import datetime

from app.types import CampaignSendTimezone

from tests.unit.helpers import build_model


class TestCampaignSendTimezoneSafeUntil:
    def test_returns_none_when_not_in_safe_hours(self) -> None:
        timezone_entry = build_model(
            CampaignSendTimezone, isInSafeHours=False, isAdjusted=True
        )

        assert timezone_entry.safe_until is None

    def test_computes_utc_close_time_respecting_dst(self) -> None:
        timezone_entry = build_model(
            CampaignSendTimezone,
            ianaTzId="America/New_York",
            sendAtLocal="2026-07-08T10:00:00",
            quietHoursMax="20:00:00",
            isInSafeHours=True,
        )

        # America/New_York is UTC-4 (EDT) in July, not the -5 standard offset.
        assert timezone_entry.safe_until == datetime.datetime(
            2026, 7, 9, 0, 0, tzinfo=datetime.UTC
        )

    def test_returns_none_for_unknown_timezone(self) -> None:
        timezone_entry = build_model(
            CampaignSendTimezone, ianaTzId="Not/AZone", isInSafeHours=True
        )

        assert timezone_entry.safe_until is None

    def test_returns_none_for_out_of_range_quiet_hours_max(self) -> None:
        # "24:00:00" is a common end-of-day convention but not a valid `time`.
        timezone_entry = build_model(
            CampaignSendTimezone, quietHoursMax="24:00:00", isInSafeHours=True
        )

        assert timezone_entry.safe_until is None