module Host::ManagedExtensions
  extend ActiveSupport::Concern

  included do
    # execute standard callbacks
    after_validation :queue_reboot
    after_save :delete_discovery_attribute_set, :update_notifications

    belongs_to :discovery_rule

    scoped_search :relation => :discovery_rule, :on => :name, :rename => :discovery_rule, :complete_value => true
  end

  def queue_reboot
    return unless errors.empty? && Setting[:discovery_reboot]
    return if new_record? # Discovered Hosts already exist, and new_records will break `find`
    return unless type_changed? and ::Host::Base.find(self.id).type == "Host::Discovered"
    # reboot task must be high priority and there is no compensation action apparently
    if facts['discovery_kexec'] && provisioning_template(:kind => 'kexec')
      post_queue.create(:name => _("Reloading kernel on %s") % self, :priority => 10000, :action => [self, :setKexec])
    else
      post_queue.create(:name => _("Rebooting %s") % self, :priority => 10000, :action => [self, :setReboot])
    end
  end

  def setReboot
    old.becomes(Host::Discovered).reboot
    # It is too late to report error in the post_queue, we catch them and
    # continue. If flash is implemented for new hosts (http://projects.theforeman.org/issues/10559)
    # we can report the error to the user perhaps.
    true
  rescue ::Foreman::Exception => e
    Foreman::Logging.exception("Unable to reboot", e)
    true
  end

  def delReboot
    # no reboot on orchestration rollback
  end

  def setKexec
    template = provisioning_template(:kind => 'kexec')
    raise ::Foreman::Exception.new(N_("Kexec template not associated with operating system")) unless template
    @host = self
    @kexec_kernel, @kexec_initrd = operatingsystem.boot_files_uri(@host.medium, @host.architecture, @host)
    # try to parse JSON and error out early
    json = JSON.parse(unattended_render(template))
    ::Foreman::Exception.new(N_("Kernel kexec URL is invalid: '%s'"), json['kernel']) unless json['kernel'] =~ /\Ahttp.+\Z/
    ::Foreman::Exception.new(N_("Init RAM kexec URL is invalid: '%s'"), json['initrd']) unless json['initrd'] =~ /\Ahttp.+\Z/
    old.becomes(Host::Discovered).kexec json.to_json
    true
  rescue ::Foreman::Exception => e
    Foreman::Logging.exception("Unable to kexec", e)
    true
  end

  def delKexec
    # no kexec on orchestration rollback
  end

  def delete_discovery_attribute_set
    return if new_record?
    DiscoveryAttributeSet.where(:host_id => self.id).destroy_all if type_changed?
  end

  def update_notifications
    return if new_record?
    return unless type_changed?
    ForemanDiscovery::UINotifications::DestroyHost.deliver!(self)
  end
end