Put HTTPSignatures, WebFinger and ActivityStream alongside with ActivityPub

lib/federation/web_finger/xml_builder.ex

@@ -0,0 +1,46 @@
+# Portions of this file are derived from Pleroma:
+# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social>
+# SPDX-License-Identifier: AGPL-3.0-only
+# Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/xml_builder.ex
+
+defmodule Mobilizon.Federation.WebFinger.XmlBuilder do
+  @moduledoc """
+  Builds XRD for WebFinger host_meta.
+  """
+
+  def to_xml({tag, attributes, content}) do
+    open_tag = make_open_tag(tag, attributes)
+    content_xml = to_xml(content)
+
+    "<#{open_tag}>#{content_xml}</#{tag}>"
+  end
+
+  def to_xml({tag, %{} = attributes}) do
+    open_tag = make_open_tag(tag, attributes)
+
+    "<#{open_tag} />"
+  end
+
+  def to_xml({tag, content}), do: to_xml({tag, %{}, content})
+
+  def to_xml(content) when is_binary(content), do: to_string(content)
+
+  def to_xml(content) when is_list(content) do
+    content
+    |> Enum.map(&to_xml/1)
+    |> Enum.join()
+  end
+
+  def to_xml(%NaiveDateTime{} = time), do: NaiveDateTime.to_iso8601(time)
+
+  def to_doc(content), do: ~s(<?xml version="1.0" encoding="UTF-8"?>) <> to_xml(content)
+
+  defp make_open_tag(tag, attributes) do
+    attributes_string =
+      attributes
+      |> Enum.map(fn {attribute, value} -> "#{attribute}=\"#{value}\"" end)
+      |> Enum.join(" ")
+
+    [tag, attributes_string] |> Enum.join(" ") |> String.trim()
+  end
+end