# Copyright (c) 2015, PLUMgrid Inc, http://plumgrid.com

# This file contains functions used by the hooks to deploy PLUMgrid Director.

from charmhelpers.contrib.openstack.neutron import neutron_plugin_attribute
from copy import deepcopy
from charmhelpers.core.hookenv import (
    log,
    config,
)
from charmhelpers.contrib.openstack import templating
from charmhelpers.core.host import set_nic_mtu
from collections import OrderedDict
from charmhelpers.contrib.storage.linux.ceph import modprobe
from charmhelpers.contrib.openstack.utils import (
    os_release,
)
from charmhelpers.core.host import (
    service_start,
    service_stop,
)
import pg_dir_context
import subprocess
import time
import os

LXC_CONF = '/etc/libvirt/lxc.conf'
TEMPLATES = 'templates/'
PG_LXC_DATA_PATH = '/var/lib/libvirt/filesystems/plumgrid-data'

PG_CONF = '%s/conf/pg/plumgrid.conf' % PG_LXC_DATA_PATH
PG_KA_CONF = '%s/conf/etc/keepalived.conf' % PG_LXC_DATA_PATH
PG_DEF_CONF = '%s/conf/pg/nginx.conf' % PG_LXC_DATA_PATH
PG_HN_CONF = '%s/conf/etc/hostname' % PG_LXC_DATA_PATH
PG_HS_CONF = '%s/conf/etc/hosts' % PG_LXC_DATA_PATH
PG_IFCS_CONF = '%s/conf/pg/ifcs.conf' % PG_LXC_DATA_PATH
AUTH_KEY_PATH = '%s/root/.ssh/authorized_keys' % PG_LXC_DATA_PATH

BASE_RESOURCE_MAP = OrderedDict([
    (PG_KA_CONF, {
        'services': ['plumgrid'],
        'contexts': [pg_dir_context.PGDirContext()],
    }),
    (PG_CONF, {
        'services': ['plumgrid'],
        'contexts': [pg_dir_context.PGDirContext()],
    }),
    (PG_DEF_CONF, {
        'services': ['plumgrid'],
        'contexts': [pg_dir_context.PGDirContext()],
    }),
    (PG_HN_CONF, {
        'services': ['plumgrid'],
        'contexts': [pg_dir_context.PGDirContext()],
    }),
    (PG_HS_CONF, {
        'services': ['plumgrid'],
        'contexts': [pg_dir_context.PGDirContext()],
    }),
    (PG_IFCS_CONF, {
        'services': [],
        'contexts': [pg_dir_context.PGDirContext()],
    }),
])


def determine_packages():
    '''
    Returns list of packages required by PLUMgrid director as specified
    in the neutron_plugins dictionary in charmhelpers.
    '''
    return neutron_plugin_attribute('plumgrid', 'packages', 'neutron')


def register_configs(release=None):
    '''
    Returns an object of the Openstack Tempating Class which contains the
    the context required for all templates of this charm.
    '''
    release = release or os_release('neutron-common', base='kilo')
    configs = templating.OSConfigRenderer(templates_dir=TEMPLATES,
                                          openstack_release=release)
    for cfg, rscs in resource_map().iteritems():
        configs.register(cfg, rscs['contexts'])
    return configs


def resource_map():
    '''
    Dynamically generate a map of resources that will be managed for a single
    hook execution.
    '''
    resource_map = deepcopy(BASE_RESOURCE_MAP)
    return resource_map


def restart_map():
    '''
    Constructs a restart map based on charm config settings and relation
    state.
    '''
    return {cfg: rscs['services'] for cfg, rscs in resource_map().iteritems()}


def ensure_files():
    '''
    Ensures PLUMgrid specific files exist before templates are written.
    '''
    #_exec_cmd(cmd=['mkdir', '/etc/nova'])
    #_exec_cmd(cmd=['touch', 'neutron_plugin.conf'])
    pass


def restart_pg():
    '''
    Stops and Starts PLUMgrid service after flushing iptables.
    '''
    service_stop('plumgrid')
    time.sleep(2)
    _exec_cmd(cmd=['iptables', '-F'])
    service_start('plumgrid')
    time.sleep(5)


def stop_pg():
    '''
    Stops PLUMgrid service.
    '''
    service_stop('plumgrid')
    time.sleep(2)


def load_iovisor():
    '''
    Loads iovisor kernel module.
    '''
    modprobe('iovisor')


def remove_iovisor():
    '''
    Removes iovisor kernel module.
    '''
    _exec_cmd(cmd=['rmmod', 'iovisor'], error_msg='Error Loading IOVisor Kernel Module')


def ensure_mtu():
    '''
    Ensures required MTU of the underlying networking of the node.
    '''
    log("Changing MTU of juju-br0 and all attached interfaces")
    interface_mtu = config('network-device-mtu')
    cmd = subprocess.check_output(["brctl", "show", "juju-br0"])
    words = cmd.split()
    for word in words:
        if 'eth' in word:
            set_nic_mtu(word, interface_mtu)
    set_nic_mtu('juju-br0', interface_mtu)


def _exec_cmd(cmd=None, error_msg='Command exited with ERRORs', fatal=False):
    '''
    Function to execute any bash command on the node.
    '''
    if cmd is None:
        log("No command specified")
    else:
        if fatal:
            subprocess.check_call(cmd)
        else:
            try:
                subprocess.check_call(cmd)
            except subprocess.CalledProcessError:
                log(error_msg)


def add_lcm_key():
    '''
    Adds public key of PLUMgrid-lcm to authorized keys of PLUMgrid Director.
    '''
    key = config('lcm-ssh-key')
    if key == 'null':
        log('lcm key not specified')
        return 0
    file_write_type = 'w+'
    if os.path.isfile(AUTH_KEY_PATH):
        file_write_type = 'a'
        try:
            fr = open(AUTH_KEY_PATH, 'r')
        except IOError:
            log('plumgrid-lxc not installed yet')
            return 0
        for line in fr:
            if key in line:
                log('key already added')
                return 0
    try:
        fa = open(AUTH_KEY_PATH, file_write_type)
    except IOError:
        log('Error opening file to append')
        return 0
    fa.write(key)
    fa.write('\n')
    fa.close()