import os

from oslo.config import cfg
from nova.i18n import _LW

from nova.openstack.common import log as logging
from nova.openstack.common import fileutils
from nova import utils

CONF = cfg.CONF
LOG = logging.getLogger(__name__)

class LXDConfigObject(object):
    def __init__(self, **kwargs):
        super(LXDConfigObject, self).__init__()

    def set_config(self):
        pass

class LXDConfigTemplate(LXDConfigObject):
    def __init__(self, instance, image_meta):
        super(LXDConfigTemplate, self).__init__()
        self.instance = instance
        self.image_meta = image_meta

    def set_config(self):
        templates = []
        if (self.image_meta and
            self.image_meta.get('properties', {}).get('template')):
                lxc_template = self.image_meta['properties'].get('template')
        else:
            lxc_template = CONF.lxd.lxd_default_template

        path = os.listdir(CONF.lxd.lxd_template_dir)
        for line in path:
            templates.append(line.replace('lxc-', ''))

        if lxc_template in templates:
            config_file = os.path.join(CONF.lxd.lxd_root_dir,
                          self.instance, 'config')

            f = open(config_file, 'w')
            f.write('lxc.include = %s/%s.common.conf\n' % (CONF.lxd.lxd_config_dir,
                                                           lxc_template))
            f.write('lxc.include = %s/%s.userns.conf\n' % (CONF.lxd.lxd_config_dir,
                                                            lxc_template))


class LXDConfigSetName(LXDConfigObject):
    def __init__(self, container, instance):
        super(LXDConfigSetName, self).__init__()
        self.container = container
        self.instance = instance

    def set_config(self):
        self.container.append_config_item('lxc.utsname',
                                          self.instance)

class LXDConfigSetRoot(LXDConfigObject):
    def __init__(self, container, instance):
        super(LXDConfigSetRoot, self).__init__()
        self.container = container
        self.instance = instance
        self.container_rootfs = os.path.join(CONF.lxd.lxd_root_dir,
                                             self.instance,
                                             'rootfs')

    def set_config(self):
        self.container.append_config_item('lxc.rootfs',
                                          self.container_rootfs)

class LXDConfigSetLog(LXDConfigObject):
    def __init__(self, container, instance):
        super(LXDConfigSetLog, self).__init__()
        self.container = container
        self.instance = instance

    def set_config(self):
        container_logfile = os.path.join(CONF.lxd.lxd_root_dir,
                                         self.instance,
                                         'logfile')
        self.container.append_config_item('lxc.logfile',
                                          container_logfile)

class LXDConfigConsole(LXDConfigObject):
    def __init__(self, container, instance):
        super(LXDConfigConsole, self).__init__()
        self.container = container
        self.instance = instance

    def set_config(self):
        console_log = os.path.join(CONF.lxd.lxd_root_dir,
                                   self.instance,
                                   'console.log')
        self.container.append_config_item('lxc.console.logfile',
                                          console_log)
        utils.execute('touch', console_log)


class LXDUserConfig(LXDConfigObject):
    def __init__(self, container, idmap):
        super(LXDUserConfig, self).__init__()
        self.container = container
        self.idmap = idmap

    def set_config(self):
        for ent in self.idmap.lxc_conf_lines():
            self.container.append_config_item(*ent)

class LXDSetLimits(LXDConfigObject):
    def __init__(self, container, instance):
        super(LXDSetLimits, self).__init__()
        self.container = container
        self.instance = instance

    def set_config(self):
        flavor = self.instance.get_flavor()
        self.container.append_config_item(
            'lxc.cgroup.memory.limit_in_bytes',
            '%sM' % flavor.memory_mb)