dont use mapset

lib/alerts/alert.ex

@@ -152,13 +152,13 @@ defmodule Alerts.Alert do
   defp set_direction_id(%InformedEntity{} = entity) do
     stop = Stops.Repo.get(entity.stop)
 
-    if entity.direction_id == MapSet.new() && stop.child_ids == [] do
+    if entity.direction_id == nil && stop.child_ids == [] do
       direction_id =
         stop.id
         |> RoutePatterns.Repo.by_stop_id()
         |> Enum.filter(&(&1.route_id == entity.route))
         |> Enum.map(& &1.direction_id)
-        |> MapSet.new()
+        |> List.first()
 
       %InformedEntity{entity | direction_id: direction_id}
     else

lib/alerts/informed_entity.ex

@@ -5,13 +5,13 @@ defmodule Alerts.InformedEntity do
             route_type: nil,
             stop: nil,
             trip: nil,
-            direction_id: MapSet.new(),
+            direction_id: nil,
             facility: nil,
             activities: @empty_activities
 
   @type t :: %Alerts.InformedEntity{
           activities: MapSet.t(activity),
-          direction_id: MapSet.t(integer()),
+          direction_id: 0 | 1 | nil,
           facility: String.t() | nil,
           route: String.t() | nil,
           route_type: String.t() | nil,

lib/alerts/informed_entity_set.ex

@@ -59,11 +59,6 @@ defmodule Alerts.InformedEntitySet do
     Map.put(set, :activities, map_set)
   end
 
-  defp add_entity_field_to_set({:direction_id, %MapSet{} = value}, set) do
-    map_set = MapSet.union(set.direction_id, MapSet.new(value))
-    Map.put(set, :direction_id, map_set)
-  end
-
   defp add_entity_field_to_set({key, value}, set) do
     map_set = Map.get(set, key)
     map_set = MapSet.put(map_set, value)

lib/alerts/parser.ex

@@ -45,20 +45,12 @@ defmodule Alerts.Parser do
         route: entity["route"],
         stop: entity["stop"],
         trip: entity["trip"],
-        direction_id: do_direction_id(entity["direction_id"]),
+        direction_id: entity["direction_id"],
         facility: entity["facility"],
         activities: MapSet.new(Enum.map(entity["activities"], &do_activity/1))
       }
     end
 
-    defp do_direction_id(nil) do
-      MapSet.new()
-    end
-
-    defp do_direction_id(direction_id) do
-      MapSet.new([direction_id])
-    end
-
     @spec do_activity(String.t()) :: Alerts.InformedEntity.activity_type()
     defp do_activity("BOARD"), do: :board
     defp do_activity("EXIT"), do: :exit

lib/route_patterns/repo.ex

@@ -54,11 +54,6 @@ defmodule RoutePatterns.Repo do
     |> api_all()
   end
 
-  def by_route_and_stop_id(route_id, stop_id) do
-    [route: route_id, stop: stop_id]
-    |> api_all()
-  end
-
   @decorate cacheable(cache: @cache, on_error: :nothing, opts: [ttl: @ttl])
   defp api_all(opts) do
     case RoutePatternsApi.all(opts) do