggregate value(s)"
  
      duration = float
      "The difference, in seconds, between the oldest and newest timestamp"
  
      duration_start = datetime.datetime
      "UTC date and time of the earliest timestamp, or the query start time"
  
      duration_end = datetime.datetime
      "UTC date and time of the oldest timestamp, or the query end time"
  
      period = int
      "The difference, in seconds, between the period start and end"
  
      period_start = datetime.datetime
      "UTC date and time of the period start"
  
      period_end = datetime.datetime
      "UTC date and time of the period end"
  
      def __init__(self, start_timestamp=None, end_timestamp=None, **kwds):
          super(Statistics, self).__init__(**kwds)
          self._update_duration(start_timestamp, end_timestamp)
  
      def _update_duration(self, start_timestamp, end_timestamp):
          # "Clamp" the timestamps we return to the original time
          # range, excluding the offset.
          if (start_timestamp and
                  self.duration_start and
                  self.duration_start < start_timestamp):
              self.duration_start = start_timestamp
              LOG.debug(_('clamping min timestamp to range'))
          if (end_timestamp and
                  self.duration_end and
                  self.duration_end > end_timestamp):
              self.duration_end = end_timestamp
              LOG.debug(_('clamping max timestamp to range'))
  
          # If we got valid timestamps back, compute a duration in seconds.
          #
          # If the min > max after clamping then we know the
          # timestamps on the samples fell outside of the time
          # range we care about for the query, so treat them as
          # "invalid."
          #
          # If the timestamps are invalid, return None as a
          # sentinel indicating that there is something "funny"
          # about the range.
          if (self.duration_start and
                  self.duration_end and
                  self.duration_start <= self.duration_end):
              self.duration = timeutils.delta_seconds(self.duration_start,
                                                      self.duration_end)
          else:
              self.duration_start = self.duration_end = self.duration = None
  
      @classmethod
      def sample(cls):
          return cls(unit='GiB',
                     min=1,
                     max=9,
                     avg=4.5,
                     sum=45,
                     count=10,
                     duration_start=datetime.datetime(2013, 1, 4, 16, 42),
                     duration_end=datetime.datetime(2013, 1, 4, 16, 47),
                     period=7200,
                     period_start=datetime.datetime(2013, 1, 4, 16, 00),
                     period_end=datetime.datetime(2013, 1, 4, 18, 00),
                     )
  
  
  class Aggregate(_Base):
  
      func = wsme.wsattr(wtypes.text, mandatory=True)
      "The aggregation function name"
  
      param = wsme.wsattr(wtypes.text, default=None)
      "The paramter to the aggregation function"
  
      def __init__(self, **kwargs):
          super(Aggregate, self).__init__(**kwargs)
  
      @staticmethod
      def validate(aggregate):
          return aggregate
  
      @classmethod
      def sample(cls):
          return cls(func='cardinality',
                     param='resource_id')
  
  
  class MeterController(rest.RestController):
      """Manages operations on a single meter."""
      _custom_actions = {
          'statistics': ['GET'],
      }
  
      def __init__(self, meter_name):
          pecan.request.context['meter_name'] = meter_name
          self.meter_name = meter_name
  
      @wsme_pecan.wsexpose([OldSample], [Query], int)
      def get_all(self, q=None, limit=None):
          """Return samples for the meter.
  
          :param q: Filter rules for the data to be returned.
          :param limit: Maximum number of samples to return.
          """
          q = q or []
          if limit and limit < 0:
              raise ClientSideError(_("Limit must be positive"))
          kwargs = _query_to_kwargs(q, storage.SampleFilter.__init__)
          kwargs['meter'] = self.meter_name
          f = storage.SampleFilter(**kwargs)
          return [OldSample.from_db_model(e)
                  for e in pecan.request.storage_conn.get_samples(f, limit=limit)
                  ]
  
      @wsme_pecan.wsexpose([OldSample], body=[OldSample])
      def post(self, samples):
          """Post a list of new Samples to Telemetry.
  
          :param samples: a list of samples within the request body.
          """
          now = timeutils.utcnow()
          auth_project = acl.get_limited_to_project(pecan.request.headers)
          def_source = pecan.request.cfg.sample_source
          def_project_id = pecan.request.headers.get('X-Project-Id')
          def_user_id = pecan.request.headers.get('X-User-Id')
  
          published_samples = []
          for s in samples:
              if self.meter_name != s.counter_name:
                  raise wsme.exc.InvalidInput('counter_name', s.counter_name,
                                              'should be %s' % self.meter_name)
  
              if s.message_id:
                  raise wsme.exc.InvalidInput('message_id', s.message_id,
                                              'The message_id must not be set')
  
              if s.counter_type not in sample.TYPES:
                  raise wsme.exc.InvalidInput('counter_type', s.counter_type,
                                              'The counter type must be: ' +
                                              ', '.join(sample.TYPES))
  
              s.user_id = (s.user_id or def_user_id)
              s.project_id = (s.project_id or def_project_id)
              s.source = '%s:%s' % (s.project_id, (s.source or def_source))
              s.timestamp = (s.timestamp or now)
  
              if auth_project and auth_project != s.project_id:
                  # non admin user trying to cross post to another project_id
                  auth_msg = 'can not post samples to other projects'
                  raise wsme.exc.InvalidInput('project_id', s.project_id,
                                              auth_msg)
  
              published_sample = sample.Sample(
                  name=s.counter_name,
                  type=s.counter_type,
                  unit=s.counter_unit,
                  volume=s.counter_volume,
                  user_id=s.user_id,
                  project_id=s.project_id,
                  resource_id=s.resource_id,
                  timestamp=s.timestamp.isoformat(),
                  resource_metadata=utils.restore_nesting(s.resource_metadata,
                                                          separator='.'),
                  source=s.source)
              published_samples.append(published_sample)
  
              s.message_id = published_sample.id
  
          with pecan.request.pipeline_manager.publisher(
                  context.get_admin_context()) as publisher:
              publisher(published_samples)
  
          return samples
  
      @wsme_pecan.wsexpose([Statistics], [Query], [unicode], int, [Aggregate])
      def statistics(self, q=None, groupby=None, period=None, aggregate=None):
          """Computes the statistics of the samples in the time range given.
  
          :param q: Filter rules for the data to be returned.
          :param groupby: Fields for group by aggregation
          :param period: Returned result will be an array of statistics for a
                         period long of that number of seconds.
          :param aggregate: The selectable aggregation functions to be applied.
          """
          q = q or []
          groupby = groupby or []
          aggregate = aggregate or []
  
          if period and period < 0:
              raise ClientSideError(_("Period must be positive."))
  
          kwargs = _query_to_kwargs(q, storage.SampleFilter.__init__)
          kwargs['meter'] = self.meter_name
          f = storage.SampleFilter(**kwargs)
          g = _validate_groupby_fields(groupby)
  
          aggregate = utils.uniq(aggregate, ['func', 'param'])
          computed = pecan.request.storage_conn.get_meter_statistics(f,
                                                                     period,
                                                                     g,
                                                                     aggregate)
          LOG.debug(_('computed value coming from %r'),
                    pecan.request.storage_conn)
          # Find the original timestamp in the query to use for clamping
          # the duration returned in the statistics.
          start = end = None
          for i in q:
              if i.field == 'timestamp' and i.op in ('lt', 'le'):
                  end = timeutils.parse_isotime(i.value).replace(tzinfo=None)
              elif i.field == 'timestamp' and i.op in ('gt', 'ge'):
                  start = timeutils.parse_isotime(i.value).replace(tzinfo=None)
  
          return [Statistics(start_timestamp=start,
                             end_timestamp=end,
                             **c.as_dict())
                  for c in computed]
  
  
  class Meter(_Base):
      """One category of measurements."""
  
