# Copyright 2013 Red Hat, Inc.
# All Rights Reserved.
#
#    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.

from http import client as http_client

from pecan import rest

from ironic import api
from ironic.api.controllers import link
from ironic.api.controllers.v1 import utils as api_utils
from ironic.api import method
from ironic.common import args
from ironic.common import exception
from ironic.common.i18n import _
from ironic.common import metrics_utils
from ironic.drivers import base as driver_base
from ironic import objects

METRICS = metrics_utils.get_metrics_logger(__name__)

# Property information for drivers:
#   key = driver name;
#   value = dictionary of properties of that driver:
#             key = property name.
#             value = description of the property.
# NOTE(rloo). This is cached for the lifetime of the API service. If one or
# more conductor services are restarted with new driver versions, the API
# service should be restarted.
_DRIVER_PROPERTIES = {}

# Vendor information for drivers:
#   key = driver name;
#   value = dictionary of vendor methods of that driver:
#             key = method name.
#             value = dictionary with the metadata of that method.
# NOTE(lucasagomes). This is cached for the lifetime of the API
# service. If one or more conductor services are restarted with new driver
# versions, the API service should be restarted.
_VENDOR_METHODS = {}

# RAID (logical disk) configuration information for drivers:
#   key = driver name;
#   value = dictionary of RAID configuration information of that driver:
#             key = property name.
#             value = description of the property
# NOTE(rloo). This is cached for the lifetime of the API service. If one or
# more conductor services are restarted with new driver versions, the API
# service should be restarted.
_RAID_PROPERTIES = {}


def hide_fields_in_newer_versions(driver):
    """This method hides fields that were added in newer API versions.

    Certain fields were introduced at certain API versions.
    These fields are only made available when the request's API version
    matches or exceeds the versions when these fields were introduced.
    """
    if not api_utils.allow_storage_interface():
        driver.pop('default_storage_interface', None)
        driver.pop('enabled_storage_interfaces', None)

    if not api_utils.allow_rescue_interface():
        driver.pop('default_rescue_interface', None)
        driver.pop('enabled_rescue_interfaces', None)

    if not api_utils.allow_bios_interface():
        driver.pop('default_bios_interface', None)
        driver.pop('enabled_bios_interfaces', None)

    if not api_utils.allow_firmware_interface():
        driver.pop('default_firmware_interface', None)
        driver.pop('enabled_firmware_interfaces', None)


def convert_with_links(name, hosts, detail=False, interface_info=None,
                       fields=None, sanitize=True):
    """Convert driver/hardware type info to a dict.

    :param name: name of a hardware type.
    :param hosts: list of conductor hostnames driver is active on.
    :param detail: boolean, whether to include detailed info, such as
                    the 'type' field and default/enabled interfaces fields.
    :param interface_info: optional list of dicts of hardware interface
                            info.
    :param fields: list of fields to preserve, or ``None`` to preserve default
    :param sanitize: boolean,  sanitize driver
    :returns: dict representing the driver object.
    """
    driver = {
        'name': name,
        'hosts': hosts,
        'links': [
            link.make_link('self',
                           api.request.public_url,
                           'drivers', name),
            link.make_link('bookmark',
                           api.request.public_url,
                           'drivers', name,
                           bookmark=True)
        ]
    }
    if api_utils.allow_links_node_states_and_driver_properties():
        driver['properties'] = [
            link.make_link('self',
                           api.request.public_url,
                           'drivers', name + "/properties"),
            link.make_link('bookmark',
                           api.request.public_url,
                           'drivers', name + "/properties",
                           bookmark=True)
        ]

    if api_utils.allow_dynamic_drivers():
        # NOTE(dtantsur): only dynamic drivers (based on hardware types)
        # are supported starting with the Rocky release.
        driver['type'] = 'dynamic'
        if detail:
            if interface_info is None:
                # TODO(jroll) objectify this
                interface_info = (objects.Conductor
                                  .list_hardware_type_interfaces_dict(
                                      api.request.context,
                                      [name]))
            for iface_type in driver_base.ALL_INTERFACES:
                default = None
                enabled = set()
                for iface in interface_info:
                    if iface['interface_type'] == iface_type:
                        iface_name = iface['interface_name']
                        enabled.add(iface_name)
                        # NOTE(jroll) this assumes the default is the same
                        # on all conductors
                        if iface['default']:
                            default = iface_name

