#!/usr/bin/env python3
#
# Copyright 2016 Canonical Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#  http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


import os
import sys
import uuid
from base64 import b64decode

_path = os.path.dirname(os.path.realpath(__file__))
_root = os.path.abspath(os.path.join(_path, '..'))


def _add_path(path):
    if path not in sys.path:
        sys.path.insert(1, path)


_add_path(_root)


from subprocess import (
    check_call,
)

from cinder_utils import (
    determine_packages,
    disable_package_apache_site,
    do_openstack_upgrade,
    juju_log,
    migrate_database,
    configure_lvm_storage,
    register_configs,
    restart_map,
    run_in_apache,
    services,
    service_enabled,
    service_restart,
    CLUSTER_RES,
    CINDER_CONF,
    CINDER_API_CONF,
    CEPH_CONF,
    setup_ipv6,
    check_local_db_actions_complete,
    filesystem_mounted,
    assess_status,
    scrub_old_style_ceph,
    pause_unit_helper,
    resume_unit_helper,
    remove_old_packages,
)

from cinder_contexts import ceph_config_file

from charmhelpers.core.hookenv import (
    config,
    DEBUG,
    Hooks,
    local_unit,
    log,
    open_port,
    related_units,
    relation_get,
    relation_ids,
    relation_set,
    service_name,
    status_set,
    storage_get,
    storage_list,
    UnregisteredHookError,
)

from charmhelpers.fetch import (
    apt_install,
    apt_update,
    filter_installed_packages,
)

from charmhelpers.core.host import (
    lsb_release,
    service_reload,
    service_start,
    umount,
)

from charmhelpers.contrib.openstack.utils import (
    config_value_changed,
    configure_installation_source,
    openstack_upgrade_available,
    sync_db_with_multi_ipv6_addresses,
    os_release,
    is_unit_paused_set,
    pausable_restart_on_change as restart_on_change,
    CompareOpenStackReleases,
    series_upgrade_prepare,
    series_upgrade_complete,
    is_db_maintenance_mode,
)

from charmhelpers.contrib.openstack.alternatives import remove_alternative

from charmhelpers.contrib.storage.linux.ceph import (
    send_request_if_needed,
    is_request_complete,
    ensure_ceph_keyring,
    CephBrokerRq,
    delete_keyring,
)

from charmhelpers.contrib.hahelpers.apache import (
    get_ca_cert,
    install_ca_cert,
)

from charmhelpers.contrib.hahelpers.cluster import (
    is_clustered,
    is_elected_leader,
)

from charmhelpers.contrib.openstack.ha.utils import (
    generate_ha_relation_data,
)

from charmhelpers.payload.execd import execd_preinstall
from charmhelpers.contrib.network.ip import (
    get_relation_ip,
)
from charmhelpers.contrib.openstack.ip import (
    canonical_url,
    PUBLIC, INTERNAL, ADMIN
)
from charmhelpers.contrib.openstack.cert_utils import (
    get_certificate_request,
    process_certificates,
)
from charmhelpers.contrib.openstack.context import ADDRESS_TYPES

from charmhelpers.contrib.charmsupport import nrpe
from charmhelpers.contrib.hardening.harden import harden

from charmhelpers.contrib.openstack.policyd import (
    maybe_do_policyd_overrides,
    maybe_do_policyd_overrides_on_config_changed,
)

hooks = Hooks()

CONFIGS = register_configs()


@hooks.hook('install.real')
@harden()
def install():
    status_set('maintenance', 'Executing pre-install')
    execd_preinstall()
    conf = config()
    src = conf['openstack-origin']
    if (lsb_release()['DISTRIB_CODENAME'] == 'precise' and
            src == 'distro'):
        src = 'cloud:precise-folsom'
    configure_installation_source(src)

    status_set('maintenance', 'Installing apt packages')
    apt_update()
    # (ajkavanagh) LP: #1989538
    # Tactical fix to force openstack-release to match the configured
    # installation source; note that it comes after apt_update().
    apt_install(['openstack-release'], fatal=False, quiet=True)
    apt_install(determine_packages(), fatal=True)

    if service_enabled('api'):
        if run_in_apache():
            disable_package_apache_site()
        # call the policy overrides handler which will install any policy
        # overrides
        maybe_do_policyd_overrides(
            os_release('cinder-common'),
            'cinder',
            restart_handler=lambda: service_restart('cinder-api'))

    # Make sure iscsid has a unique InitiatorName by starting iscsid
    # and invoking /lib/open-iscsi/startup-checks.sh indirectly as
    # ExecStartPre script of it
    service_start('iscsid')