      name = wtypes.text
      "The unique name for the meter"
  
      type = wtypes.Enum(str, *sample.TYPES)
      "The meter type (see :ref:`measurements`)"
  
      unit = wtypes.text
      "The unit of measure"
  
      resource_id = wtypes.text
      "The ID of the :class:`Resource` for which the measurements are taken"
  
      project_id = wtypes.text
      "The ID of the project or tenant that owns the resource"
  
      user_id = wtypes.text
      "The ID of the user who last triggered an update to the resource"
  
      source = wtypes.text
      "The ID of the source that identifies where the meter comes from"
  
      meter_id = wtypes.text
      "The unique identifier for the meter"
  
      def __init__(self, **kwargs):
          meter_id = '%s+%s' % (kwargs['resource_id'], kwargs['name'])
          # meter_id is of type Unicode but base64.encodestring() only accepts
          # strings. See bug #1333177
          meter_id = base64.encodestring(meter_id.encode('utf-8'))
          kwargs['meter_id'] = meter_id
          super(Meter, self).__init__(**kwargs)
  
      @classmethod
      def sample(cls):
          return cls(name='instance',
                     type='gauge',
                     unit='instance',
                     resource_id='bd9431c1-8d69-4ad3-803a-8d4a6b89fd36',
                     project_id='35b17138-b364-4e6a-a131-8f3099c5be68',
                     user_id='efd87807-12d2-4b38-9c70-5f5c2ac427ff',
                     source='openstack',
                     )
  
  
  class MetersController(rest.RestController):
      """Works on meters."""
  
      @pecan.expose()
      def _lookup(self, meter_name, *remainder):
          return MeterController(meter_name), remainder
  
      @wsme_pecan.wsexpose([Meter], [Query])
      def get_all(self, q=None):
          """Return all known meters, based on the data recorded so far.
  
          :param q: Filter rules for the meters to be returned.
          """
          q = q or []
  
          # Timestamp field is not supported for Meter queries
          kwargs = _query_to_kwargs(q, pecan.request.storage_conn.get_meters,
                                    allow_timestamps=False)
          return [Meter.from_db_model(m)
                  for m in pecan.request.storage_conn.get_meters(**kwargs)]
  
  
  class Sample(_Base):
      """One measurement."""
  
      id = wtypes.text
      "The unique identifier for the sample."
  
      meter = wtypes.text
      "The meter name this sample is for."
  
      type = wtypes.Enum(str, *sample.TYPES)
      "The meter type (see :ref:`measurements`)"
  
      unit = wtypes.text
      "The unit of measure."
  
      volume = float
      "The metered value."
  
      user_id = wtypes.text
      "The user this sample was taken for."
  
      project_id = wtypes.text
      "The project this sample was taken for."
  
      resource_id = wtypes.text
      "The :class:`Resource` this sample was taken for."
  
      source = wtypes.text
      "The source that identifies where the sample comes from."
  
      timestamp = datetime.datetime
      "When the sample has been generated."
  
      recorded_at = datetime.datetime
      "When the sample has been recorded."
  
      metadata = {wtypes.text: wtypes.text}
      "Arbitrary metadata associated with the sample."
  
      @classmethod
      def from_db_model(cls, m):
          return cls(id=m.message_id,
                     meter=m.counter_name,
                     type=m.counter_type,
                     unit=m.counter_unit,
                     volume=m.counter_volume,
                     user_id=m.user_id,
                     project_id=m.project_id,
                     resource_id=m.resource_id,
                     source=m.source,
                     timestamp=m.timestamp,
                     recorded_at=m.recorded_at,
                     metadata=_flatten_metadata(m.resource_metadata))
  
      @classmethod
      def sample(cls):
          return cls(id=str(uuid.uuid1()),
                     meter='instance',
                     type='gauge',
                     unit='instance',
                     volume=1,
                     resource_id='bd9431c1-8d69-4ad3-803a-8d4a6b89fd36',
                     project_id='35b17138-b364-4e6a-a131-8f3099c5be68',
                     user_id='efd87807-12d2-4b38-9c70-5f5c2ac427ff',
                     timestamp=timeutils.utcnow(),
                     recorded_at=datetime.datetime.utcnow(),
                     source='openstack',
                     metadata={'name1': 'value1',
                               'name2': 'value2'},
                     )
  
  
  class SamplesController(rest.RestController):
      """Controller managing the samples."""
  
      @wsme_pecan.wsexpose([Sample], [Query], int)
      def get_all(self, q=None, limit=None):
          """Return all known samples, based on the data recorded so far.
  
          :param q: Filter rules for the samples to be returned.
          :param limit: Maximum number of samples to be returned.
          """
          q = q or []
  
          if limit and limit < 0:
              raise ClientSideError(_("Limit must be positive"))
          kwargs = _query_to_kwargs(q, storage.SampleFilter.__init__)
          f = storage.SampleFilter(**kwargs)
          return map(Sample.from_db_model,
                     pecan.request.storage_conn.get_samples(f, limit=limit))
  
      @wsme_pecan.wsexpose(Sample, wtypes.text)
      def get_one(self, sample_id):
          """Return a sample
  
          :param sample_id: the id of the sample
          """
          f = storage.SampleFilter(message_id=sample_id)
  
          samples = list(pecan.request.storage_conn.get_samples(f))
          if len(samples) < 1:
              raise EntityNotFound(_('Sample'), sample_id)
  
          return Sample.from_db_model(samples[0])
  
  
  class ComplexQuery(_Base):
      """Holds a sample query encoded in json."""
  
      filter = wtypes.text
      "The filter expression encoded in json."
  
      orderby = wtypes.text
      "List of single-element dicts for specifing the ordering of the results."
  
      limit = int
      "The maximum number of results to be returned."
  
      @classmethod
      def sample(cls):
          return cls(filter='{"and": [{"and": [{"=": ' +
                            '{"counter_name": "cpu_util"}}, ' +
                            '{">": {"counter_volume": 0.23}}, ' +
                            '{"<": {"counter_volume": 0.26}}]}, ' +
                            '{"or": [{"and": [{">": ' +
                            '{"timestamp": "2013-12-01T18:00:00"}}, ' +
                            '{"<": ' +
                            '{"timestamp": "2013-12-01T18:15:00"}}]}, ' +
                            '{"and": [{">": ' +
                            '{"timestamp": "2013-12-01T18:30:00"}}, ' +
                            '{"<": ' +
                            '{"timestamp": "2013-12-01T18:45:00"}}]}]}]}',
                     orderby='[{"counter_volume": "ASC"}, ' +
                             '{"timestamp": "DESC"}]',
                     limit=42
                     )
  
  
  def _list_to_regexp(items, regexp_prefix=""):
      regexp = ["^%s$" % item for item in items]
      regexp = regexp_prefix + "|".join(regexp)
      return regexp
  
  
  class ValidatedComplexQuery(object):
      complex_operators = ["and", "or"]
      order_directions = ["asc", "desc"]
      simple_ops = ["=", "!=", "<", ">", "<=", "=<", ">=", "=>"]
      regexp_prefix = "(?i)"
  
      complex_ops = _list_to_regexp(complex_operators, regexp_prefix)
      simple_ops = _list_to_regexp(simple_ops, regexp_prefix)
      order_directions = _list_to_regexp(order_directions, regexp_prefix)
  
      timestamp_fields = ["timestamp", "state_timestamp"]
  
