ed_Ads_Ad $ad, $args ) {
        $cache_busting_auto = isset( $args['placement_type'] ) && ( ! isset( $args['cache-busting'] ) || $args['cache-busting'] === self::OPTION_AUTO );

        if ( $cache_busting_auto ) {
            $js_array = & $this->passive_cache_busting_placements;
            $id = $args['previous_id'];
        } else {
            $js_array = & $this->passive_cache_busting_ads;
            $id = $args['id'];
        }
        $uniq_key = $id . '_' . ++self::$adOffset;

		$not_head                        = ! $this->isHead || ( isset( $args['placement_type'] ) && $args['placement_type'] !== 'header' );
		$elementid                       = $not_head ? $this->generate_elementid() : null;
		$args['cache_busting_elementid'] = $ad->args['cache_busting_elementid'] = $elementid;
		$placement_id                    = ! empty( $args['output']['placement_id'] ) ? $args['output']['placement_id'] : '';
		$output_string                   = $not_head ? $this->create_wrapper( $elementid, $placement_id, $args ) : '';

        $js_array[ $uniq_key ] = array(
            'elementid' => array( $elementid ),
            'ads' => array( $ad->id => $this->get_passive_cb_for_ad( $ad ) ), // only 1 ad
        );


        if ( $cache_busting_auto ) {
            $placements = Advanced_Ads::get_ad_placements_array();
            $test_id = isset( $args['test_id'] ) ? $args['test_id'] : null;

            $js_array[ $uniq_key ]['type'] = 'ad';
            $js_array[ $uniq_key ]['id'] = $ad->id;
            $js_array[ $uniq_key ]['placement_info']  = $this->get_placement_info( $id );
            $js_array[ $uniq_key ]['test_id'] = $test_id;

            if ( $ad_for_adblocker = Advanced_Ads_Pro_Module_Ads_For_Adblockers::get_ad_for_adblocker( $args ) ) {
                $js_array[ $uniq_key ]['ads_for_ab'] = array( $ad_for_adblocker->id => $this->get_passive_cb_for_ad( $ad_for_adblocker ) );
            }

            if ( 'ajax' === $this->fallback_method ) {
                $ajax_info = $this->server_info->get_ajax_for_passive_placement( $ad, $args, $elementid );
                if ( $ajax_info ) {
                    $js_array[ $uniq_key ] = array_merge( $js_array[ $uniq_key ], $ajax_info );
                }
            }
        }

        $js_array[ $uniq_key ] = apply_filters(
            'advanced-ads-cache-busting-item',
            $js_array[ $uniq_key ],
            array(
                'method' => $cache_busting_auto ? 'placement' : 'ad',
                'args' => $args
            )
        );

        return $output_string;
    }

    /**
     * add data related to group and group placement to js array
     *
     * @param obj $adgroup Advanced_Ads_Group
     * @param array/null $ordered_ad_ids ordered ids of the ads that belong to the group
     * @param array $args argument passed to the 'get_ad_by_group' function
     * @param str $uniq_key Property name in JS array.
     * @param array $group_ads Group ads.
     * @return string
     */
    private function get_passive_overriden_group( Advanced_Ads_Group $adgroup, $ordered_ad_ids, $args, $uniq_key, $group_ads ) {
        $cache_busting_auto = isset( $args['placement_type'] ) && ( ! isset( $args['cache-busting'] ) || $args['cache-busting'] === self::OPTION_AUTO );

        if ( $cache_busting_auto ) {
            $js_array = & $this->passive_cache_busting_placements;
            $id = $args['previous_id'];
        } else {
            $js_array = & $this->passive_cache_busting_groups;
            $id = $args['id'];
        }
        $uniq_key = $id . '_' . $uniq_key;

		$not_head                        = ! $this->isHead || ( isset( $args['placement_type'] ) && $args['placement_type'] !== 'header' );
		$elementid                       = $not_head ? $this->generate_elementid() : null;
		$args['cache_busting_elementid'] = $adgroup->ad_args['cache_busting_elementid'] = $elementid;
		$placement_id                    = ! empty( $args['output']['placement_id'] ) ? $args['output']['placement_id'] : '';
		$output_string                   = $not_head ? $this->create_wrapper( $elementid, $placement_id, $args ) : '';

        if ( ( $ad_count = apply_filters( 'advanced-ads-group-ad-count', $adgroup->ad_count, $adgroup ) ) === 'all' ) {
            $ad_count = 999;
        }