                default_key = 'default_%s_interface' % iface_type
                enabled_key = 'enabled_%s_interfaces' % iface_type
                driver[default_key] = default
                driver[enabled_key] = list(enabled)

    hide_fields_in_newer_versions(driver)

    if not sanitize:
        return driver

    driver_sanitize(driver, fields)

    return driver


def driver_sanitize(driver, fields=None):
    if fields is not None:
        api_utils.sanitize_dict(driver, fields)
        api_utils.check_for_invalid_fields(fields, driver)


def _check_allow_driver_fields(fields):
    if (fields is not None and api.request.version.minor
            < api.controllers.v1.versions.MINOR_77_DRIVER_FIELDS_SELECTOR):
        raise exception.NotAcceptable()


def list_convert_with_links(hardware_types, detail=False, fields=None):
    """Convert drivers and hardware types to an API-serializable object.

    :param hardware_types: dict mapping hardware type names to conductor
                            hostnames.
    :param detail: boolean, whether to include detailed info, such as
                    the 'type' field and default/enabled interfaces fields.
    :param fields: list of fields to preserve, or ``None`` to preserve default
    :returns: an API-serializable driver collection object.
    """
    drivers = []
    collection = {
        'drivers': drivers
    }

    # NOTE(jroll) we return hardware types in all API versions,
    # but restrict type/default/enabled fields to 1.30.
    # This is checked in Driver.convert_with_links(), however also
    # checking here can save us a DB query.
    if api_utils.allow_dynamic_drivers() and detail:
        iface_info = objects.Conductor.list_hardware_type_interfaces_dict(
            api.request.context,
            list(hardware_types))
    else:
        iface_info = []

    for htname in hardware_types:
        interface_info = [i for i in iface_info
                          if i['hardware_type'] == htname]
        drivers.append(
            convert_with_links(htname,
                               list(hardware_types[htname]),
                               detail=detail,
                               interface_info=interface_info,
                               fields=fields))
    return collection


class DriverPassthruController(rest.RestController):
    """REST controller for driver passthru.

    This controller allow vendors to expose cross-node functionality in the
    Ironic API. Ironic will merely relay the message from here to the specified
    driver, no introspection will be made in the message body.
    """

    _custom_actions = {
        'methods': ['GET']
    }

    @METRICS.timer('DriverPassthruController.methods')
    @method.expose()
    @args.validate(driver_name=args.string)
    def methods(self, driver_name):
        """Retrieve information about vendor methods of the given driver.

        :param driver_name: name of the driver.
        :returns: dictionary with <vendor method name>:<method metadata>
                  entries.
        :raises DriverNotFound: if the driver name is invalid or the
                 driver cannot be loaded.
        """
        api_utils.check_policy('baremetal:driver:vendor_passthru')

        if driver_name not in _VENDOR_METHODS:
            topic = api.request.rpcapi.get_topic_for_driver(driver_name)
            ret = api.request.rpcapi.get_driver_vendor_passthru_methods(
                api.request.context, driver_name, topic=topic)
            _VENDOR_METHODS[driver_name] = ret

        return _VENDOR_METHODS[driver_name]

    @METRICS.timer('DriverPassthruController._default')
    @method.expose()
    @method.body('data')
    @args.validate(driver_name=args.string, method=args.string)
    def _default(self, driver_name, method, data=None):
        """Call a driver API extension.

        :param driver_name: name of the driver to call.
        :param method: name of the method, to be passed to the vendor
                       implementation.
        :param data: body of data to supply to the specified method.
        """

        api_utils.check_policy('baremetal:driver:vendor_passthru')

        topic = api.request.rpcapi.get_topic_for_driver(driver_name)
        resp = api_utils.vendor_passthru(driver_name, method, topic,
                                         data=data, driver_passthru=True)
        api.response.status_code = resp.status_code
        return resp.obj


class DriverRaidController(rest.RestController):

    _custom_actions = {
        'logical_disk_properties': ['GET']
    }

    @METRICS.timer('DriverRaidController.logical_disk_properties')
    @method.expose()
    @args.validate(driver_name=args.string)
    def logical_disk_properties(self, driver_name):
        """Returns the logical disk properties for the driver.

        .. parameters:: ../../api-ref/source/parameters.yaml

           :driver_name: Name of the driver.

