# Copyright (c) 2026 Krzysztof Rudnicki. MIT licence.
"""Catching up on reports the bot was offline for."""

from __future__ import annotations

from typing import TYPE_CHECKING

import pytest

from signal_bot.stats.nightly import (
    CATCHUP_LIMIT,
    LAST_REPORTED_KEY,
    closing_periods,
    days_to_report,
    mark_reported,
)

if TYPE_CHECKING:
    from signal_bot.store import Store

GROUP = "group-a=="


def test_a_group_with_no_marker_gets_only_the_latest_day(store: Store) -> None:
    """A new group, and the first run after this release, must not backlog."""
    assert days_to_report(store, GROUP, "2026-09-01") == ["2026-09-01"]


def test_an_up_to_date_group_owes_nothing(store: Store) -> None:
    mark_reported(store, GROUP, "2026-09-01")
    assert days_to_report(store, GROUP, "2026-09-01") == []


def test_the_day_after_the_marker_is_owed(store: Store) -> None:
    mark_reported(store, GROUP, "2026-08-31")
    assert days_to_report(store, GROUP, "2026-09-01") == ["2026-09-01"]


def test_an_outage_is_caught_up_oldest_first(store: Store) -> None:
    """Four days offline: all four get posted, in the order they happened."""
    mark_reported(store, GROUP, "2026-08-28")
    assert days_to_report(store, GROUP, "2026-09-01") == [
        "2026-08-29",
        "2026-08-30",
        "2026-08-31",
        "2026-09-01",
    ]


def test_catch_up_is_bounded(store: Store) -> None:
    """A month offline must not open with a month of back-posts."""
    mark_reported(store, GROUP, "2026-07-01")
    days = days_to_report(store, GROUP, "2026-09-01")
    assert len(days) == CATCHUP_LIMIT
    # The most recent ones, not the oldest.
    assert days[-1] == "2026-09-01"
    assert days[0] == "2026-08-26"


def test_a_marker_ahead_of_the_latest_day_owes_nothing(store: Store) -> None:
    """Defends the clock going backwards, e.g. an NTP correction."""
    mark_reported(store, GROUP, "2026-09-05")
    assert days_to_report(store, GROUP, "2026-09-01") == []


def test_the_marker_is_per_group(store: Store) -> None:
    mark_reported(store, GROUP, "2026-09-01")
    assert store.meta(GROUP, LAST_REPORTED_KEY) == "2026-09-01"
    assert store.meta("group-b==", LAST_REPORTED_KEY) is None


def test_a_month_boundary_is_crossed_by_the_date(store: Store) -> None:
    mark_reported(store, GROUP, "2026-08-30")
    assert days_to_report(store, GROUP, "2026-09-02") == [
        "2026-08-31",
        "2026-09-01",
        "2026-09-02",
    ]


@pytest.mark.parametrize(
    ("day", "expected"),
    [
        # A Sunday closes a week.
        ("2026-09-06", ["tydzień 36"]),
        # The last day of a month closes it.
        ("2026-09-30", ["wrzesień 2026"]),
        # 31 December closes both the month and the year.
        ("2026-12-31", ["grudzień 2026", "2026"]),
        # A Sunday mid-month closes the week only.
        ("2026-08-30", ["tydzień 35"]),
        # An ordinary Tuesday closes nothing.
        ("2026-09-15", []),
        # 28 February in a leap year is not a month end.
        ("2028-02-28", []),
        ("2028-02-29", ["luty 2028"]),
    ],
)
def test_closing_periods(day: str, expected: list[str]) -> None:
    """Keyed off the day being reported, so a catch-up still gets it right."""
    assert [period.label for period in closing_periods(day)] == expected