remove_room_from_cals.py

"""
Remove all events associated to a given room from the four calendar files
generated by pretalx:
    schedule.ics
    schedule.json
    schedule.xcal
    schedule.xml
This is mostly useful to remove posters from the calendar files. Just schedule
all posters in a single room and then run this script.
"""
import argparse
import json
import os
from bs4 import BeautifulSoup
import ics


def _process_json_cal(path, room):
    modified = False

    with open(path) as f:
        data = json.load(f)
    for day_dict in data['schedule']['conference']['days']:
        if room in day_dict['rooms']:
            del(day_dict['rooms'][room])
            modified = True

    if not modified:
        return

    with open(path, 'w') as f:
        json.dump(data, f)


def _process_xml_cal(path, room):
    modified = False

    with open(path) as f:
        soup = BeautifulSoup(f, 'xml')
    for day in soup.schedule.find_all('day'):
        valid_elements = []
        for el in day.contents:
            if getattr(el, 'name', None) == 'room' and el['name'] == room:
                if valid_elements:
                    valid_elements.pop()
                continue
            valid_elements.append(el)
        if len(valid_elements) != len(day.contents):
            modified = True
            day.contents = valid_elements

    if not modified:
        return

    with open(path, 'w') as f:
        f.write(soup.prettify())


def _process_xcal(path, room):
    modified = False

    with open(path) as f:
        soup = BeautifulSoup(f, 'xml')

    cal = soup.iCalendar.vcalendar
    valid_elements = []
    for el in cal.contents:
        if getattr(el, 'name', None) == 'vevent' and \
                el.location.string == room:
            if valid_elements:
                valid_elements.pop()
            continue
        valid_elements.append(el)
    if len(valid_elements) != len(cal.contents):
        modified = True
        cal.contents = valid_elements

    if not modified:
        return

    with open(path, 'w') as f:
        f.write(soup.prettify())


def _process_ics(path, room):
    with open(path) as f:
        cal = ics.Calendar(f.read())

    valid_events = set()
    for e in list(cal.events):
        if e.location == room:
            continue
        valid_events.add(e)
    if len(valid_events) == len(cal.events):
        return

    cal.events = valid_events
    with open(path, 'w') as f:
        f.write(str(cal))


PROCESSORS = {
    '.json': _process_json_cal,
    '.xml': _process_xml_cal,
    '.xcal': _process_xcal,
    '.ics': _process_ics,
}


def process(cal_files, room):
    for cal_file in cal_files:
        _, ext = os.path.splitext(cal_file)
        if ext not in PROCESSORS:
            continue
        PROCESSORS[ext](cal_file, room)


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('--room', '-r', type=str, required=True,
                        help='room name')
    parser.add_argument('calendar_files', metavar='FILE', nargs='+',
                        help='calendar files to process')
    args = parser.parse_args()
    process(args.calendar_files, room=args.room)