#    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 six

from neutron.agent.ovsdb.native import commands
from neutron.agent.ovsdb.native import idlutils

from networking_ovn._i18n import _
from networking_ovn.common import utils


# TODO(rtheis): These wrapper functions are't needed once OpenStack
# global requirements guarantee an ovs python version with mutate
# support.

def _is_ovs_mutate_available(row):
    # Checking for the addvalue method should be sufficient.
    return callable(getattr(row, 'addvalue', None))


def _addvalue_to_list(row, column, new_value):
    # If available, use mutate support to add the value.
    if _is_ovs_mutate_available(row):
        row.addvalue(column, new_value)
    else:
        row.verify(column)
        column_values = getattr(row, column, [])
        if new_value not in column_values:
            column_values.append(new_value)
            setattr(row, column, column_values)


def _delvalue_from_list(row, column, old_value):
    # If available, use mutate support to delete the value.
    if _is_ovs_mutate_available(row):
        row.delvalue(column, old_value)
    else:
        row.verify(column)
        column_values = getattr(row, column, [])
        if old_value in column_values:
            column_values.remove(old_value)
            setattr(row, column, column_values)


def _updatevalues_in_list(row, column, new_values=None, old_values=None):
    new_values = new_values or []
    old_values = old_values or []

    # If available, use mutate support to add/delete the values.
    if _is_ovs_mutate_available(row):
        for new_value in new_values:
            row.addvalue(column, new_value)
        for old_value in old_values:
            row.delvalue(column, old_value)
    else:
        row.verify(column)
        column_values = getattr(row, column, [])
        for new_value in new_values:
            if new_value not in column_values:
                column_values.append(new_value)
        for old_value in old_values:
            if old_value in column_values:
                column_values.remove(old_value)
        setattr(row, column, column_values)


def get_lsp_dhcpv4_options_uuids(lsp, lsp_name):
    # Get dhcpv4_options uuids from Logical_Switch_Port, which are references
    # of port dhcpv4 options in DHCP_Options table.
    uuids = set()
    for dhcp_opts in getattr(lsp, 'dhcpv4_options', []):
        external_ids = getattr(dhcp_opts, 'external_ids', {})
        if external_ids.get('port_id') == lsp_name:
            uuids.add(dhcp_opts.uuid)
    return uuids


class AddLSwitchCommand(commands.BaseCommand):
    def __init__(self, api, name, may_exist, **columns):
        super(AddLSwitchCommand, self).__init__(api)
        self.name = name
        self.columns = columns
        self.may_exist = may_exist

    def run_idl(self, txn):
        if self.may_exist:
            lswitch = idlutils.row_by_value(self.api.idl, 'Logical_Switch',
                                            'name', self.name, None)
            if lswitch:
                return
        row = txn.insert(self.api._tables['Logical_Switch'])
        row.name = self.name
        for col, val in self.columns.items():
            setattr(row, col, val)


class DelLSwitchCommand(commands.BaseCommand):
    def __init__(self, api, name, if_exists):
        super(DelLSwitchCommand, self).__init__(api)
        self.name = name
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lswitch = idlutils.row_by_value(self.api.idl, 'Logical_Switch',
                                            'name', self.name)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Switch %s does not exist") % self.name
            raise RuntimeError(msg)

        self.api._tables['Logical_Switch'].rows[lswitch.uuid].delete()


class LSwitchSetExternalIdCommand(commands.BaseCommand):
    def __init__(self, api, name, field, value, if_exists):
        super(LSwitchSetExternalIdCommand, self).__init__(api)
        self.name = name
        self.field = field
        self.value = value
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lswitch = idlutils.row_by_value(self.api.idl, 'Logical_Switch',
                                            'name', self.name)

