from datetime import datetime
from functools import reduce
import itertools
import operator

from django.conf import settings
from django.contrib.syndication.views import Feed
from django.shortcuts import render
from django.utils.feedgenerator import Rss201rev2Feed

from .blog.models import Entry as BlogEntry
from .news.models import PressRelease


class ConservancyFeedBase(Feed):
    def copyright_holder(self):
        return "Software Freedom Conservancy"

    def license_no_html(self):
        return "Licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License."

    def item_copyright(self, item):
        year = 2008
        for attr in ('pub_date', 'date_created', 'date_last_modified'):
            if hasattr(item, attr):
                if hasattr(getattr(item, attr), 'year'):
                    year = getattr(getattr(item, attr), 'year')
                    break
        return 'Copyright (C) %d, %s.  %s' % (year, self.copyright_holder(), self.license_no_html())

    def item_extra_kwargs(self, item):
        year = 2008
        for attr in ('pub_date', 'date_created', 'date_last_modified'):
            if hasattr(item, attr):
                if hasattr(getattr(item, attr), 'year'):
                    year = getattr(getattr(item, attr), 'year')
                    break
        return { 'year' : year }

class PressReleaseFeed(Feed):
    get_absolute_url = '/feeds/news/'
    title = "Software Freedom Conservancy News"
    link = "/news/"
    description = ""

    def items(self):
        return PressRelease.objects.filter(pub_date__lte=datetime.now(),
                                           sites__id__exact=settings.SITE_ID).order_by('-pub_date')[:10]
    def item_title(self, item):
        return item.headline

    def item_description(self, item):
        return item.summary

    def item_pubdate(self, item):
        return item.pub_date

class OmnibusFeedType(Rss201rev2Feed):
    def root_attributes(self):
        attrs = super().root_attributes()
        attrs['xmlns:itunes'] = 'http://www.itunes.com/dtds/podcast-1.0.dtd'
        attrs['xmlns:atom'] = 'http://www.w3.org/2005/Atom'
        attrs['xmlns:media'] = 'http://search.yahoo.com/mrss/'
        attrs['xmlns:dc'] = "http://purl.org/dc/elements/1.1/"
        return attrs

    def add_root_elements(self, handler):
        super().add_root_elements(handler)

    def add_item_elements(self, handler, item):
        super().add_item_elements(handler, item)
        # Block things that don't have an enclosure from iTunes in
        # case someone uploads this feed there.
        handler.addQuickElement("itunes:block", 'Yes')

class OmnibusFeed(ConservancyFeedBase):
    get_absolute_url = '/feeds/omnibus/'
    feed_type = OmnibusFeedType
    link ="/news/"
    title = "The Software Freedom Conservancy"
    description = "An aggregated feed of all RSS content available from the Software Freedom Conservancy, including both news items and blogs."
    title_template = "feeds/omnibus_title.html"
    description_template = "feeds/omnibus_description.html"
    author_email = "info@sfconservancy.org"
    author_link = "https://sfconservancy.org/"
    author_name = "Software Freedom Conservancy"

    def item_title(self, item):
        return item.headline

    def item_description(self, item):
        return item.summary

    def item_enclosure_mime_type(self):
        return "audio/mpeg"

    def item_enclosure_url(self, item):
        if hasattr(item, 'mp3_path'):
            return "https://sfconservancy.org" + item.mp3_path
    def item_enclosure_length(self, item):
        if hasattr(item, 'mp3_path'):
            return item.mp3_length

    def item_author_name(self, item):
        if item.omnibus_type == "blog":
            return item.author.formal_name
        else:
            return "Software Freedom Conservancy"

    def item_author_link(self, obj):
        return "https://sfconservancy.org"

    def item_author_email(self, item):
        if item.omnibus_type == "news":
            return "info@sfconservancy.org"
        elif hasattr(item, 'author'):
            return "%s@sfconservancy.org" % item.author
        else:
            return "info@sfconservancy.org"

    def item_pubdate(self, item):
        if item.omnibus_type == "event":
            return item.date_created
        else:
            return item.pub_date

    def item_link(self, item):
        return item.get_absolute_url()

