[#2526] Allow for 0..n ZGW API groups to be configured

This is a first step towards allowing multiple ZGW backends
throughout the platform. To maintain backwards compatibility
with the current datamodel, we proxy the current service
config fields to the new ZGWApiGroupConfig model as we
work our way towards making all ZGW client invocations
multi-backend aware.

src/open_inwoner/openzaak/admin.py

@@ -18,23 +18,20 @@
     ZaakTypeInformatieObjectTypeConfig,
     ZaakTypeResultaatTypeConfig,
     ZaakTypeStatusTypeConfig,
+    ZGWApiGroupConfig,
 )
 
 
+class ZGWApiGroupConfig(admin.StackedInline):
+    model = ZGWApiGroupConfig
+    extra = 0
+
+
 @admin.register(OpenZaakConfig)
 class OpenZaakConfigAdmin(SingletonModelAdmin):
+    inlines = [ZGWApiGroupConfig]
+
     fieldsets = (
-        (
-            None,
-            {
-                "fields": [
-                    "zaak_service",
-                    "catalogi_service",
-                    "document_service",
-                    "form_service",
-                ]
-            },
-        ),
         (
             "Advanced options",
             {

src/open_inwoner/openzaak/migrations/0049_add_multiple_zgw_backends_config.py

@@ -0,0 +1,91 @@
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("zgw_consumers", "0019_alter_service_uuid"),
+        ("openzaak", "0047_delete_statustranslation"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="ZGWApiGroupConfig",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                (
+                    "name",
+                    models.CharField(
+                        help_text="A recognisable name for this set of ZGW APIs.",
+                        max_length=255,
+                        verbose_name="name",
+                    ),
+                ),
+                (
+                    "drc_service",
+                    models.ForeignKey(
+                        limit_choices_to={"api_type": "drc"},
+                        null=True,
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="zgwset_drc_config",
+                        to="zgw_consumers.service",
+                        verbose_name="Documenten API",
+                    ),
+                ),
+                (
+                    "form_service",
+                    models.OneToOneField(
+                        limit_choices_to={"api_type": "orc"},
+                        null=True,
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="zgwset_orc_form_config",
+                        to="zgw_consumers.service",
+                        verbose_name="Form API",
+                    ),
+                ),
+                (
+                    "open_zaak_config",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="api_groups",
+                        to="openzaak.openzaakconfig",
+                    ),
+                ),
+                (
+                    "zrc_service",
+                    models.ForeignKey(
+                        limit_choices_to={"api_type": "zrc"},
+                        null=True,
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="zgwset_zrc_config",
+                        to="zgw_consumers.service",
+                        verbose_name="Zaken API",
+                    ),
+                ),
+                (
+                    "ztc_service",
+                    models.ForeignKey(
+                        limit_choices_to={"api_type": "ztc"},
+                        null=True,
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="zgwset_ztc_config",
+                        to="zgw_consumers.service",
+                        verbose_name="Catalogi API",
+                    ),
+                ),
+            ],
+            options={
+                "verbose_name": "ZGW API set",
+                "verbose_name_plural": "ZGW API sets",
+            },
+        ),
+    ]

src/open_inwoner/openzaak/migrations/0050_migrate_zgw_root_fields_to_multi_backend.py

@@ -0,0 +1,55 @@
+import logging
+from django.db import migrations
+
+
+logger = logging.getLogger(__name__)
+
+
+def migrate_zgw_service_config_to_default_group_config(apps, schema_editor):
+    ZGWApiGroupConfig = apps.get_model("openzaak", "ZGWApiGroupConfig")
+    OpenZaakConfig = apps.get_model("openzaak", "OpenZaakConfig")
+
+    for config in OpenZaakConfig.objects.all():
+        # OpenZaakConfig.objects.select_for_update().get(pk=config.pk)  # Lock
+        ZGWApiGroupConfig.objects.create(
+            name="Migrated default config",
+            zrc_service=config.zaak_service,
+            drc_service=config.document_service,
+            ztc_service=config.catalogi_service,
+            form_service=config.form_service,
+            open_zaak_config=config,
+        )
+
+
+def reverse_migrate_zgw_service_config_to_default_group_config(apps, schema_editor):
+    OpenZaakConfig = apps.get_model("openzaak", "OpenZaakConfig")
+
+    for config in OpenZaakConfig.objects.all():
+        if config.api_groups.count() == 0:
+            continue
+
+        if config.api_groups.count() > 1:
+            logger.warning("Multiple API groups to choose from, picking first")
+
+        group_config = config.api_groups.first()
+        config.zaak_service = group_config.zrc_service
+        config.document_service = group_config.drc_service
+        config.catalogi_service = group_config.ztc_service
+        config.form_service = group_config.form_service
+        config.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("zgw_consumers", "0019_alter_service_uuid"),
+        ("openzaak", "0049_add_multiple_zgw_backends_config"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            migrate_zgw_service_config_to_default_group_config,
+            reverse_code=reverse_migrate_zgw_service_config_to_default_group_config,
+            atomic=True,
+        ),
+    ]

src/open_inwoner/openzaak/migrations/0051_drop_root_zgw_fields.py

@@ -0,0 +1,34 @@
+# Generated by Django 4.2.11 on 2024-06-04 10:02
+
+import logging
+from django.db import migrations
+
+
+logger = logging.getLogger(__name__)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("zgw_consumers", "0019_alter_service_uuid"),
+        ("openzaak", "0050_migrate_zgw_root_fields_to_multi_backend"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="openzaakconfig",
+            name="catalogi_service",
+        ),
+        migrations.RemoveField(
+            model_name="openzaakconfig",
+            name="document_service",
+        ),
+        migrations.RemoveField(
+            model_name="openzaakconfig",
+            name="form_service",
+        ),
+        migrations.RemoveField(
+            model_name="openzaakconfig",
+            name="zaak_service",
+        ),
+    ]