core/counter: add generic operation logs and implements it for Sellings and Refilling deletions

core/migrations/0034_operationlog.py

@@ -0,0 +1,52 @@
+# Generated by Django 2.2.6 on 2019-11-13 21:17
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("core", "0033_auto_20191006_0049"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="OperationLog",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("date", models.DateTimeField(auto_now_add=True, verbose_name="date")),
+                ("label", models.CharField(max_length=255, verbose_name="label")),
+                (
+                    "operation_type",
+                    models.CharField(
+                        choices=[
+                            ("SELLING_DELETION", "Selling deletion"),
+                            ("REFILLING_DELETION", "Refilling deletion"),
+                        ],
+                        default="SELLING_DELETION",
+                        max_length=40,
+                        verbose_name="operation type",
+                    ),
+                ),
+                (
+                    "operator",
+                    models.ForeignKey(
+                        null=True,
+                        on_delete=django.db.models.deletion.SET_NULL,
+                        related_name="logs",
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+            ],
+        ),
+    ]