Add checking and updating DeepL usage information

lib/outlook/translators.ex

@@ -16,12 +16,10 @@ defmodule Outlook.Translators do
 
   def get_deepl_account!(id), do: Repo.get!(DeeplAccount, id)
 
-  def get_deepl_auth_key(user_id) do
-    query =
-      from DeeplAccount,
-        where: [user_id: ^user_id],
-        select: [:auth_key]
-    Repo.one!(query)
+  def get_deepl_auth_key(user) do
+    deepl_account_for_user(user)
+    |> select([:auth_key])
+    |> Repo.one()
     |> Map.get(:auth_key)
   end
 
@@ -45,6 +43,10 @@ defmodule Outlook.Translators do
     DeeplAccount.changeset(deepl_account, attrs)
   end
 
+  def increase_our_character_count(user, billed_characters) do
+    deepl_account_for_user(user)
+    |> Repo.update_all([inc: [our_character_count: billed_characters]])
+  end
 
   def translate(translation, current_user) do
     %{lang: target_lang,
@@ -64,6 +66,11 @@ defmodule Outlook.Translators do
     Task.start_link(Deepl, :translate, args)
   end
 
+  defp deepl_account_for_user(user) when is_struct(user), do: deepl_account_for_user(user.id)
+  defp deepl_account_for_user(user_id) do
+    DeeplAccount |> where(user_id: ^user_id)
+  end
+
   defp prepare_article(tree) do
     # Logger.info "so far."
     HtmlDocComponent.render_doc(%{tree: tree})