        $passive_ads = array();
        foreach ( $group_ads as $group_ad ) {
            $passive_ads[ $group_ad->id ] = $this->get_passive_cb_for_ad( $group_ad );
        }

        $js_array[ $uniq_key ] = array (
            'type'=> 'group',
            'id' => $adgroup->id,
            'elementid' => array( $elementid ),
            'ads' => $passive_ads,
            'group_info' => array(
                'id' => $adgroup->id,
                'name' => $adgroup->name,
				'weights' => $adgroup->get_ad_weights( $ordered_ad_ids ),
                'type' => $adgroup->type,
                'ordered_ad_ids' => $ordered_ad_ids,
                'ad_count' => $ad_count,
            ),
        );

        // deprecated after Advaned Ads Slider > 1.3.1
        if ( 'slider' === $adgroup->type && defined( 'AAS_VERSION' ) && version_compare( AAS_VERSION, '1.3.1', '<=' ) ) {
            $slider_options = Advanced_Ads_Slider::get_slider_options( $adgroup );
            $js_array[ $uniq_key ]['group_info']['slider_options'] = $slider_options;
        }



        if ( Advanced_Ads_Pro_Group_Refresh::is_enabled( $adgroup ) ) {
            $js_array[ $uniq_key ]['group_info']['refresh_enabled'] = true;
            $js_array[ $uniq_key ]['group_info']['refresh_interval_for_ads'] = Advanced_Ads_Pro_Group_Refresh::get_ad_intervals( $adgroup );
        }

        $advads_plugin = Advanced_Ads::get_instance();
        $label = '';
        if ( method_exists( $advads_plugin, 'get_label' ) ) {
            $placement_state = isset( $args['ad_label'] ) ? $args['ad_label'] : 'default';
            $label = Advanced_Ads::get_instance()->get_label( $placement_state );
        }

        if ( $cache_busting_auto ) {
            $placements = Advanced_Ads::get_ad_placements_array();
            $js_array[ $uniq_key ]['placement_info']  = $this->get_placement_info( $id );
            $js_array[ $uniq_key ]['test_id'] = isset( $args['test_id'] ) ? $args['test_id'] : null;

            if ( $ad_for_adblocker = Advanced_Ads_Pro_Module_Ads_For_Adblockers::get_ad_for_adblocker(
                array_diff_key( $args, array( 'ad_label' => false ) )
            ) ) {
                $js_array[ $uniq_key ]['ads_for_ab'] = array( $ad_for_adblocker->id => $this->get_passive_cb_for_ad( $ad_for_adblocker ) );
            }

            if ( 'ajax' === $this->fallback_method ) {
                $ajax_info = $this->server_info->get_ajax_for_passive_placement( $group_ads, $args, $elementid );
                if ( $ajax_info ) {
                    $js_array[ $uniq_key ] = array_merge( $js_array[ $uniq_key ], $ajax_info );
                }
            }
        }

        $js_array[ $uniq_key ] = apply_filters( 'advanced-ads-pro-passive-cb-group-data', $js_array[ $uniq_key ], $adgroup, $elementid );

        // Add wrapper around group.
        if ( ( ! empty( $adgroup->wrapper ) || $label )
            && is_array( $adgroup->wrapper )
            && class_exists( 'Advanced_Ads_Utils' ) && method_exists( 'Advanced_Ads_Utils' , 'build_html_attributes' )
        ) {
			$before = '<div' . Advanced_Ads_Utils::build_html_attributes( $adgroup->wrapper ) . '>'
                . $label
                . apply_filters( 'advanced-ads-output-wrapper-before-content-group', '', $adgroup );

            $after = apply_filters( 'advanced-ads-output-wrapper-after-content-group', '', $adgroup )
                . '</div>';
            if ( ! empty( $adgroup->ad_args['placement_clearfix'] ) ) {
                $after .= '<br style="clear: both; display: block; float: none; "/>';
            }

            $js_array[ $uniq_key ]['group_wrap'][] = array(
                'before' => $before,
                'after' => $after,
            );

