"""How far a host's clock is from Steward's (milestone 490): the agent stamps
each post with sent_at, Steward compares it with the moment it arrived, and
the host page says it in words, graded by Settings → Thresholds' clock
drift (30 s warn, 5 min critical by default)."""
from datetime import datetime, timezone

import pytest

from plugins.host_agent import agent as a
from plugins.host_agent.routes import clock_offset, clock_words
from steward.core.settings import to_thresholds_cfg

RECEIVED = datetime(2026, 10, 8, 10, 0, 0, tzinfo=timezone.utc)
TH = to_thresholds_cfg({})


def test_the_agent_stamps_each_post_with_its_own_clock():
    payload = a.build_payload(samples=[{"ts": "2026-10-08T10:00:00+00:00"}], hostname="h", metadata={})
    sent = datetime.fromisoformat(payload["sent_at"])
    assert sent.tzinfo is not None
    assert abs((sent - datetime.now(timezone.utc)).total_seconds()) < 5
    assert a.AGENT_VERSION >= "1.12.0"


@pytest.mark.parametrize("sent_at, offset", [
    ("2026-10-08T10:00:05+00:00", 5.0),          # the host is ahead
    ("2026-10-08T09:57:50Z", -130.0),            # behind, Z suffix
    ("2026-10-08T06:00:00.250-04:00", 0.25),     # another zone, the same moment
])
def test_the_offset_is_the_hosts_clock_against_steward_on_arrival(sent_at, offset):
    assert clock_offset(sent_at, RECEIVED) == offset


@pytest.mark.parametrize("sent_at", [None, "", "yesterday", 1728381600, "2026-10-08T10:00:05"])
def test_no_usable_stamp_is_no_offset(sent_at):
    # An agent before 1.12.0 sends none; a naive time says nothing about a zone.
    assert clock_offset(sent_at, RECEIVED) is None


@pytest.mark.parametrize("offset, words, tone", [
    (None, "", "unknown"),
    (0.3, "clock in step", "ok"),
    (-0.9, "clock in step", "ok"),
    (12.4, "clock 12s ahead", "ok"),
    (29.9, "clock 29s ahead", "ok"),
    (-130, "clock 2m 10s behind", "warn"),
    (31, "clock 31s ahead", "warn"),
    (-3600, "clock 1h behind", "crit"),
])
def test_the_host_page_says_it_in_words(offset, words, tone):
    assert clock_words(offset, TH) == (words, tone)


def test_the_cutoff_is_the_operators():
    th = to_thresholds_cfg({"thresholds.clock_warn_s": 5, "thresholds.clock_crit_s": 60})
    assert clock_words(12.4, th) == ("clock 12s ahead", "warn")
    assert clock_words(-90, th)[1] == "crit"