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

# This file contains functions used by the hooks to enable PLUMgrid
# in Openstack.

from collections import OrderedDict
from copy import deepcopy
import os
import subprocess
import neutron_plumgrid_context
from charmhelpers.contrib.openstack import templating
from charmhelpers.contrib.openstack.neutron import neutron_plugin_attribute
from charmhelpers.contrib.python.packages import pip_install
from charmhelpers.fetch import (
    apt_cache
)
from charmhelpers.core.hookenv import (
    log,
    config,
    is_leader,
    relation_set
)
from charmhelpers.contrib.openstack.utils import (
    os_release,
)

TEMPLATES = 'templates/'

PG_PACKAGES = [
    'plumgrid-pythonlib'
]

NEUTRON_CONF_DIR = "/etc/neutron"
SOURCES_LIST = '/etc/apt/sources.list'
SU_FILE = '/etc/sudoers.d/neutron_sudoers'
PLUMGRID_CONF = '%s/plugins/plumgrid/plumgrid.ini' % NEUTRON_CONF_DIR
PGLIB_CONF = '%s/plugins/plumgrid/plumlib.ini' % NEUTRON_CONF_DIR
PGRC = '%s/plugins/plumgrid/pgrc' % NEUTRON_CONF_DIR

BASE_RESOURCE_MAP = OrderedDict([
    (SU_FILE, {
        'services': [],
        'contexts': [neutron_plumgrid_context.NeutronPGPluginContext()],
    }),
    (PLUMGRID_CONF, {
        'services': ['neutron-server'],
        'contexts': [neutron_plumgrid_context.NeutronPGPluginContext()],
    }),
    (PGLIB_CONF, {
        'services': ['neutron-server'],
        'contexts': [neutron_plumgrid_context.NeutronPGPluginContext()],
    }),
    (PGRC, {
        'services': ['neutron-server'],
        'contexts': [neutron_plumgrid_context.NeutronPGPluginContext()],
    }),
])

NETWORKING_PLUMGRID_VERSION = OrderedDict([
    ('kilo', '2015.1.1.1'),
    ('liberty', '2015.2.1.1'),
    ('mitaka', '2016.1.1.1'),
])


def configure_pg_sources():
    '''
    Returns true if install sources is updated in sources.list file
    '''
    try:
        with open(SOURCES_LIST, 'r+') as sources:
            all_lines = sources.readlines()
            sources.seek(0)
            for i in (line for line in all_lines if "plumgrid" not in line):
                sources.write(i)
            sources.truncate()
        sources.close()
    except IOError:
        raise IOError('Unable to access /etc/apt/sources.list')


def determine_packages():
    '''
    Returns list of packages required to be installed alongside neutron to
    enable PLUMgrid in Openstack.
    '''
    pkgs = []
    tag = config('plumgrid-build')
    for pkg in PG_PACKAGES:
        if tag == 'latest':
            pkgs.append(pkg)
        else:
            if tag in [i.ver_str for i in apt_cache()[pkg].version_list]:
                pkgs.append('%s=%s' % (pkg, tag))
            else:
                error_msg = \
                    "Build version '%s' for package '%s' not available" \
                    % (tag, pkg)
                raise ValueError(error_msg)
    return pkgs


def resource_map():
    '''
    Dynamically generate a map of resources that will be managed for a single
    hook execution.
    '''
    resource_map = deepcopy(BASE_RESOURCE_MAP)
    is_legacy_mode = config('manage-neutron-plugin-legacy-mode')
    if is_legacy_mode:
        del resource_map[PLUMGRID_CONF]
    return resource_map


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')
    if release < 'kilo':
        raise ValueError('OpenStack %s release not supported' % release)

    configs = templating.OSConfigRenderer(templates_dir=TEMPLATES,
                                          openstack_release=release)
    for cfg, rscs in resource_map().iteritems():
        configs.register(cfg, rscs['contexts'])
    return configs


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


def ensure_files():
    '''
    Ensures PLUMgrid specific files exist before templates are written.
    '''
    install_networking_plumgrid()
    os.chmod('/etc/sudoers.d/neutron_sudoers', 0o440)


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 install_networking_plumgrid():
    '''
    Installs networking-plumgrid package
    '''
    release = os_release('neutron-common', base='kilo')
    if config('networking-plumgrid-version') is None:
        package_version = NETWORKING_PLUMGRID_VERSION[release]
    else:
        package_version = config('networking-plumgrid-version')
    package_name = 'networking-plumgrid==%s' % package_version
    if config('pip-proxy') != "None":
        pip_install(package_name, fatal=True, proxy=config('pip-proxy'))
    else:
        pip_install(package_name, fatal=True)
    if is_leader() and package_version != '2015.1.1.1':
        migrate_neutron_db()


def migrate_neutron_db():
    release = os_release('neutron-common', base='kilo')
    _exec_cmd(cmd=[('plumgrid-db-manage' if release == 'kilo'
                    else 'neutron-db-manage'), 'upgrade', 'heads'],
              error_msg="db-manage command executed with errors",
              fatal=False)


def set_neutron_relation():
    settings = {
        'neutron-plugin': 'plumgrid',
        'core-plugin': neutron_plugin_attribute('plumgrid', 'driver',
                                                'neutron'),
        'neutron-plugin-config': neutron_plugin_attribute('plumgrid',
                                                          'config', 'neutron'),
        'service-plugins': ' ',
        'quota-driver': 'neutron.db.quota_db.DbQuotaDriver',
    }

    relation_set(relation_settings=settings)