"""
Views for the gigs application.

"""
import collections
import datetime

from django.db import connection
from django.shortcuts import render

from gigs.models import Band, Gig


def gigs(request):
    """
    This view function renders the main gigs view, showing upcoming and past
    gigs as well as some statistics.

    """
    today = datetime.date.today()
    gigs = Gig.objects.select_related('venue', 'flyer', 'venue__city',
              'venue__city__state', 'venue__city__country')
    upcoming = []
    previous = []

    # To avoid many, many database hits in the template, we get all the
    # bands out at once. We also get the many-to-many intermediate table
    # that Django generated for us so we can associate bands to gigs.
    # Since we don't know about this table we drop into raw SQL to get
    # the contents.

    bands = dict((band.id, band) for band in Band.objects.all())
    cursor = connection.cursor()
    cursor.execute('SELECT * FROM gigs_gig_bands')
    gig_bands = collections.defaultdict(list)
    for row in cursor.fetchall():
        gig_bands[row[1]].append(bands[row[2]])

    for gig in gigs:
        gig.bands_ = gig_bands[gig.id]
        if gig.date >= today:
            upcoming.append(gig)
        else:
            previous.append(gig)

    upcoming.reverse()

    stats = {}
    venues = set()
    cities = set()
    states = set()
    countries = set()
    for gig in previous:
        venues.add(gig.venue.id)
        cities.add(gig.venue.city.id)
        if gig.venue.city.state:
            states.add(gig.venue.city.state.id)
        if gig.venue.city.country:
            countries.add(gig.venue.city.country.id)

    stats['count'] = len(previous)
    stats['venues'] = len(venues)
    stats['cities'] = len(cities)
    stats['states'] = len(states)
    stats['countries'] = len(countries)
    stats['bands'] = len(bands)

    flyer_gigs = Gig.objects.exclude(flyer__isnull = True).select_related(
         'venue', 'flyer').order_by('-date')

    return render(request, 'gigs/gigs.html', {
         'upcoming' : upcoming,
         'previous' : previous,
         'stats' : stats,
         'flyer_gigs' : flyer_gigs,
         })