epicyon/happening.py

__filename__ = "happening.py"
__author__ = "Bob Mottram"
__license__ = "AGPL3+"
__version__ = "1.3.0"
__maintainer__ = "Bob Mottram"
__email__ = "bob@libreserver.org"
__status__ = "Production"
__module_group__ = "Core"

import os
from uuid import UUID
from datetime import datetime
from datetime import timedelta

from utils import is_public_post
from utils import load_json
from utils import save_json
from utils import locate_post
from utils import has_object_dict
from utils import acct_dir
from utils import remove_html
from utils import get_display_name
from utils import delete_post
from utils import get_status_number
from filters import is_filtered
from context import get_individual_post_context


def _valid_uuid(test_uuid: str, version: int):
    """Check if uuid_to_test is a valid UUID
    """
    try:
        uuid_obj = UUID(test_uuid, version=version)
    except ValueError:
        return False

    return str(uuid_obj) == test_uuid


def _remove_event_from_timeline(event_id: str,
                                tl_events_filename: str) -> None:
    """Removes the given event Id from the timeline
    """
    if event_id + '\n' not in open(tl_events_filename).read():
        return
    with open(tl_events_filename, 'r') as fp_tl:
        events_timeline = fp_tl.read().replace(event_id + '\n', '')
        try:
            with open(tl_events_filename, 'w+') as fp2:
                fp2.write(events_timeline)
        except OSError:
            print('EX: ERROR: unable to save events timeline')


def save_event_post(base_dir: str, handle: str, post_id: str,
                    event_json: {}) -> bool:
    """Saves an event to the calendar and/or the events timeline
    If an event has extra fields, as per Mobilizon,
    Then it is saved as a separate entity and added to the
    events timeline
    See https://framagit.org/framasoft/mobilizon/-/blob/
    master/lib/federation/activity_stream/converter/event.ex
    """
    if not os.path.isdir(base_dir + '/accounts/' + handle):
        print('WARN: Account does not exist at ' +
              base_dir + '/accounts/' + handle)
    calendar_path = base_dir + '/accounts/' + handle + '/calendar'
    if not os.path.isdir(calendar_path):
        os.mkdir(calendar_path)

    # get the year, month and day from the event
    event_time = datetime.strptime(event_json['startTime'],
                                   "%Y-%m-%dT%H:%M:%S%z")
    event_year = int(event_time.strftime("%Y"))
    if event_year < 2020 or event_year >= 2100:
        return False
    event_month_number = int(event_time.strftime("%m"))
    if event_month_number < 1 or event_month_number > 12:
        return False
    event_day_of_month = int(event_time.strftime("%d"))
    if event_day_of_month < 1 or event_day_of_month > 31:
        return False

    if event_json.get('name') and event_json.get('actor') and \
       event_json.get('uuid') and event_json.get('content'):
        if not _valid_uuid(event_json['uuid'], 4):
            return False
        print('Mobilizon type event')
        # if this is a full description of an event then save it
        # as a separate json file
        events_path = base_dir + '/accounts/' + handle + '/events'
        if not os.path.isdir(events_path):
            os.mkdir(events_path)
        events_year_path = \
            base_dir + '/accounts/' + handle + '/events/' + str(event_year)
        if not os.path.isdir(events_year_path):
            os.mkdir(events_year_path)
        event_id = str(event_year) + '-' + event_time.strftime("%m") + '-' + \
            event_time.strftime("%d") + '_' + event_json['uuid']
        event_filename = events_year_path + '/' + event_id + '.json'

        save_json(event_json, event_filename)
        # save to the events timeline
        tl_events_filename = base_dir + '/accounts/' + handle + '/events.txt'

        if os.path.isfile(tl_events_filename):
            _remove_event_from_timeline(event_id, tl_events_filename)
            try:
                with open(tl_events_filename, 'r+') as tl_events_file:
                    content = tl_events_file.read()
                    if event_id + '\n' not in content:
                        tl_events_file.seek(0, 0)
                        tl_events_file.write(event_id + '\n' + content)
            except OSError as ex:
                print('EX: Failed to write entry to events file ' +
                      tl_events_filename + ' ' + str(ex))
                return False
        else:
            try:
                with open(tl_events_filename, 'w+') as tl_events_file:
                    tl_events_file.write(event_id + '\n')
            except OSError:
                print('EX: unable to write ' + tl_events_filename)

