import asyncio
import struct

from hbd.client import gateway

PROC_V4 = (
    "Iface\tDestination\tGateway \tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU\tWindow\tIRTT\n"
    "wlan0\t00000000\t0100A8C0\t0003\t0\t0\t600\t00000000\t0\t0\t0\n"
    "eth0\t00000000\t0101A8C0\t0003\t0\t0\t100\t00000000\t0\t0\t0\n"
    "wlan0\t0000A8C0\t00000000\t0001\t0\t0\t600\t00FFFFFF\t0\t0\t0\n"
)

PROC_V6 = (
    "00000000000000000000000000000000 00 00000000000000000000000000000000 00 "
    "fe800000000000000000000000000001 00000400 00000001 00000000 00000003 wlan0\n"
    "00000000000000000000000000000000 00 00000000000000000000000000000000 00 "
    "00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo\n"
    "fe800000000000000000000000000000 40 00000000000000000000000000000000 00 "
    "00000000000000000000000000000000 00000100 00000001 00000000 00000001 wlan0\n"
)

MACOS = """   route to: default
destination: default
       mask: default
    gateway: 192.168.1.1
  interface: en0
"""

WIN_V4 = """IPv4 Route Table
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1    192.168.1.50     25
          0.0.0.0          0.0.0.0        10.0.0.1        10.0.0.9     50
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    331
"""

WIN_V6 = """IPv6 Route Table
Active Routes:
 If Metric Network Destination      Gateway
 12    281 ::/0                     fe80::1
  1    331 ::1/128                  On-link
"""


def test_proc_v4_picks_lowest_metric_gateway():
    assert gateway.parse_proc_route_v4(PROC_V4) == "192.168.1.1"  # eth0, metric 100


def test_proc_v4_none_without_default_route():
    assert gateway.parse_proc_route_v4(PROC_V4.splitlines()[0] + "\n") is None


def test_proc_v6_skips_reject_and_non_default():
    assert gateway.parse_proc_route_v6(PROC_V6) == "fe80::1"


def test_macos():
    assert gateway.parse_macos_route(MACOS) == "192.168.1.1"
    assert gateway.parse_macos_route("route: writing to routing socket: not in table") is None


def test_windows_v4_lowest_metric():
    assert gateway.parse_windows_route(WIN_V4, "ipv4") == "192.168.1.1"


def test_windows_v6():
    assert gateway.parse_windows_route(WIN_V6, "ipv6") == "fe80::1"


def test_default_gateway_never_raises_on_parser_error(monkeypatch):
    """default_gateway catches all exceptions; never raises even if parser fails."""
    monkeypatch.setattr("sys.platform", "linux")
    monkeypatch.setattr(gateway, "parse_proc_route_v4", lambda _: (_ for _ in ()).throw(struct.error))
    result = asyncio.run(gateway.default_gateway("ipv4"))
    assert result is None