Extend 'Message' model admin

shiftregister/app/admin.py

@@ -57,5 +57,28 @@ class ShiftRegistrationAdmin(admin.ModelAdmin):
         return obj.helper.name
 
 
-admin.site.register(Message)
+class WasSentListFilter(admin.SimpleListFilter):
+    parameter_name = "sent"
+    title = "sent status"
+
+    def lookups(self, request, model_admin):
+        return [("0", "Not sent"), ("1", "Sent")]
+
+    def queryset(self, request, queryset):
+        if self.value() == "1":
+            return queryset.exclude(sent_at=None)
+        elif self.value() == "0":
+            return queryset.filter(sent_at=None)
+
+
+@admin.register(Message)
+class MessageAdmin(admin.ModelAdmin):
+    list_display = ("__str__", "was_sent")
+    list_filter = (WasSentListFilter,)
+
+    @admin.display(boolean=True)
+    def was_sent(self, obj):
+        return obj.sent_at is not None
+
+
 admin.site.register(LoginToken)

shiftregister/fallback/admin.py

@@ -4,6 +4,7 @@ from .models import TeamMember
 
 # Register your models here.
 
+
 @admin.register(TeamMember)
 class TeamMemberAdmin(admin.ModelAdmin):
     fields = ["name"]