        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Switch %s does not exist") % self.name
            raise RuntimeError(msg)

        lswitch.verify('external_ids')

        external_ids = getattr(lswitch, 'external_ids', {})
        external_ids[self.field] = self.value
        lswitch.external_ids = external_ids


class AddLSwitchPortCommand(commands.BaseCommand):
    def __init__(self, api, lport, lswitch, may_exist, **columns):
        super(AddLSwitchPortCommand, self).__init__(api)
        self.lport = lport
        self.lswitch = lswitch
        self.may_exist = may_exist
        self.columns = columns

    def run_idl(self, txn):
        try:
            lswitch = idlutils.row_by_value(self.api.idl, 'Logical_Switch',
                                            'name', self.lswitch)
        except idlutils.RowNotFound:
            msg = _("Logical Switch %s does not exist") % self.lswitch
            raise RuntimeError(msg)
        if self.may_exist:
            port = idlutils.row_by_value(self.api.idl,
                                         'Logical_Switch_Port', 'name',
                                         self.lport, None)
            if port:
                return

        port = txn.insert(self.api._tables['Logical_Switch_Port'])
        port.name = self.lport
        for col, val in self.columns.items():
            setattr(port, col, val)
        # add the newly created port to existing lswitch
        _addvalue_to_list(lswitch, 'ports', port.uuid)


class SetLSwitchPortCommand(commands.BaseCommand):
    def __init__(self, api, lport, if_exists, **columns):
        super(SetLSwitchPortCommand, self).__init__(api)
        self.lport = lport
        self.columns = columns
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            port = idlutils.row_by_value(self.api.idl, 'Logical_Switch_Port',
                                         'name', self.lport)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Switch Port %s does not exist") % self.lport
            raise RuntimeError(msg)

        # Delete DHCP_Options records no longer refered by this port.
        # The table rows should be consistent for the same transaction.
        # After we get a DHCP_Options row uuid from port dhcpv4_options
        # reference, the row shouldn't disappear for this transaction,
        # before we delete it.
        cur_port_dhcp_opts = get_lsp_dhcpv4_options_uuids(
            port, self.lport)
        new_port_dhcp_opts = set(self.columns.get('dhcpv4_options', []))
        for uuid in cur_port_dhcp_opts - new_port_dhcp_opts:
            self.api._tables['DHCP_Options'].rows[uuid].delete()

        for col, val in self.columns.items():
            setattr(port, col, val)


class DelLSwitchPortCommand(commands.BaseCommand):
    def __init__(self, api, lport, lswitch, if_exists):
        super(DelLSwitchPortCommand, self).__init__(api)
        self.lport = lport
        self.lswitch = lswitch
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lport = idlutils.row_by_value(self.api.idl, 'Logical_Switch_Port',
                                          'name', self.lport)
            lswitch = idlutils.row_by_value(self.api.idl, 'Logical_Switch',
                                            'name', self.lswitch)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Port %s does not exist") % self.lport
            raise RuntimeError(msg)

        _delvalue_from_list(lswitch, 'ports', lport)
        self.api._tables['Logical_Switch_Port'].rows[lport.uuid].delete()


class AddLRouterCommand(commands.BaseCommand):
    def __init__(self, api, name, may_exist, **columns):
        super(AddLRouterCommand, self).__init__(api)
        self.name = name
        self.columns = columns
        self.may_exist = may_exist

    def run_idl(self, txn):
        if self.may_exist:
            lrouter = idlutils.row_by_value(self.api.idl, 'Logical_Router',
                                            'name', self.name, None)
            if lrouter:
                return

        row = txn.insert(self.api._tables['Logical_Router'])
        row.name = self.name
        for col, val in self.columns.items():
            setattr(row, col, val)


class UpdateLRouterCommand(commands.BaseCommand):
    def __init__(self, api, name, if_exists, **columns):
        super(UpdateLRouterCommand, self).__init__(api)
        self.name = name
        self.columns = columns
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lrouter = idlutils.row_by_value(self.api.idl, 'Logical_Router',
                                            'name', self.name, None)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Router %s does not exist") % self.name
            raise RuntimeError(msg)

        if lrouter:
            for col, val in self.columns.items():
                setattr(lrouter, col, val)
            return


class DelLRouterCommand(commands.BaseCommand):
    def __init__(self, api, name, if_exists):
        super(DelLRouterCommand, self).__init__(api)
        self.name = name
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lrouter = idlutils.row_by_value(self.api.idl, 'Logical_Router',
                                            'name', self.name)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Router %s does not exist") % self.name
            raise RuntimeError(msg)

        self.api._tables['Logical_Router'].rows[lrouter.uuid].delete()


class AddLRouterPortCommand(commands.BaseCommand):
    def __init__(self, api, name, lrouter, **columns):
        super(AddLRouterPortCommand, self).__init__(api)
        self.name = name
        self.lrouter = lrouter
        self.columns = columns

