from charmhelpers.core.hookenv import (
    config,
    relation_ids,
    related_units,
    relation_get,
    log,
)
from charmhelpers.contrib.openstack import context
from charmhelpers.contrib.hahelpers.cluster import (
    determine_api_port,
    determine_apache_port,
)
from charmhelpers.contrib.openstack.utils import (
    os_release,
)


def get_l2population():
    plugin = config('neutron-plugin')
    return config('l2-population') if plugin == "ovs" else False


def get_overlay_network_type():
    overlay_net = config('overlay-network-type')
    if overlay_net not in ['vxlan', 'gre']:
        raise Exception('Unsupported overlay-network-type')
    return overlay_net


def get_l3ha():
    if config('enable-l3ha'):
        if os_release('neutron-server') < 'juno':
            log('Disabling L3 HA, enable-l3ha is not valid before Juno')
            return False
        if config('overlay-network-type') not in ['vlan', 'gre', 'vxlan']:
            log('Disabling L3 HA, enable-l3ha requires the use of the vxlan, '
                'vlan or gre overlay network')
            return False
        if get_l2population():
            log('Disabling L3 HA, l2-population must be disabled with L3 HA')
            return False
        return True
    else:
        return False


def get_dvr():
    if config('enable-dvr'):
        if os_release('neutron-server') < 'juno':
            log('Disabling DVR, enable-dvr is not valid before Juno')
            return False
        if config('overlay-network-type') != 'vxlan':
            log('Disabling DVR, enable-dvr requires the use of the vxlan '
                'overlay network')
            return False
        if get_l3ha():
            log('Disabling DVR, enable-l3ha must be disabled with dvr')
            return False
        if not get_l2population():
            log('Disabling DVR, l2-population must be enabled to use dvr')
            return False
        return True
    else:
        return False


class ApacheSSLContext(context.ApacheSSLContext):

    interfaces = ['https']
    external_ports = []
    service_namespace = 'neutron'

    def __call__(self):
        # late import to work around circular dependency
        from neutron_api_utils import determine_ports
        self.external_ports = determine_ports()
        return super(ApacheSSLContext, self).__call__()


class IdentityServiceContext(context.IdentityServiceContext):

    def __call__(self):
        ctxt = super(IdentityServiceContext, self).__call__()
        if not ctxt:
            return
        ctxt['region'] = config('region')
        return ctxt


class NeutronCCContext(context.NeutronContext):
    interfaces = []

    @property
    def network_manager(self):
        return 'neutron'

    @property
    def plugin(self):
        return config('neutron-plugin')

    @property
    def neutron_security_groups(self):
        return config('neutron-security-groups')

    @property
    def neutron_l2_population(self):
        return get_l2population()

    @property
    def neutron_overlay_network_type(self):
        return get_overlay_network_type()

    @property
    def neutron_dvr(self):
        return get_dvr()

    @property
    def neutron_l3ha(self):
        return get_l3ha()

    # Do not need the plugin agent installed on the api server
    def _ensure_packages(self):
        pass

    # Do not need the flag on the api server
    def _save_flag_file(self):
        pass

    def get_neutron_api_rel_settings(self):
        settings = {}
        for rid in relation_ids('neutron-api'):
            for unit in related_units(rid):
                rdata = relation_get(rid=rid, unit=unit)
                cell_type = rdata.get('cell_type')
                settings['nova_url'] = rdata.get('nova_url')
                settings['restart_trigger'] = rdata.get('restart_trigger')
                # If there are multiple nova-cloud-controllers joined to this
                # service in a cell deployment then ignore the non-api cell
                # ones
                if cell_type and not cell_type == "api":
                    continue

                if settings['nova_url']:
                    return settings

        return settings

    def __call__(self):
        from neutron_api_utils import api_port
        ctxt = super(NeutronCCContext, self).__call__()
        if config('neutron-plugin') == 'nsx':
            ctxt['nsx_username'] = config('nsx-username')
            ctxt['nsx_password'] = config('nsx-password')
            ctxt['nsx_tz_uuid'] = config('nsx-tz-uuid')
            ctxt['nsx_l3_uuid'] = config('nsx-l3-uuid')
            if 'nsx-controllers' in config():
                ctxt['nsx_controllers'] = \
                    ','.join(config('nsx-controllers').split())
                ctxt['nsx_controllers_list'] = \
                    config('nsx-controllers').split()
        ctxt['l2_population'] = self.neutron_l2_population
        ctxt['enable_dvr'] = self.neutron_dvr
        ctxt['l3_ha'] = self.neutron_l3ha
        if self.neutron_l3ha:
            ctxt['max_l3_agents_per_router'] = \
                config('max-l3-agents-per-router')
            ctxt['min_l3_agents_per_router'] = \
                config('min-l3-agents-per-router')
        ctxt['overlay_network_type'] = self.neutron_overlay_network_type
        ctxt['external_network'] = config('neutron-external-network')
        ctxt['verbose'] = config('verbose')
        ctxt['debug'] = config('debug')
        ctxt['neutron_bind_port'] = \
            determine_api_port(api_port('neutron-server'),
                               singlenode_mode=True)
        ctxt['quota_security_group'] = config('quota-security-group')
        ctxt['quota_security_group_rule'] = \
            config('quota-security-group-rule')
        ctxt['quota_network'] = config('quota-network')
        ctxt['quota_subnet'] = config('quota-subnet')
        ctxt['quota_port'] = config('quota-port')
        ctxt['quota_vip'] = config('quota-vip')
        ctxt['quota_pool'] = config('quota-pool')
        ctxt['quota_member'] = config('quota-member')
        ctxt['quota_health_monitors'] = config('quota-health-monitors')
        ctxt['quota_router'] = config('quota-router')
        ctxt['quota_floatingip'] = config('quota-floatingip')

        n_api_settings = self.get_neutron_api_rel_settings()
        if n_api_settings:
            ctxt.update(n_api_settings)

        flat_providers = config('flat-network-providers')
        if flat_providers:
            ctxt['network_providers'] = ','.join(flat_providers.split())

        vlan_ranges = config('vlan-ranges')
        if vlan_ranges:
            ctxt['vlan_ranges'] = ','.join(vlan_ranges.split())

        return ctxt


class HAProxyContext(context.HAProxyContext):
    interfaces = ['ceph']

    def __call__(self):
        '''
        Extends the main charmhelpers HAProxyContext with a port mapping
        specific to this charm.
        Also used to extend nova.conf context with correct api_listening_ports
        '''
        from neutron_api_utils import api_port
        ctxt = super(HAProxyContext, self).__call__()

        # Apache ports
        a_neutron_api = determine_apache_port(api_port('neutron-server'),
                                              singlenode_mode=True)

        port_mapping = {
            'neutron-server': [
                api_port('neutron-server'), a_neutron_api]
        }

        ctxt['neutron_bind_port'] = determine_api_port(
            api_port('neutron-server'),
            singlenode_mode=True,
        )

        # for haproxy.conf
        ctxt['service_ports'] = port_mapping
        return ctxt