#!/usr/bin/python
import sys

from charmhelpers.core.hookenv import (
    Hooks,
    config,
    is_relation_made,
    log,
    ERROR,
    relation_ids,
    relation_get,
    relation_set,
    service_name,
    unit_get,
    UnregisteredHookError,
    status_set,
)
from charmhelpers.core.host import (
    restart_on_change,
    service_restart,
)
from charmhelpers.core.strutils import (
    bool_from_string,
)
from charmhelpers.fetch import (
    apt_install,
    apt_purge,
    apt_update,
    filter_installed_packages,
)

from charmhelpers.contrib.openstack.utils import (
    config_value_changed,
    configure_installation_source,
    git_install_requested,
    openstack_upgrade_available,
    os_requires_version,
    set_os_workload_status,
)

from charmhelpers.contrib.storage.linux.ceph import (
    ensure_ceph_keyring,
    CephBrokerRq,
    delete_keyring,
    send_request_if_needed,
    is_request_complete,
)
from charmhelpers.payload.execd import execd_preinstall
from nova_compute_utils import (
    create_libvirt_secret,
    determine_packages,
    git_install,
    import_authorized_keys,
    import_keystone_ca_cert,
    initialize_ssh_keys,
    migration_enabled,
    network_manager,
    do_openstack_upgrade,
    public_ssh_key,
    restart_map,
    services,
    register_configs,
    NOVA_CONF,
    QUANTUM_CONF, NEUTRON_CONF,
    ceph_config_file, CEPH_SECRET,
    enable_shell, disable_shell,
    configure_lxd,
    fix_path_ownership,
    get_topics,
    assert_charm_supports_ipv6,
    manage_ovs,
    install_hugepages,
    REQUIRED_INTERFACES,
    check_optional_relations,
    get_hugepage_number,
)

from charmhelpers.contrib.network.ip import (
    get_ipv6_addr
)

from charmhelpers.core.unitdata import kv

from nova_compute_context import (
    CEPH_SECRET_UUID,
    assert_libvirt_imagebackend_allowed
)
from charmhelpers.contrib.charmsupport import nrpe
from charmhelpers.core.sysctl import create as create_sysctl

from socket import gethostname

hooks = Hooks()
CONFIGS = register_configs()


@hooks.hook('install.real')
def install():
    status_set('maintenance', 'Executing pre-install')
    execd_preinstall()
    configure_installation_source(config('openstack-origin'))

    status_set('maintenance', 'Installing apt packages')
    apt_update()
    apt_install(determine_packages(), fatal=True)

    status_set('maintenance', 'Git install')
    git_install(config('openstack-origin-git'))


@hooks.hook('config-changed')
@restart_on_change(restart_map())
def config_changed():
    if config('prefer-ipv6'):
        status_set('maintenance', 'configuring ipv6')
        assert_charm_supports_ipv6()

    global CONFIGS
    if git_install_requested():
        if config_value_changed('openstack-origin-git'):
            status_set('maintenance', 'Running Git install')
            git_install(config('openstack-origin-git'))
    elif not config('action-managed-upgrade'):
        if openstack_upgrade_available('nova-common'):
            status_set('maintenance', 'Running openstack upgrade')
            do_openstack_upgrade(CONFIGS)

    sysctl_dict = config('sysctl')
    if sysctl_dict:
        create_sysctl(sysctl_dict, '/etc/sysctl.d/50-nova-compute.conf')

    if migration_enabled() and config('migration-auth-type') == 'ssh':
        # Check-in with nova-c-c and register new ssh key, if it has just been
        # generated.
        status_set('maintenance', 'SSH key exchange')
        initialize_ssh_keys()
        import_authorized_keys()

    if config('enable-resize') is True:
        enable_shell(user='nova')
        status_set('maintenance', 'SSH key exchange')
        initialize_ssh_keys(user='nova')
        import_authorized_keys(user='nova', prefix='nova')
    else:
        disable_shell(user='nova')

    if config('instances-path') is not None:
        fp = config('instances-path')
        fix_path_ownership(fp, user='nova')