        }
        $js_array[ $uniq_key ] = apply_filters(
            'advanced-ads-cache-busting-item',
            $js_array[ $uniq_key ],
            array(
                'method' => $cache_busting_auto ? 'placement' : 'group',
                'args' => $args
            )
        );

        return $output_string;
    }

	/**
	 * Get placement information
	 *
	 * @param string $id Placement id.
	 * @param array $placement_info Placement information.
	 */
	private function get_placement_info( $id ) {
		// The information which passive cache-busting (`base.js`) can read.
		// When a new placement option is added and passive cache-busting needs to access it, it should be added to the array.
		$allowed_keys = array( 'id', 'lazy_load', 'test_id', 'layer_placement', 'close', 'inject_by', 'placement_position', 'pro_custom_element', 'container_id' );

		$placements = Advanced_Ads::get_ad_placements_array();
		$placement_info = $placements[ $id ];
		$placement_info['id'] = (string) $id;

		if ( ! empty( $placement_info['options'] ) && is_array( $placement_info['options'] ) ) {
			foreach ( $placement_info['options'] as $k => $option ) {
				if ( ! in_array( $k, $allowed_keys, true ) ) {
					unset( $placement_info['options'][ $k ] );
				}
			}
		}
		return $placement_info;
	}

    /**
     * add new passive ad to passive cb js array
     *
     * @param obj $ad Advanced_Ads_Ad
     * @param array $args argument passed to the 'get_ad_by_id' function
     * @param str $uniq_key Property name in JS array.
     */
    private function add_passive_ad_to_group( Advanced_Ads_Ad $ad, $args, $uniq_key ) {
        $cache_busting_auto = isset( $args['placement_type'] ) && ( ! isset( $args['cache-busting'] ) || $args['cache-busting'] === self::OPTION_AUTO );

        if ( $cache_busting_auto ) {
            $uniq_key = $args['previous_id'] . '_' . $uniq_key;
            $this->passive_cache_busting_placements[ $uniq_key ]['ads'][ $ad->id ] = $this->get_passive_cb_for_ad( $ad );
        } else {
            $uniq_key = $args['id'] . '_' . $uniq_key;
            $this->passive_cache_busting_groups[ $uniq_key ]['ads'][ $ad->id ] = $this->get_passive_cb_for_ad( $ad );
        }
    }

    /**
     * delete an ad from passive cb js array
     *
     * @param $adgroup Advanced_Ads_Group
     * @param array $args argument passed to the 'get_ad_by_id' function
     * @param str $uniq_key Property name in JS array.
     */
    private function delete_passive_group( Advanced_Ads_Group $adgroup, $args, $uniq_key ) {
        $cache_busting_auto = isset( $args['placement_type'] ) && ( ! isset( $args['cache-busting'] ) || $args['cache-busting'] === self::OPTION_AUTO );

        if ( $cache_busting_auto ) {
            $uniq_key = $args['previous_id'] . '_' . $uniq_key;
            unset( $this->passive_cache_busting_placements[ $uniq_key ] );
        } else {
            $uniq_key = $args['id'] . '_' . $uniq_key;
            unset( $this->passive_cache_busting_groups[ $uniq_key ] );
        }
    }

    /**
     * get ad info for passive cache-busting
     *
	 * @param Advanced_Ads_Ad $ad ad object.
     * @return array
     */
    public function get_passive_cb_for_ad( Advanced_Ads_Ad $ad ) {
        $ad_options = $ad->options();
		$ad->args['cache-busting'] = self::OPTION_AUTO;

        $passive_cb_for_ad = apply_filters( 'advanced-ads-pro-passive-cb-for-ad', array(
            'id' => $ad->id,
            'title' => $ad->title,
            'expiry_date' => (int) $ad->expiry_date,
			'visitors' => array_values( $ad->options( 'visitors', array() ) ),
            'content' => $ad->output( array( 'global_output' => false ) ),
            'once_per_page' => ( ! empty( $ad_options['output']['once_per_page'] ) ) ? 1 : 0,
            'debugmode' => isset( $ad->output['debugmode'] ),
			'blog_id' => get_current_blog_id(),
			'type' => $ad->type,
			'position' => isset( $ad->output['position'] ) ? $ad->output['position'] : '',
        ), $ad );

		// Consent overridden for this ad.
		$passive_cb_for_ad['privacy']['ignore'] = ! empty( $ad_options['privacy']['ignore-consent'] );
		// This ad has custom code and therefore needs consent (if not overridden above).
		$passive_cb_for_ad['privacy']['needs_consent'] = ! empty( Advanced_Ads_Pro::get_instance()->get_custom_code( $ad ) );

