class Ability
  include CanCan::Ability

  # alias_action :index, :show, :to => :read
  # alias_action :new, :to => :create
  # alias_action :edit, :to => :update

  def initialize(user)
    user ||= login_as_trial_user

    if user.role? :admin
      can :manage, :all
    end

    if user.role? :moderator
      can :manage, :all
    end

    if user.role? :user
      can :read, :all
      can :create, :all
      can :destroy, :all do |obj_class, obj|
       obj.try(:user) == user
       3.minutes.ago <= obj.created_at
     end
      can :update, :all do |obj_class, obj|
       obj.try(:user) == user
       3.minutes.ago <= obj.created_at
      end
      can :destroy, UserSession do |us|
        user == us.try(:user)
      end
      cannot :create, UserSession
      cannot :create, User
      cannot :destroy, User
    end

    if user.role? :guest
      can :read, :all
      can :create, UserSession
      cannot :destroy, UserSession
      can :create, User
    end

  end

  # private

  def login_as_trial_user
    name = "anonymous_#{Time.now.to_i * rand}"
    if User.find_by_username(name)
      UserSession.create(User.find_by_username(name),true)
    else
      guest_role = User.create(:username => name, :password => name, :password_confirmation => name, :role => "guest", :email => "change@this.com")
      UserSession.create(guest_role, true)
    end
    @current_user_session = UserSession.find
    guest_role
  end

end