# -*- encoding: utf-8 -*-
#
# Copyright 2013 Hewlett-Packard Development Company, L.P.
#
# 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.
"""
Base classes for storage engines
"""

import abc

from oslo_config import cfg
from oslo_db import api as db_api


_BACKEND_MAPPING = {'sqlalchemy': 'ironic.db.sqlalchemy.api'}
IMPL = db_api.DBAPI.from_config(cfg.CONF, backend_mapping=_BACKEND_MAPPING,
                                lazy=True)


def get_instance():
    """Return a DB API instance."""
    return IMPL


class Connection(object, metaclass=abc.ABCMeta):
    """Base class for storage system connections."""

    @abc.abstractmethod
    def __init__(self):
        """Constructor."""

    @abc.abstractmethod
    def get_nodeinfo_list(self, columns=None, filters=None, limit=None,
                          marker=None, sort_key=None, sort_dir=None):
        """Get specific columns for matching nodes.

        Return a list of the specified columns for all nodes that match the
        specified filters.

        :param columns: List of column names to return.
                        Defaults to 'id' column when columns == None.
        :param filters: Filters to apply. Defaults to None.

                        :associated: True | False
                        :reserved: True | False
                        :reserved_by_any_of: [conductor1, conductor2]
                        :maintenance: True | False
                        :retired: True | False
                        :chassis_uuid: uuid of chassis
                        :driver: driver's name
                        :provision_state: provision state of node
                        :provisioned_before:
                            nodes with provision_updated_at field before this
                            interval in seconds
        :param limit: Maximum number of nodes to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: direction in which results should be sorted.
                         (asc, desc)
        :returns: A list of tuples of the specified columns.
        """

    @abc.abstractmethod
    def get_node_list(self, filters=None, limit=None, marker=None,
                      sort_key=None, sort_dir=None):
        """Return a list of nodes.

        :param filters: Filters to apply. Defaults to None.

                        :associated: True | False
                        :reserved: True | False
                        :maintenance: True | False
                        :chassis_uuid: uuid of chassis
                        :driver: driver's name
                        :provision_state: provision state of node
                        :provisioned_before:
                            nodes with provision_updated_at field before this
                            interval in seconds
        :param limit: Maximum number of nodes to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: direction in which results should be sorted.
                         (asc, desc)
        """

    @abc.abstractmethod
    def check_node_list(self, idents):
        """Check a list of node identities and map it to UUIDs.

        This call takes a list of node names and/or UUIDs and tries to convert
        them to UUIDs. It fails early if any identities cannot possible be used
        as names or UUIDs.

        :param idents: List of identities.
        :returns: A mapping from requests identities to node UUIDs.
        :raises: NodeNotFound if some identities were not found or cannot be
            valid names or UUIDs.
        """

    @abc.abstractmethod
    def reserve_node(self, tag, node_id):
        """Reserve a node.

        To prevent other ManagerServices from manipulating the given
        Node while a Task is performed, mark it reserved by this host.

        :param tag: A string uniquely identifying the reservation holder.
        :param node_id: A node id or uuid.
        :returns: A Node object.
        :raises: NodeNotFound if the node is not found.
        :raises: NodeLocked if the node is already reserved.
        """

    @abc.abstractmethod
    def release_node(self, tag, node_id):
        """Release the reservation on a node.

        :param tag: A string uniquely identifying the reservation holder.
        :param node_id: A node id or uuid.
        :raises: NodeNotFound if the node is not found.
        :raises: NodeLocked if the node is reserved by another host.
        :raises: NodeNotLocked if the node was found to not have a
                 reservation at all.
        """

    @abc.abstractmethod
    def create_node(self, values):
        """Create a new node.

        :param values: A dict containing several items used to identify
                       and track the node, and several dicts which are passed
                       into the Drivers when managing this node. For example:

                       ::

                        {
                         'uuid': uuidutils.generate_uuid(),
                         'instance_uuid': None,
                         'power_state': states.POWER_OFF,
                         'provision_state': states.AVAILABLE,
                         'driver': 'ipmi',
                         'driver_info': { ... },
                         'properties': { ... },
                         'extra': { ... },
                        }
        :raises: InvalidParameterValue if 'values' contains 'tags' or 'traits'.
        :returns: A node.
        """

    @abc.abstractmethod
    def get_node_by_id(self, node_id):
        """Return a node.

