Extract parameter parsing to controller helper

app/controllers/carto/superadmin/metrics_controller_helper.rb

@@ -20,7 +20,14 @@ module Carto::Superadmin
 
     private
 
-    def get_usage(user, org, date_from, date_to, only_services, totals)
+    def get_usage(user, org)
+      only_services = params[:services] || []
+      raise ArgumentError.new('services must be an array') unless only_services.is_a?(Array)
+      only_services = only_services.map(&:to_sym)
+      date_to = params[:to] ? Date.parse(params[:to]) : Date.today
+      date_from = params[:from] ? Date.parse(params[:from]) : last_billing_cycle
+      totals = params[:totals].present? && params[:totals] == 'true'
+
       usage = {}
       USAGE_METRICS_RETRIEVERS.each do |retriever|
         services = retriever.services

app/controllers/carto/superadmin/organizations_controller.rb

@@ -12,25 +12,22 @@ module Carto
       ssl_required :usage
       before_filter :load_organization
 
-      rescue_from ArgumentError, with: :render_date_format_error
+      rescue_from ArgumentError, with: :render_format_error
 
       def usage
-        services = params[:services] || []
-        return render(json: { error: 'services must be an array' }, status: 422) unless services.is_a?(Array)
-        services = services.map(&:to_sym)
-        date_to = params[:to] ? Date.parse(params[:to]) : Date.today
-        date_from = params[:from] ? Date.parse(params[:from]) : @organization.owner.last_billing_cycle
-        totals = params[:totals].present? && params[:totals] == 'true'
-
-        usage = get_usage(nil, @organization, date_from, date_to, services, totals)
+        usage = get_usage(nil, @organization)
 
         respond_with(usage)
       end
 
       private
 
-      def render_date_format_error
-        render(json: { error: 'Invalid date format' }, status: 422)
+      def last_billing_cycle
+        @organization.owner.last_billing_cycle
+      end
+
+      def render_format_error(exception)
+        render(json: { error: exception.message }, status: 422)
       end
 
       def load_organization

app/controllers/carto/superadmin/users_controller.rb

@@ -12,24 +12,22 @@ module Carto
       ssl_required :usage
       before_filter :load_user
 
-      rescue_from ArgumentError, with: :render_date_format_error
+      rescue_from ArgumentError, with: :render_format_error
 
       def usage
-        services = params[:services] || []
-        return render(json: { error: 'services must be an array' }, status: 422) unless services.is_a?(Array)
-        services = services.map(&:to_sym)
-        date_to = params[:to] ? Date.parse(params[:to]) : Date.today
-        date_from = params[:from] ? Date.parse(params[:from]) : @user.last_billing_cycle
-        totals = params[:totals].present? && params[:totals] == 'true'
-        usage = get_usage(@user, nil, date_from, date_to, services, totals)
+        usage = get_usage(@user, nil)
 
         respond_with(usage)
       end
 
       private
 
-      def render_date_format_error
-        render(json: { error: 'Invalid date format' }, status: 422)
+      def last_billing_cycle
+        @user.last_billing_cycle
+      end
+
+      def render_format_error(exception)
+        render(json: { error: exception.message }, status: 422)
       end
 
       def load_user