symposion_app/pinaxcon/raffle/models.py

from django.db import models

from pinaxcon.raffle.mixins import PrizeMixin, RaffleMixin


class Raffle(RaffleMixin, models.Model):
    """
    Stores a single Raffle object, related to one or many
    :model:`pinaxcon_registrasion.Product`, which  is usually a raffle ticket,
    but can be set to tickets or other products for door prizes.
    """
    description = models.CharField(max_length=255)
    products = models.ManyToManyField('registrasion.Product')

    def __str__(self):
        return self.description


class Prize(PrizeMixin, models.Model):
    """
    Stores a Prize for a given :model:`pinaxcon_raffle.Raffle`.

    Once `winning_ticket` has been set to a :model:`pinaxcon_raffle.DrawnTicket`
    object, no further changes are permitted unless the object is explicitely
    unlocked.
    """
    description = models.CharField(max_length=255)
    raffle = models.ForeignKey('pinaxcon_raffle.Raffle', related_name='prizes')
    order = models.PositiveIntegerField()
    winning_ticket = models.OneToOneField(
        'pinaxcon_raffle.DrawnTicket', null=True,
        blank=True, related_name='+', on_delete=models.PROTECT
    )

    class Meta:
        unique_together = ('raffle', 'order')

    def __str__(self):
        return f"{self.order}. Prize: {self.description}"


class PrizeAudit(models.Model):
    """
    Stores an audit event for changes to a particular :model:`pinaxcon_raffle.Prize`.
    """
    reason = models.CharField(max_length=255)
    prize = models.ForeignKey('pinaxcon_raffle.Prize', related_name='audit_events')

    user = models.ForeignKey('auth.User')
    timestamp = models.DateTimeField(auto_now_add=True)

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

    def __str__(self):
        return self.reason


class Draw(models.Model):
    """
    Stores a draw for a given :model:`pinaxcon_raffle.Raffle`, along with audit fields
    for the creating :model:`auth.User` and the creation timestamp.
    """
    raffle = models.ForeignKey('pinaxcon_raffle.Raffle', related_name='draws')
    drawn_by = models.ForeignKey('auth.User')
    drawn_time = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"{self.raffle}: {self.drawn_time}"


class DrawnTicket(models.Model):
    """
    Stores the result of a ticket draw, along with the corresponding
    :model:`pinaxcon_raffle.Draw`, :model:`pinaxcon_raffle.Prize` and the
    :model:`registrasion.commerce.LineItem` from which it was generated.
    """
    ticket = models.CharField(max_length=255)

    draw = models.ForeignKey('pinaxcon_raffle.Draw')
    prize = models.ForeignKey('pinaxcon_raffle.Prize')
    lineitem = models.ForeignKey('registrasion.LineItem')

    def __str__(self):
        return f"{self.ticket}: {self.draw.raffle}"