nk20/apps/note/models/transactions.py

226 lines
5.5 KiB
Python

# Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later
from django.db import models
from django.urls import reverse
from django.utils import timezone
from django.utils.translation import gettext_lazy as _
from polymorphic.models import PolymorphicModel
from .notes import Note, NoteClub
"""
Defines transactions
"""
class TemplateCategory(models.Model):
"""
Defined a recurrent transaction category
Example: food, softs, ...
"""
name = models.CharField(
verbose_name=_("name"),
max_length=31,
unique=True,
)
class Meta:
verbose_name = _("transaction category")
verbose_name_plural = _("transaction categories")
def __str__(self):
return str(self.name)
class TransactionTemplate(models.Model):
"""
Defined a recurrent transaction
associated to selling something (a burger, a beer, ...)
"""
name = models.CharField(
verbose_name=_('name'),
max_length=255,
unique=True,
error_messages={'unique': _("A template with this name already exist")},
)
destination = models.ForeignKey(
NoteClub,
on_delete=models.PROTECT,
related_name='+', # no reverse
verbose_name=_('destination'),
)
amount = models.PositiveIntegerField(
verbose_name=_('amount'),
help_text=_('in centimes'),
)
category = models.ForeignKey(
TemplateCategory,
on_delete=models.PROTECT,
verbose_name=_('type'),
max_length=31,
)
display = models.BooleanField(
default=True,
)
description = models.CharField(
verbose_name=_('description'),
max_length=255,
blank=True,
)
class Meta:
verbose_name = _("transaction template")
verbose_name_plural = _("transaction templates")
def get_absolute_url(self):
return reverse('note:template_update', args=(self.pk,))
class Transaction(PolymorphicModel):
"""
General transaction between two :model:`note.Note`
amount is store in centimes of currency, making it a positive integer
value. (from someone to someone else)
"""
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'), )
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")
indexes = [
models.Index(fields=['created_at']),
models.Index(fields=['source']),
models.Index(fields=['destination']),
]
def save(self, *args, **kwargs):
"""
When saving, also transfer money between two notes
"""
if self.source.pk == self.destination.pk:
# When source == destination, no money is transfered
super().save(*args, **kwargs)
return
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)
@property
def total(self):
return self.amount * self.quantity
@property
def type(self):
return _('transfer')
class TemplateTransaction(Transaction):
"""
Special type of :model:`note.Transaction` associated to a :model:`note.TransactionTemplate`.
"""
template = models.ForeignKey(
TransactionTemplate,
null=True,
on_delete=models.SET_NULL,
)
category = models.ForeignKey(
TemplateCategory,
on_delete=models.PROTECT,
)
@property
def type(self):
return _('template')
class SpecialTransaction(Transaction):
"""
Special type of :model:`note.Transaction` associated to transactions with special notes
"""
last_name = models.CharField(
max_length=255,
verbose_name=_("name"),
)
first_name = models.CharField(
max_length=255,
verbose_name=_("first_name"),
)
bank = models.CharField(
max_length=255,
verbose_name=_("bank")
)
class MembershipTransaction(Transaction):
"""
Special type of :model:`note.Transaction` associated to a :model:`member.Membership`.
"""
membership = models.OneToOneField(
'member.Membership',
on_delete=models.PROTECT,
related_name='transaction',
)
class Meta:
verbose_name = _("membership transaction")
verbose_name_plural = _("membership transactions")
@property
def type(self):
return _('membership')