# All plugins should include this module. It defines the basic
# operations that all plugins are supposed to support.
module Plugin

  def Plugin.included(c)
    # Callback, called whenever another class or module includes this
    # one. The parameter given is the name of the class or module
    # that included us.
    @includers ||= []
    @includers << c    
  end

  def Plugin.includers
    return @includers
  end

  def describe_domain(domain)
    # Provide a "description" of the domain. This is output along
    # with the domain name and can be anything of use to the system
    # administrator.
    raise NotImplementedError
  end

  def describe_account(account)
    # Provide a "description" of the account. This is output along
    # with the domain name and can be anything of use to the system
    # administrator.
    raise NotImplementedError
  end

  def delete_domain(domain)
    # Delete the given domain.
    raise NotImplementedError
  end

  def delete_account(account)
    # Delete the given account.
    raise NotImplementedError
  end

  def get_leftover_domains(db_domains)
    # Given a list of domains, determine which domains belonging to this plugin
    # are not contained in the given list.
    raise NotImplementedError
  end

  def get_leftover_accounts(db_accounts)
    # Given a list of accounts, determine which accounts belonging to this plugin
    # are not contained in the given list.
    raise NotImplementedError
  end
end