Add actual policy file

steal_emoji_policy.ex

@@ -0,0 +1,79 @@
+defmodule Pleroma.Web.ActivityPub.MRF.StealEmojiPolicy do
+  require Logger
+  @moduledoc "Detect new emoji and steal them"
+  @behaviour Pleroma.Web.ActivityPub.MRF
+
+  defp has_emojo(installed_emoji, str) do
+    result = for emojo <- installed_emoji, elem(emojo, 0) == str, do: true
+    length(result) == 1
+  end
+
+  @impl true
+  def filter(%{"object" => %{"emoji" => foreign_emoji}} = object) do
+    num_foreign_emoji = Kernel.map_size(foreign_emoji)
+
+    if num_foreign_emoji > 0 do
+      Logger.debug("#{num_foreign_emoji} EMOJI TO PROCESS")
+      installed_emoji = Pleroma.Emoji.get_all()
+
+      new_files =
+        for {emojo_shortcode, emojo_url} <- foreign_emoji,
+            !has_emojo(installed_emoji, emojo_shortcode) do
+          Logger.debug("HANDLING EMOJO")
+          cond do
+            String.contains?(emojo_shortcode, "/") ->
+              Logger.error("BAD EMOJO SHORTCODE: #{emojo_shortcode}")
+
+            !String.starts_with(emojo_url, "https://") ->
+              Logger.error("BAD EMOJO URL: #{emojo_url}")
+
+            true ->
+              Logger.debug("GOOD EMOJO")
+              remote_emojo = HTTPoison.get!(emojo_url)
+
+              if remote_emojo.status_code == 200 do
+                with {:ok, current_dir} <- File.cwd() do
+                  new_file =
+                    current_dir <>
+                      "/priv/static/emoji/stolen/" <> emojo_shortcode <> Path.extname(emojo_url)
+
+                  try do
+                    {:ok, file} = File.open(new_file, [:write])
+                    IO.binwrite(file, remote_emojo.body)
+                    File.close(file)
+                    Logger.debug("SAVED EMOJO")
+                  rescue
+                    RuntimeError ->
+                      _ = "Error"
+                      Logger.error("FAILED TO SAVE EMOJO: #{new_file}")
+                  end
+
+                  new_file
+                end
+              else
+                Logger.error("FAILED TO DOWNLOAD EMOJO: #{emojo_url}")
+              end
+          end
+        end
+
+      Logger.debug("EMOJI FILES: #{inspect(new_files)}")
+
+      if length(new_files) > 0 do
+        Logger.debug("RELOADING EMOJI")
+        Pleroma.Emoji.reload()
+      else
+        Logger.debug("NO EMOJI TO LOAD")
+      end
+    end
+
+    {:ok, object}
+  end
+
+  @impl true
+  def filter(object) do
+    {:ok, object}
+  end
+
+  @impl true
+  def describe, do: {:ok, %{}}
+end