Implement state_ids federation endpoint

lib/matrix_server/key_server.ex

@@ -48,8 +48,6 @@ defmodule MatrixServer.KeyServer do
     object = Map.drop(object, [:signatures, :unsigned])
 
     with {:ok, json} <- MatrixServer.encode_canonical_json(object) do
-      IO.puts(json)
-
       signature =
         json
         |> :enacl.sign_detached(private_key)

lib/matrix_server/room_server.ex

@@ -60,10 +60,16 @@ defmodule MatrixServer.RoomServer do
     GenServer.call(pid, {:server_in_room, domain})
   end
 
+  @spec get_state_at_event(pid(), Event.t()) :: {[Event.t()], [Event.t()]}
   def get_state_at_event(pid, event) do
     GenServer.call(pid, {:get_state_at_event, event})
   end
 
+  @spec get_state_ids_at_event(pid(), Event.t()) :: {[String.t()], [String.t()]}
+  def get_state_ids_at_event(pid, event) do
+    GenServer.call(pid, {:get_state_ids_at_event, event})
+  end
+
   ### Implementation
 
   @impl true
@@ -128,6 +134,26 @@ defmodule MatrixServer.RoomServer do
     {:reply, {state_events, auth_chain}, state}
   end
 
+  def handle_call({:get_state_ids_at_event, %Event{room_id: room_id} = event}, _from, state) do
+    room_events =
+      Event
+      |> where([e], e.room_id == ^room_id)
+      |> select([e], {e.event_id, e})
+      |> Repo.all()
+      |> Enum.into(%{})
+
+    state_set = StateResolution.resolve(event, false)
+    state_events = Enum.map(state_set, fn {_, %Event{event_id: event_id}} -> event_id end)
+
+    auth_chain =
+      state_set
+      |> Map.values()
+      |> StateResolution.full_auth_chain(room_events)
+      |> MapSet.to_list()
+
+    {:reply, {state_events, auth_chain}, state}
+  end
+
   defp create_room_insert_events(room, account, %CreateRoom{
          room_version: room_version,
          preset: preset,

lib/matrix_server_web/federation/authenticate_server.ex

@@ -49,7 +49,6 @@ defmodule MatrixServerWeb.Federation.AuthenticateServer do
              ServerKeyInfo.with_fresh_signing_keys(origin) do
         Enum.find_value(keys, false, fn %SigningKey{signing_key: signing_key} ->
           with {:ok, decoded_key} <- MatrixServer.decode_base64(signing_key) do
-            IO.puts(encoded_object)
             MatrixServer.sign_verify(raw_sig, encoded_object, decoded_key)
           else
             _ -> false

lib/matrix_server_web/federation/controllers/event_controller.ex

@@ -43,6 +43,22 @@ defmodule MatrixServerWeb.Federation.EventController do
         "event_id" => event_id,
         "room_id" => room_id
       }) do
+    get_state_or_state_ids(conn, :state, origin, event_id, room_id)
+  end
+
+  def state(conn, _), do: put_error(conn, :missing_param)
+
+  def state_ids(%Plug.Conn{assigns: %{origin: origin}} = conn, %{
+        "event_id" => event_id,
+        "room_id" => room_id
+      }) do
+    get_state_or_state_ids(conn, :state_ids, origin, event_id, room_id)
+  end
+
+  def state_ids(conn, _), do: put_error(conn, :missing_param)
+
+  @spec get_state_or_state_ids(Plug.Conn.t(), :state | :state_ids, String.t(), String.t(), String.t()) :: Plug.Conn.t()
+  defp get_state_or_state_ids(conn, state_or_state_ids, origin, event_id, room_id) do
     query =
       Event
       |> where([e], e.event_id == ^event_id and e.room_id == ^room_id)
@@ -53,7 +69,11 @@ defmodule MatrixServerWeb.Federation.EventController do
         case RoomServer.get_room_server(room) do
           {:ok, pid} ->
             if RoomServer.server_in_room(pid, origin) do
-              {state_events, auth_chain} = RoomServer.get_state_at_event(pid, event)
+              {state_events, auth_chain} =
+                case state_or_state_ids do
+                  :state -> RoomServer.get_state_at_event(pid, event)
+                  :state_ids -> RoomServer.get_state_ids_at_event(pid, event)
+                end
 
               data = %{
                 auth_chain: auth_chain,
@@ -75,6 +95,4 @@ defmodule MatrixServerWeb.Federation.EventController do
         put_error(conn, :not_found, "Event or room not found.")
     end
   end
-
-  def state(conn, _), do: put_error(conn, :missing_param)
 end

lib/matrix_server_web/federation/http_client.ex

@@ -73,14 +73,19 @@ defmodule MatrixServerWeb.Federation.HTTPClient do
     Tesla.get(client, path)
   end
 
+  def get_state_ids(client, room_id, event_id) do
+    path =
+      RouteHelpers.event_path(Endpoint, :state_ids, room_id) |> Tesla.build_url(event_id: event_id)
+
+    Tesla.get(client, path)
+  end
+
   defp tesla_request(method, client, path, request_schema) do
     with {:ok, %Tesla.Env{body: body}} <- Tesla.request(client, url: path, method: method),
          %Ecto.Changeset{valid?: true} = cs <- apply(request_schema, :changeset, [body]) do
       {:ok, Ecto.Changeset.apply_changes(cs)}
     else
-      x ->
-        IO.inspect(x)
-        :error
+      _ -> :error
     end
   end
 end

lib/matrix_server_web/router.ex

@@ -66,6 +66,7 @@ defmodule MatrixServerWeb.Router do
       get "/query/profile", QueryController, :profile
       get "/event/:event_id", EventController, :event
       get "/state/:room_id", EventController, :state
+      get "/state_ids/:room_id", EventController, :state_ids
     end
   end