# from django.shortcuts import render
from django.views.generic import TemplateView
from django.http import Http404
from django.db.models import Q

from datetime import date

from mainsite.models import Publication


class HomeView(TemplateView):
    ''' Website's homepage '''
    template_name = 'mainsite/homepage.html'


class WriteArticleView(TemplateView):
    ''' Tell the readers how they can contribute to the BOcal '''
    template_name = 'mainsite/write_article.html'


class PublicationListView(TemplateView):
    ''' Display a list of publications (generic class).

    Reimplement `get_publications` (called with the url template args in a
    place where you can Http404) in subclasses to get it working. '''

    template_name = 'mainsite/publications_list_view.html'

    def get_context_data(self, **kwargs):
        context = super(PublicationListView, self).get_context_data(**kwargs)

        publications = self.get_publications(**kwargs)

        if len(publications) == 0:
            raise Http404
        context['publications'] = publications

        return context


class YearView(PublicationListView):
    ''' Display a year worth of BOcals '''
    def get_publications(self, year, nYear):
        try:
            year, nYear = int(year), int(nYear)
        except ValueError:
            raise Http404

        if year + 1 != nYear:
            raise Http404

        publications = Publication.objects.filter(
            Q(is_special=False) | Q(in_year_view_anyway=True),
            date__gte=date(year, 8, 1),
            date__lt=date(nYear, 8, 1))

        return publications


class SpecialPublicationsView(PublicationListView):
    ''' Display the list of special publications '''
    def get_publications(self):
        publications = Publication.objects\
            .filter(is_special=True)\
            .order_by('-date')
        return publications