    # create a directory for the calendar year
    if not os.path.isdir(calendar_path + '/' + str(event_year)):
        os.mkdir(calendar_path + '/' + str(event_year))

    # calendar month file containing event post Ids
    calendar_filename = calendar_path + '/' + str(event_year) + \
        '/' + str(event_month_number) + '.txt'

    # Does this event post already exist within the calendar month?
    if os.path.isfile(calendar_filename):
        if post_id in open(calendar_filename).read():
            # Event post already exists
            return False

    # append the post Id to the file for the calendar month
    try:
        with open(calendar_filename, 'a+') as calendar_file:
            calendar_file.write(post_id + '\n')
    except OSError:
        print('EX: unable to append ' + calendar_filename)

    # create a file which will trigger a notification that
    # a new event has been added
    cal_notify_filename = base_dir + '/accounts/' + handle + '/.newCalendar'
    notify_str = \
        '/calendar?year=' + str(event_year) + '?month=' + \
        str(event_month_number) + '?day=' + str(event_day_of_month)
    try:
        with open(cal_notify_filename, 'w+') as cal_file:
            cal_file.write(notify_str)
    except OSError:
        print('EX: unable to write ' + cal_notify_filename)
        return False
    return True


def _is_happening_event(tag: {}) -> bool:
    """Is this tag an Event or Place ActivityStreams type?
    """
    if not tag.get('type'):
        return False
    if tag['type'] != 'Event' and tag['type'] != 'Place':
        return False
    return True


def _is_happening_post(post_json_object: {}) -> bool:
    """Is this a post with tags?
    """
    if not post_json_object:
        return False
    if not has_object_dict(post_json_object):
        return False
    if not post_json_object['object'].get('tag'):
        return False
    return True


def get_todays_events(base_dir: str, nickname: str, domain: str,
                      curr_year: int, curr_month_number: int,
                      curr_day_of_month: int) -> {}:
    """Retrieves calendar events for today
    Returns a dictionary of lists containing Event and Place activities
    """
    now = datetime.now()
    if not curr_year:
        year = now.year
    else:
        year = curr_year
    if not curr_month_number:
        month_number = now.month
    else:
        month_number = curr_month_number
    if not curr_day_of_month:
        day_number = now.day
    else:
        day_number = curr_day_of_month

    calendar_filename = \
        acct_dir(base_dir, nickname, domain) + \
        '/calendar/' + str(year) + '/' + str(month_number) + '.txt'
    events = {}
    if not os.path.isfile(calendar_filename):
        return events

    calendar_post_ids = []
    recreate_events_file = False
    with open(calendar_filename, 'r') as events_file:
        for post_id in events_file:
            post_id = post_id.replace('\n', '').replace('\r', '')
            post_filename = locate_post(base_dir, nickname, domain, post_id)
            if not post_filename:
                recreate_events_file = True
                continue

            post_json_object = load_json(post_filename)
            if not _is_happening_post(post_json_object):
                continue

            public_event = is_public_post(post_json_object)

            post_event = []
            day_of_month = None
            for tag in post_json_object['object']['tag']:
                if not _is_happening_event(tag):
                    continue
                # this tag is an event or a place
                if tag['type'] == 'Event':
                    # tag is an event
                    if not tag.get('startTime'):
                        continue
                    event_time = \
                        datetime.strptime(tag['startTime'],
                                          "%Y-%m-%dT%H:%M:%S%z")
                    if int(event_time.strftime("%Y")) == year and \
                       int(event_time.strftime("%m")) == month_number and \
                       int(event_time.strftime("%d")) == day_number:
                        day_of_month = str(int(event_time.strftime("%d")))
                        if '#statuses#' in post_id:
                            # link to the id so that the event can be
                            # easily deleted
                            tag['post_id'] = post_id.split('#statuses#')[1]
                            tag['id'] = post_id.replace('#', '/')
                            tag['sender'] = post_id.split('#statuses#')[0]
                            tag['sender'] = tag['sender'].replace('#', '/')
                            tag['public'] = public_event
                        post_event.append(tag)
                else:
                    # tag is a place
                    post_event.append(tag)
            if post_event and day_of_month:
                calendar_post_ids.append(post_id)
                if not events.get(day_of_month):
                    events[day_of_month] = []
                events[day_of_month].append(post_event)

