import datetime

from django.core.exceptions import ObjectDoesNotExist
from django.core.urlresolvers import reverse
from django.contrib.comments.models import Comment
from django.contrib.sitemaps import Sitemap
from blog.models import Post

class BlogSitemap(Sitemap):
    """
    Return sitemap entries for each blog post.
    """

    def items(self):
        return Post.objects.public()

    def changefreq(self, obj):
        if not obj.comments_enabled:
            return "monthly"
        else:
            return "weekly"

    def lastmod(self, obj):
        # comments also update the modification date
        try:
            lastcomment = Comment.objects.for_model(obj).latest('submit_date')
            if lastcomment.submit_date > obj.mod_date:
                return lastcomment.submit_date
            return obj.mod_date
        except ObjectDoesNotExist:
            return obj.mod_date

    def priority(self, obj):
        return 0.7


class NamedURLSitemap(Sitemap):
    """
    Given a set of named URLs, returns sitemap items for each.
    """
    def __init__(self, names):
        self.names = names

    def items(self):
        return self.names

    def changefreq(self, obj):
        return "weekly"

    def lastmod(self, obj):
        return datetime.datetime.now()

    def location(self, obj):
        return reverse(obj)

# vim: set ts=4 sw=4 et: