module PrivateMessages
  module HasPrivateMessage
    extend ActiveSupport::Concern
      
      included do
      end

      module ClassMethods
        # Sets up a model have private messages, defining the child class as specified in :class_name (typically "Messages").
        # Provided the following instance messages:
        # *  <tt>sent_messages</tt> - returns a collection of messages for which this object is the sender.
        # *  <tt>received_messages</tt> - returns a collection of messages for which this object is the recipient.
        def has_private_message(options = {})
          options[:class_name] ||= 'Message'

          unless included_modules.include? InstanceMethods
            class_attribute :options
            table_name = options[:class_name].constantize.table_name
            
            has_many :sent_messages, -> {
                        
                        where("#{table_name}.sender_deleted = false").order("#{table_name}.created_at DESC")
                      },
                      :class_name => options[:class_name], :foreign_key => 'sender_id'
                      #:includes => :recipient,
                       #
                        #.order("#{table_name}.created_at DESC")
                        
                        #:order => "#{table_name}.created_at DESC",
                        #:conditions => ["#{table_name}.sender_deleted = ?", false]
                                


            has_many :received_messages, ->{
                        where("#{table_name}.recipient_deleted = false").order("#{table_name}.created_at DESC")
                      },
                     :class_name => options[:class_name],
                     :foreign_key => 'recipient_id'
                     #, ->
                     #{
                     #   :includes => :sender,
                     #   :order => "#{table_name}.created_at DESC",
                     #   :conditions => [, false]
                     #}

            #extend ClassMethods
            include InstanceMethods
          end 
          self.options = options
        end 
      end 

      #module ClassMethods #:nodoc:
        # None yet...
        
      #end

      module InstanceMethods
        # Returns true or false based on if this user has any unread messages
        def unread_messages?
          unread_message_count > 0 ? true : false
        end
        
        # Returns the number of unread messages for this user
        def unread_message_count
          eval options[:class_name] + '.count(:conditions => ["recipient_id = ? AND read_at IS NULL and recipient_deleted = ?", self, false])'
        end
      end 

    end
  end


ActiveRecord::Base.send :include, PrivateMessages::HasPrivateMessage