Allow admins to upload domain blocklists

Fixes #804

bookwyrm/views/federation.py

@@ -1,6 +1,8 @@
 """ manage federated servers """
+import json
 from django.contrib.auth.decorators import login_required, permission_required
 from django.core.paginator import Paginator
+from django.db import transaction
 from django.shortcuts import get_object_or_404, redirect
 from django.template.response import TemplateResponse
 from django.utils.decorators import method_decorator
@@ -63,6 +65,39 @@ class AddFederatedServer(View):
         return redirect("settings-federated-server", server.id)
 
 
+class ImportServerBlocklist(View):
+    """ manually add a server """
+
+    def get(self, request):
+        """ add server form """
+        return TemplateResponse(request, "settings/server_blocklist.html")
+
+    def post(self, request):
+        """ add a server from the admin panel """
+        json_data = json.load(
+            request.FILES["json_file"]
+        )
+        failed = []
+        success_count = 0
+        for item in json_data:
+            server_name = item.get("instance")
+            if not server_name:
+                failed.append(item)
+                continue
+            info_link = item.get("url")
+
+            with transaction.atomic():
+                server, _ = models.FederatedServer.objects.get_or_create(
+                    server_name=server_name,
+                )
+                server.notes = info_link
+                server.save()
+                server.block()
+            success_count += 1
+        data = {"failed": failed, "succeeded": success_count}
+        return TemplateResponse(request, "settings/server_blocklist.html", data)
+
+
 @method_decorator(login_required, name="dispatch")
 @method_decorator(
     permission_required("bookwyrm.control_federation", raise_exception=True),