@hooks.hook('config-changed')
@restart_on_change(restart_map(), stopstart=True)
@harden()
def config_changed():
    # if we are paused, delay doing any config changed hooks.
    # It is forced on the resume.
    if is_unit_paused_set():
        log("Unit is pause or upgrading. Skipping config_changed", "WARN")
        return

    conf = config()

    if conf['prefer-ipv6']:
        status_set('maintenance', 'configuring ipv6')
        setup_ipv6()
        sync_db_with_multi_ipv6_addresses(config('database'),
                                          config('database-user'))

    e_mountpoint = config('ephemeral-unmount')
    if e_mountpoint and filesystem_mounted(e_mountpoint):
        umount(e_mountpoint)

    # configure block devices either local or from juju storage
    _configure_block_devices()

    if not config('action-managed-upgrade'):
        if openstack_upgrade_available('cinder-common'):
            status_set('maintenance', 'Running openstack upgrade')
            do_openstack_upgrade(configs=CONFIGS)
            # NOTE(jamespage) tell any storage-backends we just upgraded
            for rid in relation_ids('storage-backend'):
                relation_set(relation_id=rid,
                             upgrade_nonce=uuid.uuid4())
            # NOTE(hopem) tell any backup-backends we just upgraded
            for rid in relation_ids('backup-backend'):
                relation_set(relation_id=rid,
                             upgrade_nonce=uuid.uuid4())

    # overwrite config is not in conf file. so We can't use restart_on_change
    if config_value_changed('overwrite') and not is_unit_paused_set():
        service_restart('cinder-volume')

    CONFIGS.write_all()
    if service_enabled('api'):
        configure_https()
        open_port(config('api-listening-port'))
    else:
        # Install CA cert to communicate with Keystone and Glance
        ca_cert = get_ca_cert()
        if ca_cert:
            install_ca_cert(b64decode(ca_cert))
    update_nrpe_config()

    for rid in relation_ids('cluster'):
        cluster_joined(relation_id=rid)
    for r_id in relation_ids('ha'):
        ha_joined(relation_id=r_id)
    # NOTE(jamespage):
    # ensure any new volume endpoints are created. Note that this
    # is normally done after an openstack series upgrade, but this
    # was not performed historically so always execute to ensure
    # any upgrades where this step was missed are fixed.
    for rid in relation_ids('identity-service'):
        identity_joined(rid=rid)

    if service_enabled('api'):
        # call the policy overrides handler which will install any policy
        # overrides
        maybe_do_policyd_overrides_on_config_changed(
            os_release('cinder-common'),
            'cinder',
            restart_handler=lambda: service_restart('cinder-api'))


@hooks.hook('storage.real')
@restart_on_change(restart_map(), stopstart=True)
def storage_changed():
    _configure_block_devices()
    CONFIGS.write_all()


def _configure_block_devices():
    """Configure block devices, either from Juju storage or as a local block
    device configured in the config.
    """
    if service_enabled('volume'):
        block_devices = []
        # first see if a specified block device is configured
        conf = config()
        if conf['block-device'] not in [None, 'None', 'none']:
            block_devices.extend(conf['block-device'].split())
        # now see if there are any Juju storage devies configured
        storage_ids = storage_list('block-devices')
        storage_devs = [storage_get('location', s) for s in storage_ids]
        # add them into the block_devices:
        block_devices.extend(storage_devs)
        if block_devices:
            status_set('maintenance', 'Checking configuration of lvm storage')
        # Note that there may be None now, and remove-missing is set to true,
        # so we still have to run the function regardless of whether
        # block_devices is an empty list or not.
        configure_lvm_storage(block_devices,
                              conf['volume-group'],
                              conf['overwrite'] in ['true', 'True', True],
                              conf['remove-missing'],
                              conf['remove-missing-force'])


@hooks.hook('shared-db-relation-joined')
def db_joined():
    if config('prefer-ipv6'):
        sync_db_with_multi_ipv6_addresses(config('database'),
                                          config('database-user'))
    else:
        # Avoid churn check for access-network early
        access_network = None
        for unit in related_units():
            access_network = relation_get(unit=unit,
                                          attribute='access-network')
            if access_network:
                break
        host = get_relation_ip('shared-db', cidr_network=access_network)

        conf = config()
        relation_set(database=conf['database'],
                     username=conf['database-user'],
                     hostname=host)