      def __init__(self, query, db_model, additional_name_mapping=None,
                   metadata_allowed=False):
          additional_name_mapping = additional_name_mapping or {}
          self.name_mapping = {"user": "user_id",
                               "project": "project_id"}
          self.name_mapping.update(additional_name_mapping)
          valid_keys = db_model.get_field_names()
          valid_keys = list(valid_keys) + self.name_mapping.keys()
          valid_fields = _list_to_regexp(valid_keys)
  
          if metadata_allowed:
              valid_filter_fields = valid_fields + "|^metadata\.[\S]+$"
          else:
              valid_filter_fields = valid_fields
  
          schema_value = {
              "oneOf": [{"type": "string"},
                        {"type": "number"},
                        {"type": "boolean"}],
              "minProperties": 1,
              "maxProperties": 1}
  
          schema_value_in = {
              "type": "array",
              "items": {"oneOf": [{"type": "string"},
                                  {"type": "number"}]},
              "minItems": 1}
  
          schema_field = {
              "type": "object",
              "patternProperties": {valid_filter_fields: schema_value},
              "additionalProperties": False,
              "minProperties": 1,
              "maxProperties": 1}
  
          schema_field_in = {
              "type": "object",
              "patternProperties": {valid_filter_fields: schema_value_in},
              "additionalProperties": False,
              "minProperties": 1,
              "maxProperties": 1}
  
          schema_leaf_in = {
              "type": "object",
              "patternProperties": {"(?i)^in$": schema_field_in},
              "additionalProperties": False,
              "minProperties": 1,
              "maxProperties": 1}
  
          schema_leaf_simple_ops = {
              "type": "object",
              "patternProperties": {self.simple_ops: schema_field},
              "additionalProperties": False,
              "minProperties": 1,
              "maxProperties": 1}
  
          schema_and_or_array = {
              "type": "array",
              "items": {"$ref": "#"},
              "minItems": 2}
  
          schema_and_or = {
              "type": "object",
              "patternProperties": {self.complex_ops: schema_and_or_array},
              "additionalProperties": False,
              "minProperties": 1,
              "maxProperties": 1}
  
          schema_not = {
              "type": "object",
              "patternProperties": {"(?i)^not$": {"$ref": "#"}},
              "additionalProperties": False,
              "minProperties": 1,
              "maxProperties": 1}
  
          self.schema = {
              "oneOf": [{"$ref": "#/definitions/leaf_simple_ops"},
                        {"$ref": "#/definitions/leaf_in"},
                        {"$ref": "#/definitions/and_or"},
                        {"$ref": "#/definitions/not"}],
              "minProperties": 1,
              "maxProperties": 1,
              "definitions": {"leaf_simple_ops": schema_leaf_simple_ops,
                              "leaf_in": schema_leaf_in,
                              "and_or": schema_and_or,
                              "not": schema_not}}
  
          self.orderby_schema = {
              "type": "array",
              "items": {
                  "type": "object",
                  "patternProperties":
                      {valid_fields:
                          {"type": "string",
                           "pattern": self.order_directions}},
                  "additionalProperties": False,
                  "minProperties": 1,
                  "maxProperties": 1}}
  
          self.original_query = query
  
      def validate(self, visibility_field):
          """Validates the query content and does the necessary conversions."""
          if self.original_query.filter is wtypes.Unset:
              self.filter_expr = None
          else:
              self.filter_expr = json.loads(self.original_query.filter)
              self._validate_filter(self.filter_expr)
              self._replace_isotime_with_datetime(self.filter_expr)
              self._convert_operator_to_lower_case(self.filter_expr)
              self._normalize_field_names_for_db_model(self.filter_expr)
  
          self._force_visibility(visibility_field)
  
          if self.original_query.orderby is wtypes.Unset:
              self.orderby = None
          else:
              self.orderby = json.loads(self.original_query.orderby)
              self._validate_orderby(self.orderby)
              self._convert_orderby_to_lower_case(self.orderby)
              self._normalize_field_names_in_orderby(self.orderby)
  
          if self.original_query.limit is wtypes.Unset:
              self.limit = None
          else:
              self.limit = self.original_query.limit
  
          if self.limit is not None and self.limit <= 0:
              msg = _('Limit should be positive')
              raise ClientSideError(msg)
  
      @staticmethod
      def _convert_orderby_to_lower_case(orderby):
          for orderby_field in orderby:
              utils.lowercase_values(orderby_field)
  
      def _normalize_field_names_in_orderby(self, orderby):
          for orderby_field in orderby:
              self._replace_field_names(orderby_field)
  
      def _traverse_postorder(self, tree, visitor):
          op = tree.keys()[0]
          if op.lower() in self.complex_operators:
              for i, operand in enumerate(tree[op]):
                  self._traverse_postorder(operand, visitor)
          if op.lower() == "not":
              self._traverse_postorder(tree[op], visitor)
  
          visitor(tree)
  
      def _check_cross_project_references(self, own_project_id,
                                          visibility_field):
          """Do not allow other than own_project_id."""
          def check_project_id(subfilter):
              op = subfilter.keys()[0]
              if (op.lower() not in self.complex_operators
                      and subfilter[op].keys()[0] == visibility_field
                      and subfilter[op][visibility_field] != own_project_id):
                  raise ProjectNotAuthorized(subfilter[op][visibility_field])
  
          self._traverse_postorder(self.filter_expr, check_project_id)
  
      def _force_visibility(self, visibility_field):
          """Force visibility field.
  
          If the tenant is not admin insert an extra
          "and <visibility_field>=<tenant's project_id>" clause to the query.
          """
          authorized_project = acl.get_limited_to_project(pecan.request.headers)
          is_admin = authorized_project is None
          if not is_admin:
              self._restrict_to_project(authorized_project, visibility_field)
              self._check_cross_project_references(authorized_project,
                                                   visibility_field)
  
      def _restrict_to_project(self, project_id, visibility_field):
          restriction = {"=": {visibility_field: project_id}}
          if self.filter_expr is None:
              self.filter_expr = restriction
          else:
              self.filter_expr = {"and": [restriction, self.filter_expr]}
  
      def _replace_isotime_with_datetime(self, filter_expr):
          def replace_isotime(subfilter):
              op = subfilter.keys()[0]
              if (op.lower() not in self.complex_operators
                      and subfilter[op].keys()[0] in self.timestamp_fields):
                  field = subfilter[op].keys()[0]
                  date_time = self._convert_to_datetime(subfilter[op][field])
                  subfilter[op][field] = date_time
  
          self._traverse_postorder(filter_expr, replace_isotime)
  
      def _normalize_field_names_for_db_model(self, filter_expr):
          def _normalize_field_names(subfilter):
              op = subfilter.keys()[0]
              if op.lower() not in self.complex_operators:
                  self._replace_field_names(subfilter.values()[0])
          self._traverse_postorder(filter_expr,
                                   _normalize_field_names)
  
      def _replace_field_names(self, subfilter):
          field = subfilter.keys()[0]
          value = subfilter[field]
          if field in self.name_mapping:
              del subfilter[field]
              subfilter[self.name_mapping[field]] = value
          if field.startswith("metadata."):
              del subfilter[field]
              subfilter["resource_" + field] = value
  
      def _convert_operator_to_lower_case(self, filter_expr):
          self._traverse_postorder(filter_expr, utils.lowercase_keys)
  
      @staticmethod
      def _convert_to_datetime(isotime):
          try:
              date_time = timeutils.parse_isotime(isotime)
              date_time = date_time.replace(tzinfo=None)
              return date_time
          except ValueError:
              LOG.exception(_("String %s is not a valid isotime") % isotime)
              msg = _('Failed to parse the timestamp value %s') % isotime
              raise ClientSideError(msg)
  
      def _validate_filter(self, filter_expr):
          jsonschema.validate(filter_expr, self.schema)
  
      def _validate_orderby(self, orderby_expr):
          jsonschema.validate(orderby_expr, self.orderby_schema)
  
  
  class Resource(_Base):
      """An externally defined object for which samples have been received."""
  