        :param node_id: The id of a node.
        :returns: A node.
        """

    @abc.abstractmethod
    def get_node_by_uuid(self, node_uuid):
        """Return a node.

        :param node_uuid: The uuid of a node.
        :returns: A node.
        """

    @abc.abstractmethod
    def get_node_by_name(self, node_name):
        """Return a node.

        :param node_name: The logical name of a node.
        :returns: A node.
        """

    @abc.abstractmethod
    def get_node_by_instance(self, instance):
        """Return a node.

        :param instance: The instance uuid to search for.
        :returns: A node.
        :raises: InstanceNotFound if the instance is not found.
        :raises: InvalidUUID if the instance uuid is invalid.
        """

    @abc.abstractmethod
    def destroy_node(self, node_id):
        """Destroy a node and its associated resources.

        Destroy a node, including any associated ports, port groups,
        tags, traits, volume connectors, and volume targets.

        :param node_id: The ID or UUID of a node.
        """

    @abc.abstractmethod
    def update_node(self, node_id, values):
        """Update properties of a node.

        :param node_id: The id or uuid of a node.
        :param values: Dict of values to update.
                       May be a partial list, eg. when setting the
                       properties for a driver. For example:

                       ::

                        {
                         'driver_info':
                             {
                              'my-field-1': val1,
                              'my-field-2': val2,
                             }
                        }
        :returns: A node.
        :raises: NodeAssociated
        :raises: NodeNotFound
        """

    @abc.abstractmethod
    def get_port_by_id(self, port_id):
        """Return a network port representation.

        :param port_id: The id of a port.
        :returns: A port.
        """

    @abc.abstractmethod
    def get_port_by_uuid(self, port_uuid):
        """Return a network port representation.

        :param port_uuid: The uuid of a port.
        :returns: A port.
        """

    @abc.abstractmethod
    def get_port_by_address(self, address):
        """Return a network port representation.

        :param address: The MAC address of a port.
        :returns: A port.
        """

    @abc.abstractmethod
    def get_port_list(self, limit=None, marker=None,
                      sort_key=None, sort_dir=None):
        """Return a list of ports.

        :param limit: Maximum number of ports to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: direction in which results should be sorted.
                         (asc, desc)
        """

    @abc.abstractmethod
    def get_ports_by_node_id(self, node_id, limit=None, marker=None,
                             sort_key=None, sort_dir=None):
        """List all the ports for a given node.

        :param node_id: The integer node ID.
        :param limit: Maximum number of ports to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted
        :param sort_dir: direction in which results should be sorted
                         (asc, desc)
        :returns: A list of ports.
        """

    @abc.abstractmethod
    def get_ports_by_portgroup_id(self, portgroup_id, limit=None, marker=None,
                                  sort_key=None, sort_dir=None):
        """List all the ports for a given portgroup.

        :param portgroup_id: The integer portgroup ID.
        :param limit: Maximum number of ports to return.
        :param marker: The last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted
        :param sort_dir: Direction in which results should be sorted
                         (asc, desc)
        :returns: A list of ports.
        """

    @abc.abstractmethod
    def create_port(self, values):
        """Create a new port.

        :param values: Dict of values.
        """

    @abc.abstractmethod
    def update_port(self, port_id, values):
        """Update properties of an port.

        :param port_id: The id or MAC of a port.
        :param values: Dict of values to update.
        :returns: A port.
        """

    @abc.abstractmethod
    def destroy_port(self, port_id):
        """Destroy an port.

        :param port_id: The id or MAC of a port.
        """

    @abc.abstractmethod
    def get_portgroup_by_id(self, portgroup_id):
        """Return a network portgroup representation.

        :param portgroup_id: The id of a portgroup.
        :returns: A portgroup.
        :raises: PortgroupNotFound
        """

    @abc.abstractmethod
    def get_portgroup_by_uuid(self, portgroup_uuid):
        """Return a network portgroup representation.

        :param portgroup_uuid: The uuid of a portgroup.
        :returns: A portgroup.
        :raises: PortgroupNotFound
        """

    @abc.abstractmethod
    def get_portgroup_by_address(self, address):
        """Return a network portgroup representation.

        :param address: The MAC address of a portgroup.
        :returns: A portgroup.
        :raises: PortgroupNotFound
        """

    @abc.abstractmethod
    def get_portgroup_by_name(self, name):
        """Return a network portgroup representation.

