# Copyright 2017 Hewlett Packard Enterprise Development LP
#
# 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.

__author__ = 'HPE'

from six.moves.urllib import parse
import sushy

from proliantutils import exception
from proliantutils.ilo import operations
from proliantutils import log


"""
Class specific for Redfish APIs.
"""

GET_POWER_STATE_MAP = {
    sushy.SYSTEM_POWER_STATE_ON: 'ON',
    sushy.SYSTEM_POWER_STATE_POWERING_ON: 'ON',
    sushy.SYSTEM_POWER_STATE_OFF: 'OFF',
    sushy.SYSTEM_POWER_STATE_POWERING_OFF: 'OFF'
}

PROLIANT_SYSTEM_ID = '1'

LOG = log.get_logger(__name__)


class RedfishOperations(operations.IloOperations):
    """Operations supported on redfish based hardware.

    This is the list of APIs which are currently supported via Redfish mode
    of operation. This is a growing list which needs to be updated as and when
    the existing API/s (of its cousin RIS and RIBCL interfaces) are migrated.

    --- START ---

    * get_product_name(self)
    * get_host_power_status(self)

    --- END ---

    """

    def __init__(self, redfish_controller_ip, username, password,
                 bios_password=None, cacert=None, root_prefix='/redfish/v1/'):
        """A class representing supported RedfishOperations

        :param redfish_controller_ip: The ip address of the Redfish controller.
        :param username: User account with admin/server-profile access
            privilege
        :param password: User account password
        :param bios_password: bios password
        :param cacert: a path to a CA_BUNDLE file or directory with
            certificates of trusted CAs. If set to None, the driver will
            ignore verifying the SSL certificate; if it's a path the driver
            will use the specified certificate or one of the certificates in
            the directory. Defaults to None.
        :param root_prefix: The default URL prefix. This part includes
            the root service and version. Defaults to /redfish/v1
        """
        super(RedfishOperations, self).__init__()
        address = ('https://' + redfish_controller_ip)
        LOG.debug('Redfish address: %s', address)
        verify = False if cacert is None else cacert

        # for error reporting purpose
        self.host = redfish_controller_ip
        self._root_prefix = root_prefix

        try:
            self._sushy = sushy.Sushy(
                address, username=username, password=password,
                root_prefix=root_prefix, verify=verify)
        except sushy.exceptions.SushyError as e:
            msg = (self._('The Redfish controller at "%(controller)s" has '
                          'thrown error. Error %(error)s') %
                   {'controller': address, 'error': str(e)})
            LOG.debug(msg)
            raise exception.IloConnectionError(msg)

    def _get_system_collection_path(self):
        """Helper function to find the SystemCollection path"""
        systems_col = self._sushy.json.get('Systems')
        if not systems_col:
            raise exception.MissingAttributeError(attribute='Systems',
                                                  resource=self._root_prefix)
        return systems_col.get('@odata.id')

    def _get_sushy_system(self, system_id):
        """Get the sushy system for system_id

        :param system_id: The identity of the System resource
        :returns: the Sushy system instance
        :raises: IloError
        """
        system_url = parse.urljoin(self._get_system_collection_path(),
                                   system_id)
        try:
            return self._sushy.get_system(system_url)
        except sushy.exceptions.SushyError as e:
            msg = (self._('The Redfish System "%(system)s" was not found. '
                          'Error %(error)s') %
                   {'system': system_id, 'error': str(e)})
            LOG.debug(msg)
            raise exception.IloError(msg)

    def get_product_name(self):
        """Gets the product name of the server.

        :returns: server model name.
        :raises: IloError, on an error from iLO.
        """
        # Assuming only one system present as part of collection,
        # as we are dealing with iLO's here.
        sushy_system = self._get_sushy_system(PROLIANT_SYSTEM_ID)
        return sushy_system.json.get('Model')

    def get_host_power_status(self):
        """Request the power state of the server.

        :returns: Power State of the server, 'ON' or 'OFF'
        :raises: IloError, on an error from iLO.
        """
        # Assuming only one sushy_system present as part of collection,
        # as we are dealing with iLO's here.
        sushy_system = self._get_sushy_system(PROLIANT_SYSTEM_ID)
        return GET_POWER_STATE_MAP.get(sushy_system.power_state)