      resource_id = wtypes.text
      "The unique identifier for the resource"
  
      project_id = wtypes.text
      "The ID of the owning project or tenant"
  
      user_id = wtypes.text
      "The ID of the user who created the resource or updated it last"
  
      first_sample_timestamp = datetime.datetime
      "UTC date & time not later than the first sample known for this resource"
  
      last_sample_timestamp = datetime.datetime
      "UTC date & time not earlier than the last sample known for this resource"
  
      metadata = {wtypes.text: wtypes.text}
      "Arbitrary metadata associated with the resource"
  
      links = [Link]
      "A list containing a self link and associated meter links"
  
      source = wtypes.text
      "The source where the resource come from"
  
      def __init__(self, metadata=None, **kwds):
          metadata = metadata or {}
          metadata = _flatten_metadata(metadata)
          super(Resource, self).__init__(metadata=metadata, **kwds)
  
      @classmethod
      def sample(cls):
          return cls(resource_id='bd9431c1-8d69-4ad3-803a-8d4a6b89fd36',
                     project_id='35b17138-b364-4e6a-a131-8f3099c5be68',
                     user_id='efd87807-12d2-4b38-9c70-5f5c2ac427ff',
                     timestamp=datetime.datetime.utcnow(),
                     source="openstack",
                     metadata={'name1': 'value1',
                               'name2': 'value2'},
                     links=[Link(href=('http://localhost:8777/v2/resources/'
                                       'bd9431c1-8d69-4ad3-803a-8d4a6b89fd36'),
                                 rel='self'),
                            Link(href=('http://localhost:8777/v2/meters/volume?'
                                       'q.field=resource_id&'
                                       'q.value=bd9431c1-8d69-4ad3-803a-'
                                       '8d4a6b89fd36'),
                                 rel='volume')],
                     )
  
  
  class ResourcesController(rest.RestController):
      """Works on resources."""
  
      def _resource_links(self, resource_id, meter_links=1):
          links = [_make_link('self', pecan.request.host_url, 'resources',
                              resource_id)]
          if meter_links:
              for meter in pecan.request.storage_conn.get_meters(
                      resource=resource_id):
                  query = {'field': 'resource_id', 'value': resource_id}
                  links.append(_make_link(meter.name, pecan.request.host_url,
                                          'meters', meter.name, query=query))
          return links
  
      @wsme_pecan.wsexpose(Resource, unicode)
      def get_one(self, resource_id):
          """Retrieve details about one resource.
  
          :param resource_id: The UUID of the resource.
          """
          authorized_project = acl.get_limited_to_project(pecan.request.headers)
          resources = list(pecan.request.storage_conn.get_resources(
              resource=resource_id, project=authorized_project))
          if not resources:
              raise EntityNotFound(_('Resource'), resource_id)
          return Resource.from_db_and_links(resources[0],
                                            self._resource_links(resource_id))
  
      @wsme_pecan.wsexpose([Resource], [Query], int)
      def get_all(self, q=None, meter_links=1):
          """Retrieve definitions of all of the resources.
  
          :param q: Filter rules for the resources to be returned.
          :param meter_links: option to include related meter links
          """
          q = q or []
          kwargs = _query_to_kwargs(q, pecan.request.storage_conn.get_resources)
          resources = [
              Resource.from_db_and_links(r,
                                         self._resource_links(r.resource_id,
                                                              meter_links))
              for r in pecan.request.storage_conn.get_resources(**kwargs)]
          return resources
  
  
  class AlarmThresholdRule(_Base):
      meter_name = wsme.wsattr(wtypes.text, mandatory=True)
      "The name of the meter"
  
      # FIXME(sileht): default doesn't work
      # workaround: default is set in validate method
      query = wsme.wsattr([Query], default=[])
      """The query to find the data for computing statistics.
      Ownership settings are automatically included based on the Alarm owner.
      """
  
      period = wsme.wsattr(wtypes.IntegerType(minimum=1), default=60)
      "The time range in seconds over which query"
  
      comparison_operator = AdvEnum('comparison_operator', str,
                                    'lt', 'le', 'eq', 'ne', 'ge', 'gt',
                                    default='eq')
      "The comparison against the alarm threshold"
  
      threshold = wsme.wsattr(float, mandatory=True)
      "The threshold of the alarm"
  
      statistic = AdvEnum('statistic', str, 'max', 'min', 'avg', 'sum',
                          'count', default='avg')
      "The statistic to compare to the threshold"
  
      evaluation_periods = wsme.wsattr(wtypes.IntegerType(minimum=1), default=1)
      "The number of historical periods to evaluate the threshold"
  
      exclude_outliers = wsme.wsattr(bool, default=False)
      "Whether datapoints with anomalously low sample counts are excluded"
  
      def __init__(self, query=None, **kwargs):
          if query:
              query = [Query(**q) for q in query]
          super(AlarmThresholdRule, self).__init__(query=query, **kwargs)
  
      @staticmethod
      def validate(threshold_rule):
          # note(sileht): wsme default doesn't work in some case
          # workaround for https://bugs.launchpad.net/wsme/+bug/1227039
          if not threshold_rule.query:
              threshold_rule.query = []
  
          # Timestamp is not allowed for AlarmThresholdRule query, as the alarm
          # evaluator will construct timestamp bounds for the sequence of
          # statistics queries as the sliding evaluation window advances
          # over time.
          _validate_query(threshold_rule.query, storage.SampleFilter.__init__,
                          allow_timestamps=False)
          return threshold_rule
  
      @property
      def default_description(self):
          return (_('Alarm when %(meter_name)s is %(comparison_operator)s a '
                    '%(statistic)s of %(threshold)s over %(period)s seconds') %
                  dict(comparison_operator=self.comparison_operator,
                       statistic=self.statistic,
                       threshold=self.threshold,
                       meter_name=self.meter_name,
                       period=self.period))
  
      def as_dict(self):
          rule = self.as_dict_from_keys(['period', 'comparison_operator',
                                         'threshold', 'statistic',
                                         'evaluation_periods', 'meter_name',
                                         'exclude_outliers'])
          rule['query'] = [q.as_dict() for q in self.query]
          return rule
  
      @classmethod
      def sample(cls):
          return cls(meter_name='cpu_util',
                     period=60,
                     evaluation_periods=1,
                     threshold=300.0,
                     statistic='avg',
                     comparison_operator='gt',
                     query=[{'field': 'resource_id',
                             'value': '2a4d689b-f0b8-49c1-9eef-87cae58d80db',
                             'op': 'eq',
                             'type': 'string'}])
  
  
  class AlarmCombinationRule(_Base):
      operator = AdvEnum('operator', str, 'or', 'and', default='and')
      "How to combine the sub-alarms"
  
      alarm_ids = wsme.wsattr([wtypes.text], mandatory=True)
      "List of alarm identifiers to combine"
  
      @property
      def default_description(self):
          joiner = ' %s ' % self.operator
          return _('Combined state of alarms %s') % joiner.join(self.alarm_ids)
  
      def as_dict(self):
          return self.as_dict_from_keys(['operator', 'alarm_ids'])
  
      @staticmethod
      def validate(rule):
          rule.alarm_ids = sorted(set(rule.alarm_ids), key=rule.alarm_ids.index)
          if len(rule.alarm_ids) <= 1:
              raise ClientSideError(_('Alarm combination rule should contain at'
                                      ' least two different alarm ids.'))
          return rule
  
