Add anonymous and remote participations

lib/web/controllers/page_controller.ex

@@ -4,6 +4,9 @@ defmodule Mobilizon.Web.PageController do
   """
   use Mobilizon.Web, :controller
 
+  alias Mobilizon.Events.{Comment, Event}
+  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Tombstone
   alias Mobilizon.Web.Cache
 
   plug(:put_layout, false)
@@ -13,40 +16,65 @@ defmodule Mobilizon.Web.PageController do
 
   def actor(conn, %{"name" => name}) do
     {status, actor} = Cache.get_local_actor_by_name(name)
-    render_or_error(conn, &ok_status?/2, status, :actor, actor)
+    render_or_error(conn, &ok_status?/3, status, :actor, actor)
   end
 
   def event(conn, %{"uuid" => uuid}) do
     {status, event} = Cache.get_public_event_by_uuid_with_preload(uuid)
-    render_or_error(conn, &ok_status_and_is_visible?/2, status, :event, event)
+    render_or_error(conn, &checks?/3, status, :event, event)
   end
 
   def comment(conn, %{"uuid" => uuid}) do
     {status, comment} = Cache.get_comment_by_uuid_with_preload(uuid)
-    render_or_error(conn, &ok_status_and_is_visible?/2, status, :comment, comment)
+    render_or_error(conn, &checks?/3, status, :comment, comment)
+  end
+
+  def interact(conn, %{"uri" => uri}) do
+    case ActivityPub.fetch_object_from_url(uri) do
+      {:ok, %Event{uuid: uuid}} -> redirect(conn, to: "/events/#{uuid}")
+      {:ok, %Comment{uuid: uuid}} -> redirect(conn, to: "/comments/#{uuid}")
+      _ -> {:error, :not_found}
+    end
   end
 
   defp render_or_error(conn, check_fn, status, object_type, object) do
-    if check_fn.(status, object) do
-      case object do
-        %Mobilizon.Tombstone{} ->
-          conn
-          |> put_status(:gone)
-          |> render(object_type, object: object)
+    case check_fn.(conn, status, object) do
+      true ->
+        case object do
+          %Tombstone{} ->
+            conn
+            |> put_status(:gone)
+            |> render(object_type, object: object)
 
-        _ ->
-          render(conn, object_type, object: object)
-      end
-    else
-      {:error, :not_found}
+          _ ->
+            render(conn, object_type, object: object)
+        end
+
+      :remote ->
+        redirect(conn, external: object.url)
+
+      false ->
+        {:error, :not_found}
     end
   end
 
   defp is_visible?(%{visibility: v}), do: v in [:public, :unlisted]
-  defp is_visible?(%Mobilizon.Tombstone{}), do: true
+  defp is_visible?(%Tombstone{}), do: true
 
   defp ok_status?(status), do: status in [:ok, :commit]
-  defp ok_status?(status, _), do: ok_status?(status)
+  defp ok_status?(_conn, status, _), do: ok_status?(status)
 
-  defp ok_status_and_is_visible?(status, o), do: ok_status?(status) and is_visible?(o)
+  defp ok_status_and_is_visible?(_conn, status, o),
+    do: ok_status?(status) and is_visible?(o)
+
+  defp checks?(conn, status, o) do
+    if ok_status_and_is_visible?(conn, status, o) do
+      if is_local?(o) == :remote && get_format(conn) == "activity-json", do: :remote, else: true
+    else
+      false
+    end
+  end
+
+  defp is_local?(%Event{local: local}), do: if(local, do: true, else: :remote)
+  defp is_local?(%Comment{local: local}), do: if(local, do: true, else: :remote)
 end