"""The Hosts list calls out a host whose clock is more than 30 s from
Steward's, and names Steward's own clock when every host disagrees with it
by about the same amount (milestone 490)."""
from functools import partial

from steward.hosts.service import clock_trouble as _trouble

clock_trouble = partial(_trouble, limit=30)   # Settings → Thresholds' default warning


def _a(secs, fresh=True):
    return {"fresh": fresh, "clock_off_secs": secs}


def test_clocks_in_step_say_nothing():
    assert clock_trouble({}) is None
    assert clock_trouble({"a": _a(0.4), "b": _a(29.9), "c": _a(None)}) is None


def test_a_drifting_host_is_named_worst_first():
    out = clock_trouble({"a": _a(0.2), "b": _a(45), "c": _a(600), "d": _a(900, fresh=False)})
    # A host that stopped reporting is not judged on an old reading.
    assert out["hosts"] == [("c", 600), ("b", 45)] and out["steward"] is False


def test_every_host_off_by_the_same_amount_points_at_steward():
    out = clock_trouble({"a": _a(121), "b": _a(119.5), "c": _a(120.2)})
    assert out["steward"] is True and out["typical"] == 120.2
    # One host alone cannot say whose clock is wrong.
    assert clock_trouble({"a": _a(120)})["steward"] is False
    # Off by very different amounts: each host is its own problem.
    assert clock_trouble({"a": _a(40), "b": _a(600)})["steward"] is False
    # One host in step: Steward's clock agrees with it.
    assert clock_trouble({"a": _a(120), "b": _a(121), "c": _a(0.3)})["steward"] is False