import datetime import dateutil.parser import logging import operator from pytz import utc class CalendarSync(): """class for syncronize calendar with google """ logger = logging.getLogger('CalendarSync') def __init__(self, gcalendar, converter): self.gcalendar = gcalendar self.converter = converter @staticmethod def _events_list_compare(items_src, items_dst, key='iCalUID'): """ compare list of events by key Arguments: items_src {list of dict} -- source events items_dst {list of dict} -- dest events key {str} -- name of key to compare (default: {'iCalUID'}) Returns: tuple -- (items_to_insert, items_to_update, items_to_delete) """ def get_key(item): return item[key] keys_src = set(map(get_key, items_src)) keys_dst = set(map(get_key, items_dst)) keys_to_insert = keys_src - keys_dst keys_to_update = keys_src & keys_dst keys_to_delete = keys_dst - keys_src def items_by_keys(items, key_name, keys): return list(filter(lambda item: item[key_name] in keys, items)) items_to_insert = items_by_keys(items_src, key, keys_to_insert) items_to_update = list(zip(items_by_keys( items_src, key, keys_to_update), items_by_keys(items_dst, key, keys_to_update))) items_to_delete = items_by_keys(items_dst, key, keys_to_delete) return items_to_insert, items_to_update, items_to_delete def _filter_events_to_update(self): """ filter 'to_update' events by 'updated' datetime """ def filter_updated(event_tuple): new, old = event_tuple return dateutil.parser.parse(new['updated']) > dateutil.parser.parse(old['updated']) self.to_update = list(filter(filter_updated, self.to_update)) @staticmethod def _filter_events_by_date(events, date, op): """ filter events by start datetime Arguments: events -- events list date {datetime} -- datetime to compare op {operator} -- comparsion operator Returns: list of filtred events """ def filter_by_date(event): event_start = event['start'] event_date = None if 'date' in event_start: event_date = event_start['date'] if 'dateTime' in event_start: event_date = event_start['dateTime'] return op(dateutil.parser.parse(event_date), date) return list(filter(filter_by_date, events)) @staticmethod def _tz_aware_datetime(date): """make tz aware datetime from datetime/date (utc if no tzinfo) Arguments: date - date or datetime / with or without tzinfo Returns: datetime with tzinfo """ if not isinstance(date, datetime.datetime): date = datetime.datetime(date.year, date.month, date.day) if date.tzinfo is None: date = date.replace(tzinfo=utc) return date def prepare_sync(self, start_date): """prepare sync lists by comparsion of events Arguments: start_date -- date/datetime to start sync """ start_date = CalendarSync._tz_aware_datetime(start_date) events_src = self.converter.events_to_gcal() events_dst = self.gcalendar.list_events_from(start_date) # divide source events by start datetime events_src_pending = CalendarSync._filter_events_by_date( events_src, start_date, operator.ge) events_src_past = CalendarSync._filter_events_by_date( events_src, start_date, operator.lt) events_src = None # first events comparsion self.to_insert, self.to_update, self.to_delete = CalendarSync._events_list_compare( events_src_pending, events_dst) events_src_pending, events_dst = None, None # find in events 'to_delete' past events from source, for update (move to past) _, add_to_update, self.to_delete = CalendarSync._events_list_compare( events_src_past, self.to_delete) self.to_update.extend(add_to_update) events_src_past = None # find if events 'to_insert' exists in gcalendar, for update them add_to_update, self.to_insert = self.gcalendar.find_exists( self.to_insert) self.to_update.extend(add_to_update) add_to_update = None # exclude outdated events from 'to_update' list, by 'updated' field self._filter_events_to_update() self.logger.info('prepared to sync: ( insert: %d, update: %d, delete: %d )', len(self.to_insert), len(self.to_update), len(self.to_delete)) def apply(self): """apply sync (insert, update, delete), using prepared lists of events """ self.gcalendar.insert_events(self.to_insert) self.gcalendar.update_events(self.to_update) self.gcalendar.delete_events(self.to_delete) self.logger.info('sync done') self.to_insert, self.to_update, self.to_delete = [], [], []