		/**
		 * Collect blog data before `restore_current_blog` is called.
		 */
		if ( class_exists( 'Advanced_Ads_Tracking_Util', false ) && method_exists( 'Advanced_Ads_Tracking_Util', 'collect_blog_data' ) ) {
			$tracking_utils = Advanced_Ads_Tracking_Util::get_instance();
			$tracking_utils->collect_blog_data();
		}

        return $passive_cb_for_ad;
    }

    /**
     * return wrapper and js code to load the ad
     *
     * @param obj $ad Advanced_Ads_Ad
     * @param array $args argument passed to the 'get_ad_by_id' function
     * @return string/bool $overridden_ad
     */
    public function get_overridden_ajax_ad( $ad, $args ) {
        $overridden_ad = false;
        $test_id = isset( $args['test_id'] ) ? $args['test_id'] : null;
        $needs_backend = $this->ad_needs_backend_request( $ad );

        if ( 'static' !== $needs_backend || $test_id ) {
            $query = self::build_js_query( $args);
            $overridden_ad = $this->get_override_content( $query );
        }

        return $overridden_ad;
    }

	/**
	 * Determine if backend request is needed.
	 *
	 * @param Advanced_Ads_Ad $ad Ad object.
	 * @return string
	 *     'static'   Do not use cache-busting. There are no dynamic conditions, all users will see the same.
	 *     'off'      Do not use cache-busting (fallback).
	 *     'ajax'     Use AJAX request (fallback).
	 *     'passive'  Use passive cache-busting.
	 */
    public function ad_needs_backend_request( Advanced_Ads_Ad $ad ) {
        $ad_options = $ad->options();
		$visitors = $ad->options( 'visitors', array() );

		// code is evaluated as php if setting was never saved or php is allowed
        $allow_php = ( 'plain' === $ad->type && ( ! isset( $ad->output['allow_php'] ) || $ad->output['allow_php'] ) );
        // if there is at least one visitor condition (check old "visitor" and new "visitors" conditions)
		$is_visitor_conditions = ! empty( $visitors );
        $is_group = 'group' === $ad->type;
        $has_shortcode = ! empty( $ad_options['output']['has_shortcode'] )
            // The Rich Content ad type saved long time ago.
            || ( ! isset( $ad_options['output']['has_shortcode'] ) && $ad->type === 'content' );
        $is_lazy_load = $this->lazy_load_module_enabled && isset( $ad_options['lazy_load'] ) && 'enabled' === $ad_options['lazy_load'];
        // Check if there is conditions that need backend request.
        $has_not_js_conditions = false;
		if ( ! empty( $visitors ) ) {
            // Conditions that can be checked using js.
            $js_visitor_conditions = array(
                'mobile',
                'referrer_url',
                'user_agent',
                'request_uri',
                'browser_lang',
                'cookie',
                'page_impressions',
                'ad_impressions',
                'new_visitor',
                'device_width',
                'tablet',
            );

			if ( $this->fallback_method === 'ajax'
				&& isset( $ad_options['placement_type'] )
			) {
                // Conditions that can be checked by passive cache-busting only if cookies exist.
                // If not, ajax cache-busting will not be used.
                $all_server_conditions = $this->server_info->get_all_server_conditions();
                $js_visitor_conditions = array_merge( $js_visitor_conditions, array_keys( $all_server_conditions ) );
            }


            $js_visitor_conditions = apply_filters( 'advanced-ads-js-visitor-conditions', $js_visitor_conditions );

            foreach ( $visitors as $visitor ) {
                if ( ! in_array( $visitor['type'], $js_visitor_conditions ) ) {
                    // Use AJAX cache-busting, or disable cache-busting.
                    $has_not_js_conditions = true;
                }
            }
        }

        $has_tracking = false;
        if ( class_exists( 'Advanced_Ads_Tracking', false ) &&
            ( ( isset( $ad_options['tracking']['impression_limit'] ) && $ad_options['tracking']['impression_limit'] ) ||
            ( isset( $ad_options['tracking']['click_limit'] ) && $ad_options['tracking']['click_limit'] ) )
        ) {
            // Use AJAX cache-busting, or disable cache-busting.
            $has_tracking = true;
        }