        :param name: The logical name of a portgroup.
        :returns: A portgroup.
        :raises: PortgroupNotFound
        """

    @abc.abstractmethod
    def get_portgroup_list(self, limit=None, marker=None,
                           sort_key=None, sort_dir=None):
        """Return a list of portgroups.

        :param limit: Maximum number of portgroups to return.
        :param marker: The last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: Direction in which results should be sorted.
                         (asc, desc)
        :returns: A list of portgroups.
        """

    @abc.abstractmethod
    def get_portgroups_by_node_id(self, node_id, limit=None, marker=None,
                                  sort_key=None, sort_dir=None):
        """List all the portgroups for a given node.

        :param node_id: The integer node ID.
        :param limit: Maximum number of portgroups to return.
        :param marker: The last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted
        :param sort_dir: Direction in which results should be sorted
                         (asc, desc)
        :returns: A list of portgroups.
        """

    @abc.abstractmethod
    def create_portgroup(self, values):
        """Create a new portgroup.

        :param values: Dict of values with the following keys:
                       'id'
                       'uuid'
                       'name'
                       'node_id'
                       'address'
                       'extra'
                       'created_at'
                       'updated_at'
        :returns: A portgroup
        :raises: PortgroupDuplicateName
        :raises: PortgroupMACAlreadyExists
        :raises: PortgroupAlreadyExists
        """

    @abc.abstractmethod
    def update_portgroup(self, portgroup_id, values):
        """Update properties of a portgroup.

        :param portgroup_id: The UUID or MAC of a portgroup.
        :param values: Dict of values to update.
                       May contain the following keys:
                       'uuid'
                       'name'
                       'node_id'
                       'address'
                       'extra'
                       'created_at'
                       'updated_at'
        :returns: A portgroup.
        :raises: InvalidParameterValue
        :raises: PortgroupNotFound
        :raises: PortgroupDuplicateName
        :raises: PortgroupMACAlreadyExists
        """

    @abc.abstractmethod
    def destroy_portgroup(self, portgroup_id):
        """Destroy a portgroup.

        :param portgroup_id: The UUID or MAC of a portgroup.
        :raises: PortgroupNotEmpty
        :raises: PortgroupNotFound
        """

    @abc.abstractmethod
    def create_chassis(self, values):
        """Create a new chassis.

        :param values: Dict of values.
        """

    @abc.abstractmethod
    def get_chassis_by_id(self, chassis_id):
        """Return a chassis representation.

        :param chassis_id: The id of a chassis.
        :returns: A chassis.
        """

    @abc.abstractmethod
    def get_chassis_by_uuid(self, chassis_uuid):
        """Return a chassis representation.

        :param chassis_uuid: The uuid of a chassis.
        :returns: A chassis.
        """

    @abc.abstractmethod
    def get_chassis_list(self, limit=None, marker=None,
                         sort_key=None, sort_dir=None):
        """Return a list of chassis.

        :param limit: Maximum number of chassis to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: direction in which results should be sorted.
                         (asc, desc)
        """

    @abc.abstractmethod
    def update_chassis(self, chassis_id, values):
        """Update properties of an chassis.

        :param chassis_id: The id or the uuid of a chassis.
        :param values: Dict of values to update.
        :returns: A chassis.
        """

    @abc.abstractmethod
    def destroy_chassis(self, chassis_id):
        """Destroy a chassis.

        :param chassis_id: The id or the uuid of a chassis.
        """

    @abc.abstractmethod
    def register_conductor(self, values, update_existing=False):
        """Register an active conductor with the cluster.

        :param values: A dict of values which must contain the following:

                       ::

                        {
                         'hostname': the unique hostname which identifies
                                     this Conductor service.
                         'drivers': a list of supported drivers.
                         'version': the version of the object.Conductor
                        }
        :param update_existing: When false, registration will raise an
                                exception when a conflicting online record
                                is found. When true, will overwrite the
                                existing record. Default: False.
        :returns: A conductor.
        :raises: ConductorAlreadyRegistered
        """

    @abc.abstractmethod
    def get_conductor_list(self, limit=None, marker=None,
                           sort_key=None, sort_dir=None):
        """Return a list of conductors.

        :param limit: Maximum number of conductors to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: direction in which results should be sorted.
                         (asc, desc)
        """

    @abc.abstractmethod
    def get_conductor(self, hostname, online=True):
        """Retrieve a conductor's service record from the database.

