"""
Generated by ChatGPT 3.5 (https://chatgpt.com/c/103d4f23-7c8f-484f-9598-d38187e933f2)
"""

from datetime import datetime, timedelta

from icalendar import Calendar, Event


def mothering_sunday(year: int) -> datetime:  # pylint: disable=too-many-locals
    """
    Calculate Mothering Sunday (UK) for a particular year

    Args:
        year (int): year to calculate Mothering Sunday

    Returns:
        datetime: datetime object for Mothering Sunday
    """

    # Calculate Easter Sunday
    a = year % 19
    b = year // 100
    c = year % 100
    d = b // 4
    e = b % 4
    f = (b + 8) // 25
    g = (b - f + 1) // 3
    h = (19 * a + b - d - g + 15) % 30
    i = c // 4
    k = c % 4
    l = (32 + 2 * e + 2 * i - h - k) % 7
    m = (a + 11 * h + 22 * l) // 451
    month = (h + l - 7 * m + 114) // 31
    day = ((h + l - 7 * m + 114) % 31) + 1
    easter_sunday = datetime(year, month, day)

    # Calculate Mothering Sunday
    final_day = easter_sunday - timedelta(weeks=3)
    return final_day


def generate_ical() -> None:
    """
    Generate an ICAL file for Mothering Sunday (UK)
    """
    cal = Calendar()
    cal.add("prodid", "-//Mothering Sunday Calendar//wallace.sh//")
    cal.add("version", "2.0")

    for year in range(datetime.now().year, datetime.now().year + 10):
        date = mothering_sunday(year)
        # Ensure Mothering Sunday falls on a Sunday
        if date.weekday() != 6:  # 6 corresponds to Sunday
            date += timedelta(days=6 - date.weekday())
        event = Event()
        event.add("summary", "Mothering Sunday")
        event.add("dtstart", date)
        event.add("dtend", date + timedelta(days=1))
        cal.add_component(event)

    with open("mothering_sunday.ics", "wb") as f:
        f.write(cal.to_ical())


if __name__ == "__main__":
    generate_ical()