refactor: remove unused parts of Signs UI config

PA/ESS sign modes configured in Signs UI were only used by "v1" screen
logic, so we no longer need to parse or store this data.

lib/screens/signs_ui_config/cache.ex

@@ -5,50 +5,19 @@ defmodule Screens.SignsUiConfig.Cache do
 
   use Screens.Cache.Client, table: :signs_ui_config
 
-  @type table_contents :: list(table_entry)
-
-  @type table_entry ::
-          {{:sign_mode, sign_id :: String.t()}, atom()}
-          | {{:time_ranges, zone_id :: String.t()}, %{optional(atom()) => time_range}}
+  @type entry :: {{:headways, headway_key()}, headway_values()}
 
+  @type headway_key :: String.t()
+  @type headway_values :: %{optional(atom()) => time_range()}
   @type time_range :: {low :: integer(), high :: integer()}
 
-  # Implementation notes:
-  # Table entries use 2-part tuples as keys, to distinguish sign mode entries from time range entries.
-  # They look like:
-  # - Sign mode entry: {{:sign_mode, sign_id}, mode}
-  # - Time ranges entry: {{:time_ranges, line_or_trunk}, %{off_peak: {low, high}, peak: {low, high}, saturday: {low, high}, sunday: {low, high}}}
-  #
-  # To look up the mode that a given sign is in for example, use:
-  # [[mode]] = :ets.match(@table, {{:sign_mode, sign_id}, :"$1})
-
-  def all_signs_in_headway_mode?(sign_ids) do
-    all_signs_in_modes?(sign_ids, [:headway])
-  end
-
-  def all_signs_inactive?(sign_ids) do
-    all_signs_in_modes?(sign_ids, [:off, :static_text])
-  end
-
-  def time_ranges(line_or_trunk) do
-    with_table default: nil do
-      case :ets.match(@table, {{:time_ranges, line_or_trunk}, :"$1"}) do
-        [[ranges]] -> ranges
-        [] -> nil
+  @spec headways(headway_key()) :: headway_values()
+  def headways(key) do
+    with_table default: %{} do
+      case :ets.match(@table, {{:headways, key}, :"$1"}) do
+        [[headways]] -> headways
+        [] -> %{}
       end
     end
   end
-
-  defp all_signs_in_modes?([], _modes), do: false
-
-  defp all_signs_in_modes?(sign_ids, modes) do
-    with_table default: false do
-      Enum.all?(sign_ids, fn sign_id ->
-        case :ets.match(@table, {{:sign_mode, sign_id}, :"$1"}) do
-          [[mode]] -> mode in modes
-          [] -> false
-        end
-      end)
-    end
-  end
 end

lib/screens/signs_ui_config/cache/engine.ex

@@ -3,9 +3,7 @@ defmodule Screens.SignsUiConfig.Cache.Engine do
   Engine for the Signs UI config cache.
   """
 
-  alias Screens.SignsUiConfig.Cache
-  alias Screens.SignsUiConfig.Fetch
-  alias Screens.SignsUiConfig.Parse
+  alias Screens.SignsUiConfig.{Fetch, Parse}
 
   @behaviour Screens.Cache.Engine
 
@@ -14,13 +12,9 @@ defmodule Screens.SignsUiConfig.Cache.Engine do
 
   @impl true
   def update_table(current_version) do
-    with {:ok, body, new_version} <- Fetch.fetch_config(current_version),
-         {:ok, deserialized} <- Jason.decode(body) do
-      config = Parse.parse_config(deserialized)
-
-      table_entries = config_to_table_entries(config)
-
-      {:replace, table_entries, new_version}
+    with {:ok, file_contents, new_version} <- Fetch.fetch_config(current_version),
+         {:ok, decoded_config} <- Jason.decode(file_contents) do
+      {:replace, Parse.parse_config(decoded_config), new_version}
     else
       :unchanged -> :unchanged
       _ -> :error
@@ -32,13 +26,4 @@ defmodule Screens.SignsUiConfig.Cache.Engine do
 
   @impl true
   def update_failure_error_log_threshold_minutes, do: 2
-
-  @spec config_to_table_entries(config :: tuple()) :: Cache.table_contents()
-  defp config_to_table_entries({sign_modes, time_ranges}) do
-    sign_modes = Enum.map(sign_modes, fn {id, mode} -> {{:sign_mode, id}, mode} end)
-
-    time_ranges = Enum.map(time_ranges, fn {id, ranges} -> {{:time_ranges, id}, ranges} end)
-
-    sign_modes ++ time_ranges
-  end
 end

lib/screens/signs_ui_config/parse.ex

@@ -1,18 +1,14 @@
 defmodule Screens.SignsUiConfig.Parse do
   @moduledoc false
 
-  def parse_config(%{"configured_headways" => headways, "signs" => signs}) do
-    time_ranges =
-      headways
-      |> Enum.map(fn {id, data} -> {id, parse_time_ranges(data)} end)
-      |> Enum.into(%{})
+  alias Screens.SignsUiConfig.Cache
 
-    sign_modes = parse_sign_modes(signs)
-
-    {sign_modes, time_ranges}
+  @spec parse_config(map()) :: list(Cache.entry())
+  def parse_config(%{"configured_headways" => headways}) do
+    Enum.map(headways, fn {key, value} -> {{:headways, key}, parse_headways(value)} end)
   end
 
-  defp parse_time_ranges(map) do
+  defp parse_headways(map) do
     for {key, field} <- [
           off_peak: "off_peak",
           peak: "peak",
@@ -27,18 +23,4 @@ defmodule Screens.SignsUiConfig.Parse do
 
   defp parse_time_range(%{"range_low" => low, "range_high" => high}), do: {low, high}
   defp parse_time_range(_), do: nil
-
-  defp parse_sign_modes(signs) do
-    signs
-    |> Enum.map(fn {_, %{"id" => id, "mode" => mode}} -> {id, parse_sign_mode(mode)} end)
-    |> Enum.into(%{})
-  end
-
-  for mode <- ~w[auto headway off static_text temporary_terminal]a do
-    mode_string = Atom.to_string(mode)
-
-    defp parse_sign_mode(unquote(mode_string)), do: unquote(mode)
-  end
-
-  defp parse_sign_mode(_), do: :unknown
 end

lib/screens/v2/candidate_generator/dup/departures.ex

@@ -363,10 +363,10 @@ defmodule Screens.V2.CandidateGenerator.Dup.Departures do
         not (branch_station?(stop_ids) and branch_alert?(interpreted_alert))
 
     if headway_mode? do
-      time_ranges = SignsUiConfig.Cache.time_ranges(headway_id)
+      headways = SignsUiConfig.Cache.headways(headway_id)
       current_time_period = Screens.Util.time_period(current_time)
 
-      case time_ranges do
+      case headways do
         %{^current_time_period => {lo, hi}} ->
           {:active, {lo, hi}, interpreted_alert.headsign}
 

test/fixtures/signs_ui_config.json

@@ -90,6 +90,5 @@
         "range_low": 9
       }
     }
-  },
-  "signs": {}
+  }
 }