story_repository.rb

class StoryRepository
  def initialize(user = nil, params = {})
    @user = user
    @params = params
  end

  def hottest
    hottest = Story.base.positive_ranked.not_hidden_by(@user)
    hottest = hottest.filter_tags(@params[:exclude_tags] || [])
    hottest.order('hotness')
  end

  def hidden
    hidden = Story.base.hidden_by(@user).filter_tags(@params[:exclude_tags] || [])
    hidden.order("hotness")
  end

  def newest
    newest = Story.base.filter_tags(@params[:exclude_tags] || [])
    newest.order("stories.id DESC")
  end

  def newest_by_user(user)
    Story.base.where(user_id: user.id).order("stories.id DESC")
  end

  def saved
    saved = Story.base.saved_by(@user).filter_tags(@params[:exclude_tags] || [])
    saved.order("hotness")
  end

  def tagged(tag)
    tagged = Story.base.positive_ranked.where(
      Story.arel_table[:id].in(
        Tagging.arel_table.where(
          Tagging.arel_table[:tag_id].eq(tag.id)
        ).project(
          Tagging.arel_table[:story_id]
        )
      )
    )
    tagged.order("stories.created_at DESC")
  end

  def top(length)
    top = Story.base.where("created_at >= (NOW() - INTERVAL " <<
      "#{length[:dur]} #{length[:intv].upcase})")
    top.order("#{Story.score_sql} DESC")
  end
end