#--
# Copyright (C) 2007 Dimitrij Denissenko
# Please read LICENSE document for more information.
#++
module TicketPropertyGlobal

  def self.included(base)
    base.extend(ClassMethods)    
    base.class_eval do 
      has_many :tickets

      validates_presence_of :name
      validates_uniqueness_of :name    
      
      include(InstanceMethods)
    end    
  end
    
  module ClassMethods
    def default
      find_by_default_value(true) || find(:first)
    end  
    
    def global?
      true
    end
  end

  module InstanceMethods

    # Refuse to "disable" the default_value!
    def default_value=(value)
      before = read_attribute(:default_value)    
      result = write_attribute(:default_value, value)
      after = read_attribute(:default_value)        
      if before and not after
        write_attribute(:default_value, true) 
      else
        result
      end
    end
  
    protected
  
      def before_destroy
        return false if self.default_value?
        
        unless self.tickets.count.zero? 
          default_id = self.class.default.id
          attribute = self.class.name.downcase + '_id'
          self.tickets.each do |ticket|         
            ticket.update_attribute(attribute, default_id)
          end
        end
        true
      end
      
      def before_save      
        self.class.update_all(['default_value = ?', false]) if self.default_value?
      end
  
  end      

end