Mastodon API: Add exclude_visibilities parameter to the timeline and notification endpoints

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -596,6 +596,49 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
   defp restrict_visibility(query, _visibility), do: query
 
+  defp exclude_visibility(query, %{"exclude_visibilities" => visibility})
+       when is_list(visibility) do
+    if Enum.all?(visibility, &(&1 in @valid_visibilities)) do
+      from(
+        a in query,
+        where:
+          not fragment(
+            "activity_visibility(?, ?, ?) = ANY (?)",
+            a.actor,
+            a.recipients,
+            a.data,
+            ^visibility
+          )
+      )
+    else
+      Logger.error("Could not exclude visibility to #{visibility}")
+      query
+    end
+  end
+
+  defp exclude_visibility(query, %{"exclude_visibilities" => visibility})
+       when visibility in @valid_visibilities do
+    from(
+      a in query,
+      where:
+        not fragment(
+          "activity_visibility(?, ?, ?) = ?",
+          a.actor,
+          a.recipients,
+          a.data,
+          ^visibility
+        )
+    )
+  end
+
+  defp exclude_visibility(query, %{"exclude_visibilities" => visibility})
+       when visibility not in @valid_visibilities do
+    Logger.error("Could not exclude visibility to #{visibility}")
+    query
+  end
+
+  defp exclude_visibility(query, _visibility), do: query
+
   defp restrict_thread_visibility(query, _, %{skip_thread_containment: true} = _),
     do: query
 
@@ -960,6 +1003,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     |> restrict_muted_reblogs(opts)
     |> Activity.restrict_deactivated_users()
     |> exclude_poll_votes(opts)
+    |> exclude_visibility(opts)
   end
 
   def fetch_activities(recipients, opts \\ %{}, pagination \\ :keyset) do