        :param hostname: The hostname of the conductor service.
        :param online: Specify the filter value on the `online` field when
                       querying conductors. The ``online`` field is ignored if
                       this value is set to None.
        :returns: A conductor.
        :raises: ConductorNotFound if the conductor with given hostname does
                 not exist or doesn't meet the specified online expectation.
        """

    @abc.abstractmethod
    def unregister_conductor(self, hostname):
        """Remove this conductor from the service registry immediately.

        :param hostname: The hostname of this conductor service.
        :raises: ConductorNotFound
        """

    @abc.abstractmethod
    def touch_conductor(self, hostname):
        """Mark a conductor as active by updating its 'updated_at' property.

        :param hostname: The hostname of this conductor service.
        :raises: ConductorNotFound
        """

    @abc.abstractmethod
    def get_active_hardware_type_dict(self, use_groups=False):
        """Retrieve hardware types for the registered and active conductors.

        :param use_groups: Whether to factor conductor_group into the keys.
        :returns: A dict which maps hardware type names to the set of hosts
                  which support them. For example:

                  ::

                    {hardware-type-a: set([host1, host2]),
                     hardware-type-b: set([host2, host3])}
        """

    @abc.abstractmethod
    def get_offline_conductors(self, field='hostname'):
        """Get a list conductors that are offline (dead).

        :param field: A field to return, hostname by default.
        :returns: A list of requested fields of offline conductors.
        """

    @abc.abstractmethod
    def get_online_conductors(self):
        """Get a list conductor hostnames that are online and active.

        :returns: A list of conductor hostnames.
        """

    @abc.abstractmethod
    def list_conductor_hardware_interfaces(self, conductor_id):
        """List all registered hardware interfaces for a conductor.

        :param conductor_id: Database ID of conductor.
        :returns: List of ``ConductorHardwareInterfaces`` objects.
        """

    @abc.abstractmethod
    def list_hardware_type_interfaces(self, hardware_types):
        """List registered hardware interfaces for given hardware types.

        This is restricted to only active conductors.
        :param hardware_types: list of hardware types to filter by.
        :returns: list of ``ConductorHardwareInterfaces`` objects.
        """

    @abc.abstractmethod
    def register_conductor_hardware_interfaces(self, conductor_id,
                                               hardware_type, interface_type,
                                               interfaces, default_interface):
        """Registers hardware interfaces for a conductor.

        :param conductor_id: Database ID of conductor to register for.
        :param hardware_type: Name of hardware type for the interfaces.
        :param interface_type: Type of interfaces, e.g. 'deploy' or 'boot'.
        :param interfaces: List of interface names to register.
        :param default_interface: String, the default interface for this
                                  hardware type and interface type.
        :raises: ConductorHardwareInterfacesAlreadyRegistered if at least one
                 of the interfaces in the combination of all parameters is
                 already registered.
        """

    @abc.abstractmethod
    def unregister_conductor_hardware_interfaces(self, conductor_id):
        """Unregisters all hardware interfaces for a conductor.

        :param conductor_id: Database ID of conductor to unregister for.
        """

    @abc.abstractmethod
    def touch_node_provisioning(self, node_id):
        """Mark the node's provisioning as running.

        Mark the node's provisioning as running by updating its
        'provision_updated_at' property.

        :param node_id: The id of a node.
        :raises: NodeNotFound
        """

    @abc.abstractmethod
    def set_node_tags(self, node_id, tags):
        """Replace all of the node tags with specified list of tags.

        This ignores duplicate tags in the specified list.

        :param node_id: The id of a node.
        :param tags: List of tags.
        :returns: A list of NodeTag objects.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def unset_node_tags(self, node_id):
        """Remove all tags of the node.

        :param node_id: The id of a node.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def get_node_tags_by_node_id(self, node_id):
        """Get node tags based on its id.

        :param node_id: The id of a node.
        :returns: A list of NodeTag objects.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def add_node_tag(self, node_id, tag):
        """Add tag to the node.

        If the node_id and tag pair already exists, this should still
        succeed.

        :param node_id: The id of a node.
        :param tag: A tag string.
        :returns: the NodeTag object.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def delete_node_tag(self, node_id, tag):
        """Delete specified tag from the node.

