from django.utils import timezone
from django.utils.translation import gettext, gettext_lazy as _
from django.utils.translation import ngettext
from wagtail.admin.ui.tables import Column, DateColumn
from wagtail.admin.ui.tables.pages import PageStatusColumn, PageTitleColumn
from wagtail.admin.views.pages.listing import IndexView
from wagtail.admin.viewsets.pages import PageListingViewSet

from dnscms.admin import ListingRedirectChooseParentView
from events.models import EventPage


class EventDateColumn(Column):
    def get_value(self, instance):
        occurrences = list(instance.occurrences.order_by("start"))
        if not occurrences:
            return "—"
        if len(occurrences) == 1:
            local = timezone.localtime(occurrences[0].start)
            return local.strftime(gettext("%Y-%m-%d at %H:%M"))
        count = len(occurrences)
        return ngettext("%(count)d occurrence", "%(count)d occurrences", count) % {"count": count}


class OrganizersColumn(Column):
    def get_value(self, instance):
        names = list(instance.organizers.values_list("name", flat=True))
        if not names:
            return "—"
        if len(names) == 1:
            return names[0]
        return f"{names[0]} (+{len(names) - 1})"


class EventPageIndexView(IndexView):
    def annotate_queryset(self, pages):
        pages = super().annotate_queryset(pages)
        return pages.prefetch_related(
            "occurrences",
            "organizer_links__organizer",
        )


class EventChooseParentView(ListingRedirectChooseParentView):
    listing_url_name = "events:index"


class EventPageListingViewSet(PageListingViewSet):
    model = EventPage
    index_view_class = EventPageIndexView
    choose_parent_view_class = EventChooseParentView
    icon = "date"
    menu_label = _("Events")
    menu_order = 1
    add_to_admin_menu = True
    ordering = "-latest_revision_created_at"

    columns = [
        PageTitleColumn("title", label=_("Title"), sort_key="title", classname="title"),
        EventDateColumn("event_date", label=_("Date"), width="13%"),
        OrganizersColumn("organizers", label=_("Organizers"), width="12%"),
        DateColumn(
            "latest_revision_created_at",
            label=_("Updated"),
            sort_key="latest_revision_created_at",
            width="10%",
        ),
        PageStatusColumn("status", label=_("Status"), sort_key="live", width="10%"),
    ]


event_page_listing_viewset = EventPageListingViewSet("events")