# http://groups.google.ca/group/django-users/browse_thread/thread/d22e8a8f378cf0e2

    def items(self):
        blogs = BlogEntry.objects.filter(pub_date__lte=datetime.now()).order_by('-pub_date')[:25]
        for bb in blogs:
            bb.omnibus_type = "blog"
            bb.omnibus_feed_description_template = "feeds/blog_description.html"
            bb.omnibus_feed_title_template = "feeds/blog_title.html"

        news = PressRelease.objects.filter(pub_date__lte=datetime.now(),
                                           sites__id__exact=settings.SITE_ID).order_by('-pub_date')[:25]
        for nn in news:
            nn.omnibus_type = "news"
            nn.omnibus_feed_description_template = "feeds/news_description.html"
            nn.omnibus_feed_title_template = "feeds/news_title.html"

        a  = [ ii for ii in itertools.chain(blogs, news)]
        a.sort(key=operator.attrgetter('pub_date'), reverse=True)
        return a


    def item_extra_kwargs(self, item):
        return super().item_extra_kwargs(item)

class BlogFeed(ConservancyFeedBase):
    link = "/blog/"
    get_absolute_url = '/feeds/blog/'

    def get_object(self, request):
        return request

    def title(self, obj):
        answer = "The Software Freedom Conservancy Blog"

        GET = obj.GET
        tags = []
        if 'author' in GET:
            tags = GET.getlist('author')
        if 'tag' in GET:
            tags += GET.getlist('tag')

        if len(tags) == 1:
            answer += " (" + tags[0] + ")"
        elif len(tags) > 1:
            firstTime = True
            done = {}
            for tag in tags:
                if tag in done:
                    continue
                if firstTime:
                    answer += " ("
                    firstTime = False
                else:
                    answer += ", "
                answer += tag
                done[tag] = tag
            answer += ")"
        else:
            answer += "."
        return answer

    def description(self, obj):
        answer = "Blogs at the Software Freedom Conservancy"

        GET = obj.GET
        tags = []
        if 'author' in GET:
            tags = GET.getlist('author')
        if 'tag' in GET:
            tags += GET.getlist('tag')

        done = {}
        if len(tags) == 1:
            answer += " tagged with " + tags[0]
        elif len(tags) > 1:
            firstTime = True
            for tag in tags:
                if tag in done:
                    continue
                if firstTime:
                    answer += " tagged with "
                    firstTime = False
                else:
                    answer += " or "
                answer += tag
                done[tag] = tag
        else:
            answer = "All blogs at the Software Freedom Conservancy"
        answer += "."

        return answer

    def item_title(self, item):
        return item.headline

    def item_description(self, item):
        return item.summary

    def item_author_name(self, item):
        return item.author.formal_name

    def item_author_email(self, item):
        return "%s@sfconservancy.org" % item.author

    def item_pubdate(self, item):
        return item.pub_date

    def items(self, obj):
        GET = obj.GET

        def OR_filter(field_name, subfield_name, objs):
            from django.db.models import Q
            return reduce(lambda x, y: x | y,
                          [Q(**{'{}__{}'.format(field_name, subfield_name): x})
                           for x in objs])

        queryset = BlogEntry.objects.filter(pub_date__lte=datetime.now())

        if 'author' in GET:
            authors = GET.getlist('author')
            queryset = queryset.filter(OR_filter('author', 'username', authors))

        if 'tag' in GET:
            tags = GET.getlist('tag')
            queryset = queryset.filter(OR_filter('tags', 'slug', tags))

        return queryset.order_by('-pub_date')[:10]


def view(request):
    """Listing of all available feeds
    """

    feeds = (PressReleaseFeed, BlogFeed, OmnibusFeed)
    return render(request, "feeds.html", {'feeds': feeds})