From f6d09fafee83514889bbcf6531e0bc01e33b0b16 Mon Sep 17 00:00:00 2001
From: "Haelwenn (lanodan) Monnier" <contact@hacktivis.me>
Date: Sun, 1 Mar 2020 09:48:32 +0100
Subject: [PATCH] Add support for remote favicons

---
 lib/pleroma/user.ex                           | 30 +++++++++++++++++++
 .../web/mastodon_api/views/account_view.ex    |  3 +-
 test/support/http_request_mock.ex             |  4 +++
 .../mastodon_api/views/account_view_test.exs  |  2 ++
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index e98332744..25ea112a2 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -2253,4 +2253,34 @@ def sanitize_html(%User{} = user, filter) do
     |> Map.put(:bio, HTML.filter_tags(user.bio, filter))
     |> Map.put(:fields, fields)
   end
+
+  def get_cached_favicon(%User{} = user) do
+    key = "favicon:#{user.ap_id}"
+    Cachex.fetch!(:user_cache, key, fn _ -> get_favicon(user) end)
+  end
+
+  def get_cached_favicon(_user) do
+    nil
+  end
+
+  def get_favicon(user) do
+    try do
+      with url <- user.ap_id,
+           true <- is_binary(url),
+           {:ok, %Tesla.Env{body: html}} <- Pleroma.HTTP.get(url),
+           favicon_rel <-
+             html
+             |> Floki.parse_document!()
+             |> Floki.attribute("link[rel=icon]", "href")
+             |> List.first(),
+           favicon_url <- URI.merge(URI.parse(url), favicon_rel) |> to_string(),
+           true <- is_binary(favicon_url) do
+        favicon_url
+      else
+        _ -> nil
+      end
+    rescue
+      _ -> nil
+    end
+  end
 end
diff --git a/lib/pleroma/web/mastodon_api/views/account_view.ex b/lib/pleroma/web/mastodon_api/views/account_view.ex
index a6e64b4ab..efe835e3c 100644
--- a/lib/pleroma/web/mastodon_api/views/account_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/account_view.ex
@@ -245,7 +245,8 @@ defp do_render("show.json", %{user: user} = opts) do
         hide_favorites: user.hide_favorites,
         relationship: relationship,
         skip_thread_containment: user.skip_thread_containment,
-        background_image: image_url(user.background) |> MediaProxy.url()
+        background_image: image_url(user.background) |> MediaProxy.url(),
+        favicon: User.get_cached_favicon(user) |> MediaProxy.url()
       }
     }
     |> maybe_put_role(user, opts[:for])
diff --git a/test/support/http_request_mock.ex b/test/support/http_request_mock.ex
index da04ac6f1..4d33c6250 100644
--- a/test/support/http_request_mock.ex
+++ b/test/support/http_request_mock.ex
@@ -1342,6 +1342,10 @@ def get("https://relay.mastodon.host/actor", _, _, _) do
     {:ok, %Tesla.Env{status: 200, body: File.read!("test/fixtures/relay/relay.json")}}
   end
 
+  def get("http://localhost:4001/users/" <> _, _, _, _) do
+    {:ok, %Tesla.Env{status: 200, body: File.read!("test/fixtures/tesla_mock/7369654.html")}}
+  end
+
   def get(url, query, body, headers) do
     {:error,
      "Mock response not implemented for GET #{inspect(url)}, #{query}, #{inspect(body)}, #{
diff --git a/test/web/mastodon_api/views/account_view_test.exs b/test/web/mastodon_api/views/account_view_test.exs
index 80b1f734c..e01a7c1ee 100644
--- a/test/web/mastodon_api/views/account_view_test.exs
+++ b/test/web/mastodon_api/views/account_view_test.exs
@@ -75,6 +75,7 @@ test "Represent a user account" do
       pleroma: %{
         ap_id: user.ap_id,
         background_image: "https://example.com/images/asuka_hospital.png",
+        favicon: nil,
         confirmation_pending: false,
         tags: [],
         is_admin: false,
@@ -152,6 +153,7 @@ test "Represent a Service(bot) account" do
       pleroma: %{
         ap_id: user.ap_id,
         background_image: nil,
+        favicon: nil,
         confirmation_pending: false,
         tags: [],
         is_admin: false,