3 files changed, 54 insertions, 6 deletions
diff --git a/lib/pleroma/activity/html.ex b/lib/pleroma/activity/html.ex
new file mode 100644
index 000000000..0bf393836
--- /dev/null
+++ b/lib/pleroma/activity/html.ex
@@ -0,0 +1,45 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Activity.HTML do
+  alias Pleroma.HTML
+  alias Pleroma.Object
+
+  @cachex Pleroma.Config.get([:cachex, :provider], Cachex)
+
+  def get_cached_scrubbed_html_for_activity(
+        content,
+        scrubbers,
+        activity,
+        key \\ "",
+        callback \\ fn x -> x end
+      ) do
+    key = "#{key}#{generate_scrubber_signature(scrubbers)}|#{activity.id}"
+
+    @cachex.fetch!(:scrubber_cache, key, fn _key ->
+      object = Object.normalize(activity, fetch: false)
+      HTML.ensure_scrubbed_html(content, scrubbers, object.data["fake"] || false, callback)
+    end)
+  end
+
+  def get_cached_stripped_html_for_activity(content, activity, key) do
+    get_cached_scrubbed_html_for_activity(
+      content,
+      FastSanitize.Sanitizer.StripTags,
+      activity,
+      key,
+      &HtmlEntities.decode/1
+    )
+  end
+
+  defp generate_scrubber_signature(scrubber) when is_atom(scrubber) do
+    generate_scrubber_signature([scrubber])
+  end
+
+  defp generate_scrubber_signature(scrubbers) do
+    Enum.reduce(scrubbers, "", fn scrubber, signature ->
+      "#{signature}#{to_string(scrubber)}"
+    end)
+  end
+end
diff --git a/lib/pleroma/activity/ir/topics.ex b/lib/pleroma/activity/ir/topics.ex
index d94395fc1..7a603a615 100644
--- a/lib/pleroma/activity/ir/topics.ex
+++ b/lib/pleroma/activity/ir/topics.ex
@@ -48,14 +48,12 @@ defmodule Pleroma.Activity.Ir.Topics do
     tags
   end
 
-  defp hashtags_to_topics(%{data: %{"tag" => tags}}) do
-    tags
-    |> Enum.filter(&is_bitstring(&1))
-    |> Enum.map(fn tag -> "hashtag:" <> tag end)
+  defp hashtags_to_topics(object) do
+    object
+    |> Object.hashtags()
+    |> Enum.map(fn hashtag -> "hashtag:" <> hashtag end)
   end
 
-  defp hashtags_to_topics(_), do: []
-
   defp remote_topics(%{local: true}), do: []
 
   defp remote_topics(%{actor: actor}) when is_binary(actor),
diff --git a/lib/pleroma/activity/queries.ex b/lib/pleroma/activity/queries.ex
index a6b02a889..4632651b0 100644
--- a/lib/pleroma/activity/queries.ex
+++ b/lib/pleroma/activity/queries.ex
@@ -14,6 +14,11 @@ defmodule Pleroma.Activity.Queries do
   alias Pleroma.Activity
   alias Pleroma.User
 
+  @spec by_id(query(), String.t()) :: query()
+  def by_id(query \\ Activity, id) do
+    from(a in query, where: a.id == ^id)
+  end
+
   @spec by_ap_id(query, String.t()) :: query
   def by_ap_id(query \\ Activity, ap_id) do
     from(