#!/usr/bin/python

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

import glob
import os
import shutil
import sys

import ceph
from charmhelpers.core.hookenv import (
    log,
    DEBUG,
    config,
    is_leader,
    relation_ids,
    related_units,
    relation_get,
    relation_set,
    remote_unit,
    Hooks, UnregisteredHookError,
    service_name,
    status_set,)
from charmhelpers.core.host import (
    mkdir,
    cmp_pkgrevno,)
from charmhelpers.fetch import (
    apt_install,
    apt_update,
    filter_installed_packages,
    add_source
)
from charmhelpers.payload.execd import execd_preinstall
from charmhelpers.contrib.openstack.alternatives import install_alternative

from charmhelpers.core.templating import render

from ceph_broker import (
    process_requests
)

from utils import get_unit_hostname
from charmhelpers.contrib.hardening.harden import harden

hooks = Hooks()


def install_upstart_scripts():
    # Only install upstart configurations for older versions
    if cmp_pkgrevno('ceph', "0.55.1") < 0:
        for x in glob.glob('files/upstart/*.conf'):
            shutil.copy(x, '/etc/init/')


@hooks.hook('install.real')
@harden()
def install():
    execd_preinstall()
    add_source(config('source'), config('key'))
    apt_update(fatal=True)
    apt_install(packages=ceph.PACKAGES, fatal=True)
    install_upstart_scripts()


def emit_cephconf():

    cephcontext = {
        'auth_supported': config('auth-supported'),
        'mon_hosts': config('monitor-hosts'),
        'fsid': config('fsid'),
        'use_syslog': str(config('use-syslog')).lower(),
        'loglevel': config('loglevel'),
    }

    # Install ceph.conf as an alternative to support
    # co-existence with other charms that write this file
    charm_ceph_conf = "/var/lib/charm/{}/ceph.conf".format(service_name())
    mkdir(os.path.dirname(charm_ceph_conf), owner=ceph.ceph_user(),
          group=ceph.ceph_user())
    render('ceph.conf', charm_ceph_conf, cephcontext, perms=0o644)
    install_alternative('ceph.conf', '/etc/ceph/ceph.conf',
                        charm_ceph_conf, 100)
    keyring = 'ceph.client.admin.keyring'
    keyring_path = '/etc/ceph/' + keyring
    ctx = {'admin_key': config('admin-key')}
    user = ceph.ceph_user()
    render(keyring, keyring_path, ctx, owner=user, perms=0o600)

    keyring = 'keyring'
    keyring_path = (
        '/var/lib/ceph/mon/ceph-' +
        get_unit_hostname() +
        '/' +
        keyring)
    render('mon.keyring', keyring_path, ctx, owner=user, perms=0o600)

    notify_radosgws()
    notify_client()


@hooks.hook('config-changed')
@harden()
def config_changed():
    emit_cephconf()


def notify_radosgws():
    for relid in relation_ids('radosgw'):
        for unit in related_units(relid):
            radosgw_relation(relid=relid, unit=unit)


def notify_client():
    for relid in relation_ids('client'):
        client_relation_joined(relid)


@hooks.hook('radosgw-relation-changed')
@hooks.hook('radosgw-relation-joined')
def radosgw_relation(relid=None, unit=None):
    # Install radosgw for admin tools
    apt_install(packages=filter_installed_packages(['radosgw']))
    if not unit:
        unit = remote_unit()

    # NOTE: radosgw needs some usage OSD storage, so defer key
    #       provision until OSD units are detected.
    if ready():
        log('mon cluster in quorum and osds related '
            '- providing radosgw with keys')
        ceph_addrs = config('monitor-hosts')
        data = {
            'fsid': config('fsid'),
            'radosgw_key': ceph.get_radosgw_key(),
            'auth': config('auth-supported'),
            'ceph-public-address': ceph_addrs,
        }

        settings = relation_get(rid=relid, unit=unit)
        """Process broker request(s)."""
        if 'broker_req' in settings:
            rsp = process_requests(settings['broker_req'])
            unit_id = unit.replace('/', '-')
            unit_response_key = 'broker-rsp-' + unit_id
            data[unit_response_key] = rsp

        log('relation_set (%s): %s' % (relid, str(data)), level=DEBUG)
        relation_set(relation_id=relid, relation_settings=data)
    else:
        log('FSID or admin key not provided, please configure them')


@hooks.hook('client-relation-joined')
def client_relation_joined(relid=None):
    if ready():
        service_name = None
        if relid is None:
            units = [remote_unit()]
            service_name = units[0].split('/')[0]
        else:
            units = related_units(relid)
            if len(units) > 0:
                service_name = units[0].split('/')[0]

        if service_name is not None:
            ceph_addrs = config('monitor-hosts')
            data = {'key': ceph.get_named_key(service_name),
                    'auth': config('auth-supported'),
                    'ceph-public-address': ceph_addrs}

            log('relation_set (%s): %s' % (relid, str(data)), level=DEBUG)
            relation_set(relation_id=relid,
                         relation_settings=data)
    else:
        log('FSID or admin key not provided, please configure them')


@hooks.hook('client-relation-changed')
def client_relation_changed():
    """Process broker requests from ceph client relations."""
    if ready():
        settings = relation_get()
        if 'broker_req' in settings:
            # the request is processed only by the leader as reported by juju
            if not is_leader():
                log("Not leader - ignoring broker request", level=DEBUG)
            else:
                rsp = process_requests(settings['broker_req'])
                unit_id = remote_unit().replace('/', '-')
                unit_response_key = 'broker-rsp-' + unit_id
                # broker_rsp is being left for backward compatibility,
                # unit_response_key superscedes it
                data = {
                    'broker_rsp': rsp,
                    unit_response_key: rsp,
                }
                log('relation_set: %s' % str(data), level=DEBUG)
                relation_set(relation_settings=data)
    else:
        log('FSID or admin key not provided, please configure them')


def ready():
    return config('fsid') and config('admin-key')


def assess_status():
    '''Assess status of current unit'''
    if ready():
        status_set('active', 'Ready to proxy settings')
    else:
        status_set('blocked', 'Ensure FSID and admin-key are set')


@hooks.hook('update-status')
@harden()
def update_status():
    log('Updating status.')


if __name__ == '__main__':
    try:
        hooks.execute(sys.argv)
    except UnregisteredHookError as e:
        log('Unknown hook {} - skipping.'.format(e))
    assess_status()