Overdue invoice cancelling

app/models/invoice.rb

@@ -7,6 +7,8 @@ class Invoice < ActiveRecord::Base
 
   accepts_nested_attributes_for :invoice_items
 
+  scope :unbinded, -> { where('id NOT IN (SELECT invoice_id FROM account_activities)') }
+
   attr_accessor :billing_email
   validates :billing_email, format: { with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i }, allow_blank: true
 
@@ -113,7 +115,11 @@ class Invoice < ActiveRecord::Base
   class << self
     def cancel_overdue_invoices
       cr_at = Time.zone.now - Setting.days_to_keep_overdue_invoices_active.days
-      self.class.where('due_date < ? AND created_at < ?', Time.zone.now, cr_at)
+      invoices = Invoice.unbinded.where(
+        'due_date < ? AND created_at < ? AND cancelled_at IS NULL', Time.zone.now, cr_at
+      )
+
+      invoices.update_all(cancelled_at: Time.zone.now)
     end
   end
 end

config/initializers/initial_settings.rb

@@ -30,6 +30,7 @@ if con.present? && con.table_exists?('settings')
   Setting.save_default(:eis_invoice_contact, 'Martti Õigus')
   Setting.save_default(:invoice_number_min, '131050')
   Setting.save_default(:invoice_number_max, '149999')
+  Setting.save_default(:days_to_keep_overdue_invoices_active, 30)
 end
 
 # dev only setting

spec/models/invoice_spec.rb

@@ -70,6 +70,11 @@ describe Invoice do
       ii.item_sum_without_vat.should == BigDecimal.new('150.0')
     end
 
+    it 'should cancel overdue invoices' do
+      Fabricate(:invoice, created_at: Time.zone.now - 35.days, due_date: Time.zone.now - 1.days)
+      Invoice.cancel_overdue_invoices.should == 1
+    end
+
     # it 'should have one version' do
     #   with_versioning do
     #     @invoice.versions.should == []