        $has_test = ! empty( $ad_options['test_id'] );

        $hidden_without_consent = false;
        if ( empty( $ad_options['privacy']['ignore-consent'] )
            && class_exists( 'Advanced_Ads_Privacy' ) ) {
            $privacy_options = Advanced_Ads_Privacy::get_instance()->options();
            $npa_adsense = $ad->type === 'adsense' &&  ! empty( $privacy_options['show-non-personalized-adsense'] );
            // Check if the ad is invisible until consent is given.
            if ( ! empty( $privacy_options['enabled'] )
                // If the content method is 'cookie'.
                && ! empty( $privacy_options['consent-method'] ) // && empty( $privacy_options['show-without-consent'] )
                // Non-personalized Adsense are visible even without consent.
                && ! $npa_adsense
            ) {
                $hidden_without_consent = true;
            }
        }
        $specific_days = ! empty( $ad_options['weekdays']['enabled'] );
        $checks_placement_cookies = ( ! empty( $ad_options['layer_placement']['close']['enabled'] )
            && ! empty( $ad_options['layer_placement']['close']['timeout_enabled'] ) )
        || ( ! empty( $ad_options['close']['enabled'] )
            && ! empty( $ad_options['close']['timeout_enabled'] ) );

        if ( $allow_php || $is_group || $has_shortcode || $has_not_js_conditions || $has_tracking ) {
            // Use AJAX cache-busting, or disable cache-busting.
            $return = $this->fallback_method;
		} elseif ( $is_visitor_conditions || $is_lazy_load || $hidden_without_consent || $specific_days || $checks_placement_cookies ) {
            // Passive cache-busting.
            $return = 'passive';
        } else {
            $return = 'static';
        }


        $return = apply_filters( 'advanced-ads-pro-ad-needs-backend-request', $return, $ad, $this->fallback_method );
        return $return;
    }

    /**
     * Determine if all ads of a group are static.
     *
     * @param Advanced_Ads_Ad[] $group_ads An array of ad objects.
     * @param Advanced_Ads_Group $adgroup Group object.
     * @return bool
     */
    private function group_ads_static( $group_ads, $adgroup ) {
        if ( 0 === count( $group_ads )  ) {
            return true;
        }
        if ( 1 === count( $group_ads ) ) {
            return 'static' === $this->ad_needs_backend_request( $group_ads[0] );
        }

        return false;
    }

	/**
	 * Prepare query for js handler
	 *
	 * @param array $arguments
	 * @return array query
	 */
	public static function build_js_query( $arguments ) {
		// base query (required keys)
		$query = array(
			'id' => (string) $arguments['id'],
			'method' => (string) $arguments['method'],
		);
		$arguments['global_output'] = true;

		// process further arguments (optional keys)
		$params = array_diff_key( $arguments, array( 'id' => false, 'method' => false ) );

		if ( $params !== array() ) {
			$query['params'] = $params;
		}
		return $query;
	}

    /**
     * Determine override option for query.
     *
     * @param array $query
     *
     * @return boolean
     */
    protected function can_override( $query ) {
        $params = isset( $query['params'] ) ? $query['params'] : array();

        // allow disable cache-busting according to placement settings
        if ( $query['method'] === 'placement' && ! isset( $params['cache-busting'] ) ) {
            $placement_options = Advanced_Ads::get_ad_placements_array();

            if ( isset( $placement_options[ $query['id'] ]['options']['cache-busting'] ) ) {
                $params['cache-busting'] = $placement_options[ $query['id'] ]['options']['cache-busting'];
            }
        }

        return isset( $params['cache-busting'] ) && $params['cache-busting'] === self::OPTION_ON;
    }

    /**
     * Check if passive cache-busting can be used.
     *
     * @param array $args argument passed to ads.
     * @return bool
     */
    private function can_override_passive( $args ) {
        if ( ! empty( $args['wp_the_query']['is_feed'] ) || ! array_key_exists( 'previous_method', $args ) || ! array_key_exists( 'previous_id', $args ) ) {
            return false;
        }

