# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2012 Cloudbase Solutions Srl
# 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.

"""
Management class for host operations.
"""
import os
import platform

from oslo.config import cfg

from nova.openstack.common import jsonutils
from nova.openstack.common import log as logging
from nova.virt.hyperv import constants
from nova.virt.hyperv import hostutils
from nova.virt.hyperv import pathutils

CONF = cfg.CONF
CONF.import_opt('my_ip', 'nova.netconf')
LOG = logging.getLogger(__name__)


class HostOps(object):
    def __init__(self):
        self._stats = None
        self._hostutils = hostutils.HostUtils()
        self._pathutils = pathutils.PathUtils()

    def _get_cpu_info(self):
        """Get the CPU information.
        :returns: A dictionary containing the main properties
        of the central processor in the hypervisor.
        """
        cpu_info = dict()

        processors = self._hostutils.get_cpus_info()

        w32_arch_dict = constants.WMI_WIN32_PROCESSOR_ARCHITECTURE
        cpu_info['arch'] = w32_arch_dict.get(processors[0]['Architecture'],
                                             'Unknown')
        cpu_info['model'] = processors[0]['Name']
        cpu_info['vendor'] = processors[0]['Manufacturer']

        topology = dict()
        topology['sockets'] = len(processors)
        topology['cores'] = processors[0]['NumberOfCores']
        topology['threads'] = (processors[0]['NumberOfLogicalProcessors'] /
                               processors[0]['NumberOfCores'])
        cpu_info['topology'] = topology

        features = list()
        for fkey, fname in constants.PROCESSOR_FEATURE.items():
            if self._hostutils.is_cpu_feature_present(fkey):
                features.append(fname)
        cpu_info['features'] = features

        return cpu_info

    def _get_memory_info(self):
        (total_mem_kb, free_mem_kb) = self._hostutils.get_memory_info()
        total_mem_mb = total_mem_kb / 1024
        free_mem_mb = free_mem_kb / 1024
        return (total_mem_mb, free_mem_mb, total_mem_mb - free_mem_mb)

    def _get_local_hdd_info_gb(self):
        drive = os.path.splitdrive(self._pathutils.get_instances_dir())[0]
        (size, free_space) = self._hostutils.get_volume_info(drive)

        total_gb = size / (1024 ** 3)
        free_gb = free_space / (1024 ** 3)
        used_gb = total_gb - free_gb
        return (total_gb, free_gb, used_gb)

    def _get_hypervisor_version(self):
        """Get hypervisor version.
        :returns: hypervisor version (ex. 12003)
        """
        version = self._hostutils.get_windows_version().replace('.', '')
        LOG.debug(_('Windows version: %s ') % version)
        return version

    def get_available_resource(self):
        """Retrieve resource info.

        This method is called when nova-compute launches, and
        as part of a periodic task.

        :returns: dictionary describing resources

        """
        LOG.debug(_('get_available_resource called'))

        (total_mem_mb,
         free_mem_mb,
         used_mem_mb) = self._get_memory_info()

        (total_hdd_gb,
         free_hdd_gb,
         used_hdd_gb) = self._get_local_hdd_info_gb()

        cpu_info = self._get_cpu_info()
        cpu_topology = cpu_info['topology']
        vcpus = (cpu_topology['sockets'] *
                 cpu_topology['cores'] *
                 cpu_topology['threads'])

        dic = {'vcpus': vcpus,
               'memory_mb': total_mem_mb,
               'memory_mb_used': used_mem_mb,
               'local_gb': total_hdd_gb,
               'local_gb_used': used_hdd_gb,
               'hypervisor_type': "hyperv",
               'hypervisor_version': self._get_hypervisor_version(),
               'hypervisor_hostname': platform.node(),
               'vcpus_used': 0,
               'cpu_info': jsonutils.dumps(cpu_info)}

        return dic

    def _update_stats(self):
        LOG.debug(_("Updating host stats"))

        (total_mem_mb, free_mem_mb, used_mem_mb) = self._get_memory_info()
        (total_hdd_gb,
         free_hdd_gb,
         used_hdd_gb) = self._get_local_hdd_info_gb()

        data = {}
        data["disk_total"] = total_hdd_gb
        data["disk_used"] = used_hdd_gb
        data["disk_available"] = free_hdd_gb
        data["host_memory_total"] = total_mem_mb
        data["host_memory_overhead"] = used_mem_mb
        data["host_memory_free"] = free_mem_mb
        data["host_memory_free_computed"] = free_mem_mb
        data["supported_instances"] = [('i686', 'hyperv', 'hvm'),
                                       ('x86_64', 'hyperv', 'hvm')]
        data["hypervisor_hostname"] = platform.node()

        self._stats = data

    def get_host_stats(self, refresh=False):
        """Return the current state of the host.

           If 'refresh' is True, run the update first.
        """
        LOG.debug(_("get_host_stats called"))

        if refresh or not self._stats:
            self._update_stats()
        return self._stats

    def host_power_action(self, host, action):
        """Reboots, shuts down or powers up the host."""
        pass

    def get_host_ip_addr(self):
        host_ip = CONF.my_ip
        if not host_ip:
            # Return the first available address
            host_ip = self._hostutils.get_local_ips()[0]
        LOG.debug(_("Host IP address is: %s"), host_ip)
        return host_ip