move apps to own dir

apps/note/models/transactions.py

@@ -0,0 +1,114 @@
+# -*- 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")