class Eco::API::UseCases::DefaultCases::SwitchSupervisorCase < Eco::API::Common::Loaders::UseCase
  name "switch-supervisor"
  type :transform

  def main(people, session, options, usecase)
    supers   = session.new_job("main", "supers", :update, usecase, :core)

    old_sup, new_sup = get_supers(people).tap do |supers|
      inform(*supers, session.logger)
    end

    micro.with_each_subordinate(old_sup, people) do |subordinate|
      subordinate.supervisor_id = new_sup&.id
      supers.add(subordinate)
    end.tap do |subordinates|
      unless subordinates.length > 0
        sup_str = "#{old_sup.external_id} (#{old_sup.name} - #{old_sup.email})"
        session.logger.error("There are no subordinates for supervisor #{sup_str}. Aborting...")
        exit(1)
      end
    end
  end

  private

  def get_supers(people)
    micro            = session.micro
    old_id,  new_id  = get_super_ids(options)
    old_sup, new_sup = [nil, nil]

    micro.with_supervisor(old_id, people) do |supervisor|
      unless old_sup = supervisor
        session.logger.error("Couldn't find any user with that id (old-super): '#{old_id}'. Aborting...")
        exit(1)
      end
    end

    micro.with_supervisor(new_id, people) do |supervisor|
      unless new_sup = supervisor
        session.logger.error("Couldn't find any user with that id (new-super): '#{new_id}'. Aborting...")
        exit(1)
      end
    end

    [old_sup, new_sup]
  end

  def get_super_ids(options)
    unless old_id = options.dig(:super, :old)
      session.logger.error("You haven't specified the original supervisor. Aborting...")
      exit(1)
    end

    # we could be setting the supervisor to nil
    unless options[:super].key?(:new)
      session.logger.error("You haven't specified the new supervisor. Aborting...")
      exit(1)
    end

    [old_id, options.dig(:super, :new)]
  end

  def inform(old_sup, new_sup, logger)
    msg  = "Switching supervisor '#{old_sup.name}' (#{old_sup.external_id}) "
    msg += "to '#{new_sup&.name}' (#{new_sup&.external_id})"
    logger.info(msg)
  end
end