    # if some posts have been deleted then regenerate the calendar file
    if recreate_events_file:
        try:
            with open(calendar_filename, 'w+') as calendar_file:
                for post_id in calendar_post_ids:
                    calendar_file.write(post_id + '\n')
        except OSError:
            print('EX: unable to write ' + calendar_filename)

    return events


def _ical_date_string(date_str: str) -> str:
    """Returns an icalendar formatted date
    """
    date_str = date_str.replace('-', '')
    date_str = date_str.replace(':', '')
    return date_str.replace(' ', '')


def _dav_encode_token(year: int, month_number: int,
                      message_id: str) -> str:
    """Returns a token corresponding to a calendar event
    """
    return str(year) + '_' + str(month_number) + '_' + \
        message_id.replace('/', '--').replace('#', '--')


def _icalendar_day(base_dir: str, nickname: str, domain: str,
                   day_events: [], person_cache: {},
                   http_prefix: str) -> str:
    """Returns a day's events in icalendar format
    """
    ical_str = ''
    print('icalendar: ' + str(day_events))
    for event_post in day_events:
        event_description = None
        event_place = None
        post_id = None
        sender_name = ''
        sender_actor = None
        event_is_public = False
        event_start = None
        event_end = None

        for evnt in event_post:
            if evnt['type'] == 'Event':
                if evnt.get('id'):
                    post_id = evnt['id']
                if evnt.get('startTime'):
                    event_start = \
                        datetime.strptime(evnt['startTime'],
                                          "%Y-%m-%dT%H:%M:%S%z")
                if evnt.get('endTime'):
                    event_end = \
                        datetime.strptime(evnt['startTime'],
                                          "%Y-%m-%dT%H:%M:%S%z")
                if 'public' in evnt:
                    if evnt['public'] is True:
                        event_is_public = True
                if evnt.get('sender'):
                    # get display name from sending actor
                    if evnt.get('sender'):
                        sender_actor = evnt['sender']
                        disp_name = \
                            get_display_name(base_dir, sender_actor,
                                             person_cache)
                        if disp_name:
                            sender_name = \
                                '<a href="' + sender_actor + '">' + \
                                disp_name + '</a>'
                if evnt.get('name'):
                    event_description = evnt['name'].strip()
            elif evnt['type'] == 'Place':
                if evnt.get('name'):
                    event_place = evnt['name']

        print('icalendar: ' + str(post_id) + ' ' +
              str(event_start) + ' ' + str(event_description) + ' ' +
              str(sender_actor))

        if not post_id or not event_start or not event_end or \
           not event_description or not sender_actor:
            continue

        # find the corresponding post
        post_filename = locate_post(base_dir, nickname, domain, post_id)
        if not post_filename:
            continue

        post_json_object = load_json(post_filename)
        if not post_json_object:
            continue

        # get the published date from the post
        if not post_json_object.get('object'):
            continue
        if not isinstance(post_json_object['object'], dict):
            continue
        if not post_json_object['object'].get('published'):
            continue
        if not isinstance(post_json_object['object']['published'], str):
            continue
        published = \
            _ical_date_string(post_json_object['object']['published'])

        event_start = \
            _ical_date_string(event_start.strftime("%Y-%m-%dT%H:%M:%SZ"))
        event_end = \
            _ical_date_string(event_end.strftime("%Y-%m-%dT%H:%M:%SZ"))

        token_year = int(event_start.split('-')[0])
        token_month_number = int(event_start.split('-')[1])
        uid = _dav_encode_token(token_year, token_month_number, post_id)

