class Cafe(models.Model):
    name = models.CharField(max_length=100)
    owner = models.ForeignKey(User)
    description = models.TextField()
    adress = models.TextField()
    image = models.ImageField()
    registered_at = models.DateField()
    last_updated = models.DateField()
    rating = models.FloatField(default=0)

    def calc_rating(self):
        comments = CommentCafe.objects.filter(cafe_id = self.id)
        rating = (0.0+sum([obj.rating for obj in comments]))/len(comments)
        rating = round(rating, 2)
        x = 0.25 # value for round rating
        rating = round(rating * (1 / x)) / (1 / x)
        self.rating = rating
        self.save()

    def __unicode__(self):
        return "%s ( %s... )" % (self.name, self.description[:100])


class Product(models.Model):
    cafe = models.ForeignKey(Cafe)
    name = models.CharField(max_length=70)
    description = models.TextField()
    image = models.ImageField()
    last_updated = models.DateField()

    def __unicode__(self):
        return "%s ( %s... )" % (self.name, self.description[:50])


class Comment(models.Model):
    class Meta:
        abstract = True

    user = models.ForeignKey(User)
    rating = models.PositiveSmallIntegerField()
    text = models.CharField(max_length=250)
    created_at = models.DateTimeField()

    def __unicode__(self):
        return "%s (%d) : %s" % (self.user.first_name, self.rating,
                                self.text[:50])


class CommentCafe(Comment):
    cafe = models.ForeignKey(Cafe)


class CommentProduct(Comment):
    product = models.ForeignKey(Product)