"""
This file contains the core Models used in gpp
"""
import datetime

from django.db import models
from django.contrib.auth.models import User


class UserLastVisit(models.Model):
    """
    This model represents timestamps indicating a user's last visit to the
    site.
    """
    user = models.ForeignKey(User, unique=True)
    last_visit = models.DateTimeField(db_index=True)


class AnonLastVisit(models.Model):
    """
    This model represents timestamps for the last visit from non-authenticated
    users.
    """
    ip = models.CharField(max_length=16, db_index=True, unique=True)
    last_visit = models.DateTimeField(db_index=True)


class Statistic(models.Model):
    """
    This model keeps track of site statistics. Currently, the only statistic
    is the maximum number of users online. This stat is computed by a mgmt.
    command that is run on a cron job to peek at the previous two models.
    """
    max_users = models.IntegerField()
    max_users_date = models.DateTimeField()
    max_anon_users = models.IntegerField()
    max_anon_users_date = models.DateTimeField()

    def __unicode__(self):
        return u'%d users on %s' % (self.max_users, 
                self.max_users_date.strftime('%Y-%m-%d %H:%M:%S'))