        ical_str += \
            'BEGIN:VEVENT\n' + \
            'DTSTAMP:' + published + '\n' + \
            'UID:' + uid + '\n' + \
            'DTSTART:' + event_start + '\n' + \
            'DTEND:' + event_end + '\n' + \
            'STATUS:CONFIRMED\n'
        descr = remove_html(event_description)
        if len(descr) < 255:
            ical_str += \
                'SUMMARY:' + descr + '\n'
        else:
            ical_str += \
                'SUMMARY:' + descr[255:] + '\n'
            ical_str += \
                'DESCRIPTION:' + descr + '\n'
        if event_is_public:
            ical_str += \
                'CATEGORIES:APPOINTMENT,PUBLIC\n'
        else:
            ical_str += \
                'CATEGORIES:APPOINTMENT\n'
        if sender_name:
            ical_str += \
                'ORGANIZER;CN=' + remove_html(sender_name) + ':' + \
                sender_actor + '\n'
        else:
            ical_str += \
                'ORGANIZER:' + sender_actor + '\n'
        if event_place:
            ical_str += \
                'LOCATION:' + remove_html(event_place) + '\n'
        ical_str += 'END:VEVENT\n'
    return ical_str


def get_todays_events_icalendar(base_dir: str, nickname: str, domain: str,
                                year: int, month_number: int,
                                day_number: int, person_cache: {},
                                http_prefix: str) -> str:
    """Returns today's events in icalendar format
    """
    day_events = None
    events = \
        get_todays_events(base_dir, nickname, domain,
                          year, month_number, day_number)
    if events:
        if events.get(str(day_number)):
            day_events = events[str(day_number)]

    ical_str = \
        'BEGIN:VCALENDAR\n' + \
        'PRODID:-//Fediverse//NONSGML Epicyon//EN\n' + \
        'VERSION:2.0\n'
    if not day_events:
        print('icalendar daily: ' + nickname + '@' + domain + ' ' +
              str(year) + '-' + str(month_number) +
              '-' + str(day_number) + ' ' + str(day_events))
        ical_str += 'END:VCALENDAR\n'
        return ical_str

    ical_str += \
        _icalendar_day(base_dir, nickname, domain, day_events, person_cache,
                       http_prefix)

    ical_str += 'END:VCALENDAR\n'
    return ical_str


def get_month_events_icalendar(base_dir: str, nickname: str, domain: str,
                               year: int,
                               month_number: int,
                               person_cache: {},
                               http_prefix: str) -> str:
    """Returns today's events in icalendar format
    """
    month_events = \
        get_calendar_events(base_dir, nickname, domain, year,
                            month_number)

    ical_str = \
        'BEGIN:VCALENDAR\n' + \
        'PRODID:-//Fediverse//NONSGML Epicyon//EN\n' + \
        'VERSION:2.0\n'
    if not month_events:
        ical_str += 'END:VCALENDAR\n'
        return ical_str

    print('icalendar month: ' + str(month_events))
    for day_of_month in range(1, 32):
        if not month_events.get(str(day_of_month)):
            continue
        day_events = month_events[str(day_of_month)]
        ical_str += \
            _icalendar_day(base_dir, nickname, domain,
                           day_events, person_cache,
                           http_prefix)

    ical_str += 'END:VCALENDAR\n'
    return ical_str


def day_events_check(base_dir: str, nickname: str, domain: str,
                     curr_date) -> bool:
    """Are there calendar events for the given date?
    """
    year = curr_date.year
    month_number = curr_date.month
    day_number = curr_date.day

    calendar_filename = \
        acct_dir(base_dir, nickname, domain) + \
        '/calendar/' + str(year) + '/' + str(month_number) + '.txt'
    if not os.path.isfile(calendar_filename):
        return False

    events_exist = False
    with open(calendar_filename, 'r') as events_file:
        for post_id in events_file:
            post_id = post_id.replace('\n', '').replace('\r', '')
            post_filename = locate_post(base_dir, nickname, domain, post_id)
            if not post_filename:
                continue

            post_json_object = load_json(post_filename)
            if not _is_happening_post(post_json_object):
                continue

