Expose correct relay address in federation

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/graphql/resolvers/admin.ex

@@ -468,12 +468,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
         context: %{current_user: %User{role: role}}
       })
       when is_admin(role) do
-    has_relay = Actors.has_relay?(domain)
     remote_relay = Actors.get_relay(domain)
     local_relay = Relay.get_actor()
 
     result = %{
-      has_relay: has_relay,
+      has_relay: !is_nil(remote_relay),
+      relay_address:
+        if(is_nil(remote_relay),
+          do: nil,
+          else: "#{remote_relay.preferred_username}@#{remote_relay.domain}"
+        ),
       follower_status: follow_status(remote_relay, local_relay),
       followed_status: follow_status(local_relay, remote_relay)
     }

lib/graphql/schema/admin.ex

@@ -216,6 +216,10 @@ defmodule Mobilizon.GraphQL.Schema.AdminType do
       description:
         "Whether this instance has a relay, meaning that it's a Mobilizon instance that we can follow"
     )
+
+    field(:relay_address, :string,
+      description: "If this instance has a relay, it's federated username"
+    )
   end
 
   @desc """

lib/mobilizon/actors/actors.ex

@@ -1297,16 +1297,6 @@ defmodule Mobilizon.Actors do
     :ok
   end
 
-  @spec has_relay?(String.t()) :: boolean()
-  def has_relay?(domain) do
-    Actor
-    |> where(
-      [a],
-      a.preferred_username == "relay" and a.domain == ^domain and a.type == :Application
-    )
-    |> Repo.exists?()
-  end
-
   @doc """
   Returns a relay actor, either `relay@domain` (Mobilizon) or `domain@domain` (Mastodon)
   """