        // Prevent non-header placement from being collected through wp_head.
        if ( doing_action( 'wp_head' ) && isset( $args['placement_type'] ) && 'header' !== $args['placement_type']
            && ! $this->can_inject_during_wp_head() ) {
            return false;
        }

        if ( isset( $args['cache-busting'] ) && $args['cache-busting'] === self::OPTION_IGNORE ) {
            return false;
        }

        return true;
    }

    /**
     * Prepare ad for js handler.
     *
     * @param array $query
     * @return string
     */
    protected function get_override_content( $query ) {
        $content = '';

        // Prevent non-header placement from being collected through wp_head.
        if ( doing_action( 'wp_head' ) && isset( $query['params']['placement_type'] ) && 'header' !== $query['params']['placement_type']
            && ! $this->can_inject_during_wp_head() ) {
            return $content;
        }

        // <head> scripts require no wrapper
        if ( ! $this->isHead
            || ( isset( $query['params']['placement_type'] ) && $query['params']['placement_type'] !== 'header' )
        ) {
            $query['elementid'] = $this->generate_elementid();

            // Get placement id
            if ( ! empty( $query['method'] ) && 'placement' === $query['method'] && ! empty( $query['id'] )  ) {
                // Cache-busting: "ajax"
                $placement_id = $query['id'];
            } elseif( ! empty( $query['params']['output']['placement_id'] )  ) {
                // AJAX fallback
                $placement_id = $query['params']['output']['placement_id'];
            } else {
                $placement_id = '';
            }

			$content .= $this->create_wrapper( $query['elementid'], $placement_id, $query['params'] );
        }

        $query = $this->get_ajax_query( $query );
        self::$ajax_queries[] = $query;


        return $content;
    }

	/**
	 * Get ajax query.
	 *
	 * @param array $query
	 * @param bool $request_placement Whether or not to request top level placement.
	 * @return array
	 */
    public function get_ajax_query( $query, $request_placement = true ) {
        // Request placement.
        if ( $request_placement && isset( $query['params']['output']['placement_id'] ) ) {
            $query['method'] = 'placement';
            $query['id'] = $query['params']['output']['placement_id'];
        }
        $query['blog_id'] = get_current_blog_id();

        /**
         * Collect blog data before `restore_current_blog` is called.
         */
        if ( class_exists( 'Advanced_Ads_Tracking_Util', false ) && method_exists( 'Advanced_Ads_Tracking_Util', 'collect_blog_data' ) ) {
            $tracking_utils = Advanced_Ads_Tracking_Util::get_instance();
            $tracking_utils->collect_blog_data();
        }

        // Check if the `advanced-ads-ajax-ad-select-arguments` filter exists.
        if ( ! empty( $query['params'] ) && version_compare( ADVADS_VERSION, '1.24.0', '>' ) ) {
			$query['params'] = $this->remove_default_ajax_args( $this->ajax_default_args, $query['params'] );
			$query['params'] = $this->extract_general_ajax_args( $query['params'] );

        }

		return $query;
    }

	/**
	 * Remove default AJAX arguments to reduce the size of the array printed in footer.
	 *
	 * @param array $default Default arguments.
	 * @param array $source A full list of arguments that we need to be minifed.
	 * @return array Minified array (source array that does not contain default arguments).
	 */
	private function remove_default_ajax_args( $default, $source ) {
		$result = array();

		foreach ( $source as $key => $f ) {
			if ( ! array_key_exists( $key, $default ) ) {
				$result[ $key ] = $source[ $key ];
				continue;
			}

			if ( $source[ $key ] === $default[ $key ] ) {
				continue;
			}

			if (
				! is_array( $default[ $key ] )
				|| ! is_array( $source[ $key ] )
			) {
				$result[ $key ] = $source[ $key ];
				continue;
			}

			$key_result = $this->remove_default_ajax_args( $default[ $key ], $source[ $key ] );
			if ( $key_result !== array() ) {
				$result[ $key ] = $key_result;
			}
		}

		return $result;
	}

	/**
	 * Extract general AJAX arguments into separate array to reduce the size of the array printed in footer.
	 *
	 * @param array $source A full list of arguments to extract general arguments from.
	 * @return array A list of arguments with general arguments removed.
	 */
	private function extract_general_ajax_args( $source ) {
		if ( wp_doing_ajax() ) {
			// Do nothing because we are not able to add data to the footer array.
			return $source;
		}
		if ( isset( $source['post'] ) ) {
			$ref = array_search( $source['post'], $this->ajax_queries_args, true );
			if ( $ref === false ) {
				$ref = 'r' . count( $this->ajax_queries_args );
				$this->ajax_queries_args[ $ref ] = $source['post'];
			}
			$source['post'] = $ref;
		}
		return $source;
	}

