nk20/note/models/transactions.py

115 lines
2.9 KiB
Python

# -*- mode: python; coding: utf-8 -*-
# Copyright (C) 2018-2019 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later
from django.db import models
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from .notes import Note
"""
Defines transactions
"""
class TransactionTemplate(models.Model):
name = models.CharField(
verbose_name=_('name'),
max_length=255,
)
destination = models.ForeignKey(
Note,
on_delete=models.PROTECT,
related_name='+', # no reverse
verbose_name=_('destination'),
)
amount = models.PositiveIntegerField(
verbose_name=_('amount'),
help_text=_('in centimes'),
)
template_type = models.CharField(
verbose_name=_('type'),
max_length=31
)
class Meta:
verbose_name = _("transaction template")
verbose_name_plural = _("transaction templates")
class Transaction(models.Model):
source = models.ForeignKey(
Note,
on_delete=models.PROTECT,
related_name='+',
verbose_name=_('source'),
)
destination = models.ForeignKey(
Note,
on_delete=models.PROTECT,
related_name='+',
verbose_name=_('destination'),
)
created_at = models.DateTimeField(
verbose_name=_('created at'),
default=timezone.now,
)
quantity = models.PositiveIntegerField(
verbose_name=_('quantity'),
default=1,
)
amount = models.PositiveIntegerField(
verbose_name=_('amount'),
)
transaction_type = models.CharField(
verbose_name=_('type'),
max_length=31,
)
reason = models.CharField(
verbose_name=_('reason'),
max_length=255,
)
valid = models.BooleanField(
verbose_name=_('valid'),
default=True,
)
class Meta:
verbose_name = _("transaction")
verbose_name_plural = _("transactions")
def save(self, *args, **kwargs):
"""
When saving, also transfer money between two notes
"""
created = self.pk is None
to_transfer = self.amount * self.quantity
if not created:
# Revert old transaction
old_transaction = Transaction.objects.get(pk=self.pk)
if old_transaction.valid:
self.source.balance += to_transfer
self.destination.balance -= to_transfer
if self.valid:
self.source.balance -= to_transfer
self.destination.balance += to_transfer
# Save notes
self.source.save()
self.destination.save()
super().save(*args, **kwargs)
class MembershipTransaction(Transaction):
membership = models.OneToOneField(
'member.Membership',
on_delete=models.PROTECT,
related_name='transaction',
)
class Meta:
verbose_name = _("membership transaction")
verbose_name_plural = _("membership transactions")