        :param node_id: The id of a node.
        :param tag: A tag string.
        :raises: NodeNotFound if the node is not found.
        :raises: NodeTagNotFound if the tag is not found.
        """

    @abc.abstractmethod
    def node_tag_exists(self, node_id, tag):
        """Check if the specified tag exist on the node.

        :param node_id: The id of a node.
        :param tag: A tag string.
        :returns: True if the tag exists otherwise False.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def get_node_by_port_addresses(self, addresses):
        """Find a node by any matching port address.

        :param addresses: list of port addresses (e.g. MACs).
        :returns: Node object.
        :raises: NodeNotFound if none or several nodes are found.
        """

    @abc.abstractmethod
    def get_volume_connector_list(self, limit=None, marker=None,
                                  sort_key=None, sort_dir=None):
        """Return a list of volume connectors.

        :param limit: Maximum number of volume connectors to return.
        :param marker: The last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: Direction in which results should be sorted.
                         (asc, desc)
        :returns: A list of volume connectors.
        :raises: InvalidParameterValue If sort_key does not exist.
        """

    @abc.abstractmethod
    def get_volume_connector_by_id(self, db_id):
        """Return a volume connector representation.

        :param db_id: The integer database ID of a volume connector.
        :returns: A volume connector with the specified ID.
        :raises: VolumeConnectorNotFound If a volume connector
                 with the specified ID is not found.
        """

    @abc.abstractmethod
    def get_volume_connector_by_uuid(self, connector_uuid):
        """Return a volume connector representation.

        :param connector_uuid: The UUID of a connector.
        :returns: A volume connector with the specified UUID.
        :raises: VolumeConnectorNotFound If a volume connector
                 with the specified UUID is not found.
        """

    @abc.abstractmethod
    def get_volume_connectors_by_node_id(self, node_id, limit=None,
                                         marker=None, sort_key=None,
                                         sort_dir=None):
        """List all the volume connectors for a given node.

        :param node_id: The integer node ID.
        :param limit: Maximum number of volume connectors to return.
        :param marker: The last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted
        :param sort_dir: Direction in which results should be sorted
                         (asc, desc)
        :returns: A list of volume connectors.
        :raises: InvalidParameterValue If sort_key does not exist.
        """

    @abc.abstractmethod
    def create_volume_connector(self, connector_info):
        """Create a new volume connector.

        :param connector_info: Dictionary containing information about the
                               connector. Example::

                                   {
                                       'uuid': '000000-..',
                                       'type': 'wwnn',
                                       'connector_id': '00:01:02:03:04:05:06',
                                       'node_id': 2
                                   }

        :returns: A volume connector.
        :raises: VolumeConnectorTypeAndIdAlreadyExists If a connector
                 already exists with a matching type and connector_id.
        :raises: VolumeConnectorAlreadyExists If a volume connector with
                 the same UUID already exists.
        """

    @abc.abstractmethod
    def update_volume_connector(self, ident, connector_info):
        """Update properties of a volume connector.

        :param ident: The UUID or integer ID of a volume connector.
        :param connector_info: Dictionary containing the information about
                               connector to update.
        :returns: A volume connector.
        :raises: VolumeConnectorTypeAndIdAlreadyExists If another
                 connector already exists with a matching type and
                 connector_id field.
        :raises: VolumeConnectorNotFound If a volume connector
                 with the specified ident does not exist.
        :raises: InvalidParameterValue When a UUID is included in
                 connector_info.
        """

    @abc.abstractmethod
    def destroy_volume_connector(self, ident):
        """Destroy a volume connector.

        :param ident: The UUID or integer ID of a volume connector.
        :raises: VolumeConnectorNotFound If a volume connector
                 with the specified ident does not exist.
        """

    @abc.abstractmethod
    def get_volume_target_list(self, limit=None, marker=None,
                               sort_key=None, sort_dir=None):
        """Return a list of volume targets.

        :param limit: Maximum number of volume targets to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: direction in which results should be sorted.
                         (asc, desc)
        :returns: A list of volume targets.
        :raises: InvalidParameterValue if sort_key does not exist.
        """

    @abc.abstractmethod
    def get_volume_target_by_id(self, db_id):
        """Return a volume target representation.

        :param db_id: The database primary key (integer) ID of a volume target.
        :returns: A volume target.
        :raises: VolumeTargetNotFound if no volume target with this ID
                 exists.
        """

    @abc.abstractmethod
    def get_volume_target_by_uuid(self, uuid):
        """Return a volume target representation.

