1 files changed, 139 insertions, 0 deletions
diff --git a/lib/pleroma/web/activity_pub/mrf/tag_policy.ex b/lib/pleroma/web/activity_pub/mrf/tag_policy.ex
new file mode 100644
index 000000000..b242e44e6
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/mrf/tag_policy.ex
@@ -0,0 +1,139 @@
+# 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.TagPolicy do
+  alias Pleroma.User
+  @behaviour Pleroma.Web.ActivityPub.MRF
+
+  defp get_tags(%User{tags: tags}) when is_list(tags), do: tags
+  defp get_tags(_), do: []
+
+  defp process_tag(
+         "mrf_tag:media-force-nsfw",
+         %{"type" => "Create", "object" => %{"attachment" => child_attachment} = object} = message
+       )
+       when length(child_attachment) > 0 do
+    tags = (object["tag"] || []) ++ ["nsfw"]
+
+    object =
+      object
+      |> Map.put("tags", tags)
+      |> Map.put("sensitive", true)
+
+    message = Map.put(message, "object", object)
+
+    {:ok, message}
+  end
+
+  defp process_tag(
+         "mrf_tag:media-strip",
+         %{"type" => "Create", "object" => %{"attachment" => child_attachment} = object} = message
+       )
+       when length(child_attachment) > 0 do
+    object = Map.delete(object, "attachment")
+    message = Map.put(message, "object", object)
+
+    {:ok, message}
+  end
+
+  defp process_tag(
+         "mrf_tag:force-unlisted",
+         %{"type" => "Create", "to" => to, "cc" => cc, "actor" => actor} = message
+       ) do
+    user = User.get_cached_by_ap_id(actor)
+
+    if Enum.member?(to, "https://www.w3.org/ns/activitystreams#Public") do
+      to =
+        List.delete(to, "https://www.w3.org/ns/activitystreams#Public") ++ [user.follower_address]
+
+      cc =
+        List.delete(cc, user.follower_address) ++ ["https://www.w3.org/ns/activitystreams#Public"]
+
+      object =
+        message["object"]
+        |> Map.put("to", to)
+        |> Map.put("cc", cc)
+
+      message =
+        message
+        |> Map.put("to", to)
+        |> Map.put("cc", cc)
+        |> Map.put("object", object)
+
+      {:ok, message}
+    else
+      {:ok, message}
+    end
+  end
+
+  defp process_tag(
+         "mrf_tag:sandbox",
+         %{"type" => "Create", "to" => to, "cc" => cc, "actor" => actor} = message
+       ) do
+    user = User.get_cached_by_ap_id(actor)
+
+    if Enum.member?(to, "https://www.w3.org/ns/activitystreams#Public") or
+         Enum.member?(cc, "https://www.w3.org/ns/activitystreams#Public") do
+      to =
+        List.delete(to, "https://www.w3.org/ns/activitystreams#Public") ++ [user.follower_address]
+
+      cc = List.delete(cc, "https://www.w3.org/ns/activitystreams#Public")
+
+      object =
+        message["object"]
+        |> Map.put("to", to)
+        |> Map.put("cc", cc)
+
+      message =
+        message
+        |> Map.put("to", to)
+        |> Map.put("cc", cc)
+        |> Map.put("object", object)
+
+      {:ok, message}
+    else
+      {:ok, message}
+    end
+  end
+
+  defp process_tag(
+         "mrf_tag:disable-remote-subscription",
+         %{"type" => "Follow", "actor" => actor} = message
+       ) do
+    user = User.get_cached_by_ap_id(actor)
+
+    if user.local == true do
+      {:ok, message}
+    else
+      {:reject, nil}
+    end
+  end
+
+  defp process_tag("mrf_tag:disable-any-subscription", %{"type" => "Follow"}), do: {:reject, nil}
+
+  defp process_tag(_, message), do: {:ok, message}
+
+  def filter_message(actor, message) do
+    User.get_cached_by_ap_id(actor)
+    |> get_tags()
+    |> Enum.reduce({:ok, message}, fn
+      tag, {:ok, message} ->
+        process_tag(tag, message)
+
+      _, error ->
+        error
+    end)
+  end
+
+  @impl true
+  def filter(%{"object" => target_actor, "type" => "Follow"} = message),
+    do: filter_message(target_actor, message)
+
+  @impl true
+  def filter(%{"actor" => actor, "type" => "Create"} = message),
+    do: filter_message(actor, message)
+
+  @impl true
+  def filter(message), do: {:ok, message}
+end