from datetime import datetime

from agr_assistent.core.context import (
    MAX_FOLLOW_UP_EXCHANGES,
    FollowUpContext,
    build_messages,
    format_datetime,
)


class FakeClock:
    def __init__(self) -> None:
        self.now = 1000.0

    def __call__(self) -> float:
        return self.now


def test_build_messages_adds_date_context_and_request() -> None:
    context = [{"role": "user", "content": "погода?"}, {"role": "assistant", "content": "солнце"}]

    messages = build_messages("  будь краток  ", context, "а завтра?", datetime(2026, 9, 17, 4, 5))

    assert messages == [
        {"role": "system", "content": "будь краток\n\nСейчас четверг, 17 сентября 2026 года, 04:05."},
        *context,
        {"role": "user", "content": "а завтра?"},
    ]


def test_format_datetime() -> None:
    assert format_datetime(datetime(2026, 3, 1, 23, 59)) == "воскресенье, 1 марта 2026 года, 23:59"


def test_follow_up_is_available_only_within_window() -> None:
    clock = FakeClock()
    context = FollowUpContext(window_seconds=120, clock=clock)

    context.remember("погода?", "солнце")
    clock.now += 119
    assert [m["content"] for m in context.recent()] == ["погода?", "солнце"]

    clock.now += 2
    assert context.recent() == []


def test_follow_up_chain_extends_window_and_keeps_last_exchanges() -> None:
    clock = FakeClock()
    context = FollowUpContext(window_seconds=60, clock=clock)

    for index in range(MAX_FOLLOW_UP_EXCHANGES + 2):
        context.remember(f"вопрос {index}", f"ответ {index}")
        clock.now += 50  # каждый следующий вопрос успевает в окно предыдущего

    requests = [m["content"] for m in context.recent() if m["role"] == "user"]
    assert requests == [f"вопрос {i}" for i in range(2, MAX_FOLLOW_UP_EXCHANGES + 2)]


def test_chain_restarts_after_pause() -> None:
    clock = FakeClock()
    context = FollowUpContext(window_seconds=60, clock=clock)

    context.remember("старый", "ответ")
    clock.now += 61
    context.remember("новый", "ответ")

    assert [m["content"] for m in context.recent()] == ["новый", "ответ"]


def test_zero_window_disables_follow_ups_and_empty_replies_are_ignored() -> None:
    clock = FakeClock()
    assert FollowUpContext(window_seconds=0, clock=clock).recent() == []

    context = FollowUpContext(window_seconds=60, clock=clock)
    context.remember("вопрос", "   ")
    assert context.recent() == []