        :param uuid: The UUID of a volume target.
        :returns: A volume target.
        :raises: VolumeTargetNotFound if no volume target with this UUID
                 exists.
        """

    @abc.abstractmethod
    def get_volume_targets_by_node_id(self, node_id, limit=None,
                                      marker=None, sort_key=None,
                                      sort_dir=None):
        """List all the volume targets for a given node.

        :param node_id: The integer node ID.
        :param limit: Maximum number of volume targets to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted
        :param sort_dir: direction in which results should be sorted
                         (asc, desc)
        :returns: A list of volume targets.
        :raises: InvalidParameterValue if sort_key does not exist.
        """

    @abc.abstractmethod
    def get_volume_targets_by_volume_id(self, volume_id, limit=None,
                                        marker=None, sort_key=None,
                                        sort_dir=None):
        """List all the volume targets for a given volume id.

        :param volume_id: The UUID of the volume.
        :param limit: Maximum number of volume targets to return.
        :param marker: the last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted
        :param sort_dir: direction in which results should be sorted
                         (asc, desc)
        :returns: A list of volume targets.
        :raises: InvalidParameterValue if sort_key does not exist.
        """

    @abc.abstractmethod
    def create_volume_target(self, target_info):
        """Create a new volume target.

        :param target_info: Dictionary containing the information about the
                            volume target. Example::

                                   {
                                       'uuid': '000000-..',
                                       'node_id': 2,
                                       'boot_index': 0,
                                       'volume_id': '12345678-...'
                                       'volume_type': 'some type',
                                   }
        :returns: A volume target.
        :raises: VolumeTargetBootIndexAlreadyExists if a volume target already
                 exists with the same boot index and node ID.
        :raises: VolumeTargetAlreadyExists if a volume target with the same
                 UUID exists.
        """

    @abc.abstractmethod
    def update_volume_target(self, ident, target_info):
        """Update information for a volume target.

        :param ident: The UUID or integer ID of a volume target.
        :param target_info: Dictionary containing the information about
                            volume target to update.
        :returns: A volume target.
        :raises: InvalidParameterValue if a UUID is included in target_info.
        :raises: VolumeTargetBootIndexAlreadyExists if a volume target already
                 exists with the same boot index and node ID.
        :raises: VolumeTargetNotFound if no volume target with this ident
                 exists.
        """

    @abc.abstractmethod
    def destroy_volume_target(self, ident):
        """Destroy a volume target.

        :param ident: The UUID or integer ID of a volume target.
        :raises: VolumeTargetNotFound if a volume target with the specified
                 ident does not exist.
        """

    @abc.abstractmethod
    def get_not_versions(self, model_name, versions):
        """Returns objects with versions that are not the specified versions.

        :param model_name: the name of the model (class) of desired objects
        :param versions: list of versions of objects not to be returned
        :returns: list of the DB objects
        :raises: IronicException if there is no class associated with the name
        """

    @abc.abstractmethod
    def check_versions(self, ignore_models=()):
        """Checks the whole database for incompatible objects.

        This scans all the tables in search of objects that are not supported;
        i.e., those that are not specified in
        `ironic.common.release_mappings.RELEASE_MAPPING`.

        :param ignore_models: List of model names to skip.
        :returns: A Boolean. True if all the objects have supported versions;
                  False otherwise.
        """

    @abc.abstractmethod
    def update_to_latest_versions(self, context, max_count):
        """Updates objects to their latest known versions.

        This scans all the tables and for objects that are not in their latest
        version, updates them to that version.

        :param context: the admin context
        :param max_count: The maximum number of objects to migrate. Must be
                          >= 0. If zero, all the objects will be migrated.
        :returns: A 2-tuple, 1. the total number of objects that need to be
                  migrated (at the beginning of this call) and 2. the number
                  of migrated objects.
        """

    @abc.abstractmethod
    def set_node_traits(self, node_id, traits, version):
        """Replace all of the node traits with specified list of traits.

        This ignores duplicate traits in the specified list.

        :param node_id: The id of a node.
        :param traits: List of traits.
        :param version: the version of the object.Trait.
        :returns: A list of NodeTrait objects.
        :raises: InvalidParameterValue if setting the traits would exceed the
            per-node traits limit.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def unset_node_traits(self, node_id):
        """Remove all traits of the node.

        :param node_id: The id of a node.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def get_node_traits_by_node_id(self, node_id):
        """Get node traits based on its id.

