Restrict statuses that contain user's irreversible filters

lib/pleroma/filter.ex

@@ -34,10 +34,18 @@ defmodule Pleroma.Filter do
     Repo.one(query)
   end
 
-  def get_filters(%User{id: user_id} = _user) do
+  def get_active(query) do
+    from(f in query, where: is_nil(f.expires_at) or f.expires_at > ^NaiveDateTime.utc_now())
+  end
+
+  def get_irreversible(query) do
+    from(f in query, where: f.hide)
+  end
+
+  def get_by_user(query, %User{id: user_id} = _user) do
     query =
       from(
-        f in Pleroma.Filter,
+        f in query,
         where: f.user_id == ^user_id,
         order_by: [desc: :id]
       )
@@ -95,4 +103,34 @@ defmodule Pleroma.Filter do
     |> validate_required([:phrase, :context])
     |> Repo.update()
   end
+
+  def compose_regex(user_or_filters, format \\ :postgres)
+
+  def compose_regex(%User{} = user, format) do
+    __MODULE__
+    |> get_active()
+    |> get_irreversible()
+    |> get_by_user(user)
+    |> compose_regex(format)
+  end
+
+  def compose_regex([_ | _] = filters, format) do
+    phrases =
+      filters
+      |> Enum.map(& &1.phrase)
+      |> Enum.join("|")
+
+    case format do
+      :postgres ->
+        "\\y(#{phrases})\\y"
+
+      :re ->
+        ~r/\b#{phrases}\b/i
+
+      _ ->
+        nil
+    end
+  end
+
+  def compose_regex(_, _), do: nil
 end

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -10,6 +10,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
   alias Pleroma.Constants
   alias Pleroma.Conversation
   alias Pleroma.Conversation.Participation
+  alias Pleroma.Filter
   alias Pleroma.Maps
   alias Pleroma.Notification
   alias Pleroma.Object
@@ -961,6 +962,26 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
   defp restrict_instance(query, _), do: query
 
+  defp restrict_filtered(query, %{user: %User{} = user}) do
+    case Filter.compose_regex(user) do
+      nil ->
+        query
+
+      regex ->
+        from([activity, object] in query,
+          where:
+            fragment("not(?->>'content' ~* ?)", object.data, ^regex) or
+              activity.actor == ^user.ap_id
+        )
+    end
+  end
+
+  defp restrict_filtered(query, %{blocking_user: %User{} = user}) do
+    restrict_filtered(query, %{user: user})
+  end
+
+  defp restrict_filtered(query, _), do: query
+
   defp exclude_poll_votes(query, %{include_poll_votes: true}), do: query
 
   defp exclude_poll_votes(query, _) do
@@ -1099,6 +1120,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     |> restrict_muted_reblogs(restrict_muted_reblogs_opts)
     |> restrict_instance(opts)
     |> restrict_announce_object_actor(opts)
+    |> restrict_filtered(opts)
     |> Activity.restrict_deactivated_users()
     |> exclude_poll_votes(opts)
     |> exclude_chat_messages(opts)

lib/pleroma/web/mastodon_api/controllers/filter_controller.ex

@@ -22,7 +22,7 @@ defmodule Pleroma.Web.MastodonAPI.FilterController do
 
   @doc "GET /api/v1/filters"
   def index(%{assigns: %{user: user}} = conn, _) do
-    filters = Filter.get_filters(user)
+    filters = Filter.get_by_user(Filter, user)
 
     render(conn, "index.json", filters: filters)
   end