from django.conf import settings
from django.contrib.sites.models import Site
from django.contrib.syndication.views import Feed
from django.urls import reverse
from django.utils.feedgenerator import Atom1Feed
from urllib.parse import urljoin
from lemoncurry.templatetags.markdown import markdown
from ..kinds import on_home
from ..models import Entry


class Atom1FeedWithHub(Atom1Feed):
    def add_root_elements(self, handler):
        super().add_root_elements(handler)
        handler.startElement('link', {'rel': 'hub', 'href': settings.PUSH_HUB})
        handler.endElement('link')


class EntriesFeed(Feed):
    def item_title(self, entry):
        return entry.title

    def item_description(self, entry):
        return markdown(entry.content)

    def item_author_name(self, entry):
        return entry.author.name

    def item_author_email(self, entry):
        return entry.author.email

    def item_author_link(self, entry):
        base = 'https://' + Site.objects.get_current().domain
        return urljoin(base, entry.author.url)

    def item_pubdate(self, entry):
        return entry.published

    def item_updatedate(self, entry):
        return entry.updated

    def item_categories(self, entry):
        return (cat.name for cat in entry.cats.all())


class RssByKind(EntriesFeed):
    def get_object(self, request, kind):
        return kind

    def title(self, kind):
        return "{0} ~ {1}".format(
            kind.plural,
            Site.objects.get_current().name,
        )

    def link(self, kind):
        return kind.index

    def description(self, kind):
        return "all {0} at {1}".format(
            kind.plural,
            Site.objects.get_current().name,
        )

    def items(self, kind):
        return Entry.objects.filter(kind=kind.id)


class AtomByKind(RssByKind):
    feed_type = Atom1FeedWithHub
    subtitle = RssByKind.description


class RssHomeEntries(EntriesFeed):
    def title(self):
        return Site.objects.get_current().name

    def link(self):
        return reverse('home:index')

    def description(self):
        return "content from {0}".format(
            Site.objects.get_current().name,
        )

    def items(self):
        return Entry.objects.filter(kind__in=on_home)


class AtomHomeEntries(RssHomeEntries):
    feed_type = Atom1FeedWithHub
    subtitle = RssHomeEntries.description