"""Each metric's normal, by time slot (#5739): the slot arithmetic and the
registry. Learning itself runs in SQL; tests/integration/test_norms.py
covers it against Postgres."""
from __future__ import annotations

from datetime import datetime, timedelta, timezone

from steward.core import norms


def test_a_day_slot_is_the_utc_hour():
    at = datetime(2026, 10, 14, 2, 30, tzinfo=timezone(timedelta(hours=-5)))  # 07:30 UTC
    assert norms.slot_of(at, "day") == 7


def test_a_week_slot_counts_hours_from_monday_utc():
    monday = datetime(2026, 10, 12, 0, 10, tzinfo=timezone.utc)
    assert norms.slot_of(monday, "week") == 0
    assert norms.slot_of(monday + timedelta(days=2, hours=2), "week") == 50   # Wed 02:10
    assert norms.slot_of(monday + timedelta(days=6, hours=23), "week") == 167


def test_a_learned_metric_is_registered_once_with_its_floor():
    norms.learn_normal("test", "x_pct", 2)
    norms.learn_normal("test", "x_pct", 3)
    assert norms.LEARNED[("test", "x_pct")] == norms.Learned("test", "x_pct", 3.0)
    del norms.LEARNED[("test", "x_pct")]