            for tag in post_json_object['object']['tag']:
                if not _is_happening_event(tag):
                    continue
                # this tag is an event or a place
                if tag['type'] != 'Event':
                    continue
                # tag is an event
                if not tag.get('startTime'):
                    continue
                event_time = \
                    datetime.strptime(tag['startTime'],
                                      "%Y-%m-%dT%H:%M:%S%z")
                if int(event_time.strftime("%d")) != day_number:
                    continue
                if int(event_time.strftime("%m")) != month_number:
                    continue
                if int(event_time.strftime("%Y")) != year:
                    continue
                events_exist = True
                break

    return events_exist


def get_this_weeks_events(base_dir: str, nickname: str, domain: str) -> {}:
    """Retrieves calendar events for this week
    Returns a dictionary indexed by day number of lists containing
    Event and Place activities
    Note: currently not used but could be with a weekly calendar screen
    """
    now = datetime.now()
    end_of_week = now + timedelta(7)
    year = now.year
    month_number = now.month

    calendar_filename = \
        acct_dir(base_dir, nickname, domain) + \
        '/calendar/' + str(year) + '/' + str(month_number) + '.txt'

    events = {}
    if not os.path.isfile(calendar_filename):
        return events

    calendar_post_ids = []
    recreate_events_file = False
    with open(calendar_filename, 'r') as events_file:
        for post_id in events_file:
            post_id = post_id.replace('\n', '').replace('\r', '')
            post_filename = locate_post(base_dir, nickname, domain, post_id)
            if not post_filename:
                recreate_events_file = True
                continue

            post_json_object = load_json(post_filename)
            if not _is_happening_post(post_json_object):
                continue

            post_event = []
            week_day_index = None
            for tag in post_json_object['object']['tag']:
                if not _is_happening_event(tag):
                    continue
                # this tag is an event or a place
                if tag['type'] == 'Event':
                    # tag is an event
                    if not tag.get('startTime'):
                        continue
                    event_time = \
                        datetime.strptime(tag['startTime'],
                                          "%Y-%m-%dT%H:%M:%S%z")
                    if event_time >= now and event_time <= end_of_week:
                        week_day_index = (event_time - now).days()
                        post_event.append(tag)
                else:
                    # tag is a place
                    post_event.append(tag)
            if post_event and week_day_index:
                calendar_post_ids.append(post_id)
                if not events.get(week_day_index):
                    events[week_day_index] = []
                events[week_day_index].append(post_event)

    # if some posts have been deleted then regenerate the calendar file
    if recreate_events_file:
        try:
            with open(calendar_filename, 'w+') as calendar_file:
                for post_id in calendar_post_ids:
                    calendar_file.write(post_id + '\n')
        except OSError:
            print('EX: unable to write ' + calendar_filename)

    return events


def get_calendar_events(base_dir: str, nickname: str, domain: str,
                        year: int, month_number: int) -> {}:
    """Retrieves calendar events
    Returns a dictionary indexed by day number of lists containing
    Event and Place activities
    """
    calendar_filename = \
        acct_dir(base_dir, nickname, domain) + \
        '/calendar/' + str(year) + '/' + str(month_number) + '.txt'

    events = {}
    if not os.path.isfile(calendar_filename):
        return events

    calendar_post_ids = []
    recreate_events_file = False
    with open(calendar_filename, 'r') as events_file:
        for post_id in events_file:
            post_id = post_id.replace('\n', '').replace('\r', '')
            post_filename = locate_post(base_dir, nickname, domain, post_id)
            if not post_filename:
                recreate_events_file = True
                continue

            post_json_object = load_json(post_filename)
            if not _is_happening_post(post_json_object):
                continue