    def run_idl(self, txn):

        try:
            lrouter = idlutils.row_by_value(self.api.idl, 'Logical_Router',
                                            'name', self.lrouter)
        except idlutils.RowNotFound:
            msg = _("Logical Router %s does not exist") % self.lrouter
            raise RuntimeError(msg)
        try:
            idlutils.row_by_value(self.api.idl, 'Logical_Router_Port',
                                  'name', self.name)
            # The LRP entry with certain name has already exist, raise an
            # exception to notice caller. It's caller's responsibility to
            # call UpdateLRouterPortCommand to get LRP entry processed
            # correctly.
            msg = _("Logical Router Port with name \"%s\" "
                    "already exists.") % self.name
            raise RuntimeError(msg)
        except idlutils.RowNotFound:
            lrouter_port = txn.insert(self.api._tables['Logical_Router_Port'])
            lrouter_port.name = self.name
            for col, val in self.columns.items():
                setattr(lrouter_port, col, val)
            _addvalue_to_list(lrouter, 'ports', lrouter_port)


class UpdateLRouterPortCommand(commands.BaseCommand):
    def __init__(self, api, name, lrouter, if_exists, **columns):
        super(UpdateLRouterPortCommand, self).__init__(api)
        self.name = name
        self.columns = columns
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lrouter_port = idlutils.row_by_value(self.api.idl,
                                                 'Logical_Router_Port',
                                                 'name', self.name)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Router Port %s does not exist") % self.name
            raise RuntimeError(msg)

        if lrouter_port:
            for col, val in self.columns.items():
                setattr(lrouter_port, col, val)
            return


class DelLRouterPortCommand(commands.BaseCommand):
    def __init__(self, api, name, lrouter, if_exists):
        super(DelLRouterPortCommand, self).__init__(api)
        self.name = name
        self.lrouter = lrouter
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lrouter_port = idlutils.row_by_value(self.api.idl,
                                                 'Logical_Router_Port',
                                                 'name', self.name)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Router Port %s does not exist") % self.name
            raise RuntimeError(msg)
        try:
            lrouter = idlutils.row_by_value(self.api.idl, 'Logical_Router',
                                            'name', self.lrouter)
        except idlutils.RowNotFound:
            msg = _("Logical Router %s does not exist") % self.lrouter
            raise RuntimeError(msg)

        _delvalue_from_list(lrouter, 'ports', lrouter_port)


class SetLRouterPortInLSwitchPortCommand(commands.BaseCommand):
    def __init__(self, api, lswitch_port, lrouter_port):
        super(SetLRouterPortInLSwitchPortCommand, self).__init__(api)
        self.lswitch_port = lswitch_port
        self.lrouter_port = lrouter_port

    def run_idl(self, txn):
        try:
            port = idlutils.row_by_value(self.api.idl, 'Logical_Switch_Port',
                                         'name', self.lswitch_port)
        except idlutils.RowNotFound:
            msg = _("Logical Switch Port %s does not "
                    "exist") % self.lswitch_port
            raise RuntimeError(msg)

        options = {'router-port': self.lrouter_port}
        setattr(port, 'options', options)
        setattr(port, 'type', 'router')


class AddACLCommand(commands.BaseCommand):
    def __init__(self, api, lswitch, lport, **columns):
        super(AddACLCommand, self).__init__(api)
        self.lswitch = lswitch
        self.lport = lport
        self.columns = columns

    def run_idl(self, txn):
        try:
            lswitch = idlutils.row_by_value(self.api.idl, 'Logical_Switch',
                                            'name', self.lswitch)
        except idlutils.RowNotFound:
            msg = _("Logical Switch %s does not exist") % self.lswitch
            raise RuntimeError(msg)

        row = txn.insert(self.api._tables['ACL'])
        for col, val in self.columns.items():
            setattr(row, col, val)
        row.external_ids = {'neutron:lport': self.lport}
        _addvalue_to_list(lswitch, 'acls', row.uuid)


class DelACLCommand(commands.BaseCommand):
    def __init__(self, api, lswitch, lport, if_exists):
        super(DelACLCommand, self).__init__(api)
        self.lswitch = lswitch
        self.lport = lport
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lswitch = idlutils.row_by_value(self.api.idl, 'Logical_Switch',
                                            'name', self.lswitch)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Switch %s does not exist") % self.lswitch
            raise RuntimeError(msg)

        acls_to_del = []
        acls = getattr(lswitch, 'acls', [])
        for acl in acls:
            ext_ids = getattr(acl, 'external_ids', {})
            if ext_ids.get('neutron:lport') == self.lport:
                acls_to_del.append(acl)
        for acl in acls_to_del:
            acl.delete()
        _updatevalues_in_list(lswitch, 'acls', old_values=acls_to_del)


class UpdateACLsCommand(commands.BaseCommand):
    def __init__(self, api, lswitch_names, port_list, acl_new_values_dict,
                 need_compare=True, is_add_acl=True):
        """This command updates the acl list for the logical switches

        @param lswitch_names: List of Logical Switch Names
        @type lswitch_names: []
        @param port_list: Iterator of List of Ports
        @type port_list: []
        @param acl_new_values_dict: Dictionary of acls indexed by port id
        @type acl_new_values_dict: {}
        @need_compare: If acl_new_values_dict needs be compared with existing
                       acls.
        @type: Boolean.
        @is_add_acl: If updating is caused by acl adding action.
        @type: Boolean.

        """
        super(UpdateACLsCommand, self).__init__(api)
        self.lswitch_names = lswitch_names
        self.port_list = port_list
        self.acl_new_values_dict = acl_new_values_dict
        self.need_compare = need_compare
        self.is_add_acl = is_add_acl

    def _acl_list_sub(self, acl_list1, acl_list2):
        """Compute the elements in acl_list1 but not in acl_list2.

        If acl_list1 and acl_list2 were sets, the result of this routine
        could be thought of as acl_list1 - acl_list2. Note that acl_list1
        and acl_list2 cannot actually be sets as they contain dictionary
        items i.e. set([{'a':1}) doesn't work.
        """
        acl_diff = []
        for acl in acl_list1:
            if acl not in acl_list2:
                acl_diff.append(acl)
        return acl_diff

    def _compute_acl_differences(self, port_list, acl_old_values_dict,
                                 acl_new_values_dict, acl_obj_dict):
        """Compute the difference between the new and old sets of acls

        @param port_list: Iterator of a List of ports
        @type port_list: []
        @param acl_old_values_dict: Dictionary of old acl values indexed
                                    by port id
        @param acl_new_values_dict: Dictionary of new acl values indexed
                                    by port id
        @param acl_obj_dict: Dictionary of acl objects indexed by the acl
                             value in string format.
        @var acl_del_objs_dict: Dictionary of acl objects to be deleted
                                indexed by the lswitch.
        @var acl_add_values_dict: Dictionary of acl values to be added
                                  indexed by the lswitch.
        @return: (acl_del_objs_dict, acl_add_values_dict)
        @rtype: ({}, {})
        """

        acl_del_objs_dict = {}
        acl_add_values_dict = {}
        for port in port_list:
            lswitch_name = port['network_id']
            acls_old = acl_old_values_dict.get(port['id'], [])
            acls_new = acl_new_values_dict.get(port['id'], [])
            acls_del = self._acl_list_sub(acls_old, acls_new)
            acls_add = self._acl_list_sub(acls_new, acls_old)
            acl_del_objs = acl_del_objs_dict.setdefault(lswitch_name, [])
            for acl in acls_del:
                acl_del_objs.append(acl_obj_dict[str(acl)])
            acl_add_values = acl_add_values_dict.setdefault(lswitch_name, [])
            for acl in acls_add:
                # Remove lport and lswitch columns
                del acl['lswitch']
                del acl['lport']
                acl_add_values.append(acl)
        return acl_del_objs_dict, acl_add_values_dict

