#! /usr/bin/env python3

# SPDX-License-Identifier: GPL-2.0-or-later
#
# Copyright Red Hat
# Author: David Gibson <david@gibson.dropbear.id.au>

"""
Test A Simple Socket Transport

scenario/simple.py - Smallest sensible network to use passt/pasta
"""

import contextlib

from .. import address, nstool, transfer


class __SimpleNet:  # pylint: disable=R0903
    """A simple network setup scenario

    The sample network has 2 snhs (network namespaces) connected with
    a veth link:
            [simhost]   <-veth->    [gw]

    gw is set up as the default router for simhost.

    simhost has addresses:
        self.IP4 (IPv4), self.IP6 (IPv6), self.ip6_ll (IPv6 link local)

    gw has addresses:
        self.GW_IP4 (IPv4), self.GW_IP6 (IPv6),
            self.gw_ip6_ll (IPv6 link local)
        self.REMOTE_IP4 (IPv4), self.REMOTE_IP6 (IPv6)

    The "remote" addresses are on a different subnet from the others,
    so the only way for simhost to reach them is via its default
    route.  This helps to exercise that we're actually using that,
    rather than just local net routes.

    """

    IFNAME = 'veth'
    ipa_local = address.IpiAllocator()
    (IP4, IP6) = ipa_local.next_ipis()
    (GW_IP4, GW_IP6) = ipa_local.next_ipis()

    ipa_remote = address.IpiAllocator(address.TEST_NET_2,
                                      address.TEST_NET6_TASST_B)
    (REMOTE_IP4, REMOTE_IP6) = ipa_remote.next_ipis()

    def __init__(self, simhost, gw):
        self.simhost = simhost
        self.gw = gw

        ifname = self.IFNAME
        self.gw_ifname = 'gw' + ifname
        self.simhost.veth(self.IFNAME, self.gw_ifname, self.gw)

        self.gw.ifup('lo')
        self.gw.ifup(self.gw_ifname, self.GW_IP4, self.GW_IP6,
                     self.REMOTE_IP4, self.REMOTE_IP6)

        self.simhost.ifup('lo')
        self.simhost.ifup(ifname, self.IP4, self.IP6)

        # Once link is up on both sides, SLAAC will run
        self.gw_ip6_ll = self.gw.addr_wait(self.gw_ifname,
                                           family='inet6', scope='link')[0]
        self.ip6_ll = self.simhost.addr_wait(ifname,
                                             family='inet6', scope='link')[0]

        # Set up the default route
        self.simhost.fg('ip', '-4', 'route', 'add', 'default',
                        'via', f'{self.GW_IP4.ip}', capable=True)
        self.simhost.fg('ip', '-6', 'route', 'add', 'default',
                        'via', f'{self.gw_ip6_ll.ip}', 'dev', f'{ifname}',
                        capable=True)


@contextlib.contextmanager
def simple_net():
    with nstool.unshare_snh('simhost', '-Ucnpf', '--mount-proc') as simhost, \
         nstool.unshare_snh('gw', '-n', parent=simhost, capable=True) as gw:
        yield __SimpleNet(simhost, gw)


@contextlib.contextmanager
def simple_transfer4_setup():
    with simple_net() as snet:
        yield transfer.TransferTestScenario(client=snet.simhost,
                                            server=snet.gw,
                                            connect_ip=snet.REMOTE_IP4.ip,
                                            connect_port=10000)


transfer.transfer_tests(simple_transfer4_setup)


@contextlib.contextmanager
def simple_transfer6_setup():
    with simple_net() as snet:
        yield transfer.TransferTestScenario(client=snet.simhost,
                                            server=snet.gw,
                                            connect_ip=snet.REMOTE_IP6.ip,
                                            connect_port=10000)


transfer.transfer_tests(simple_transfer6_setup)