"""
This module contains view functions related to forum favorites (bookmarks).
"""
from django.contrib.auth.decorators import login_required
from django.core.urlresolvers import reverse
from django.views.decorators.http import require_POST
from django.shortcuts import get_object_or_404
from django.shortcuts import render
from django.http import HttpResponseRedirect
from django.http import HttpResponseForbidden
from django.http import Http404

from django.core.paginator import InvalidPage
from core.paginator import DiggPaginator
from forums.models import Topic
import forums.permissions as perms


@login_required
@require_POST
def favorite_topic(request, topic_id):
    """
    This function handles the "favoriting" (bookmarking) of a forum topic by a
    user.
    """
    topic = get_object_or_404(Topic.objects.select_related(), id=topic_id)
    if perms.can_access(topic.forum.category, request.user):
        topic.bookmarkers.add(request.user)
        return HttpResponseRedirect(
            reverse("forums-favorites_status", args=[topic.id]))
    return HttpResponseForbidden()


@login_required
def manage_favorites(request):
    """Display a user's favorite topics and allow them to be deleted."""

    user = request.user
    if request.method == "POST":
        if request.POST.get('delete_all'):
            user.favorite_topics.clear()
        else:
            delete_ids = request.POST.getlist('delete_ids')
            try:
                delete_ids = [int(id) for id in delete_ids]
            except ValueError:
                raise Http404
            for topic in user.favorite_topics.filter(id__in=delete_ids):
                user.favorite_topics.remove(topic)

        return HttpResponseRedirect(reverse("forums-manage_favorites"))

    page_num = request.GET.get('page', 1)
    topics = user.favorite_topics.select_related().order_by('-update_date')
    paginator = DiggPaginator(topics, 20, body=5, tail=2, margin=3, padding=2)
    try:
        page_num = int(page_num)
    except ValueError:
        page_num = 1
    try:
        page = paginator.page(page_num)
    except InvalidPage:
        raise Http404

    return render(request, 'forums/manage_topics.html', {
        'page_title': 'Favorite Topics',
        'description': 'Your favorite topics are listed below.',
        'page': page,
        })


@login_required
def favorites_status(request, topic_id):
    """Display the favorite status for the given topic."""
    topic = get_object_or_404(Topic.objects.select_related(), id=topic_id)
    is_favorite = request.user in topic.bookmarkers.all()
    return render(request, 'forums/favorite_status.html', {
        'topic': topic,
        'is_favorite': is_favorite,
        })


@login_required
@require_POST
def unfavorite_topic(request, topic_id):
    """
    Un-favorite the user from the requested topic.
    """
    topic = get_object_or_404(Topic, id=topic_id)
    topic.bookmarkers.remove(request.user)
    return HttpResponseRedirect(
        reverse("forums-favorites_status", args=[topic.id]))