    def _get_update_data_without_compare(self):
        lswitch_ovsdb_dict = {}
        for switch_name in self.lswitch_names:
            switch_name = utils.ovn_name(switch_name)
            lswitch = idlutils.row_by_value(self.api.idl, 'Logical_Switch',
                                            'name', switch_name)
            lswitch_ovsdb_dict[switch_name] = lswitch
        if self.is_add_acl:
            acl_add_values_dict = {}
            for port in self.port_list:
                switch_name = utils.ovn_name(port['network_id'])
                if switch_name not in acl_add_values_dict:
                    acl_add_values_dict[switch_name] = []
                if port['id'] in self.acl_new_values_dict:
                    acl_add_values_dict[switch_name].append(
                        self.acl_new_values_dict[port['id']])
            acl_del_objs_dict = {}
        else:
            acl_add_values_dict = {}
            acl_del_objs_dict = {}
            del_acl_matches = []
            for acl_dict in self.acl_new_values_dict.values():
                del_acl_matches.append(acl_dict['match'])
            for switch_name, lswitch in six.iteritems(lswitch_ovsdb_dict):
                if switch_name not in acl_del_objs_dict:
                    acl_del_objs_dict[switch_name] = []
                acls = getattr(lswitch, 'acls', [])
                for acl in acls:
                    if getattr(acl, 'match') in del_acl_matches:
                        acl_del_objs_dict[switch_name].append(acl)
        return lswitch_ovsdb_dict, acl_del_objs_dict, acl_add_values_dict

    def run_idl(self, txn):

        if self.need_compare:
            # Get all relevant ACLs in 1 shot
            acl_values_dict, acl_obj_dict, lswitch_ovsdb_dict = \
                self.api.get_acls_for_lswitches(self.lswitch_names)

            # Compute the difference between the new and old set of ACLs
            acl_del_objs_dict, acl_add_values_dict = \
                self._compute_acl_differences(
                    self.port_list, acl_values_dict,
                    self.acl_new_values_dict, acl_obj_dict)
        else:
            lswitch_ovsdb_dict, acl_del_objs_dict, acl_add_values_dict = \
                self._get_update_data_without_compare()

        for lswitch_name, lswitch in six.iteritems(lswitch_ovsdb_dict):
            acl_del_objs = acl_del_objs_dict.get(lswitch_name, [])
            acl_add_values = acl_add_values_dict.get(lswitch_name, [])

            # Continue if no ACLs to add or delete.
            if not acl_del_objs and not acl_add_values:
                continue

            # Delete old ACLs.
            if acl_del_objs:
                for acl_del_obj in acl_del_objs:
                    acl_del_obj.delete()

            # Add new ACLs.
            acl_add_objs = None
            if acl_add_values:
                acl_add_objs = []
                for acl_value in acl_add_values:
                    row = txn.insert(self.api._tables['ACL'])
                    for col, val in acl_value.items():
                        setattr(row, col, val)
                    acl_add_objs.append(row.uuid)

            # Update logical switch ACLs.
            _updatevalues_in_list(lswitch, 'acls',
                                  new_values=acl_add_objs,
                                  old_values=acl_del_objs)


class AddStaticRouteCommand(commands.BaseCommand):
    def __init__(self, api, lrouter, **columns):
        super(AddStaticRouteCommand, self).__init__(api)
        self.lrouter = lrouter
        self.columns = columns

    def run_idl(self, txn):
        try:
            lrouter = idlutils.row_by_value(self.api.idl, 'Logical_Router',
                                            'name', self.lrouter)
        except idlutils.RowNotFound:
            msg = _("Logical Router %s does not exist") % self.lrouter
            raise RuntimeError(msg)

        row = txn.insert(self.api._tables['Logical_Router_Static_Route'])
        for col, val in self.columns.items():
            setattr(row, col, val)
        _addvalue_to_list(lrouter, 'static_routes', row.uuid)


class DelStaticRouteCommand(commands.BaseCommand):
    def __init__(self, api, lrouter, ip_prefix, nexthop, if_exists):
        super(DelStaticRouteCommand, self).__init__(api)
        self.lrouter = lrouter
        self.ip_prefix = ip_prefix
        self.nexthop = nexthop
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            lrouter = idlutils.row_by_value(self.api.idl, 'Logical_Router',
                                            'name', self.lrouter)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Logical Router %s does not exist") % self.lrouter
            raise RuntimeError(msg)

        static_routes = getattr(lrouter, 'static_routes', [])
        for route in static_routes:
            ip_prefix = getattr(route, 'ip_prefix', '')
            nexthop = getattr(route, 'nexthop', '')
            if self.ip_prefix == ip_prefix and self.nexthop == nexthop:
                _delvalue_from_list(lrouter, 'static_routes', route)
                route.delete()
                break


