from models import Entry, EntryTag # relative import

from django.views.generic.list_detail import object_list

from sflc.apps.staff.models import Person

from django.shortcuts import get_object_or_404, render_to_response

from datetime import datetime

def OR_filter(field_name, objs):

    from django.db.models import Q

    return reduce(lambda x, y: x | y,

                  [Q(**{field_name: x.id}) for x in objs])

def last_name(person):

    return person.formal_name.rpartition(' ')[2]

def custom_index(request, queryset, *args, **kwargs):

    """Blog list view that allows scrolling and also shows an index by

    year.

    """

    kwargs = kwargs.copy()

    kwargs['extra_context'] = kwargs.get('extra_context', {}).copy()

    extra_context = kwargs['extra_context']

    date_field = kwargs['date_field']

    del kwargs['date_field']

    if not kwargs.get('allow_future', False):

        queryset = queryset.filter(**{'%s__lte' % date_field: datetime.now()})

    authors = []

    if 'author' in request.GET:

        authors = [get_object_or_404(Person, username=author)

                   for author in request.GET.getlist('author')]

        extra_context['authors'] = authors

        queryset = queryset.filter(OR_filter('author', authors))

    tags = []

    if 'tag' in request.GET:

        tags = [get_object_or_404(EntryTag, slug=tag)

                for tag in request.GET.getlist('tag')]

        extra_context['tags'] = tags

        queryset = queryset.filter(OR_filter('tags', tags))

    if authors or tags:

        query_string = '&'.join(['author=%s' % a.username for a in authors]

                                + ['tag=%s' % t.slug for t in tags])

        extra_context['query_string'] = query_string

    else:

        date_list = queryset.dates(date_field, 'year')

        extra_context['date_list'] = date_list

    return object_list(request, queryset, *args, **kwargs)

def techblog_redirect(request):

    """Redirect from the old 'techblog' to the new blog

    """

    path = request.path[len('/technology'):]

    if path == '/blog/':

        path += "?author=bkuhn"

    return relative_redirect(request, path)

def query(request):

    """Page to query the blog based on authors and tags

    """

    if request.GET:

        d = request.GET.copy()

        if 'authors' in d.getlist('all'):

            d.setlist('author', []) # remove author queries

        if 'tags' in d.getlist('all'):

            d.setlist('tag', []) # remove tag queries

        d.setlist('all', []) # remove "all" from the query string

        base_url = '/blog/'

        if 'rss' in d:

            base_url = '/feeds/blog/'

            d.setlist('rss', []) # remove it

        query_string = d.urlencode()

        return relative_redirect(request, '%s%s%s' % (base_url, '?' if query_string else '', query_string))

    else:

        authors = sorted(Person.objects.filter(currently_employed=True,

                                               entry__isnull=False).distinct(),

                         key=last_name)

        tags = EntryTag.objects.all().order_by('label')

        return render_to_response('blog/query.html',

                                  {'authors': authors, 'tags': tags})

def relative_redirect(request, path):

    from django import http

    from django.conf import settings

    host = http.get_host(request)

    if settings.FORCE_CANONICAL_HOSTNAME:

        host = settings.FORCE_CANONICAL_HOSTNAME

    url = "%s://%s%s" % (request.is_secure() and 'https' or 'http', host, path)

    return http.HttpResponseRedirect(url)