2 files changed, 75 insertions, 8 deletions
diff --git a/lib/pleroma/web/activity_pub/mrf/keyword_policy.ex b/lib/pleroma/web/activity_pub/mrf/keyword_policy.ex
new file mode 100644
index 000000000..ce6d2e529
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/mrf/keyword_policy.ex
@@ -0,0 +1,73 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.KeywordPolicy do
+  @behaviour Pleroma.Web.ActivityPub.MRF
+  defp string_matches?(string, pattern) when is_binary(pattern) do
+    String.contains?(string, pattern)
+  end
+
+  defp string_matches?(string, pattern) do
+    String.match?(string, pattern)
+  end
+
+  defp check_reject(%{"object" => %{"content" => content}} = message) do
+    if Enum.any?(Pleroma.Config.get([:mrf_keyword, :reject]), fn pattern ->
+         string_matches?(content, pattern)
+       end) do
+      {:reject, nil}
+    else
+      {:ok, message}
+    end
+  end
+
+  defp check_ftl_removal(%{"to" => to, "object" => %{"content" => content}} = message) do
+    if "https://www.w3.org/ns/activitystreams#Public" in to and
+         Enum.any?(Pleroma.Config.get([:mrf_keyword, :federated_timeline_removal]), fn pattern ->
+           string_matches?(content, pattern)
+         end) do
+      to = List.delete(to, "https://www.w3.org/ns/activitystreams#Public")
+      cc = ["https://www.w3.org/ns/activitystreams#Public" | message["cc"] || []]
+
+      message =
+        message
+        |> Map.put("to", to)
+        |> Map.put("cc", cc)
+
+      {:ok, message}
+    else
+      {:ok, message}
+    end
+  end
+
+  defp check_replace(%{"object" => %{"content" => content}} = message) do
+    content =
+      Enum.reduce(Pleroma.Config.get([:mrf_keyword, :replace]), content, fn {pattern, replacement},
+                                                                            acc ->
+        String.replace(acc, pattern, replacement)
+      end)
+
+    {:ok, put_in(message["object"]["content"], content)}
+  end
+
+  @impl true
+  def filter(%{"object" => %{"content" => nil}} = message) do
+    {:ok, message}
+  end
+
+  @impl true
+  def filter(%{"type" => "Create", "object" => %{"content" => _content}} = message) do
+    with {:ok, message} <- check_reject(message),
+         {:ok, message} <- check_ftl_removal(message),
+         {:ok, message} <- check_replace(message) do
+      {:ok, message}
+    else
+      _e ->
+        {:reject, nil}
+    end
+  end
+
+  @impl true
+  def filter(message), do: {:ok, message}
+end
diff --git a/lib/pleroma/web/activity_pub/utils.ex b/lib/pleroma/web/activity_pub/utils.ex
index 964e11c9d..da6cca4dd 100644
--- a/lib/pleroma/web/activity_pub/utils.ex
+++ b/lib/pleroma/web/activity_pub/utils.ex
@@ -142,14 +142,8 @@ defmodule Pleroma.Web.ActivityPub.Utils do
     context = context || generate_id("contexts")
     changeset = Object.context_mapping(context)
 
-    case Repo.insert(changeset) do
-      {:ok, object} ->
-        object
-
-      # This should be solved by an upsert, but it seems ecto
-      # has problems accessing the constraint inside the jsonb.
-      {:error, _} ->
-        Object.get_cached_by_ap_id(context)
+    with {:ok, object} <- Object.insert_or_get(changeset) do
+      object
     end
   end