        .. return::

           Success:
           A dictionary containing the properties that can be mentioned

           Failure:
           :UnsupportedDriverExtension: If the driver doesn't support RAID
                                        configuration.
           :NotAcceptable: If requested version of the API is less than 1.12.
           :DriverNotFound: If driver is not loaded on any of the conductors.
        """
        api_utils.check_policy(
            'baremetal:driver:get_raid_logical_disk_properties')

        if not api_utils.allow_raid_config():
            raise exception.NotAcceptable()

        if driver_name not in _RAID_PROPERTIES:
            topic = api.request.rpcapi.get_topic_for_driver(driver_name)
            try:
                info = api.request.rpcapi.get_raid_logical_disk_properties(
                    api.request.context, driver_name, topic=topic)
            except exception.UnsupportedDriverExtension as e:
                # Change error code as 404 seems appropriate because RAID is a
                # standard interface and all drivers might not have it.
                e.code = http_client.NOT_FOUND
                raise

            _RAID_PROPERTIES[driver_name] = info
        return _RAID_PROPERTIES[driver_name]


class DriversController(rest.RestController):
    """REST controller for Drivers."""

    vendor_passthru = DriverPassthruController()

    raid = DriverRaidController()
    """Expose RAID as a sub-element of drivers"""

    _custom_actions = {
        'properties': ['GET'],
    }

    @METRICS.timer('DriversController.get_all')
    @method.expose()
    @args.validate(type=args.string, detail=args.boolean,
                   fields=args.string_list)
    def get_all(self, type=None, detail=None, fields=None):
        """Retrieve a list of drivers."""
        # FIXME(tenbrae): formatting of the auto-generated REST API docs
        #              will break from a single-line doc string.
        #              This is a result of a bug in sphinxcontrib-pecanwsme
        # https://github.com/dreamhost/sphinxcontrib-pecanwsme/issues/8
        if fields and detail:
            raise exception.InvalidParameterValue(
                "Can not specify ?detail=True and fields in the same request.")

        api_utils.check_policy('baremetal:driver:get')
        api_utils.check_allow_driver_detail(detail)
        api_utils.check_allow_filter_driver_type(type)
        _check_allow_driver_fields(fields)
        if type not in (None, 'classic', 'dynamic'):
            raise exception.Invalid(_(
                '"type" filter must be one of "classic" or "dynamic", '
                'if specified.'))

        if type is None or type == 'dynamic':
            hw_type_dict = objects.Conductor.get_active_hardware_type_dict(
                api.request.context)
        else:
            # NOTE(dtantsur): we don't support classic drivers starting with
            # the Rocky release.
            hw_type_dict = {}
        return list_convert_with_links(hw_type_dict, detail=detail,
                                       fields=fields)

    @METRICS.timer('DriversController.get_one')
    @method.expose()
    @args.validate(driver_name=args.string, fields=args.string_list)
    def get_one(self, driver_name, fields=None):
        """Retrieve a single driver."""
        # NOTE(russell_h): There is no way to make this more efficient than
        # retrieving a list of drivers using the current sqlalchemy schema, but
        # this path must be exposed for Pecan to route any paths we might
        # choose to expose below it.
        api_utils.check_policy('baremetal:driver:get')

        _check_allow_driver_fields(fields)

        hw_type_dict = objects.Conductor.get_active_hardware_type_dict(
            api.request.context)
        for name, hosts in hw_type_dict.items():
            if name == driver_name:
                return convert_with_links(name, list(hosts),
                                          detail=True, fields=fields)

        raise exception.DriverNotFound(driver_name=driver_name)

    @METRICS.timer('DriversController.properties')
    @method.expose()
    @args.validate(driver_name=args.string)
    def properties(self, driver_name):
        """Retrieve property information of the given driver.

        :param driver_name: name of the driver.
        :returns: dictionary with <property name>:<property description>
                  entries.
        :raises DriverNotFound (HTTP 404): if the driver name is invalid or
                 the driver cannot be loaded.
        """
        api_utils.check_policy('baremetal:driver:get_properties')

        if driver_name not in _DRIVER_PROPERTIES:
            topic = api.request.rpcapi.get_topic_for_driver(driver_name)
            properties = api.request.rpcapi.get_driver_properties(
                api.request.context, driver_name, topic=topic)
            _DRIVER_PROPERTIES[driver_name] = properties

        return _DRIVER_PROPERTIES[driver_name]
