import datetime

import icalendar

from ..data import HIDDEN_LABEL_PREFIX, RealizedWorkSample

ZERO_DURATION = datetime.timedelta(seconds=0)
HOUR = datetime.timedelta(hours=1)
MINUTE = datetime.timedelta(minutes=1)


def create_title(sample: RealizedWorkSample) -> tuple[str,str]:
    ls = []
    desc = []
    for label_and_type in sample.labels:
        if label_and_type.startswith(HIDDEN_LABEL_PREFIX):
            continue
        if label_and_type.startswith('author:'):
            continue
        if len(ls) == 0:
            ls.append(label_and_type.split(':')[1])
        else:
            desc.append(label_and_type)
    return ' '.join(ls), '\n'.join(desc)


def generate_calendar(
    samples: list[RealizedWorkSample],
) -> icalendar.Calendar:
    max_title_parts = 2

    cal = icalendar.Calendar()
    cal.add('prodid', '-//personal_data_calendar//example.org//')
    cal.add('version', '2.0')

    for sample in samples:
        title, description = create_title(sample)

        # Create event
        event = icalendar.Event()

        event.add('summary', title)
        event.add('description', description)
        event.add('dtstart', sample.start_at)
        event.add('dtend', sample.end_at)

        for label_and_type in sample.labels:
            if label_and_type.startswith('author:'):
                event.add(
                    'organizer', 'mailto:' + label_and_type.removeprefix('author:'),
                )

        cal.add_component(event)
        del event

    return cal


def generate_icalendar_file(
    samples: list[RealizedWorkSample],
    file: str,
) -> None:
    calendar = generate_calendar(samples)

    with open(file, 'wb') as f:
        f.write(calendar.to_ical())