	/**
	 * Add default AJAX arguments that were removed to reduce the size of the array printed in footer.
	 *
	 * @see self::remove_default_ajax_args
	 *
	 * When the item in the default array is not an array, it will be replaced by the item in the minified array.
	 * When an item exists in either associative array, it will be added. Numeric keys are overridden.
	 *
	 * @param array $arguments Minified arguments.
	 * @param array $request Current ad request.
	 * @return array New arguments.
	 */
	public function add_default_ajax_arguments( $arguments, $request ) {
		if ( ! empty( $request['elementId'] ) ) {
			$arguments['cache_busting_elementid'] = $request['elementId'];
		}

		return array_replace_recursive( $this->ajax_default_args, $arguments );
	}

	/**
	 * Create wrapper for cache-busting.
	 *
	 * @param string $element_id   Id of the wrapper.
	 * @param string $placement_id Id of the placement.
	 * @param array  $args         Custom arguments of ad or group.
	 *
	 * @return string Cache-busting wrapper.
	 */
	private function create_wrapper( $element_id, $placement_id = '', $args = array() ) {
		$class = $element_id;
		if ( $placement_id ) {
			$prefix = Advanced_Ads_Plugin::get_instance()->get_frontend_prefix();
			$class .= ' ' . $prefix . $placement_id;
		}
		$style           = ! empty( $args['inline-css'] ) ? 'style="' . $args['inline-css'] . '"' : '';
		$wrapper_element = ! empty( $args['inline_wrapper_element'] ) ? 'span' : 'div';

		// TODO: `id` is deprecated.
		return '<' . $wrapper_element . ' ' . $style . ' class="' . $class . '" id="' . $element_id . '"></' . $wrapper_element . '>';
	}




    /**
     * Generate unique element id
     *
     * @return string
     */
    public function generate_elementid() {
        $prefix = Advanced_Ads_Plugin::get_instance()->get_frontend_prefix();
        return $prefix . md5( 'advanced-ads-pro-ad-' . uniqid( ++self::$adOffset, true ) );
    }

    /**
     * Check if placement can be displayed without passive cache-busting.
     *
     * @param string $id Placement id.
     * @see placement_can_display()
     * @return bool
     */
    private function placement_can_display_not_passive( $id ) {
        // We force this filter to return true when collecting placements for passive cache-busting.
        // For now revoke this behavior
        return apply_filters( 'advanced-ads-can-display-placement', true, $id );
    }

    /**
     * check if placement was closed before
     *
     * @param int $id placement id
     * @return bool whether placement can be displayed or not
     */
    public function placement_can_display( $return, $id = 0 ){
        static $checked_passive = array();

        if ( in_array( $id, $checked_passive ) ) {
            // Ignore current filter when the placement is delivered without passive cache-busting.
            return $return;
        }

        // get all placements
        $placements = Advanced_Ads::get_ad_placements_array();

        $cache_busting_auto = ! isset( $placements[ $id ]['options']['cache-busting'] ) || $placements[ $id ]['options']['cache-busting'] === self::OPTION_AUTO;

        if ( $cache_busting_auto && $this->is_passive_method_used() ) {
            $checked_passive[] = $id;
            return true;
        }

        return $return;
    }

    /**
     * determines, whether the "passive"  method is used or not
     *
     * @return bool true if the "passive" method is used, false otherwise
     */
    public function is_passive_method_used() {
        return isset( $this->options['default_auto_method'] ) && $this->options['default_auto_method'] === 'passive';
    }

    /**
     * determines, whether or not to load tracking scripts
     *
     * @param bool  $need_load_header_scripts
     * @return bool true if tracking scripts should be loaded, $need_load_header_scripts otherwise
     */
    public function load_tracking_scripts( $need_load_header_scripts ) {
        //the script is used by: passive cache-busting, 'group refresh' feature
        return true;
    }

