from datetime import date, timedelta

from django import template
from django.utils import formats, timezone
from django.utils.translation import ugettext as _

from ..models import COFActuPage, COFUtilPage

register = template.Library()


@register.filter()
def obfuscate_mail(value):
    val = value.replace('', '-').replace('@', 'arbre').replace('.', 'pont')[1:]
    return val


@register.inclusion_tag("cofcms/calendar.html", takes_context=True)
def calendar(context, month=None, year=None):
    now = timezone.now()
    if month is None:
        month_start = date(now.year, now.month, 1)
    else:
        month_start = date(year, month, 1)
    next_month = month_start + timedelta(days=32)
    next_month = date(next_month.year, next_month.month, 1)
    prev_month = month_start - timedelta(days=2)
    month_prestart = month_start - timedelta(days=month_start.weekday())
    month_postend = next_month + timedelta(days=(next_month.weekday() + 6) % 7)
    events = COFActuPage.objects.live()\
                                .filter(date_start__range=[month_prestart,
                                                           month_postend],
                                        is_event=True)\
                                .order_by('-date_start')
    events = list(events)
    weeks = []
    curday = month_prestart
    deltaday = timedelta(days=1)
    while curday < next_month and len(weeks) < 10:
        week = []
        for k in range(7):
            curevents = []
            for k in range(len(events) - 1, -1, -1):
                e = events[k]
                if e.date_start.date() > curday:
                    break
                if (e.date_start if e.date_end is None else e.date_end).date() < curday:
                    del events[k]
                else:
                    curevents.append(e)
            day = {'day': curday.day,
                   'date': curday,
                   'class': (('today ' if curday == now.date() else '')
                             + ('in ' if (curday.month == month_start.month
                                          and curday.year == month_start.year)
                                else 'out ')
                             + ('hasevent' if len(curevents) > 0 else '')),
                   'events': curevents}
            week.append(day)
            curday += deltaday
        weeks.append(week)

    # Calendar next/prev urls
    try:
        utilpage = COFUtilPage.objects.live()[0]
    except COFUtilPage.DoesNotExist:
        utilpage = None
    request = context['request']
    burl = utilpage.debugged_get_url(request) + "/"
    prev_url = burl + utilpage.reverse_subpage("calendar",
                                               args=[str(prev_month.year),
                                                     str(prev_month.month)])
    next_url = burl + utilpage.reverse_subpage("calendar",
                                               args=[str(next_month.year),
                                                     str(next_month.month)])
    context.push({"events": events, "weeks": weeks, "this_month": month_start,
                  "prev_month": prev_url, "next_month": next_url})
    return context


@register.inclusion_tag("cofcms/mini_calendar.html")
def mini_calendar(event):
    days = []
    today = timezone.now().date()
    date_start = event.date_start.date()
    date_end = event.date_end.date() if event.date_end else date_start
    week_start = date_start - timedelta(days=date_start.weekday())
    curday = week_start
    for i in range(7):
        days.append({'day': curday.day,
                     'hasevent': curday >= date_start and curday <= date_end,
                     'today': curday == today})
        curday += timedelta(days=1)
    return {"days": days}


@register.filter()
def dates(event):
    def factorize_suffix(a, b):
        i = -1
        imin = - min(len(a), len(b))
        while i > imin and a[i] == b[i]:
            i -= 1
        if i == -1:
            return (a, b, '')
        else:
            return (a[:i + 1], b[:i + 1], a[i + 1:])

    datestart_string = formats.date_format(event.date_start)
    timestart_string = formats.time_format(event.date_start)
    if event.date_end:
        if event.date_end.date() == event.date_start.date():
            if event.all_day:
                return _("le %s") % datestart_string
            else:
                return _("le %s de %s à %s") % \
                    (datestart_string,
                     timestart_string,
                     formats.time_format(event.date_end))
        else:
            dateend_string = formats.date_format(event.date_end)
            diffstart, diffend, common = factorize_suffix(datestart_string,
                                                          dateend_string)
            if event.all_day:
                return _("du %s au %s%s") % \
                    (diffstart, diffend, common)

            else:
                return _("du %s%s à %s au %s à %s") % \
                    (diffstart, common, timestart_string,
                     diffend, formats.time_format(event.date_end))
    else:
        if event.all_day:
            return _("le %s") % datestart_string
        else:
            return _("le %s à %s") % (datestart_string, timestart_string)