add payment model and migration

gaehsnitz/migrations/0001_initial.py

@@ -0,0 +1,25 @@
+# Generated by Django 4.0.6 on 2022-07-12 18:34
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Payment',
+            fields=[
+                ('id', models.SmallAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('other_party', models.TextField()),
+                ('topic', models.PositiveSmallIntegerField(choices=[(0, 'Spenden/Vorauszahlungen'), (1, 'Eintrittsgeld'), (2, 'Getränke-/Essensverkauf'), (10, 'Gelände'), (11, 'Bands'), (12, 'Getränke-/Essenseinkauf')])),
+                ('amount', models.PositiveIntegerField()),
+                ('date', models.DateField()),
+                ('note', models.TextField(blank=True)),
+            ],
+        ),
+    ]

gaehsnitz/models.py

@@ -0,0 +1,25 @@
+from django.db import models
+
+
+class Payment(models.Model):
+    class Topic(models.IntegerChoices):
+        # positive
+        donation = 0, "Spenden/Vorauszahlungen"
+        admission_fee = 1, "Eintrittsgeld"
+        supply_sale = 2, "Getränke-/Essensverkauf"
+        # negative
+        site = 10, "Gelände"
+        bands = 11, "Bands"
+        supply_purchase = 12, "Getränke-/Essenseinkauf"
+
+    other_party = models.TextField()
+    topic = models.PositiveSmallIntegerField(choices=Topic.choices)
+    amount = models.PositiveIntegerField()
+    date = models.DateField()
+    note = models.TextField(blank=True)
+
+    def is_incoming(self):
+        return self.topic < 10
+
+    def is_outgoing(self):
+        return not self.is_incoming()