from django.conf import settings

from django.core.urlresolvers import reverse

from django.http import HttpResponse, Http404, HttpResponseRedirect

from django.shortcuts import get_object_or_404, render_to_response

from django.template.loader import render_to_string

from django.utils import feedgenerator

from django.utils.translation import ugettext as _

from django.template import RequestContext

from django.contrib.auth.models import AnonymousUser  

from cm.security import get_viewable_activities

from cm.models import ApplicationConfiguration, Activity, Configuration

import time

from cm.exception import UnauthorizedException

import re

# taken from django's feedgenerator.py and changed to support multiple posts in minute

def get_tag_uri(url, date):

    "Creates a TagURI. See http://diveintomark.org/archives/2004/05/28/howto-atom-id"

    tag = re.sub('^http://', '', url)

    if date is not None:

        tag = re.sub('/', ',%s:/' % time.mktime(date.timetuple()), tag, 1)

    tag = re.sub('#', '/', tag)

    return u'tag:' + tag

def public_feed(request):

    feed_title = _(u"%(workspace_name)s's public feed" % {'workspace_name' : ApplicationConfiguration['workspace_name']})

    feed_description = _(u"Workspace %(workspace_name)s public activity feed") % {'workspace_name' : ApplicationConfiguration['workspace_name']}

    request.user = AnonymousUser()

    activitites = get_viewable_activities(request, {'view_comments' : 1, 'view_texts' : 1})

    return _feed(request, activitites, feed_title, feed_description)

def private_feed(request, key):

    private_feed_key = Configuration.objects.get_key('private_feed_key', None)

    if private_feed_key != key:

        raise Http404

    feed_title = _(u"%(workspace_name)s's private feed" % {'workspace_name' : ApplicationConfiguration['workspace_name']})

    feed_description = _(u"Workspace %(workspace_name)s private feed") % {'workspace_name' : ApplicationConfiguration['workspace_name']}

    activities = Activity.objects.filter(type__in=Activity.ACTIVITIES_TYPES).order_by('-created')

    return _feed(request, activities, feed_title, feed_description)

def _feed(request, activities, feed_title, feed_description):

    feed = feedgenerator.Atom1Feed(

        title=feed_title,

        link=settings.SITE_URL,

        description=feed_description,

        language='en' # TODO: something better to do?

    )    

    for activity in activities:

        item_data = activity.printable_data()

        item_data_text = activity.printable_data(html=False, link=False)

        item_metadata = activity.created # TODO dateformat

        item_body = render_to_string('feed/feed_item.txt',

                                   { 'title': item_data,

                                     'body' : item_metadata,

                                     }, context_instance = RequestContext(request))

        feed.add_item(title=item_data_text,

               link=settings.SITE_URL,

               description=item_body,

               pubdate=activity.created,

               unique_id=get_tag_uri(settings.SITE_URL, activity.created),

               author_name=activity.user.username if activity.user else '-',

               )

    response = HttpResponse(mimetype=feed.mime_type)

    feed.write(response, 'utf-8')

    return response

def text_feed(request, key):

    from cm.views import get_text_by_keys_or_404    

    text = get_text_by_keys_or_404(key)

    feed_title = _(u"Text %(text_title)s's public feed" % {'text_title' : text.title})

    feed_description = _(u"Public activity feed for text %(text_title)s") % {'text_title' : text.title}

    request.user = AnonymousUser()

    activitites = get_viewable_activities(request, {'view_comments' : 1, 'view_texts' : 1}, text=text)

    return _feed(request, activitites, feed_title, feed_description)

def text_feed_private(request, key, private_feed_key):

    from cm.views import get_text_by_keys_or_404    

    text = get_text_by_keys_or_404(key)

    if text.private_feed_key != private_feed_key:

        raise Http404

    feed_title = _(u"Text %(text_title)s's private feed" % {'text_title' : text.title})

    feed_description = _(u"Private activity feed for text %(text_title)s") % {'text_title' : text.title}

    activities = Activity.objects.filter(type__in=Activity.ACTIVITIES_TYPES, text=text).order_by('-created')

    return _feed(request, activities, feed_title, feed_description)