            post_event = []
            day_of_month = None
            for tag in post_json_object['object']['tag']:
                if not _is_happening_event(tag):
                    continue
                # this tag is an event or a place
                if tag['type'] == 'Event':
                    # tag is an event
                    if not tag.get('startTime'):
                        continue
                    event_time = \
                        datetime.strptime(tag['startTime'],
                                          "%Y-%m-%dT%H:%M:%S%z")
                    if int(event_time.strftime("%Y")) == year and \
                       int(event_time.strftime("%m")) == month_number:
                        day_of_month = str(int(event_time.strftime("%d")))
                        if '#statuses#' in post_id:
                            tag['post_id'] = post_id.split('#statuses#')[1]
                            tag['id'] = post_id.replace('#', '/')
                            tag['sender'] = post_id.split('#statuses#')[0]
                            tag['sender'] = tag['sender'].replace('#', '/')
                        post_event.append(tag)
                else:
                    # tag is a place
                    post_event.append(tag)

            if post_event and day_of_month:
                calendar_post_ids.append(post_id)
                if not events.get(day_of_month):
                    events[day_of_month] = []
                events[day_of_month].append(post_event)

    # if some posts have been deleted then regenerate the calendar file
    if recreate_events_file:
        try:
            with open(calendar_filename, 'w+') as calendar_file:
                for post_id in calendar_post_ids:
                    calendar_file.write(post_id + '\n')
        except OSError:
            print('EX: unable to write ' + calendar_filename)

    return events


def remove_calendar_event(base_dir: str, nickname: str, domain: str,
                          year: int, month_number: int,
                          message_id: str) -> None:
    """Removes a calendar event
    """
    calendar_filename = \
        acct_dir(base_dir, nickname, domain) + \
        '/calendar/' + str(year) + '/' + str(month_number) + '.txt'
    if not os.path.isfile(calendar_filename):
        return
    if '/' in message_id:
        message_id = message_id.replace('/', '#')
    if message_id not in open(calendar_filename).read():
        return
    lines = None
    with open(calendar_filename, 'r') as fp_cal:
        lines = fp_cal.readlines()
    if not lines:
        return
    try:
        with open(calendar_filename, 'w+') as fp_cal:
            for line in lines:
                if message_id not in line:
                    fp_cal.write(line)
    except OSError:
        print('EX: unable to write ' + calendar_filename)


def _dav_decode_token(token: str) -> (int, int, str):
    """Decodes a token corresponding to a calendar event
    """
    if '_' not in token or '--' not in token:
        return None, None, None
    token_sections = token.split('_')
    if len(token_sections) != 3:
        return None, None, None
    if not token_sections[0].isdigit():
        return None, None, None
    if not token_sections[1].isdigit():
        return None, None, None
    token_year = int(token_sections[0])
    token_month_number = int(token_sections[1])
    token_post_id = token_sections[2].replace('--', '/')
    return token_year, token_month_number, token_post_id


def dav_propfind_response(base_dir: str, nickname: str, domain: str,
                          depth: int, xml_str: str) -> str:
    """Returns the response to caldav PROPFIND
    """
    if '<d:propfind' not in xml_str or \
       '</d:propfind>' not in xml_str:
        return None
    response_str = \
        '<d:multistatus xmlns:d="DAV:" ' + \
        'xmlns:cs="http://calendarserver.org/ns/">\n' + \
        '    <d:response>\n' + \
        '        <d:href>/calendars/' + nickname + '/</d:href>\n' + \
        '        <d:propstat>\n' + \
        '            <d:prop>\n' + \
        '                <d:displayname />\n' + \
        '                <cs:getctag />\n' + \
        '            </d:prop>\n' + \
        '            <d:status>HTTP/1.1 200 OK</d:status>\n' + \
        '        </d:propstat>\n' + \
        '    </d:response>\n' + \
        '</d:multistatus>'
    return response_str


def _dav_store_event(base_dir: str, nickname: str, domain: str,
                     event_list: [], http_prefix: str,
                     system_language: str) -> bool:
    """Stores a calendar event obtained via caldav PUT
    """
    event_str = str(event_list)
    if 'DTSTAMP:' not in event_str or \
       'DTSTART:' not in event_str or \
       'DTEND:' not in event_str:
        return False
    if 'STATUS:' not in event_str and 'DESCRIPTION:' not in event_str:
        return False

