"""Models for the bulletins app.
Bulletins allow the sited admins to display and manage important notices for the website.
"""

import datetime
from django.db import models
from django.db.models import Q


class BulletinManager(models.Manager):
   """Manager for the Bulletin model."""

   def get_current(self):
      now = datetime.datetime.now()
      return self.filter(
            Q(is_enabled=True),
            Q(start_date__lte=now),
            Q(end_date__isnull=True) | Q(end_date__gte=now))


class Bulletin(models.Model):
   """Model to represent site bulletins."""
   title = models.CharField(max_length=200)
   text = models.TextField()
   start_date = models.DateTimeField(db_index=True,
         help_text='Start date for when the bulletin will be active.',)
   end_date = models.DateTimeField(blank=True, null=True, db_index=True,
         help_text='End date for the bulletin. Leave blank to keep it open-ended.')
   is_enabled = models.BooleanField(default=True, db_index=True,
         help_text='Check to allow the bulletin to be viewed on the site.')

   objects = BulletinManager()

   def __unicode__(self):
      return self.title

   class Meta:
      ordering = ('-start_date', )