# -*- coding: utf-8 -*-

"""

Provides the Meetup.com events that will be used to populate the site homepage.

"""

from django.conf import settings

from django.core.cache import cache

from django.core.exceptions import ImproperlyConfigured

from functools import wraps

from pythonkc_meetups import PythonKCMeetups

import logging

logger = logging.getLogger(__name__)

try:

api_key = settings.MEETUP_API_KEY

except AttributeError:

raise ImproperlyConfigured('MEETUP_API_KEY is required in settings')

num_past_events = getattr(settings, 'MEETUP_SHOW_PAST_EVENTS', 3)

meetups = PythonKCMeetups(api_key, num_past_events=num_past_events, http_timeout=6)

def memoize_in_cache(cache_key, cache_timeout_seconds=None):

"""

Caches the result of a no-args function. Further, a backup cache is

maintained, updated as often as the primary but waits much longer to expire

than the primary cache.

NOTE This should all go away once gondor gets schedule celery tasks that

can be used to periodically populate the meetup.com event cache (thereby

allowing visitor requests to avoid the hit).

"""

backup_cache_key = cache_key + '_backup'

backup_cache_timeout_seconds = (cache_timeout_seconds * 10000

if cache_timeout_seconds else

60 * 60 * 24)

def decorator(func):

@wraps(func)

def decorated():

value = cache.get(cache_key)

if not value:

try:

value = func()

cache.set(cache_key, value, cache_timeout_seconds)

cache.set(backup_cache_key, value,

backup_cache_timeout_seconds)

except:

value = cache.get(backup_cache_key)

if value:

logging.exception('Had to load backup value due to '

'exception')

else:

raise

return value

return decorated

return decorator

@memoize_in_cache('next_event', 60 * 5)

def get_next_event():

logging.info('Retrieving next event from Meetup.com')

upcoming_events = meetups.get_upcoming_events()

return upcoming_events[0] if upcoming_events else None

@memoize_in_cache('past_events', 60 * 60)

def get_past_events():

logging.info('Retrieving past events from Meetup.com')

return meetups.get_past_events()[:num_past_events]