module Transit
  module Package
    
    module Post
      extend ActiveSupport::Concern
      
      included do
        
        field :title,       :type => String
        field :post_date,   :type => Date
        field :slug,        :type => String
        field :teaser,      :type => String
        
        validates :title, :presence   => true
        validates :slug,  :presence   => { :allow_blank => false }, 
                          :uniqueness => { :scope => :_type, :message => "A post already exists with this exact title." }
        
        scope :published, where(:published => true, :post_date.lte => Date.today)
        modded_with :sluggable, :fields => :title, :as => :slug
        alias :timestamp_method :post_date               
      end
      
      # Grab the previous post for a previous > next link list
      #
      def previous_post
        @previous_post ||= self.class.only(:title, :slug).where(:post_date.lt => self.post_date).descending(:post_date).first
      end

      # Grab the next post for a previous > next link list
      #
      def next_post
        @next_post ||= self.class.only(:title, :slug).where(:post_date.gt => self.post_date).ascending(:post_date).first
      end
      
      def timestamp
        return "" if self.post_date.nil?
        self.post_date.strftime("%B %d, %Y")
      end
      
    end
    
  end
end