    [compute_joined(rid) for rid in relation_ids('cloud-compute')]
    for rid in relation_ids('zeromq-configuration'):
        zeromq_configuration_relation_joined(rid)

    for rid in relation_ids('neutron-plugin'):
        neutron_plugin_joined(rid)

    if is_relation_made("nrpe-external-master"):
        update_nrpe_config()

    if config('hugepages'):
        install_hugepages()

    CONFIGS.write_all()


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


@hooks.hook('amqp-relation-changed')
@hooks.hook('amqp-relation-departed')
@restart_on_change(restart_map())
def amqp_changed():
    if 'amqp' not in CONFIGS.complete_contexts():
        log('amqp relation incomplete. Peer not ready?')
        return
    CONFIGS.write(NOVA_CONF)
    # No need to write NEUTRON_CONF if neutron-plugin is managing it
    if manage_ovs():
        if network_manager() == 'quantum':
            CONFIGS.write(QUANTUM_CONF)
        if network_manager() == 'neutron':
            CONFIGS.write(NEUTRON_CONF)


@hooks.hook('shared-db-relation-joined')
def db_joined(rid=None):
    if is_relation_made('pgsql-db'):
        # error, postgresql is used
        e = ('Attempting to associate a mysql database when there is already '
             'associated a postgresql one')
        log(e, level=ERROR)
        raise Exception(e)

    relation_set(relation_id=rid,
                 nova_database=config('database'),
                 nova_username=config('database-user'),
                 nova_hostname=unit_get('private-address'))


@hooks.hook('pgsql-db-relation-joined')
def pgsql_db_joined():
    if is_relation_made('shared-db'):
        # raise error
        e = ('Attempting to associate a postgresql database when'
             ' there is already associated a mysql one')
        log(e, level=ERROR)
        raise Exception(e)

    relation_set(database=config('database'))


@hooks.hook('shared-db-relation-changed')
@restart_on_change(restart_map())
def db_changed():
    if 'shared-db' not in CONFIGS.complete_contexts():
        log('shared-db relation incomplete. Peer not ready?')
        return
    CONFIGS.write(NOVA_CONF)


@hooks.hook('pgsql-db-relation-changed')
@restart_on_change(restart_map())
def postgresql_db_changed():
    if 'pgsql-db' not in CONFIGS.complete_contexts():
        log('pgsql-db relation incomplete. Peer not ready?')
        return
    CONFIGS.write(NOVA_CONF)


@hooks.hook('image-service-relation-changed')
@restart_on_change(restart_map())
def image_service_changed():
    if 'image-service' not in CONFIGS.complete_contexts():
        log('image-service relation incomplete. Peer not ready?')
        return
    CONFIGS.write(NOVA_CONF)


@hooks.hook('cloud-compute-relation-joined')
def compute_joined(rid=None):
    # NOTE(james-page) in MAAS environments the actual hostname is a CNAME
    # record so won't get scanned based on private-address which is an IP
    # add the hostname configured locally to the relation.
    settings = {
        'hostname': gethostname()
    }
    if config('prefer-ipv6'):
        settings = {'private-address': get_ipv6_addr()[0]}
    if migration_enabled():
        auth_type = config('migration-auth-type')
        settings['migration_auth_type'] = auth_type
        if auth_type == 'ssh':
            settings['ssh_public_key'] = public_ssh_key()
        relation_set(relation_id=rid, **settings)
    if config('enable-resize'):
        settings['nova_ssh_public_key'] = public_ssh_key(user='nova')
        relation_set(relation_id=rid, **settings)


@hooks.hook('cloud-compute-relation-changed')
@restart_on_change(restart_map())
def compute_changed():
    # rewriting all configs to pick up possible net or vol manager
    # config advertised from controller.
    CONFIGS.write_all()
    import_authorized_keys()
    import_authorized_keys(user='nova', prefix='nova')
    import_keystone_ca_cert()


@hooks.hook('ceph-relation-joined')
@restart_on_change(restart_map())
def ceph_joined():
    status_set('maintenance', 'Installing apt packages')
    apt_install(filter_installed_packages(['ceph-common']), fatal=True)
    # Bug 1427660
    service_restart('libvirt-bin')


def get_ceph_request():
    rq = CephBrokerRq()
    replicas = config('ceph-osd-replication-count')
    rq.add_op_create_pool(name=config('rbd-pool'), replica_count=replicas)
    return rq


