#!/usr/bin/env python
# SPDX-License-Identifier: ISC

#
# Copyright (c) 2022 by
# Donatas Abraitis <donatas@opensourcerouting.org>
#

"""
"""

import os
import sys
import json
import pytest
import functools

CWD = os.path.dirname(os.path.realpath(__file__))
sys.path.append(os.path.join(CWD, "../"))

# pylint: disable=C0413
from lib import topotest
from lib.topogen import Topogen, TopoRouter, get_topogen
from lib.common_config import step

pytestmark = [pytest.mark.bgpd]


def build_topo(tgen):
    for routern in range(1, 7):
        tgen.add_router("r{}".format(routern))

    switch = tgen.add_switch("s1")
    switch.add_link(tgen.gears["r1"])
    switch.add_link(tgen.gears["r2"])

    switch = tgen.add_switch("s2")
    switch.add_link(tgen.gears["r2"])
    switch.add_link(tgen.gears["r3"])

    switch = tgen.add_switch("s3")
    switch.add_link(tgen.gears["r3"])
    switch.add_link(tgen.gears["r4"])


def setup_module(mod):
    tgen = Topogen(build_topo, mod.__name__)
    tgen.start_topology()

    router_list = tgen.routers()

    for i, (rname, router) in enumerate(router_list.items(), 1):
        router.load_config(
            TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
        )
        router.load_config(
            TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
        )

    tgen.start_router()


def teardown_module(mod):
    tgen = get_topogen()
    tgen.stop_topology()


def test_bgp_as_override():
    tgen = get_topogen()

    if tgen.routers_have_failure():
        pytest.skip(tgen.errors)

    r3 = tgen.gears["r3"]
    r4 = tgen.gears["r4"]

    def _bgp_converge():
        output = json.loads(r3.vtysh_cmd("show ip bgp neighbor 192.168.2.1 json"))
        expected = {
            "192.168.2.1": {
                "bgpState": "Established",
                "addressFamilyInfo": {"ipv4Unicast": {"acceptedPrefixCounter": 2}},
            }
        }
        return topotest.json_cmp(output, expected)

    def _bgp_as_override():
        output = json.loads(r4.vtysh_cmd("show bgp ipv4 unicast json"))
        expected = {
            "routes": {
                "172.16.255.1/32": [{"valid": True, "path": "65003 65002 65003"}]
            }
        }
        return topotest.json_cmp(output, expected)

    step("Initial BGP converge")
    test_func = functools.partial(_bgp_converge)
    _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
    assert result is None, "Failed to see BGP convergence on R4"

    step("Check if BGP as-override from R3 works")
    test_func = functools.partial(_bgp_as_override)
    _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
    assert result is None, "Failed to see overriden ASN (65001) from R3"


if __name__ == "__main__":
    args = ["-s"] + sys.argv[1:]
    sys.exit(pytest.main(args))