class AddAddrSetCommand(commands.BaseCommand):
    def __init__(self, api, name, may_exist, **columns):
        super(AddAddrSetCommand, self).__init__(api)
        self.name = name
        self.columns = columns
        self.may_exist = may_exist

    def run_idl(self, txn):
        if self.may_exist:
            addrset = idlutils.row_by_value(self.api.idl, 'Address_Set',
                                            'name', self.name, None)
            if addrset:
                return
        row = txn.insert(self.api._tables['Address_Set'])
        row.name = self.name
        for col, val in self.columns.items():
            setattr(row, col, val)


class DelAddrSetCommand(commands.BaseCommand):
    def __init__(self, api, name, if_exists):
        super(DelAddrSetCommand, self).__init__(api)
        self.name = name
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            addrset = idlutils.row_by_value(self.api.idl, 'Address_Set',
                                            'name', self.name)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Address set %s does not exist. "
                    "Can't delete.") % self.name
            raise RuntimeError(msg)

        self.api._tables['Address_Set'].rows[addrset.uuid].delete()


class UpdateAddrSetCommand(commands.BaseCommand):
    def __init__(self, api, name, addrs_add, addrs_remove, if_exists):
        super(UpdateAddrSetCommand, self).__init__(api)
        self.name = name
        self.addrs_add = addrs_add
        self.addrs_remove = addrs_remove
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            addrset = idlutils.row_by_value(self.api.idl, 'Address_Set',
                                            'name', self.name)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Address set %s does not exist. "
                    "Can't update addresses") % self.name
            raise RuntimeError(msg)

        _updatevalues_in_list(
            addrset, 'addresses',
            new_values=self.addrs_add,
            old_values=self.addrs_remove)


class UpdateAddrSetExtIdsCommand(commands.BaseCommand):
    def __init__(self, api, name, external_ids, if_exists):
        super(UpdateAddrSetExtIdsCommand, self).__init__(api)
        self.name = name
        self.external_ids = external_ids
        self.if_exists = if_exists

    def run_idl(self, txn):
        try:
            addrset = idlutils.row_by_value(self.api.idl, 'Address_Set',
                                            'name', self.name)
        except idlutils.RowNotFound:
            if self.if_exists:
                return
            msg = _("Address set %s does not exist. "
                    "Can't update external IDs") % self.name
            raise RuntimeError(msg)

        addrset.verify('external_ids')
        addrset_external_ids = getattr(addrset, 'external_ids', {})
        for ext_id_key, ext_id_value in six.iteritems(self.external_ids):
            addrset_external_ids[ext_id_key] = ext_id_value
        addrset.external_ids = addrset_external_ids


class AddDHCPOptionsCommand(commands.BaseCommand):
    def __init__(self, api, subnet_id, port_id=None, may_exists=True,
                 **columns):
        super(AddDHCPOptionsCommand, self).__init__(api)
        self.columns = columns
        self.may_exists = may_exists
        self.subnet_id = subnet_id
        self.port_id = port_id

    def _get_dhcp_options_row(self):
        for row in self.api._tables['DHCP_Options'].rows.values():
            external_ids = getattr(row, 'external_ids', {})
            port_id = external_ids.get('port_id')
            if self.subnet_id == external_ids.get('subnet_id'):
                if self.port_id == port_id:
                    return row

    def run_idl(self, txn):
        row = None
        if self.may_exists:
            row = self._get_dhcp_options_row()

        if not row:
            row = txn.insert(self.api._tables['DHCP_Options'])
        for col, val in self.columns.items():
            setattr(row, col, val)


class DelDHCPOptionsCommand(commands.BaseCommand):
    def __init__(self, api, row_uuid, if_exists=True):
        super(DelDHCPOptionsCommand, self).__init__(api)
        self.if_exists = if_exists
        self.row_uuid = row_uuid

    def run_idl(self, txn):
        if self.row_uuid not in self.api._tables['DHCP_Options'].rows:
            if self.if_exists:
                return
            msg = _("DHCP Options row %s does not exist") % self.row_uuid
            raise RuntimeError(msg)

        self.api._tables['DHCP_Options'].rows[self.row_uuid].delete()
