py-seasonal-hours-clock/seasonal_clock/times.py

from datetime import datetime, timedelta
from typing import List, Optional, Tuple

from astral import LocationInfo, SunDirection, sun


def collect_day_parts(
    observer: LocationInfo, date: datetime
) -> List[Tuple[str, datetime, str, str]]:
    """Collect timestamp for all parts of the day on date"""

    day_parts = []

    midnight = sun.midnight(observer, date=date)

    if midnight.date() < date.date():
        midnight = sun.midnight(observer, date=date + timedelta(days=1))
    elif midnight.date() > date.date():
        midnight = sun.midnight(observer, date=date - timedelta(days=1))

    day_parts.append(('midnight', midnight, 'Night', 'Midnight'))

    try:
        morning_blue_start = sun.blue_hour(
            observer, date=date, direction=SunDirection.RISING
        )[0]
    except ValueError:
        # At certain times and latitudes there might be no blue hour
        pass
    else:
        day_parts.append(
            (
                'morning_blue_start',
                morning_blue_start,
                'Morning blue hour',
                'Morning golden hour',
            )
        )

    try:
        golden_start, golden_end = sun.golden_hour(
            observer, date=date, direction=SunDirection.RISING
        )
    except ValueError:
        # At certain times and latitudes there might be no golden hour
        pass
    else:
        day_parts.append(
            (
                'morning_golden_start',
                golden_start,
                'Morning golden hour',
                'Full Daytime',
            )
        )
        day_parts.append(('morning_golden_end', golden_end, 'Morning', 'Noon'))

    day_parts.append(('noon', sun.noon(observer, date=date), 'Afternoon', 'Noon'))

    try:
        evening_golden_start = sun.golden_hour(
            observer, date=date, direction=SunDirection.SETTING
        )[0]
    except ValueError:
        # At certain times and latitudes there might be no golden hour
        pass
    else:
        day_parts.append(
            (
                'evening_golden_start',
                evening_golden_start,
                'Evening golden hour',
                'Evening blue hour',
            )
        )

    try:
        blue_start, blue_end = sun.blue_hour(
            observer, date=date, direction=SunDirection.SETTING
        )
    except ValueError:
        # At certain times and latitudes there might be no blue hour
        pass
    else:
        day_parts.append(
            ('evening_blue_start', blue_start, 'Evening blue hour', 'Night')
        )
        day_parts.append(('evening_blue_end', blue_end, 'Night', 'Midnight'))

    day_parts.sort(key=lambda elem: elem[1])

    return day_parts


def get_rahukaalam_times(
        observer: LocationInfo,
        date: datetime,
        surrounding_days: bool = False
) -> List[Tuple[datetime, datetime]]:
    """Get today’s Răhukăla times"""

    if surrounding_days:
        yesterday = date - timedelta(days=1)
        tomorrow = date + timedelta(days=1)
        dates = [yesterday, date, tomorrow]
    else:
        dates = [date]

    times: List[Tuple[datetime, datetime]] = []

    for day in dates:
        try:
            daytime_rahukaala = sun.rahukaalam(observer, date=day, daytime=True)
        except ValueError:
            pass
        else:
            times.append(daytime_rahukaala)

        try:
            night_rahukaala = sun.rahukaalam(observer, date=day, daytime=False)
        except ValueError:
            pass
        else:
            times.append(night_rahukaala)

    times.sort(key=lambda items: items[0])

    return times


def get_rahukaalam(
    observer: LocationInfo, date: datetime
) -> Tuple[Optional[bool], datetime]:
    """Get the time of the next Rāhukāla or, if we are in the middle of one, the time of its end"""

    times = get_rahukaalam_times(observer, date, surrounding_days=True)

    active: bool = False
    next_time: Optional[datetime] = None

    for start, end in times:
        if date < start:
            active = False
            next_time = start

            break

        if start < date < end:
            active = True
            next_time = end

            break

    if next_time is None:
        return None, None

    return active, next_time