      @classmethod
      def sample(cls):
          return cls(operator='or',
                     alarm_ids=['739e99cb-c2ec-4718-b900-332502355f38',
                                '153462d0-a9b8-4b5b-8175-9e4b05e9b856'])
  
  
  class AlarmTimeConstraint(_Base):
      """Representation of a time constraint on an alarm."""
  
      name = wsme.wsattr(wtypes.text, mandatory=True)
      "The name of the constraint"
  
      _description = None  # provide a default
  
      def get_description(self):
          if not self._description:
              return ('Time constraint at %s lasting for %s seconds'
                      % (self.start, self.duration))
          return self._description
  
      def set_description(self, value):
          self._description = value
  
      description = wsme.wsproperty(wtypes.text, get_description,
                                    set_description)
      "The description of the constraint"
  
      start = wsme.wsattr(CronType(), mandatory=True)
      "Start point of the time constraint, in cron format"
  
      duration = wsme.wsattr(wtypes.IntegerType(minimum=0), mandatory=True)
      "How long the constraint should last, in seconds"
  
      timezone = wsme.wsattr(wtypes.text, default="")
      "Timezone of the constraint"
  
      def as_dict(self):
          return self.as_dict_from_keys(['name', 'description', 'start',
                                         'duration', 'timezone'])
  
      @staticmethod
      def validate(tc):
          if tc.timezone:
              try:
                  pytz.timezone(tc.timezone)
              except Exception:
                  raise ClientSideError(_("Timezone %s is not valid")
                                        % tc.timezone)
          return tc
  
      @classmethod
      def sample(cls):
          return cls(name='SampleConstraint',
                     description='nightly build every night at 23h for 3 hours',
                     start='0 23 * * *',
                     duration=10800,
                     timezone='Europe/Ljubljana')
  
  
  class Alarm(_Base):
      """Representation of an alarm.
  
      .. note::
          combination_rule and threshold_rule are mutually exclusive. The *type*
          of the alarm should be set to *threshold* or *combination* and the
          appropriate rule should be filled.
      """
  
      alarm_id = wtypes.text
      "The UUID of the alarm"
  
      name = wsme.wsattr(wtypes.text, mandatory=True)
      "The name for the alarm"
  
      _description = None  # provide a default
  
      def get_description(self):
          rule = getattr(self, '%s_rule' % self.type, None)
          if not self._description and rule:
              return six.text_type(rule.default_description)
          return self._description
  
      def set_description(self, value):
          self._description = value
  
      description = wsme.wsproperty(wtypes.text, get_description,
                                    set_description)
      "The description of the alarm"
  
      enabled = wsme.wsattr(bool, default=True)
      "This alarm is enabled?"
  
      ok_actions = wsme.wsattr([wtypes.text], default=[])
      "The actions to do when alarm state change to ok"
  
      alarm_actions = wsme.wsattr([wtypes.text], default=[])
      "The actions to do when alarm state change to alarm"
  
      insufficient_data_actions = wsme.wsattr([wtypes.text], default=[])
      "The actions to do when alarm state change to insufficient data"
  
      repeat_actions = wsme.wsattr(bool, default=False)
      "The actions should be re-triggered on each evaluation cycle"
  
      type = AdvEnum('type', str, 'threshold', 'combination', mandatory=True)
      "Explicit type specifier to select which rule to follow below."
  
      threshold_rule = AlarmThresholdRule
      "Describe when to trigger the alarm based on computed statistics"
  
      combination_rule = AlarmCombinationRule
      """Describe when to trigger the alarm based on combining the state of
      other alarms"""
  
      time_constraints = wtypes.wsattr([AlarmTimeConstraint], default=[])
      """Describe time constraints for the alarm"""
  
      # These settings are ignored in the PUT or POST operations, but are
      # filled in for GET
      project_id = wtypes.text
      "The ID of the project or tenant that owns the alarm"
  
      user_id = wtypes.text
      "The ID of the user who created the alarm"
  
      timestamp = datetime.datetime
      "The date of the last alarm definition update"
  
      state = AdvEnum('state', str, *state_kind,
                      default='insufficient data')
      "The state offset the alarm"
  
      state_timestamp = datetime.datetime
      "The date of the last alarm state changed"
  
      def __init__(self, rule=None, time_constraints=None, **kwargs):
          super(Alarm, self).__init__(**kwargs)
  
          if rule:
              if self.type == 'threshold':
                  self.threshold_rule = AlarmThresholdRule(**rule)
              elif self.type == 'combination':
                  self.combination_rule = AlarmCombinationRule(**rule)
          if time_constraints:
              self.time_constraints = [AlarmTimeConstraint(**tc)
                                       for tc in time_constraints]
  
      @staticmethod
      def validate(alarm):
  
          Alarm.check_rule(alarm)
          if alarm.threshold_rule:
              # ensure an implicit constraint on project_id is added to
              # the query if not already present
              alarm.threshold_rule.query = _sanitize_query(
                  alarm.threshold_rule.query,
                  storage.SampleFilter.__init__,
                  on_behalf_of=alarm.project_id
              )
          elif alarm.combination_rule:
              project = _get_auth_project(alarm.project_id
                                          if alarm.project_id != wtypes.Unset
                                          else None)
              for id in alarm.combination_rule.alarm_ids:
                  alarms = list(pecan.request.alarm_storage_conn.get_alarms(
                      alarm_id=id, project=project))
                  if not alarms:
                      raise AlarmNotFound(id, project)
  
          tc_names = [tc.name for tc in alarm.time_constraints]
          if len(tc_names) > len(set(tc_names)):
              error = _("Time constraint names must be "
                        "unique for a given alarm.")
              raise ClientSideError(error)
  
          return alarm
  
      @staticmethod
      def check_rule(alarm):
          rule = '%s_rule' % alarm.type
          if getattr(alarm, rule) in (wtypes.Unset, None):
              error = _("%(rule)s must be set for %(type)s"
                        " type alarm") % {"rule": rule, "type": alarm.type}
              raise ClientSideError(error)
          if alarm.threshold_rule and alarm.combination_rule:
              error = _("threshold_rule and combination_rule "
                        "cannot be set at the same time")
              raise ClientSideError(error)
  
      @classmethod
      def sample(cls):
          return cls(alarm_id=None,
                     name="SwiftObjectAlarm",
                     description="An alarm",
                     type='combination',
                     threshold_rule=None,
                     combination_rule=AlarmCombinationRule.sample(),
                     time_constraints=[AlarmTimeConstraint.sample().as_dict()],
                     user_id="c96c887c216949acbdfbd8b494863567",
                     project_id="c96c887c216949acbdfbd8b494863567",
                     enabled=True,
                     timestamp=datetime.datetime.utcnow(),
                     state="ok",
                     state_timestamp=datetime.datetime.utcnow(),
                     ok_actions=["http://site:8000/ok"],
                     alarm_actions=["http://site:8000/alarm"],
                     insufficient_data_actions=["http://site:8000/nodata"],
                     repeat_actions=False,
                     )
  
      def as_dict(self, db_model):
          d = super(Alarm, self).as_dict(db_model)
          for k in d:
              if k.endswith('_rule'):
                  del d[k]
          d['rule'] = getattr(self, "%s_rule" % self.type).as_dict()
          d['time_constraints'] = [tc.as_dict() for tc in self.time_constraints]
          return d
  
  
  class AlarmChange(_Base):
      """Representation of an event in an alarm's history."""
  
      event_id = wtypes.text
      "The UUID of the change event"
  
      alarm_id = wtypes.text
      "The UUID of the alarm"
  
      type = wtypes.Enum(str,
                         'creation',
                         'rule change',
                         'state transition',
                         'deletion')
      "The type of change"
  
      detail = wtypes.text
      "JSON fragment describing change"
  
      project_id = wtypes.text
      "The project ID of the initiating identity"
  
      user_id = wtypes.text
      "The user ID of the initiating identity"
  
      on_behalf_of = wtypes.text
      "The tenant on behalf of which the change is being made"
  
      timestamp = datetime.datetime
      "The time/date of the alarm change"
  
      @classmethod
      def sample(cls):
          return cls(alarm_id='e8ff32f772a44a478182c3fe1f7cad6a',
                     type='rule change',
                     detail='{"threshold": 42.0, "evaluation_periods": 4}',
                     user_id="3e5d11fda79448ac99ccefb20be187ca",
                     project_id="b6f16144010811e387e4de429e99ee8c",
                     on_behalf_of="92159030020611e3b26dde429e99ee8c",
                     timestamp=datetime.datetime.utcnow(),
                     )
  
  
  class AlarmController(rest.RestController):
      """Manages operations on a single alarm."""
  
