defaults = {
    'apt': {
        'packages': {
            'isc-dhcp-server': {},
        },
    },
}


@metadata_reactor
def get_static_allocations(metadata):
    allocations = {}
    for rnode in repo.nodes:
        if rnode.metadata.get('location', '') != metadata.get('location', ''):
            continue

        for identifier, interface in rnode.metadata.get('interfaces', {}).items():
            if interface.get('dhcp', False):
                allocations[rnode.name] = {
                    'ipv4': sorted(interface['ips'])[0],
                    'mac': interface['mac'],
                }

    return {
        'dhcpd': {
            'fixed_allocations': allocations,
        }
    }


@metadata_reactor
def get_listen_interfaces(metadata):
    listen_interfaces = []
    for identfier, subnet in node.metadata.get('dhcpd/subnets', {}).items():
        listen_interfaces.append(subnet['interface'])

    return {
        'dhcpd': {
            'listen_interfaces': ' '.join(sorted(listen_interfaces)),
        }
    }


@metadata_reactor
def iptables(metadata):
    iptables = set()
    for identfier, subnet in node.metadata.get('dhcpd/subnets', {}).items():
        iptables.add('iptables -A INPUT -i {} -p udp --dport 67:68 -j ACCEPT'.format(subnet['interface']))

    return {
        'iptables': {
            'bundle_rules': {
                # iptables bundle relies on this being a list.
                'dhcpd': sorted(list(iptables)),
            },
        }
    }