refactor: parse all elevator redundancy categories

Rather than only storing whether an elevator's redundancy category
is "nearby", we now store all categories, including any associated
summary text. This is a prerequisite for displaying redundancy
summaries on the system-wide outages view.

Also extracts this logic into a dedicated module which can be mocked for
testing, removing the need for a separate fixture file.

config/test.exs

@@ -131,9 +131,7 @@ config :screens,
         headway_headsign: "Test"
       }
     ]
-  },
-  elevator_redundancy_data_path:
-    Path.join(~w[#{File.cwd!()} test fixtures elevator_redundancy_data.json])
+  }
 
 config :screens, ScreensWeb.AuthManager, secret_key: "test key"
 

lib/screens/elevator.ex

@@ -0,0 +1,47 @@
+defmodule Screens.Elevator do
+  @moduledoc """
+  Exposes hand-authored data about elevator accessibility that is currently owned by the Screens
+  team and not (yet?) available in GTFS.
+  """
+
+  alias Screens.Facilities.Facility
+  alias Screens.Log
+
+  @enforce_keys ~w[id redundancy]a
+  defstruct @enforce_keys
+
+  @type t :: %__MODULE__{id: Facility.id(), redundancy: redundancy()}
+
+  @type redundancy ::
+          :nearby
+          | :in_station
+          | {:different_station, summary :: String.t()}
+          | {:contact, summary :: String.t()}
+
+  @data :screens
+        |> :code.priv_dir()
+        |> Path.join("elevators.json")
+        |> File.read!()
+        |> Jason.decode!()
+
+  @callback get(Facility.id()) :: t() | nil
+  def get(id) do
+    case Map.get(@data, id) do
+      %{"redundancy" => 1} ->
+        %__MODULE__{id: id, redundancy: :nearby}
+
+      %{"redundancy" => 2} ->
+        %__MODULE__{id: id, redundancy: :in_station}
+
+      %{"redundancy" => 3, "summary" => summary} ->
+        %__MODULE__{id: id, redundancy: {:different_station, summary}}
+
+      %{"redundancy" => 4, "summary" => summary} ->
+        %__MODULE__{id: id, redundancy: {:contact, summary}}
+
+      _other ->
+        Log.warning("elevator_redundancy_not_found", id: id)
+        nil
+    end
+  end
+end

lib/screens/v2/candidate_generator/elevator/closures.ex

@@ -2,6 +2,7 @@ defmodule Screens.V2.CandidateGenerator.Elevator.Closures do
   @moduledoc false
 
   alias Screens.Alerts.{Alert, InformedEntity}
+  alias Screens.Elevator
   alias Screens.Log
   alias Screens.Routes.Route
   alias Screens.Stops.Stop
@@ -17,29 +18,20 @@ defmodule Screens.V2.CandidateGenerator.Elevator.Closures do
   alias Screens.V2.WidgetInstance.Elevator.Closure
   alias Screens.V2.WidgetInstance.Serializer.RoutePill
   alias ScreensConfig.Screen
-  alias ScreensConfig.V2.Elevator
+  alias ScreensConfig.V2.Elevator, as: ElevatorConfig
 
   import Screens.Inject
 
   @alert injected(Alert)
+  @elevator injected(Elevator)
   @facility injected(Screens.Facilities.Facility)
   @route injected(Route)
   @stop injected(Stop)
 
-  @elevator_redundancy_data :screens
-                            |> Application.compile_env(
-                              :elevator_redundancy_data_path,
-                              :screens
-                              |> :code.priv_dir()
-                              |> Path.join("elevators/elevator_redundancy_data.json")
-                            )
-                            |> File.read!()
-                            |> Jason.decode!()
-
   @spec elevator_status_instances(Screen.t(), NormalHeader.t(), Footer.t()) ::
           list(WidgetInstance.t())
   def elevator_status_instances(
-        %Screen{app_params: %Elevator{elevator_id: elevator_id} = config},
+        %Screen{app_params: %ElevatorConfig{elevator_id: elevator_id} = config},
         header_instance,
         footer_instance
       ) do
@@ -187,11 +179,9 @@ defmodule Screens.V2.CandidateGenerator.Elevator.Closures do
   defp has_nearby_redundancy?(%Alert{
          informed_entities: [%{facility: %{id: informed_facility_id}} | _]
        }) do
-    if data = @elevator_redundancy_data[informed_facility_id] do
-      data["nearby_redundancy?"]
-    else
-      Log.warning("elevator_redundancy_not_found", facility_id: informed_facility_id)
-      false
+    case @elevator.get(informed_facility_id) do
+      %Elevator{redundancy: :nearby} -> true
+      _ -> false
     end
   end
 end