      _custom_actions = {
          'history': ['GET'],
          'state': ['PUT', 'GET'],
      }
  
      def __init__(self, alarm_id):
          pecan.request.context['alarm_id'] = alarm_id
          self._id = alarm_id
  
      def _alarm(self):
          self.conn = pecan.request.alarm_storage_conn
          auth_project = acl.get_limited_to_project(pecan.request.headers)
          alarms = list(self.conn.get_alarms(alarm_id=self._id,
                                             project=auth_project))
          if not alarms:
              raise AlarmNotFound(alarm=self._id, auth_project=auth_project)
          return alarms[0]
  
      def _record_change(self, data, now, on_behalf_of=None, type=None):
          if not cfg.CONF.alarm.record_history:
              return
          type = type or alarm_models.AlarmChange.RULE_CHANGE
          scrubbed_data = utils.stringify_timestamps(data)
          detail = json.dumps(scrubbed_data)
          user_id = pecan.request.headers.get('X-User-Id')
          project_id = pecan.request.headers.get('X-Project-Id')
          on_behalf_of = on_behalf_of or project_id
          payload = dict(event_id=str(uuid.uuid4()),
                         alarm_id=self._id,
                         type=type,
                         detail=detail,
                         user_id=user_id,
                         project_id=project_id,
                         on_behalf_of=on_behalf_of,
                         timestamp=now)
  
          try:
              self.conn.record_alarm_change(payload)
          except NotImplementedError:
              pass
  
          # Revert to the pre-json'ed details ...
          payload['detail'] = scrubbed_data
          _send_notification(type, payload)
  
      @wsme_pecan.wsexpose(Alarm)
      def get(self):
          """Return this alarm."""
          return Alarm.from_db_model(self._alarm())
  
      @wsme_pecan.wsexpose(Alarm, body=Alarm)
      def put(self, data):
          """Modify this alarm.
  
          :param data: an alarm within the request body.
          """
          # Ensure alarm exists
          alarm_in = self._alarm()
  
          now = timeutils.utcnow()
  
          data.alarm_id = self._id
          user, project = acl.get_limited_to(pecan.request.headers)
          if user:
              data.user_id = user
          elif data.user_id == wtypes.Unset:
              data.user_id = alarm_in.user_id
          if project:
              data.project_id = project
          elif data.project_id == wtypes.Unset:
              data.project_id = alarm_in.project_id
          data.timestamp = now
          if alarm_in.state != data.state:
              data.state_timestamp = now
          else:
              data.state_timestamp = alarm_in.state_timestamp
  
          # make sure alarms are unique by name per project.
          if alarm_in.name != data.name:
              alarms = list(self.conn.get_alarms(name=data.name,
                                                 project=data.project_id))
              if alarms:
                  raise ClientSideError(
                      _("Alarm with name=%s exists") % data.name,
                      status_code=409)
  
          # should check if there is any circle in the dependency, but for
          # efficiency reason, here only check alarm cannot depend on itself
          if data.type == 'combination':
              if self._id in data.combination_rule.alarm_ids:
                  raise ClientSideError(_('Cannot specify alarm %s itself in '
                                          'combination rule') % self._id)
  
          old_alarm = Alarm.from_db_model(alarm_in).as_dict(alarm_models.Alarm)
          updated_alarm = data.as_dict(alarm_models.Alarm)
          try:
              alarm_in = alarm_models.Alarm(**updated_alarm)
          except Exception:
              LOG.exception(_("Error while putting alarm: %s") % updated_alarm)
              raise ClientSideError(_("Alarm incorrect"))
  
          alarm = self.conn.update_alarm(alarm_in)
  
          change = dict((k, v) for k, v in updated_alarm.items()
                        if v != old_alarm[k] and k not in
                        ['timestamp', 'state_timestamp'])
          self._record_change(change, now, on_behalf_of=alarm.project_id)
          return Alarm.from_db_model(alarm)
  
      @wsme_pecan.wsexpose(None, status_code=204)
      def delete(self):
          """Delete this alarm."""
          # ensure alarm exists before deleting
          alarm = self._alarm()
          self.conn.delete_alarm(alarm.alarm_id)
          change = Alarm.from_db_model(alarm).as_dict(alarm_models.Alarm)
          self._record_change(change,
                              timeutils.utcnow(),
                              type=alarm_models.AlarmChange.DELETION)
  
      # TODO(eglynn): add pagination marker to signature once overall
      #               API support for pagination is finalized
      @wsme_pecan.wsexpose([AlarmChange], [Query])
      def history(self, q=None):
          """Assembles the alarm history requested.
  
          :param q: Filter rules for the changes to be described.
          """
          q = q or []
          # allow history to be returned for deleted alarms, but scope changes
          # returned to those carried out on behalf of the auth'd tenant, to
          # avoid inappropriate cross-tenant visibility of alarm history
          auth_project = acl.get_limited_to_project(pecan.request.headers)
          conn = pecan.request.alarm_storage_conn
          kwargs = _query_to_kwargs(q, conn.get_alarm_changes, ['on_behalf_of',
                                                                'alarm_id'])
          return [AlarmChange.from_db_model(ac)
                  for ac in conn.get_alarm_changes(self._id, auth_project,
                                                   **kwargs)]
  
      @wsme.validate(state_kind_enum)
      @wsme_pecan.wsexpose(state_kind_enum, body=state_kind_enum)
      def put_state(self, state):
          """Set the state of this alarm.
  
          :param state: an alarm state within the request body.
          """
          # note(sileht): body are not validated by wsme
          # Workaround for https://bugs.launchpad.net/wsme/+bug/1227229
          if state not in state_kind:
              raise ClientSideError(_("state invalid"))
          now = timeutils.utcnow()
          alarm = self._alarm()
          alarm.state = state
          alarm.state_timestamp = now
          alarm = self.conn.update_alarm(alarm)
          change = {'state': alarm.state}
          self._record_change(change, now, on_behalf_of=alarm.project_id,
                              type=alarm_models.AlarmChange.STATE_TRANSITION)
          return alarm.state
  
      @wsme_pecan.wsexpose(state_kind_enum)
      def get_state(self):
          """Get the state of this alarm."""
          alarm = self._alarm()
          return alarm.state
  
  
  class AlarmsController(rest.RestController):
      """Manages operations on the alarms collection."""
  
