import datetime as dt
import re, logging

from .sync import Event

class IcalHelper:
    
    _WEEKDAY_MAP = {
        'Mon': 0,
        'Tue': 1,
        'Wed': 2,
        'Thu': 3,
        'Fri': 4,
        'Sat': 5,
        'Sun': 6
    }
    
    def __init__(self):
        self._l = logging.getLogger(__name__)
        self.dDay = dt.timedelta(days=1)
        self.firstDay = dt.datetime(year=dt.datetime.now().year, month=1, day=1)
        self.reTime = re.compile(r'(\d{1,2}):(\d{2})')
    
    def getStart(self, event: Event, holidays):
        self._getFirstWeekdayInYear(event.day)
        self._getFirstOccurence(event, holidays)
        pass

    def _getFirstWeekdayInYear(self, weekday):
        candidate = self.firstDay
        while candidate.weekday() != self._WEEKDAY_MAP[weekday]:
            candidate += self.dDay
        
        self._l.log(5, 'First %s in year is %s', weekday, candidate)

        return candidate
    
    def _getSortedHolidays(self, holidays):
        return sorted(holidays['holidays'], key=lambda h: h['from'])

    def _getSortedFeasts(self, holidays):
        return sorted(holidays['feasts'])

    def _getFirstOccurence(self, event: Event, holidays):
        firstWeekday = self._getFirstWeekdayInYear(event.day)
        firstWeekday.tzinfo = dt.timezone.tzname('Europe/Berlin')