#
# Copyright 2012 Canonical Ltd.
#
# Authors:
#  James Page <james.page@ubuntu.com>
#  Paul Collins <paul.collins@canonical.com>
#

import socket
import re
import os
from copy import deepcopy
from collections import OrderedDict
from charmhelpers.core.hookenv import unit_get
from charmhelpers.fetch import apt_install
from charmhelpers.contrib.openstack import context, templating

import ceph_radosgw_context

CEPHRG_HA_RES = 'grp_cephrg_vips'
TEMPLATES_DIR = 'templates'
TEMPLATES = 'templates/'
HAPROXY_CONF = '/etc/haproxy/haproxy.cfg'

BASE_RESOURCE_MAP = OrderedDict([
    (HAPROXY_CONF, {
        'contexts': [context.HAProxyContext(singlenode_mode=True),
                     ceph_radosgw_context.HAProxyContext()],
        'services': ['haproxy'],
    }),
])

try:
    import jinja2
except ImportError:
    apt_install('python-jinja2', fatal=True)
    import jinja2

try:
    import dns.resolver
except ImportError:
    apt_install('python-dnspython', fatal=True)
    import dns.resolver


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


# Hardcoded to icehouse to enable use of charmhelper templating/context tools
# Ideally these function would support non-OpenStack services
def register_configs(release='icehouse'):
    configs = templating.OSConfigRenderer(templates_dir=TEMPLATES,
                                          openstack_release=release)
    for cfg, rscs in resource_map().iteritems():
        configs.register(cfg, rscs['contexts'])
    return configs


def render_template(template_name, context, template_dir=TEMPLATES_DIR):
    templates = jinja2.Environment(
        loader=jinja2.FileSystemLoader(template_dir)
    )
    template = templates.get_template(template_name)
    return template.render(context)


def enable_pocket(pocket):
    apt_sources = "/etc/apt/sources.list"
    with open(apt_sources, "r") as sources:
        lines = sources.readlines()
    with open(apt_sources, "w") as sources:
        for line in lines:
            if pocket in line:
                sources.write(re.sub('^# deb', 'deb', line))
            else:
                sources.write(line)


def get_host_ip(hostname=None):
    try:
        if not hostname:
            hostname = unit_get('private-address')
        # Test to see if already an IPv4 address
        socket.inet_aton(hostname)
        return hostname
    except socket.error:
        # This may throw an NXDOMAIN exception; in which case
        # things are badly broken so just let it kill the hook
        answers = dns.resolver.query(hostname, 'A')
        if answers:
            return answers[0].address


def is_apache_24():
    if os.path.exists('/etc/apache2/conf-available'):
        return True
    else:
        return False