@hooks.hook('shared-db-relation-changed')
@restart_on_change(restart_map())
def db_changed():
    if is_db_maintenance_mode():
        juju_log('Database maintenance mode, aborting hook.')
        return
    if 'shared-db' not in CONFIGS.complete_contexts():
        juju_log('shared-db relation incomplete. Peer not ready?')
        return
    CONFIGS.write(CINDER_CONF)
    if is_elected_leader(CLUSTER_RES):
        # Bugs 1353135 & 1187508. Dbs can appear to be ready before the units
        # acl entry has been added. So, if the db supports passing a list of
        # permitted units then check if we're in the list.
        allowed_units = relation_get('allowed_units')
        if allowed_units and local_unit() in allowed_units.split():
            juju_log('Cluster leader, performing db sync')
            migrate_database()
        else:
            juju_log('allowed_units either not presented, or local unit '
                     'not in acl list: %s' % repr(allowed_units))


@hooks.hook('amqp-relation-joined')
def amqp_joined(relation_id=None):
    conf = config()
    relation_set(relation_id=relation_id,
                 username=conf['rabbit-user'], vhost=conf['rabbit-vhost'])


@hooks.hook('amqp-relation-changed')
@restart_on_change(restart_map())
def amqp_changed():
    if 'amqp' not in CONFIGS.complete_contexts():
        juju_log('amqp relation incomplete. Peer not ready?')
        return
    CONFIGS.write(CINDER_CONF)


@hooks.hook('amqp-relation-departed')
@restart_on_change(restart_map())
def amqp_departed():
    if 'amqp' not in CONFIGS.complete_contexts():
        juju_log('amqp relation incomplete. Peer not ready?')
        return
    CONFIGS.write(CINDER_CONF)


@hooks.hook('identity-service-relation-joined')
def identity_joined(rid=None):
    if config('vip') and not is_clustered():
        log('Defering registration until clustered', level=DEBUG)
        return

    settings = {}

    if not service_enabled('api'):
        juju_log('api service not enabled; skipping endpoint '
                 'registration')
        return

    cinder_release = os_release('cinder-common')
    if CompareOpenStackReleases(cinder_release) < 'pike':
        public_url = '{}:{}/v1/$(tenant_id)s'.format(
            canonical_url(CONFIGS, PUBLIC),
            config('api-listening-port')
        )
        internal_url = '{}:{}/v1/$(tenant_id)s'.format(
            canonical_url(CONFIGS, INTERNAL),
            config('api-listening-port')
        )
        admin_url = '{}:{}/v1/$(tenant_id)s'.format(
            canonical_url(CONFIGS, ADMIN),
            config('api-listening-port')
        )
        settings.update({
            'region': None,
            'service': None,
            'public_url': None,
            'internal_url': None,
            'admin_url': None,
            'cinder_region': config('region'),
            'cinder_service': 'cinder',
            'cinder_public_url': public_url,
            'cinder_internal_url': internal_url,
            'cinder_admin_url': admin_url,
        })
    if 'icehouse' <= CompareOpenStackReleases(cinder_release) <= 'wallaby':
        # NOTE(jamespage) register v2 endpoint as well
        public_url = '{}:{}/v2/$(tenant_id)s'.format(
            canonical_url(CONFIGS, PUBLIC),
            config('api-listening-port')
        )
        internal_url = '{}:{}/v2/$(tenant_id)s'.format(
            canonical_url(CONFIGS, INTERNAL),
            config('api-listening-port')
        )
        admin_url = '{}:{}/v2/$(tenant_id)s'.format(
            canonical_url(CONFIGS, ADMIN),
            config('api-listening-port')
        )
        settings.update({
            'cinderv2_region': config('region'),
            'cinderv2_service': 'cinderv2',
            'cinderv2_public_url': public_url,
            'cinderv2_internal_url': internal_url,
            'cinderv2_admin_url': admin_url,
        })
    if CompareOpenStackReleases(cinder_release) >= 'pike':
        # NOTE(jamespage) register v3 endpoint as well
        public_url = '{}:{}/v3/$(tenant_id)s'.format(
            canonical_url(CONFIGS, PUBLIC),
            config('api-listening-port')
        )
        internal_url = '{}:{}/v3/$(tenant_id)s'.format(
            canonical_url(CONFIGS, INTERNAL),
            config('api-listening-port')
        )
        admin_url = '{}:{}/v3/$(tenant_id)s'.format(
            canonical_url(CONFIGS, ADMIN),
            config('api-listening-port')
        )
        settings.update({
            'cinderv3_region': config('region'),
            'cinderv3_service': 'cinderv3',
            'cinderv3_public_url': public_url,
            'cinderv3_internal_url': internal_url,
            'cinderv3_admin_url': admin_url,
        })
    relation_set(relation_id=rid, **settings)


