"""A failed ping or TCP check says why (#5430): no reply, refused, no answer
in time, a name that doesn't resolve, or ping's own complaint; an ICMP check
that fell back to TCP says so."""
import asyncio
import socket

import pytest

from steward.monitors import ping


@pytest.mark.parametrize("exc,want", [
    (asyncio.TimeoutError(), "No answer on port 22 within 5 s"),
    (ConnectionRefusedError(111, "Connection refused"), "Connection refused on port 22"),
    (socket.gaierror(-2, "Name or service not known"), "Can't resolve nas.lan: Name or service not known"),
    (OSError(113, "No route to host"), "Can't connect to port 22: No route to host"),
    (RuntimeError("odd"), "odd"),
])
def test_a_tcp_failure_says_why(monkeypatch, exc, want):
    def boom(*a, **kw):
        raise exc
    monkeypatch.setattr(ping, "_connect_ms", boom)
    got = asyncio.run(ping.tcp_check("nas.lan", 22))
    assert got == {"is_up": False, "response_ms": None, "error_msg": want}


class _Proc:
    def __init__(self, returncode, stderr=b"", stdout=b""):
        self.returncode, self._stderr, self._stdout = returncode, stderr, stdout

    async def communicate(self):
        return self._stdout, self._stderr


@pytest.mark.parametrize("code,stderr,want", [
    (1, b"", "No reply within 2 s"),
    (2, b"ping: nas.lan: Name or service not known\n", "ping: nas.lan: Name or service not known"),
    (2, b"", "ping failed (exit 2)"),
])
def test_a_ping_failure_says_why(monkeypatch, code, stderr, want):
    async def spawn(*a, **kw):
        return _Proc(code, stderr)
    monkeypatch.setattr(ping.asyncio, "create_subprocess_exec", spawn)
    got = asyncio.run(ping.icmp_check("nas.lan"))
    assert got == {"is_up": False, "response_ms": None, "error_msg": want}


def test_a_reply_is_up_with_no_error(monkeypatch):
    async def spawn(*a, **kw):
        return _Proc(0)
    monkeypatch.setattr(ping.asyncio, "create_subprocess_exec", spawn)
    got = asyncio.run(ping.icmp_check("nas.lan"))
    assert got["is_up"] is True and got["error_msg"] is None


def test_a_reply_s_time_is_the_round_trip_ping_reports_not_the_process(monkeypatch):
    out = (b"PING nas.lan (192.168.0.7) 56(84) bytes of data.\n"
           b"64 bytes from 192.168.0.7: icmp_seq=1 ttl=64 time=0.412 ms\n")

    async def spawn(*a, **kw):
        await asyncio.sleep(0.05)                       # a slow process start counts for nothing
        return _Proc(0, stdout=out)
    monkeypatch.setattr(ping.asyncio, "create_subprocess_exec", spawn)
    assert asyncio.run(ping.icmp_check("nas.lan"))["response_ms"] == 0.41


@pytest.mark.parametrize("out,want", [
    (b"64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=12.3 ms", 12.3),
    (b"64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time<1 ms", 1.0),
    (b"64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.05ms", 0.05),
    (b"", None),
])
def test_ping_s_round_trip_is_read_from_its_line(out, want):
    assert ping.ping_rtt(out) == want


def test_a_tcp_connect_is_timed_apart_from_the_event_loop(monkeypatch):
    import threading

    def connect(address, port):
        assert threading.current_thread() is not threading.main_thread()
        return 0.8

    monkeypatch.setattr(ping, "_connect_ms", connect)
    assert asyncio.run(ping.tcp_check("nas.lan", 22)) == {"is_up": True, "response_ms": 0.8, "error_msg": None}


def test_without_ping_the_tcp_stand_in_says_so(monkeypatch):
    async def no_ping(*a, **kw):
        raise FileNotFoundError("ping")

    def refused(*a, **kw):
        raise ConnectionRefusedError(111, "Connection refused")
    monkeypatch.setattr(ping.asyncio, "create_subprocess_exec", no_ping)
    monkeypatch.setattr(ping, "_connect_ms", refused)
    got = asyncio.run(ping.icmp_check("nas.lan"))
    assert got["error_msg"] == "ping unavailable, TCP check instead: Connection refused on port 80"