@hooks.hook('ceph-relation-changed')
@restart_on_change(restart_map())
def ceph_changed():
    if 'ceph' not in CONFIGS.complete_contexts():
        log('ceph relation incomplete. Peer not ready?')
        return

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

    CONFIGS.write(ceph_config_file())
    CONFIGS.write(CEPH_SECRET)
    CONFIGS.write(NOVA_CONF)

    # With some refactoring, this can move into NovaComputeCephContext
    # and allow easily extended to support other compute flavors.
    if config('virt-type') in ['kvm', 'qemu', 'lxc'] and relation_get('key'):
        create_libvirt_secret(secret_file=CEPH_SECRET,
                              secret_uuid=CEPH_SECRET_UUID,
                              key=relation_get('key'))

    if (config('libvirt-image-backend') == 'rbd' and
            assert_libvirt_imagebackend_allowed()):
        if is_request_complete(get_ceph_request()):
            log('Request complete')
            # Ensure that nova-compute is restarted since only now can we
            # guarantee that ceph resources are ready.
            service_restart('nova-compute')
        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()


@hooks.hook('amqp-relation-broken',
            'image-service-relation-broken',
            'shared-db-relation-broken',
            'pgsql-db-relation-broken')
@restart_on_change(restart_map())
def relation_broken():
    CONFIGS.write_all()


@hooks.hook('upgrade-charm')
def upgrade_charm():
    # NOTE: ensure psutil install for hugepages configuration
    status_set('maintenance', 'Installing apt packages')
    apt_install(filter_installed_packages(['python-psutil']))
    for r_id in relation_ids('amqp'):
        amqp_joined(relation_id=r_id)

    if is_relation_made('nrpe-external-master'):
        update_nrpe_config()


@hooks.hook('nova-ceilometer-relation-changed')
@restart_on_change(restart_map())
def nova_ceilometer_relation_changed():
    CONFIGS.write_all()


@hooks.hook('zeromq-configuration-relation-joined')
@os_requires_version('kilo', 'nova-common')
def zeromq_configuration_relation_joined(relid=None):
    relation_set(relation_id=relid,
                 topics=" ".join(get_topics()),
                 users="nova")


@hooks.hook('zeromq-configuration-relation-changed')
@restart_on_change(restart_map())
def zeromq_configuration_relation_changed():
    CONFIGS.write(NOVA_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.add_init_service_checks(nrpe_setup, services(), current_unit)
    nrpe_setup.write()


@hooks.hook('neutron-plugin-relation-joined')
def neutron_plugin_joined(relid=None):
    relation_set(relation_id=relid,
                 hugepage_number=get_hugepage_number())


@hooks.hook('neutron-plugin-relation-changed')
@restart_on_change(restart_map())
def neutron_plugin_changed():
    settings = relation_get()
    if settings.get('enable-metadata'):
        enable_metadata = bool_from_string(settings['enable-metadata'])
    else:
        enable_metadata = False
    if 'metadata-shared-secret' in settings or enable_metadata:
        apt_update()
        apt_install(filter_installed_packages(['nova-api-metadata']),
                    fatal=True)
    else:
        apt_purge('nova-api-metadata', fatal=True)
    CONFIGS.write(NOVA_CONF)


@hooks.hook('lxd-relation-joined')
def lxd_joined(relid=None):
    relation_set(relation_id=relid,
                 user='nova')


@hooks.hook('lxd-relation-changed')
def lxc_changed():
    nonce = relation_get('nonce')
    db = kv()
    if nonce and db.get('lxd-nonce') != nonce:
        db.set('lxd-nonce', nonce)
        configure_lxd(user='nova')
        service_restart('nova-compute')


def main():
    try:
        hooks.execute(sys.argv)
    except UnregisteredHookError as e:
        log('Unknown hook {} - skipping.'.format(e))
    set_os_workload_status(CONFIGS, REQUIRED_INTERFACES,
                           charm_func=check_optional_relations)


if __name__ == '__main__':
    main()