@hooks.hook('identity-service-relation-changed')
@restart_on_change(restart_map())
def identity_changed():
    if 'identity-service' not in CONFIGS.complete_contexts():
        juju_log('identity-service relation incomplete. Peer not ready?')
        return
    if service_enabled('api'):
        CONFIGS.write(CINDER_API_CONF)
        configure_https()


@hooks.hook('identity-credentials-relation-joined')
def identity_credentials_joined(rid=None):
    if service_enabled('volume') and not service_enabled('api'):
        settings = {'username': 'cinder', 'requested_roles': 'Admin'}
        relation_set(relation_id=rid, **settings)


@hooks.hook('identity-credentials-relation-changed')
@restart_on_change(restart_map())
def identity_credentials_changed():
    if service_enabled('volume') and not service_enabled('api'):
        if 'identity-credentials' in CONFIGS.complete_contexts():
            CONFIGS.write(CINDER_CONF)


@hooks.hook('ceph-relation-joined')
def ceph_joined():
    if not os.path.isdir('/etc/ceph'):
        os.mkdir('/etc/ceph')
    apt_install('ceph-common', fatal=True)


def get_ceph_request():
    service = service_name()
    rq = CephBrokerRq()
    replicas = config('ceph-osd-replication-count')
    rq.add_op_create_pool(name=service,
                          replica_count=replicas,
                          group="volumes")
    if config('restrict-ceph-pools'):
        rq.add_op_request_access_to_group(
            name="volumes",
            object_prefix_permissions={'class-read': ['rbd_children']},
            permission='rwx')
        rq.add_op_request_access_to_group(
            name="images",
            object_prefix_permissions={'class-read': ['rbd_children']},
            permission='rwx')
        rq.add_op_request_access_to_group(
            name="vms",
            object_prefix_permissions={'class-read': ['rbd_children']},
            permission='rwx')
    return rq


@hooks.hook('ceph-relation-changed')
@restart_on_change(restart_map())
def ceph_changed(relation_id=None):
    if 'ceph' not in CONFIGS.complete_contexts():
        juju_log('ceph relation incomplete. Peer not ready?')
        return

    service = service_name()
    if not ensure_ceph_keyring(service=service,
                               user='cinder', group='cinder'):
        juju_log('Could not create ceph keyring: peer not ready?')
        return

    if is_request_complete(get_ceph_request()):
        log('Request complete')
        CONFIGS.write(CINDER_CONF)
        CONFIGS.write(ceph_config_file())
        # Ensure that cinder-volume is restarted since only now can we
        # guarantee that ceph resources are ready.
        if not is_unit_paused_set():
            service_restart('cinder-volume')
    else:
        send_request_if_needed(get_ceph_request())


@hooks.hook('ceph-relation-broken')
def ceph_broken():
    service = service_name()
    delete_keyring(service=service)
    CONFIGS.write_all()
    remove_alternative(os.path.basename(CEPH_CONF), ceph_config_file())


@hooks.hook('cluster-relation-joined')
def cluster_joined(relation_id=None):
    settings = {}

    for addr_type in ADDRESS_TYPES:
        address = get_relation_ip(
            addr_type,
            cidr_network=config('os-{}-network'.format(addr_type)))
        if address:
            settings['{}-address'.format(addr_type)] = address

    settings['private-address'] = get_relation_ip('cluster')

    relation_set(relation_id=relation_id, relation_settings=settings)

    # Only do if this is fired by cluster rel
    if not relation_id:
        check_local_db_actions_complete()


@hooks.hook('cluster-relation-changed',
            'cluster-relation-departed')
@restart_on_change(restart_map(), stopstart=True)
def cluster_changed():
    check_local_db_actions_complete()
    CONFIGS.write_all()


@hooks.hook('ha-relation-joined')
def ha_joined(relation_id=None):
    settings = generate_ha_relation_data('cinder')
    relation_set(relation_id=relation_id, **settings)


@hooks.hook('ha-relation-changed')
def ha_changed():
    clustered = relation_get('clustered')
    if not clustered or clustered in [None, 'None', '']:
        juju_log('ha_changed: hacluster subordinate not fully clustered.')
    else:
        juju_log('Cluster configured, notifying other services and updating '
                 'keystone endpoint configuration')
        for rid in relation_ids('identity-service'):
            identity_joined(rid=rid)