    /**
     * Add ad debug content
     *
     * @param arr $content
     * @param obj $ad Advanced_Ads_Ad
     * @return arr $content
     */
    public function add_debug_content( $content, Advanced_Ads_Ad $ad ) {
        $needs_backend = $this->ad_needs_backend_request( $ad );
        if ( 'off' === $needs_backend || 'ajax' === $needs_backend ) {
            $info = __( 'The ad can not work with passive cache-busting', 'advanced-ads-pro' );
        } else {
            $info = __( 'The ad can work with passive cache-busting', 'advanced-ads-pro' );
        }

        if ( $this->is_ajax ) {
            $name = _x( 'ajax', 'setting label', 'advanced-ads-pro' );
        } elseif ( isset( $ad->args['cache-busting'] ) && $ad->args['cache-busting'] === self::OPTION_AUTO ) {
            $name =  __( 'passive', 'advanced-ads-pro' );
            $info .= '<br />##advanced_ads_passive_cb_debug##'
            . sprintf( '<div class="advads-passive-cb-debug" style="display:none;" data-displayed="%s" data-hidden="%s"></div>',
                __( 'The ad is displayed on the page', 'advanced-ads-pro' ),
                __( 'The ad is not displayed on the page', 'advanced-ads-pro' )
            );
        } else {
            $name = _x( 'off', 'setting label', 'advanced-ads-pro' );
        }

        $content[] = sprintf( '%s <strong>%s</strong><br />%s', _x( 'Cache-busting:', 'placement admin label', 'advanced-ads-pro' ), $name, $info );


        return $content;
    }

    /**
     * Add placement to current ads.
     *
     * @param string $id Placement id.
     */
    private function add_placement_to_current_ads( $id ) {
        $placements = Advanced_Ads::get_ad_placements_array();
        $name = ! empty( $placements[ $id ]['name'] ) ? $placements[ $id ]['name'] : $id;
        Advanced_Ads::get_instance()->current_ads[] = array('type' => 'placement', 'id' => $id, 'title' => $name );
    }

	/**
	 * Get visitor conditions.
	 *
	 * @param Advanced_Ads_Ad $ad Ad object.
	 *
	 * @return void
	 * @deprecated
	 *
	 */
	public function get_visitors( Advanced_Ads_Ad $ad ) {
	}

    /**
     * Check if the ad can be displayed based on display limit.
     * Handle "Custom position" placements that have cache-busting disabled.
     *
     * @param bool $can_display Existing value.
     * @param obj $ad Advanced_Ads_Ad object
     * @param array $check_options
     * @return bool true if limit is not reached, false otherwise
     */
    public function can_display_by_display_limit( $can_display, Advanced_Ads_Ad $ad, $check_options ) {
        if ( ! $can_display ) {
            return false;
        }

        if ( ! $this->collecting_js_items ) {
            return $can_display;
        }

        $output_options = $ad->options( 'output' );

        if ( ! empty( $output_options['once_per_page'] ) ) {

            foreach ( $this->has_js_items as $item ) {
                if ( $item['type'] === 'ad' && absint( $item['id'] ) === $ad->id ) {
                    return false;
                }
            }
        }
        return true;
    }

	/**
	 * Check whether the module is enabled.
	 *
	 * @return bool.
	 */
	public static function is_enabled() {
		$options = Advanced_Ads_Pro::get_instance()->get_options();
		return ! empty( $options['cache-busting']['enabled'] );
	}

    /**
     * Check if placements of type other than `header` can be injected during `wp_head` action.
     */
    private function can_inject_during_wp_head() {
        return class_exists( 'Advanced_Ads_Compatibility' )
            && method_exists( 'Advanced_Ads_Compatibility', 'can_inject_during_wp_head' )
            && Advanced_Ads_Compatibility::can_inject_during_wp_head();
    }

	/**
	 * Check if TCF privacy is active; only do this when cache-busting is turned off.
	 * If yes, add a script to handle decoded ads due to TCF privacy settings.
	 */
	public function check_for_tcf_privacy() {
		$options = Advanced_Ads_Privacy::get_instance()->options();
		if ( ! isset( $options['enabled'] ) || $options['consent-method'] !== 'iab_tcf_20' ) {
			return;
		}

		wp_enqueue_script(
			// we need the same handle as with cache-busting so tracking still works.
			'advanced-ads-pro/cache_busting',
			AAP_BASE_URL . 'assets/js/privacy' . ( defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ? '' : '.min' ) . '.js',
			[ ADVADS_SLUG . '-advanced-js', 'jquery'],
			AAP_VERSION,
			true
		);
	}
}