        :param node_id: The id of a node.
        :returns: A list of NodeTrait objects.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def add_node_trait(self, node_id, trait, version):
        """Add trait to the node.

        If the node_id and trait pair already exists, this should still
        succeed.

        :param node_id: The id of a node.
        :param trait: A trait string.
        :param version: the version of the object.Trait.
        :returns: the NodeTrait object.
        :raises: InvalidParameterValue if adding the trait would exceed the
            per-node traits limit.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def delete_node_trait(self, node_id, trait):
        """Delete specified trait from the node.

        :param node_id: The id of a node.
        :param trait: A trait string.
        :raises: NodeNotFound if the node is not found.
        :raises: NodeTraitNotFound if the trait is not found.
        """

    @abc.abstractmethod
    def node_trait_exists(self, node_id, trait):
        """Check if the specified trait exists on the node.

        :param node_id: The id of a node.
        :param trait: A trait string.
        :returns: True if the trait exists otherwise False.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def create_bios_setting_list(self, node_id, settings, version):
        """Create a list of BIOSSetting records for a given node.

        :param node_id: The node id.
        :param settings: A list of BIOS Settings to be created.

                       ::

                        [
                          {
                           'name': String,
                           'value': String,
                          },
                          {
                           'name': String,
                           'value': String,
                          },
                          ...
                        ]
        :param version: the version of the object.BIOSSetting.
        :returns: A list of BIOSSetting object.
        :raises: NodeNotFound if the node is not found.
        :raises: BIOSSettingAlreadyExists if any of the setting records
            already exists.
        """

    @abc.abstractmethod
    def update_bios_setting_list(self, node_id, settings, version):
        """Update a list of BIOSSetting records.

        :param node_id: The node id.
        :param settings: A list of BIOS Settings to be updated.

                       ::

                        [
                          {
                           'name': String,
                           'value': String,
                          },
                          {
                           'name': String,
                           'value': String,
                          },
                          ...
                        ]
        :param version: the version of the object.BIOSSetting.
        :returns: A list of BIOSSetting objects.
        :raises: NodeNotFound if the node is not found.
        :raises: BIOSSettingNotFound if any of the settings is not found.
        """

    @abc.abstractmethod
    def delete_bios_setting_list(self, node_id, names):
        """Delete a list of BIOS settings.

        :param node_id: The node id.
        :param names: List of BIOS setting names to be deleted.
        :raises: NodeNotFound if the node is not found.
        :raises: BIOSSettingNotFound if any of BIOS setting name is not found.
        """

    @abc.abstractmethod
    def get_bios_setting(self, node_id, name):
        """Retrieve BIOS setting value.

        :param node_id: The node id.
        :param name: String containing name of BIOS setting to be retrieved.
        :returns: The BIOSSetting object.
        :raises: NodeNotFound if the node is not found.
        :raises: BIOSSettingNotFound if the BIOS setting is not found.
        """

    @abc.abstractmethod
    def get_bios_setting_list(self, node_id):
        """Retrieve BIOS settings of a given node.

        :param node_id: The node id.
        :returns: A list of BIOSSetting objects.
        :raises: NodeNotFound if the node is not found.
        """

    @abc.abstractmethod
    def get_allocation_by_id(self, allocation_id):
        """Return an allocation representation.

        :param allocation_id: The id of an allocation.
        :returns: An allocation.
        :raises: AllocationNotFound
        """

    @abc.abstractmethod
    def get_allocation_by_uuid(self, allocation_uuid):
        """Return an allocation representation.

        :param allocation_uuid: The uuid of an allocation.
        :returns: An allocation.
        :raises: AllocationNotFound
        """

    @abc.abstractmethod
    def get_allocation_by_name(self, name):
        """Return an allocation representation.

        :param name: The logical name of an allocation.
        :returns: An allocation.
        :raises: AllocationNotFound
        """

    @abc.abstractmethod
    def get_allocation_list(self, filters=None, limit=None, marker=None,
                            sort_key=None, sort_dir=None):
        """Return a list of allocations.

        :param filters: Filters to apply. Defaults to None.

                        :node_uuid: uuid of node
                        :state: allocation state
                        :resource_class: requested resource class
        :param limit: Maximum number of allocations to return.
        :param marker: The last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: Direction in which results should be sorted.
                         (asc, desc)
        :returns: A list of allocations.
        """

    @abc.abstractmethod
    def create_allocation(self, values):
        """Create a new allocation.