@hooks.hook('image-service-relation-changed')
@restart_on_change(restart_map())
def image_service_changed():
    CONFIGS.write(CINDER_CONF)


@hooks.hook('amqp-relation-broken',
            'identity-service-relation-broken',
            'identity-credentials-relation-broken',
            'image-service-relation-broken',
            'shared-db-relation-broken')
@restart_on_change(restart_map(), stopstart=True)
def relation_broken():
    CONFIGS.write_all()


@restart_on_change(restart_map(), stopstart=True)
def configure_https():
    '''Enables SSL API Apache config if appropriate and kicks identity-service
    with any required api updates.
    '''
    # need to write all to ensure changes to the entire request pipeline
    # propagate (c-api, haprxy, apache)
    CONFIGS.write_all()
    if 'https' in CONFIGS.complete_contexts():
        cmd = ['a2ensite', 'openstack_https_frontend']
        check_call(cmd)
    else:
        cmd = ['a2dissite', 'openstack_https_frontend']
        check_call(cmd)

    # TODO: improve this by checking if local CN certs are available
    # first then checking reload status (see LP #1433114).
    if not is_unit_paused_set():
        service_reload('apache2', restart_on_failure=True)

    for rid in relation_ids('identity-service'):
        identity_joined(rid=rid)


@hooks.hook('upgrade-charm')
@harden()
def upgrade_charm():
    apt_install(filter_installed_packages(determine_packages()),
                fatal=True)
    packages_removed = remove_old_packages()
    for rel_id in relation_ids('amqp'):
        amqp_joined(relation_id=rel_id)
    update_nrpe_config()
    scrub_old_style_ceph()
    if packages_removed:
        juju_log("Package purge detected, restarting services")
        for s in services():
            service_restart(s)

    if service_enabled('api'):
        # call the policy overrides handler which will install any policy
        # overrides
        maybe_do_policyd_overrides(
            os_release('cinder-common'),
            'cinder',
            restart_handler=lambda: service_restart('cinder-api'))

    # Make sure iscsid has a unique InitiatorName by starting iscsid
    # and invoking /lib/open-iscsi/startup-checks.sh indirectly as
    # ExecStartPre script of it
    service_start('iscsid')


@hooks.hook('storage-backend-relation-changed')
@hooks.hook('storage-backend-relation-broken')
@restart_on_change(restart_map())
def storage_backend():
    CONFIGS.write(CINDER_CONF)


@hooks.hook('backup-backend-relation-changed')
@hooks.hook('backup-backend-relation-broken')
@restart_on_change(restart_map())
def backup_backend():
    CONFIGS.write(CINDER_CONF)


@hooks.hook('nrpe-external-master-relation-joined',
            'nrpe-external-master-relation-changed')
def update_nrpe_config():
    # python-dbus is used by check_upstart_job
    apt_install('python-dbus')
    hostname = nrpe.get_nagios_hostname()
    current_unit = nrpe.get_nagios_unit_name()
    nrpe_setup = nrpe.NRPE(hostname=hostname)
    nrpe.copy_nrpe_checks()
    nrpe.add_init_service_checks(nrpe_setup, services(), current_unit)
    if service_enabled('api'):
        nrpe.add_haproxy_checks(nrpe_setup, current_unit)
    else:
        nrpe.remove_deprecated_check(nrpe_setup,
                                     ["haproxy_servers", "haproxy_queue"])
    nrpe_setup.write()


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


@hooks.hook('certificates-relation-joined')
def certs_joined(relation_id=None):
    relation_set(
        relation_id=relation_id,
        relation_settings=get_certificate_request())


@hooks.hook('certificates-relation-changed')
@restart_on_change(restart_map())
def certs_changed(relation_id=None, unit=None):
    if not service_enabled('api'):
        # Install CA cert to communicate with Keystone and Glance
        data = relation_get(rid=relation_id, unit=unit)
        ca = data.get('ca')
        if ca:
            install_ca_cert(ca.encode())
        return
    process_certificates('cinder', relation_id, unit)
    configure_https()


@hooks.hook('pre-series-upgrade')
def pre_series_upgrade():
    log("Running prepare series upgrade hook", "INFO")
    series_upgrade_prepare(
        pause_unit_helper, CONFIGS)


@hooks.hook('post-series-upgrade')
def post_series_upgrade():
    log("Running complete series upgrade hook", "INFO")
    series_upgrade_complete(
        resume_unit_helper, CONFIGS)


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