class PermissionsParser
  def initialize
  end

  def parse(key, obj, &blk)
    license = ::PermissionConfig.new key
    case obj
    when Hash
      parse_permission(obj, license, &blk)
    else
      raise "Each key must have a YAML hash that defines its permission configuration"
    end
    yield license if blk
  end      

  protected

  def parse_permission(obj, license, &blk)
    # Forget keys because I don't know what to do with them
    obj.each do |key, value|   
      raise ArgumentError, "A CanCan license can only have the keys can: and cannot:" if ![:can, :cannot].include?(key.to_sym)
      license.send :"#{key}=", value
    end
  end
end