    timestamp = None
    start_time = None
    end_time = None
    description = None
    for line in event_list:
        if line.startswith('DTSTAMP:'):
            timestamp = line.split(':', 1)[1]
        elif line.startswith('DTSTART:'):
            start_time = line.split(':', 1)[1]
        elif line.startswith('DTEND:'):
            end_time = line.split(':', 1)[1]
        elif line.startswith('SUMMARY:') or line.startswith('DESCRIPTION:'):
            description = line.split(':', 1)[1]
        elif line.startswith('LOCATION:'):
            location = line.split(':', 1)[1]

    if not timestamp or \
       not start_time or \
       not end_time or \
       not description:
        return False
    if len(timestamp) < 15:
        return False
    if len(start_time) < 15:
        return False
    if len(end_time) < 15:
        return False

    # check that the description is valid
    if is_filtered(base_dir, nickname, domain, description):
        return False

    # convert to the expected time format
    timestamp_year = timestamp[:4]
    timestamp_month = timestamp[4:][:2]
    timestamp_day = timestamp[6:][:2]
    timestamp_hour = timestamp[9:][:2]
    timestamp_min = timestamp[11:][:2]
    timestamp_sec = timestamp[13:][:2]

    if not timestamp_year.isdigit() or \
       not timestamp_month.isdigit() or \
       not timestamp_day.isdigit() or \
       not timestamp_hour.isdigit() or \
       not timestamp_min.isdigit() or \
       not timestamp_sec.isdigit():
        return False
    if int(timestamp_year) < 2020 or int(timestamp_year) > 2100:
        return False
    published = \
        timestamp_year + '-' + timestamp_month + '-' + timestamp_day + 'T' + \
        timestamp_hour + ':' + timestamp_min + ':' + timestamp_sec + 'Z'

    start_time_year = start_time[:4]
    start_time_month = start_time[4:][:2]
    start_time_day = start_time[6:][:2]
    start_time_hour = start_time[9:][:2]
    start_time_min = start_time[11:][:2]
    start_time_sec = start_time[13:][:2]

    if not start_time_year.isdigit() or \
       not start_time_month.isdigit() or \
       not start_time_day.isdigit() or \
       not start_time_hour.isdigit() or \
       not start_time_min.isdigit() or \
       not start_time_sec.isdigit():
        return False
    if int(start_time_year) < 2020 or int(start_time_year) > 2100:
        return False
    start_time = \
        start_time_year + '-' + start_time_month + '-' + \
        start_time_day + 'T' + \
        start_time_hour + ':' + start_time_min + ':' + start_time_sec + 'Z'

    end_time_year = end_time[:4]
    end_time_month = end_time[4:][:2]
    end_time_day = end_time[6:][:2]
    end_time_hour = end_time[9:][:2]
    end_time_min = end_time[11:][:2]
    end_time_sec = end_time[13:][:2]

    if not end_time_year.isdigit() or \
       not end_time_month.isdigit() or \
       not end_time_day.isdigit() or \
       not end_time_hour.isdigit() or \
       not end_time_min.isdigit() or \
       not end_time_sec.isdigit():
        return False
    if int(end_time_year) < 2020 or int(end_time_year) > 2100:
        return False
    end_time = \
        end_time_year + '-' + end_time_month + '-' + end_time_day + 'T' + \
        end_time_hour + ':' + end_time_min + ':' + end_time_sec + 'Z'

    post_id = ''
    post_context = get_individual_post_context()
    # create the status number from DTSTAMP
    status_number, published = get_status_number(published)
    # get the post id
    actor = http_prefix + "://" + domain + "/users/" + nickname
    actor2 = http_prefix + "://" + domain + "/@" + nickname
    post_id = actor + "/statuses/" + status_number