      @pecan.expose()
      def _lookup(self, alarm_id, *remainder):
          return AlarmController(alarm_id), remainder
  
      def _record_creation(self, conn, data, alarm_id, now):
          if not cfg.CONF.alarm.record_history:
              return
          type = alarm_models.AlarmChange.CREATION
          scrubbed_data = utils.stringify_timestamps(data)
          detail = json.dumps(scrubbed_data)
          user_id = pecan.request.headers.get('X-User-Id')
          project_id = pecan.request.headers.get('X-Project-Id')
          payload = dict(event_id=str(uuid.uuid4()),
                         alarm_id=alarm_id,
                         type=type,
                         detail=detail,
                         user_id=user_id,
                         project_id=project_id,
                         on_behalf_of=project_id,
                         timestamp=now)
  
          try:
              conn.record_alarm_change(payload)
          except NotImplementedError:
              pass
  
          # Revert to the pre-json'ed details ...
          payload['detail'] = scrubbed_data
          _send_notification(type, payload)
  
      @wsme_pecan.wsexpose(Alarm, body=Alarm, status_code=201)
      def post(self, data):
          """Create a new alarm.
  
          :param data: an alarm within the request body.
          """
          conn = pecan.request.alarm_storage_conn
          now = timeutils.utcnow()
  
          data.alarm_id = str(uuid.uuid4())
          user_limit, project_limit = acl.get_limited_to(pecan.request.headers)
  
          def _set_ownership(aspect, owner_limitation, header):
              attr = '%s_id' % aspect
              requested_owner = getattr(data, attr)
              explicit_owner = requested_owner != wtypes.Unset
              caller = pecan.request.headers.get(header)
              if (owner_limitation and explicit_owner
                      and requested_owner != caller):
                  raise ProjectNotAuthorized(requested_owner, aspect)
  
              actual_owner = (owner_limitation or
                              requested_owner if explicit_owner else caller)
              setattr(data, attr, actual_owner)
  
          _set_ownership('user', user_limit, 'X-User-Id')
          _set_ownership('project', project_limit, 'X-Project-Id')
  
          # Check if there's room for one more alarm
          if is_over_quota(conn, data.project_id, data.user_id):
              raise OverQuota(data)
  
          data.timestamp = now
          data.state_timestamp = now
  
          change = data.as_dict(alarm_models.Alarm)
  
          # make sure alarms are unique by name per project.
          alarms = list(conn.get_alarms(name=data.name,
                                        project=data.project_id))
          if alarms:
              raise ClientSideError(
                  _("Alarm with name='%s' exists") % data.name,
                  status_code=409)
  
          try:
              alarm_in = alarm_models.Alarm(**change)
          except Exception:
              LOG.exception(_("Error while posting alarm: %s") % change)
              raise ClientSideError(_("Alarm incorrect"))
  
          alarm = conn.create_alarm(alarm_in)
          self._record_creation(conn, change, alarm.alarm_id, now)
          return Alarm.from_db_model(alarm)
  
      @wsme_pecan.wsexpose([Alarm], [Query])
      def get_all(self, q=None):
          """Return all alarms, based on the query provided.
  
          :param q: Filter rules for the alarms to be returned.
          """
          q = q or []
          # Timestamp is not supported field for Simple Alarm queries
          kwargs = _query_to_kwargs(q,
                                    pecan.request.alarm_storage_conn.get_alarms,
                                    allow_timestamps=False)
          return [Alarm.from_db_model(m)
                  for m in pecan.request.alarm_storage_conn.get_alarms(**kwargs)]
  
  
  class TraitDescription(_Base):
      """A description of a trait, with no associated value."""
  
      type = wtypes.text
      "the data type, defaults to string"
  
      name = wtypes.text
      "the name of the trait"
  
      @classmethod
      def sample(cls):
          return cls(name='service',
                     type='string'
                     )
  
  
  class EventQuery(Query):
      """Query arguments for Event Queries."""
  
      _supported_types = ['integer', 'float', 'string', 'datetime']
  
      type = wsme.wsattr(wtypes.text, default='string')
      "the type of the trait filter, defaults to string"
  
      def __repr__(self):
          # for logging calls
          return '<EventQuery %r %s %r %s>' % (self.field,
                                               self.op,
                                               self._get_value_as_type(),
                                               self.type)
  
  
  class Trait(_Base):
      """A Trait associated with an event."""
  
      name = wtypes.text
      "The name of the trait"
  
      value = wtypes.text
      "the value of the trait"
  
      type = wtypes.text
      "the type of the trait (string, integer, float or datetime)"
  
      @staticmethod
      def _convert_storage_trait(trait):
          """Helper method to convert a storage model into an API trait instance.
  
          If an API trait instance is passed in, just return it.
          """
          if isinstance(trait, Trait):
              return trait
          value = (six.text_type(trait.value)
                   if not trait.dtype == storage.models.Trait.DATETIME_TYPE
                   else trait.value.isoformat())
          trait_type = storage.models.Trait.get_name_by_type(trait.dtype)
          return Trait(name=trait.name, type=trait_type, value=value)
  
      @classmethod
      def sample(cls):
          return cls(name='service',
                     type='string',
                     value='compute.hostname'
                     )
  
  
  class Event(_Base):
      """A System event."""
  
      message_id = wtypes.text
      "The message ID for the notification"
  
      event_type = wtypes.text
      "The type of the event"
  
      _traits = None
  
      def get_traits(self):
          return self._traits
  
      def set_traits(self, traits):
          self._traits = map(Trait._convert_storage_trait, traits)
  
      traits = wsme.wsproperty(wtypes.ArrayType(Trait),
                               get_traits,
                               set_traits)
      "Event specific properties"
  
      generated = datetime.datetime
      "The time the event occurred"
  
      @classmethod
      def sample(cls):
          return cls(
              event_type='compute.instance.update',
              generated='2013-11-11T20:00:00',
              message_id='94834db1-8f1b-404d-b2ec-c35901f1b7f0',
              traits={
                  'request_id': 'req-4e2d67b8-31a4-48af-bb2f-9df72a353a72',
                  'service': 'conductor.tem-devstack-01',
                  'tenant_id': '7f13f2b17917463b9ee21aa92c4b36d6'
              }
          )
  
  
  def requires_admin(func):
  
      @functools.wraps(func)
      def wrapped(*args, **kwargs):
          usr_limit, proj_limit = acl.get_limited_to(pecan.request.headers)
          # If User and Project are None, you have full access.
          if usr_limit and proj_limit:
              raise ProjectNotAuthorized(proj_limit)
          return func(*args, **kwargs)
  
      return wrapped
  
  
  def _event_query_to_event_filter(q):
      evt_model_filter = {
          'event_type': None,
          'message_id': None,
          'start_time': None,
          'end_time': None
      }
      traits_filter = []
  
      for i in q:
          if not i.op:
              i.op = 'eq'
          elif i.op not in operation_kind:
              error = _("operator {} is incorrect").format(i.op)
              raise ClientSideError(error)
          if i.field in evt_model_filter:
              evt_model_filter[i.field] = i.value
          else:
              traits_filter.append({"key": i.field,
                                    i.type: i._get_value_as_type(),
                                    "op": i.op})
      return storage.EventFilter(traits_filter=traits_filter, **evt_model_filter)
  
  
  class TraitsController(rest.RestController):
      """Works on Event Traits."""
  
      @requires_admin
      @wsme_pecan.wsexpose([Trait], wtypes.text, wtypes.text)
      def get_one(self, event_type, trait_name):
          """Return all instances of a trait for an event type.
  
          :param event_type: Event type to filter traits by
          :param trait_name: Trait to return values for
          """
          LOG.debug(_("Getting traits for %s") % event_type)
          return [Trait._convert_storage_trait(t)
                  for t in pecan.request.storage_conn
                  .get_traits(event_type, trait_name)]
  
      @requires_admin
      @wsme_pecan.wsexpose([TraitDescription], wtypes.text)
      def get_all(self, event_type):
          """Return all trait names for an event type.
  
