Default to 1 registration in admin, "admitted"

events/admin.py

@@ -1,10 +1,21 @@
 from django.contrib import admin
+from django import forms
 
 from .models import Event, EventRegistration
 
 
-class RegistrationInline(admin.StackedInline):
+class RegistrationFormSet(forms.BaseInlineFormSet):
+    def __init__(self, *args, **kwargs):
+        kwargs["initial"] = [
+            {"state": EventRegistration.ADMITTED}
+        ]
+        super().__init__(*args, **kwargs)
+
+
+class RegistrationInline(admin.TabularInline):
     model = EventRegistration
+    extra = 1
+    formset = RegistrationFormSet
 
 class EventAdmin(admin.ModelAdmin):
     inlines = [RegistrationInline]