from django import template
from django.utils.safestring import mark_safe
from datetime import datetime, timedelta
from pytz import timezone
from mamweb.settings import TIME_ZONE
import logging
register = template.Library()

logger = logging.getLogger(__name__)

@register.filter(name='kratke_datum', expects_localtime=True)
def kratke_datum(dt):
	# None dává None, ne-datum dává False, aby se daly použít filtry typu "default".
	if dt is None:
		return None
	if not isinstance(dt, datetime):
		logger.warning(f"Špatné volání filtru {__name__}: {dt}")
		return False
	out = f'<time datetime="{dt.isoformat()}" title="{dt.strftime("%d. %m. %Y %H:%M")}">{dt.day}.{dt.month}.<span style="text-decoration:overline">{dt.year%100}</time>'
	return mark_safe(out)