    next_str = post_id + "/replies?only_other_accounts=true&page=true"
    content = \
        '<p><span class=\"h-card\"><a href=\"' + actor2 + \
        '\" class=\"u-url mention\">@<span>' + nickname + \
        '</span></a></span>' + remove_html(description) + '</p>'
    event_json = {
        "@context": post_context,
        "id": post_id + "/activity",
        "type": "Create",
        "actor": actor,
        "published": published,
        "to": [actor],
        "cc": [],
        "object": {
            "id": post_id,
            "conversation": post_id,
            "type": "Note",
            "summary": None,
            "inReplyTo": None,
            "published": published,
            "url": actor + "/" + status_number,
            "attributedTo": actor,
            "to": [actor],
            "cc": [],
            "sensitive": False,
            "atomUri": post_id,
            "inReplyToAtomUri": None,
            "commentsEnabled": False,
            "rejectReplies": True,
            "mediaType": "text/html",
            "content": content,
            "contentMap": {
                system_language: content
            },
            "attachment": [],
            "tag": [
                {
                    "href": actor2,
                    "name": "@" + nickname + "@" + domain,
                    "type": "Mention"
                },
                {
                    "@context": "https://www.w3.org/ns/activitystreams",
                    "type": "Event",
                    "name": content,
                    "startTime": start_time,
                    "endTime": end_time
                }
            ],
            "replies": {
                "id": post_id + "/replies",
                "type": "Collection",
                "first": {
                    "type": "CollectionPage",
                    "next": next_str,
                    "partOf": post_id + "/replies",
                    "items": []
                }
            }
        }
    }
    if location:
        event_json['object']['tag'].append({
            "@context": "https://www.w3.org/ns/activitystreams",
            "type": "Place",
            "name": location
        })
    handle = nickname + '@' + domain
    outbox_dir = base_dir + '/accounts/' + handle + '/outbox'
    if not os.path.isdir(outbox_dir):
        return False
    filename = outbox_dir + '/' + post_id.replace('/', '#') + '.json'
    save_json(event_json, filename)
    save_event_post(base_dir, handle, post_id, event_json)

    return True


def dav_put_response(base_dir: str, nickname: str, domain: str,
                     depth: int, xml_str: str, http_prefix: str,
                     system_language: str) -> str:
    """Returns the response to caldav PUT
    """
    if '\n' not in xml_str:
        return None
    if 'BEGIN:VCALENDAR' not in xml_str or \
       'END:VCALENDAR' not in xml_str:
        return None
    if 'BEGIN:VEVENT' not in xml_str or \
       'END:VEVENT' not in xml_str:
        return None

    stored_count = 0
    reading_event = False
    lines_list = xml_str.split('\n')
    event_list = []
    for line in lines_list:
        line = line.strip()
        if not reading_event:
            if line == 'BEGIN:VEVENT':
                reading_event = True
                event_list = []
        else:
            if line == 'END:VEVENT':
                if event_list:
                    _dav_store_event(base_dir, nickname, domain,
                                     event_list, http_prefix,
                                     system_language)
                    stored_count += 1
                reading_event = False
            else:
                event_list.append(line)
    if stored_count == 0:
        return None
    return 'Ok'


def dav_report_response(base_dir: str, nickname: str, domain: str,
                        depth: int, xml_str: str) -> str:
    """Returns the response to caldav REPORT
    """
    if '<c:calendar-query' not in xml_str or \
       '</c:calendar-query>' not in xml_str:
        if '<c:calendar-multiget' not in xml_str or \
           '</c:calendar-multiget>' not in xml_str:
            return None
    # TODO
    return None


def dav_delete_response(base_dir: str, nickname: str, domain: str,
                        depth: int, path: str,
                        http_prefix: str, debug: bool,
                        recent_posts_cache: {}) -> str:
    """Returns the response to caldav DELETE
    """
    token = path.split('/calendars/' + nickname + '/')[1]
    token_year, token_month_number, token_post_id = \
        _dav_decode_token(token)
    if not token_year:
        return None
    post_filename = locate_post(base_dir, nickname, domain, token_post_id)
    if not post_filename:
        print('Calendar post not found ' + token_post_id)
        return None
    post_json_object = load_json(post_filename)
    if not _is_happening_post(post_json_object):
        print(token_post_id + ' is not a calendar post')
        return None
    remove_calendar_event(base_dir, nickname, domain,
                          token_year, token_month_number,
                          token_post_id)
    delete_post(base_dir, http_prefix,
                nickname, domain, post_filename,
                debug, recent_posts_cache)
    return 'Ok'