UPDATE

sensor_catalog/migrations/0003_sensorcatalog_code.py

@@ -0,0 +1,44 @@
+import re
+
+from django.db import migrations, models
+
+
+def _to_snake_case(value):
+    normalized = re.sub(r"[^a-zA-Z0-9]+", "_", (value or "").strip()).strip("_").lower()
+    return normalized or "sensor"
+
+
+def populate_sensor_codes(apps, schema_editor):
+    SensorCatalog = apps.get_model("sensor_catalog", "SensorCatalog")
+
+    used_codes = set()
+    for sensor in SensorCatalog.objects.all().order_by("id"):
+        base_code = _to_snake_case(sensor.name)
+        code = base_code
+        suffix = 2
+        while code in used_codes:
+            code = f"{base_code}_{suffix}"
+            suffix += 1
+        sensor.code = code
+        sensor.save(update_fields=["code"])
+        used_codes.add(code)
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("sensor_catalog", "0002_sensorcatalog_supported_power_sources"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="sensorcatalog",
+            name="code",
+            field=models.CharField(blank=True, db_index=True, default="", max_length=255),
+        ),
+        migrations.RunPython(populate_sensor_codes, migrations.RunPython.noop),
+        migrations.AlterField(
+            model_name="sensorcatalog",
+            name="code",
+            field=models.CharField(db_index=True, max_length=255, unique=True),
+        ),
+    ]