"""V0: PlaneClock + LatencyHistogram unit tests."""

from __future__ import annotations

import sys

sys.path.insert(0, "/mnt/dolphinng5_predict")

import pytest

from prod.clean_arch.violet.clock import LatencyHistogram, PlaneClock


def test_planeclock_seq_monotonic_and_stamp():
    c = PlaneClock("scan", staleness_budget_ns=10)
    assert c.seq == 0 and c.last_mono_ns == -1
    assert c.tick(now_ns=100) == 1
    assert c.tick(now_ns=200) == 2
    assert c.seq == 2 and c.last_mono_ns == 200


def test_planeclock_age_math_with_injected_now():
    c = PlaneClock("venue", staleness_budget_ns=1_000)
    c.tick(now_ns=5_000)
    assert c.age_ns(now_ns=5_400) == 400
    # clock never goes backwards in age
    assert c.age_ns(now_ns=4_000) == 0


def test_planeclock_staleness_boundary_is_strict():
    """age == budget → NOT stale; age > budget → stale (MHS FIX-9 lesson:
    a threshold equal to the natural refresh period must not flap)."""
    c = PlaneClock("ob", staleness_budget_ns=1_000)
    c.tick(now_ns=0)
    assert c.is_stale(now_ns=1_000) is False     # exactly at budget
    assert c.is_stale(now_ns=1_001) is True      # one ns past


def test_planeclock_never_ticked_is_not_stale():
    c = PlaneClock("account", staleness_budget_ns=1)
    assert c.age_ns(now_ns=10**12) == -1
    assert c.is_stale(now_ns=10**12) is False    # "not yet alive" ≠ "stale"


def test_planeclock_snapshot_shape():
    c = PlaneClock("scan", staleness_budget_ns=500)
    c.tick(now_ns=1)
    s = c.snapshot()
    for key in ("name", "seq", "last_mono_ns", "age_ns", "stale", "budget_ns"):
        assert key in s


def test_histogram_exact_percentiles():
    h = LatencyHistogram("t")
    for v in [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]:
        h.record(v)
    assert h.percentile_ns(0.50) == 5
    assert h.percentile_ns(0.90) == 9
    assert h.percentile_ns(0.99) == 10
    assert h.count == 10


def test_histogram_reservoir_overflow_counts_but_drops():
    h = LatencyHistogram("t", reservoir=5)
    for v in range(10):
        h.record(v)
    assert h.count == 10
    d = h.to_dict()
    assert d["retained"] == 5 and d["overflow_dropped"] == 5


def test_histogram_report_contains_percentiles():
    h = LatencyHistogram("xyz")
    h.record(1_000_000)  # 1 ms
    r = h.report()
    assert "xyz" in r and "p99" in r


if __name__ == "__main__":
    raise SystemExit(pytest.main([__file__, "-v"]))