Allow other controllers to access lndhub user balance

app/controllers/application_controller.rb

@@ -41,4 +41,26 @@ class ApplicationController < ActionController::Base
   def after_sign_in_path_for(user)
     session[:user_return_to] || root_path
   end
+
+  def lndhub_authenticate(options={})
+    if session[:ln_auth_token].present? && !options[:force_reauth]
+      @ln_auth_token = session[:ln_auth_token]
+    else
+      lndhub = Lndhub.new
+      auth_token = lndhub.authenticate(current_user)
+      session[:ln_auth_token] = auth_token
+      @ln_auth_token = auth_token
+    end
+  rescue => e
+    Sentry.capture_exception(e) if Setting.sentry_enabled?
+  end
+
+  def lndhub_fetch_balance
+    @balance = LndhubManager::FetchUserBalance.call(auth_token: @ln_auth_token)
+  rescue AuthError
+    lndhub_authenticate(force_reauth: true)
+    raise if @fetch_balance_retried
+    @fetch_balance_retried = true
+    lndhub_fetch_balance
+  end
 end