        :param values: Dict of values to create an allocation with
        :returns: An allocation
        :raises: AllocationDuplicateName
        :raises: AllocationAlreadyExists
        """

    @abc.abstractmethod
    def update_allocation(self, allocation_id, values, update_node=True):
        """Update properties of an allocation.

        :param allocation_id: Allocation ID
        :param values: Dict of values to update.
        :param update_node: If True and node_id is updated, update the node
            with instance_uuid and traits from the allocation
        :returns: An allocation.
        :raises: AllocationNotFound
        :raises: AllocationDuplicateName
        :raises: InstanceAssociated
        :raises: NodeAssociated
        """

    @abc.abstractmethod
    def take_over_allocation(self, allocation_id, old_conductor_id,
                             new_conductor_id):
        """Do a take over for an allocation.

        The allocation is only updated if the old conductor matches the
        provided value, thus guarding against races.

        :param allocation_id: Allocation ID
        :param old_conductor_id: The conductor ID we expect to be the current
            ``conductor_affinity`` of the allocation.
        :param new_conductor_id: The conductor ID of the new
            ``conductor_affinity``.
        :returns: True if the take over was successful, False otherwise.
        :raises: AllocationNotFound
        """

    @abc.abstractmethod
    def destroy_allocation(self, allocation_id):
        """Destroy an allocation.

        :param allocation_id: Allocation ID
        :raises: AllocationNotFound
        """

    @abc.abstractmethod
    def create_deploy_template(self, values):
        """Create a deployment template.

        :param values: A dict describing the deployment template. For example:

                     ::

                      {
                       'uuid': uuidutils.generate_uuid(),
                       'name': 'CUSTOM_DT1',
                      }
        :raises: DeployTemplateDuplicateName if a deploy template with the same
            name exists.
        :raises: DeployTemplateAlreadyExists if a deploy template with the same
            UUID exists.
        :returns: A deploy template.
        """

    @abc.abstractmethod
    def update_deploy_template(self, template_id, values):
        """Update a deployment template.

        :param template_id: ID of the deployment template to update.
        :param values: A dict describing the deployment template. For example:

                     ::

                      {
                       'uuid': uuidutils.generate_uuid(),
                       'name': 'CUSTOM_DT1',
                      }
        :raises: DeployTemplateDuplicateName if a deploy template with the same
            name exists.
        :raises: DeployTemplateNotFound if the deploy template does not exist.
        :returns: A deploy template.
        """

    @abc.abstractmethod
    def destroy_deploy_template(self, template_id):
        """Destroy a deployment template.

        :param template_id: ID of the deployment template to destroy.
        :raises: DeployTemplateNotFound if the deploy template does not exist.
        """

    @abc.abstractmethod
    def get_deploy_template_by_id(self, template_id):
        """Retrieve a deployment template by ID.

        :param template_id: ID of the deployment template to retrieve.
        :raises: DeployTemplateNotFound if the deploy template does not exist.
        :returns: A deploy template.
        """

    @abc.abstractmethod
    def get_deploy_template_by_uuid(self, template_uuid):
        """Retrieve a deployment template by UUID.

        :param template_uuid: UUID of the deployment template to retrieve.
        :raises: DeployTemplateNotFound if the deploy template does not exist.
        :returns: A deploy template.
        """

    @abc.abstractmethod
    def get_deploy_template_by_name(self, template_name):
        """Retrieve a deployment template by name.

        :param template_name: name of the deployment template to retrieve.
        :raises: DeployTemplateNotFound if the deploy template does not exist.
        :returns: A deploy template.
        """

    @abc.abstractmethod
    def get_deploy_template_list(self, limit=None, marker=None,
                                 sort_key=None, sort_dir=None):
        """Retrieve a list of deployment templates.

        :param limit: Maximum number of deploy templates to return.
        :param marker: The last item of the previous page; we return the next
                       result set.
        :param sort_key: Attribute by which results should be sorted.
        :param sort_dir: Direction in which results should be sorted.
                         (asc, desc)
        :returns: A list of deploy templates.
        """

    @abc.abstractmethod
    def get_deploy_template_list_by_names(self, names):
        """Return a list of deployment templates with one of a list of names.

        :param names: List of names to filter by.
        :returns: A list of deploy templates.
        """