          :param event_type: Event type to filter traits by
          """
          get_trait_name = storage.models.Trait.get_name_by_type
          return [TraitDescription(name=t['name'],
                                   type=get_trait_name(t['data_type']))
                  for t in pecan.request.storage_conn
                  .get_trait_types(event_type)]
  
  
  class EventTypesController(rest.RestController):
      """Works on Event Types in the system."""
  
      traits = TraitsController()
  
      @pecan.expose()
      def get_one(self, event_type):
          pecan.abort(404)
  
      @requires_admin
      @wsme_pecan.wsexpose([unicode])
      def get_all(self):
          """Get all event types."""
          return list(pecan.request.storage_conn.get_event_types())
  
  
  class EventsController(rest.RestController):
      """Works on Events."""
  
      @requires_admin
      @wsme_pecan.wsexpose([Event], [EventQuery])
      def get_all(self, q=None):
          """Return all events matching the query filters.
  
          :param q: Filter arguments for which Events to return
          """
          q = q or []
          event_filter = _event_query_to_event_filter(q)
          return [Event(message_id=event.message_id,
                        event_type=event.event_type,
                        generated=event.generated,
                        traits=event.traits)
                  for event in
                  pecan.request.storage_conn.get_events(event_filter)]
  
      @requires_admin
      @wsme_pecan.wsexpose(Event, wtypes.text)
      def get_one(self, message_id):
          """Return a single event with the given message id.
  
          :param message_id: Message ID of the Event to be returned
          """
          event_filter = storage.EventFilter(message_id=message_id)
          events = [event for event
                    in pecan.request.storage_conn.get_events(event_filter)]
          if not events:
              raise EntityNotFound(_("Event"), message_id)
  
          if len(events) > 1:
              LOG.error(_("More than one event with "
                          "id %s returned from storage driver") % message_id)
  
          event = events[0]
  
          return Event(message_id=event.message_id,
                       event_type=event.event_type,
                       generated=event.generated,
                       traits=event.traits)
  
  
  class QuerySamplesController(rest.RestController):
      """Provides complex query possibilities for samples."""
  
      @wsme_pecan.wsexpose([Sample], body=ComplexQuery)
      def post(self, body):
          """Define query for retrieving Sample data.
  
          :param body: Query rules for the samples to be returned.
          """
          sample_name_mapping = {"resource": "resource_id",
                                 "meter": "counter_name",
                                 "type": "counter_type",
                                 "unit": "counter_unit",
                                 "volume": "counter_volume"}
  
          query = ValidatedComplexQuery(body,
                                        storage.models.Sample,
                                        sample_name_mapping,
                                        metadata_allowed=True)
          query.validate(visibility_field="project_id")
          conn = pecan.request.storage_conn
          return [Sample.from_db_model(s)
                  for s in conn.query_samples(query.filter_expr,
                                              query.orderby,
                                              query.limit)]
  
  
  class QueryAlarmHistoryController(rest.RestController):
      """Provides complex query possibilites for alarm history."""
      @wsme_pecan.wsexpose([AlarmChange], body=ComplexQuery)
      def post(self, body):
          """Define query for retrieving AlarmChange data.
  
          :param body: Query rules for the alarm history to be returned.
          """
          query = ValidatedComplexQuery(body,
                                        alarm_models.AlarmChange)
          query.validate(visibility_field="on_behalf_of")
          conn = pecan.request.alarm_storage_conn
          return [AlarmChange.from_db_model(s)
                  for s in conn.query_alarm_history(query.filter_expr,
                                                    query.orderby,
                                                    query.limit)]
  
  
  class QueryAlarmsController(rest.RestController):
      """Provides complex query possibilities for alarms."""
      history = QueryAlarmHistoryController()
  
      @wsme_pecan.wsexpose([Alarm], body=ComplexQuery)
      def post(self, body):
          """Define query for retrieving Alarm data.
  
          :param body: Query rules for the alarms to be returned.
          """
          query = ValidatedComplexQuery(body,
                                        alarm_models.Alarm)
          query.validate(visibility_field="project_id")
          conn = pecan.request.alarm_storage_conn
          return [Alarm.from_db_model(s)
                  for s in conn.query_alarms(query.filter_expr,
                                             query.orderby,
                                             query.limit)]
  
  
  class QueryController(rest.RestController):
  
      samples = QuerySamplesController()
      alarms = QueryAlarmsController()
  
  
  def _flatten_capabilities(capabilities):
      return dict((k, v) for k, v in utils.recursive_keypairs(capabilities))
  
  
  class Capabilities(_Base):
      """A representation of the API and storage capabilities.
  
      Usually constrained by restrictions imposed by the storage driver.
      """
  
      api = {wtypes.text: bool}
      "A flattened dictionary of API capabilities"
      storage = {wtypes.text: bool}
      "A flattened dictionary of storage capabilities"
      alarm_storage = {wtypes.text: bool}
      "A flattened dictionary of storage capabilities"
  
      @classmethod
      def sample(cls):
          return cls(
              api=_flatten_capabilities({
                  'meters': {'pagination': True,
                             'query': {'simple': True,
                                       'metadata': True,
                                       'complex': False}},
                  'resources': {'pagination': False,
                                'query': {'simple': True,
                                          'metadata': True,
                                          'complex': False}},
                  'samples': {'pagination': True,
                              'groupby': True,
                              'query': {'simple': True,
                                        'metadata': True,
                                        'complex': True}},
                  'statistics': {'pagination': True,
                                 'groupby': True,
                                 'query': {'simple': True,
                                           'metadata': True,
                                           'complex': False},
                                 'aggregation': {'standard': True,
                                                 'selectable': {
                                                     'max': True,
                                                     'min': True,
                                                     'sum': True,
                                                     'avg': True,
                                                     'count': True,
                                                     'stddev': True,
                                                     'cardinality': True,
                                                     'quartile': False}}},
                  'alarms': {'query': {'simple': True,
                                       'complex': True},
                             'history': {'query': {'simple': True,
                                                   'complex': True}}},
                  'events': {'query': {'simple': True}},
              }),
              storage=_flatten_capabilities({'production_ready': True}),
              alarm_storage=_flatten_capabilities({'production_ready': True}),
          )
  
  
  class CapabilitiesController(rest.RestController):
      """Manages capabilities queries."""
  
      @wsme_pecan.wsexpose(Capabilities)
      def get(self):
          """Returns a flattened dictionary of API capabilities.
  
          Capabilities supported by the currently configured storage driver.
          """
          # variation in API capabilities is effectively determined by
          # the lack of strict feature parity across storage drivers
          conn = pecan.request.storage_conn
          alarm_conn = pecan.request.alarm_storage_conn
          driver_capabilities = conn.get_capabilities().copy()
          driver_capabilities['alarms'] = alarm_conn.get_capabilities()['alarms']
          driver_perf = conn.get_storage_capabilities()
          alarm_driver_perf = alarm_conn.get_storage_capabilities()
          return Capabilities(api=_flatten_capabilities(driver_capabilities),
                              storage=_flatten_capabilities(driver_perf),
                              alarm_storage=_flatten_capabilities(
                                  alarm_driver_perf))
  
  
  class V2Controller(object):
      """Version 2 API controller root."""
  
      resources = ResourcesController()
      meters = MetersController()
      samples = SamplesController()
      alarms = AlarmsController()
      event_types = EventTypesController()
      events = EventsController()
      query = QueryController()
      capabilities = CapabilitiesController()
  