[Python] Check if now is any event in iCalendar data

ics.py

"""Utilities for iCalendar (ICS) data."""

from datetime import datetime
from zoneinfo import ZoneInfo

import recurring_ical_events  # type: ignore[reportMissingTypeStubs]
from aws_lambda_powertools import Logger
from icalendar import Calendar

logger = Logger()


def check_if_now_in_event(ics: str, timezone: str = "Asia/Tokyo") -> bool:
    """Check if the current time is within at least one VEVENT in an iCalendar string.

    Args:
        ics (str): iCalendar string.
        timezone (str | None): IANA time-zone. Defaults to "Asia/Tokyo".

    Returns:
        bool: Whether the current time is within any VEVENT in the iCalendar string.
    """
    logger.info("ics: %s", ics)
    if not ics:
        logger.info("No iCalendar data")
        return False
    else:
        now = datetime.now(ZoneInfo(timezone))
        logger.info("now: %s", now)
        try:
            events = recurring_ical_events.of(Calendar.from_ical(ics)).at(now)
        except Exception:
            logger.exception("Error parsing iCalendar data")
            return False
        else:
            logger.info("events: %s", events)
            return len(events) > 0

test_ics.py

"""Unit tests for ics module."""

import pytest
from freezegun import freeze_time

from ics import check_if_now_in_event

_MEETING_ICS = """\
BEGIN:VCALENDAR
BEGIN:VEVENT
UID:[email protected]
DTSTART;TZID=Asia/Tokyo:20250419T090000
DTEND;TZID=Asia/Tokyo:20250419T100000
SUMMARY:Morning meeting
END:VEVENT
END:VCALENDAR
"""

_ALL_DAY_ICS = """\
BEGIN:VCALENDAR
BEGIN:VEVENT
UID:[email protected]
DTSTART;VALUE=DATE:20250419
DTEND;VALUE=DATE:20250420
SUMMARY:Holiday
END:VEVENT
END:VCALENDAR
"""

_EMPTY_ICS = """\
BEGIN:VCALENDAR
END:VCALENDAR
"""

_DURATION_ICS = """\
BEGIN:VCALENDAR
BEGIN:VEVENT
UID:[email protected]
DTSTART;TZID=Asia/Tokyo:20250419T130000
DURATION:PT1H
SUMMARY:Lunch meeting
END:VEVENT
END:VCALENDAR
"""

_NO_END_OR_DURATION_DATE_ICS = """\
BEGIN:VCALENDAR
BEGIN:VEVENT
UID:[email protected]
DTSTART;TZID=DATE:20250419
SUMMARY:Quick check-in
END:VEVENT
END:VCALENDAR
"""

_NO_END_OR_DURATION_DATETIME_ICS = """\
BEGIN:VCALENDAR
BEGIN:VEVENT
UID:[email protected]
DTSTART;TZID=Asia/Tokyo:20250419T150000
SUMMARY:Quick check-in
END:VEVENT
END:VCALENDAR
"""

_NO_SUMMARY_ICS = """\
BEGIN:VCALENDAR
BEGIN:VEVENT
UID:[email protected]
DTSTART;TZID=Asia/Tokyo:20250419T170000
DTEND;TZID=Asia/Tokyo:20250419T180000
END:VEVENT
END:VCALENDAR
"""

_RRULE_UNTIL_ICS = """\
BEGIN:VCALENDAR
BEGIN:VEVENT
DTSTART;TZID=Asia/Tokyo:20250701T090000
DTEND;TZID=Asia/Tokyo:20250701T170000
RRULE:FREQ=DAILY;UNTIL=20250831T170000;BYMONTH=7,8
EXDATE;TZID=Asia/Tokyo:20250814T090000
EXDATE;TZID=Asia/Tokyo:20250815T090000
END:VEVENT
END:VCALENDAR
"""

_RRULE_COUNT_ICS = """\
BEGIN:VCALENDAR
BEGIN:VEVENT
DTSTART;TZID=Asia/Tokyo:20250701T090000
DTEND;TZID=Asia/Tokyo:20250701T170000
RRULE:FREQ=DAILY;COUNT=90
EXDATE;TZID=Asia/Tokyo:20250814T090000
EXDATE;TZID=Asia/Tokyo:20250815T090000
END:VEVENT
END:VCALENDAR
"""


@pytest.mark.parametrize(
    ("ics_str", "now", "expected"),
    [
        ("", "2025-04-19 09:30:00+09:00", False),
        ("invalid-ics", "2025-04-19 09:30:00+09:00", False),
        (_MEETING_ICS, "2025-04-19 09:30:00+09:00", True),
        (_MEETING_ICS, "2025-04-19 08:59:00+09:00", False),
        (_MEETING_ICS, "2025-04-19 10:01:00+09:00", False),
        (_ALL_DAY_ICS, "2025-04-19 12:00:00+09:00", True),
        (_ALL_DAY_ICS, "2025-04-21 00:00:00+09:00", False),
        (_EMPTY_ICS, "2025-04-19 12:00:00+09:00", False),
        (_DURATION_ICS, "2025-04-19 13:30:00+09:00", True),
        (_DURATION_ICS, "2025-04-19 14:01:00+09:00", False),
        (_NO_END_OR_DURATION_DATE_ICS, "2025-04-19 15:00:00+09:00", True),
        (_NO_END_OR_DURATION_DATE_ICS, "2025-04-20 15:00:00+09:00", False),
        (_NO_END_OR_DURATION_DATETIME_ICS, "2025-04-19 15:00:00+09:00", True),
        (_NO_END_OR_DURATION_DATETIME_ICS, "2025-04-19 15:01:00+09:00", False),
        (_NO_SUMMARY_ICS, "2025-04-19 17:30:00+09:00", True),
        (_RRULE_UNTIL_ICS, "2025-07-01 10:00:00+09:00", True),
        (_RRULE_UNTIL_ICS, "2025-07-01 18:00:00+09:00", False),
        (_RRULE_UNTIL_ICS, "2025-08-15 10:00:00+09:00", False),
        (_RRULE_UNTIL_ICS, "2025-08-15 18:00:00+09:00", False),
        (_RRULE_UNTIL_ICS, "2025-08-31 10:00:00+09:00", True),
        (_RRULE_UNTIL_ICS, "2025-08-31 18:00:00+09:00", False),
        (_RRULE_COUNT_ICS, "2025-07-01 10:00:00+09:00", True),
        (_RRULE_COUNT_ICS, "2025-07-01 18:00:00+09:00", False),
        (_RRULE_COUNT_ICS, "2025-08-15 10:00:00+09:00", False),
        (_RRULE_COUNT_ICS, "2025-08-15 18:00:00+09:00", False),
        (_RRULE_COUNT_ICS, "2025-08-31 10:00:00+09:00", True),
        (_RRULE_COUNT_ICS, "2025-08-31 18:00:00+09:00", False),
    ],
)
def test_check_if_now_in_event(ics_str: str, now: str, expected: bool) -> None:
    with freeze_time(now):
        assert check_if_now_in_event(ics_str) is expected