class Scenario < ActiveRecord::Base
  attr_accessible :name, :agent_ids, :description, :public

  belongs_to :user, :counter_cache => :scenario_count, :inverse_of => :scenarios
  has_many :scenario_memberships, :dependent => :destroy, :inverse_of => :scenario
  has_many :agents, :through => :scenario_memberships, :inverse_of => :scenarios

  before_save :make_guid

  validates_presence_of :name, :user

  validate :agents_are_owned

  protected

  def make_guid
    self.guid = SecureRandom.hex unless guid.present?
  end

  def agents_are_owned
    errors.add(:agents, "must be owned by you") unless agents.all? {|s| s.user == user }
  end
end