{
			$script .= '};';
		}

		$script .= '
        window.addEventListener(\'LazyLoad::Initialized\', function (e) {
            var lazyLoadInstance = e.detail.instance;

            if (window.MutationObserver) {
                var observer = new MutationObserver(function(mutations) {
                    var image_count = 0;
                    var iframe_count = 0;
                    var rocketlazy_count = 0;

                    mutations.forEach(function(mutation) {
                        for (var i = 0; i < mutation.addedNodes.length; i++) {
                            if (typeof mutation.addedNodes[i].getElementsByTagName !== \'function\') {
                                continue;
                            }

                            if (typeof mutation.addedNodes[i].getElementsByClassName !== \'function\') {
                                continue;
                            }

                            images = mutation.addedNodes[i].getElementsByTagName(\'img\');
                            is_image = mutation.addedNodes[i].tagName == "IMG";
                            iframes = mutation.addedNodes[i].getElementsByTagName(\'iframe\');
                            is_iframe = mutation.addedNodes[i].tagName == "IFRAME";
                            rocket_lazy = mutation.addedNodes[i].getElementsByClassName(\'rocket-lazyload\');

                            image_count += images.length;
			                iframe_count += iframes.length;
			                rocketlazy_count += rocket_lazy.length;

                            if(is_image){
                                image_count += 1;
                            }

                            if(is_iframe){
                                iframe_count += 1;
                            }
                        }
                    } );

                    if(image_count > 0 || iframe_count > 0 || rocketlazy_count > 0){
                        lazyLoadInstance.update();
                    }
                } );

                var b      = document.getElementsByTagName("body")[0];
                var config = { childList: true, subtree: true };

                observer.observe(b, config);
            }
        }, false);';

		return $script;
	}

	/**
	 * CL: Gets the JavaScript literal for a lazyload option.
	 *
	 * @param string $option Lazyload option name.
	 * @param mixed  $value  Lazyload option value.
	 * @return string|null
	 */
	private function getLazyloadOptionValue( $option, $value ) {
		if ( 'container' === $option ) {
			return $this->getLazyloadContainerOptionValue( $value );
		}

		if ( 0 === strpos( $option, 'callback_' ) ) {
			return $this->getLazyloadCallbackOptionValue( $value );
		}

		if ( in_array( $option, [ 'cancel_on_exit', 'unobserve_entered', 'unobserve_completed', 'use_native' ], true ) ) {
			return $this->getBooleanOptionValue( $value );
		}

		$encoded = wp_json_encode( $value );

		return false === $encoded ? null : $encoded;
	}

	/**
	 * CL: Gets a safe JavaScript expression for the lazyload container option.
	 *
	 * @param mixed $value Container option value.
	 * @return string|null
	 */
	private function getLazyloadContainerOptionValue( $value ) {
		if ( ! is_string( $value ) ) {
			return null;
		}

		$value              = trim( $value );
		$allowed_containers = [
			'document'                 => true,
			'window.document'          => true,
			'document.body'            => true,
			'document.documentElement' => true,
		];

		return isset( $allowed_containers[ $value ] ) ? $value : null;
	}

	/**
	 * CL: Gets a safe JavaScript expression for a lazyload callback option.
	 *
	 * @param mixed $value Callback option value.
	 * @return string|null
	 */
	private function getLazyloadCallbackOptionValue( $value ) {
		if ( ! is_string( $value ) ) {
			return null;
		}

		$value = trim( $value );

		if ( '' === $value ) {
			return null;
		}

		return preg_match( '/^(?:window\.)?[A-Za-z_$][A-Za-z0-9_$]*(?:\.[A-Za-z_$][A-Za-z0-9_$]*)*$/', $value ) ? $value : null;
	}

	/**
	 * CL: Gets a JavaScript boolean literal for a lazyload option.
	 *
	 * @param mixed $value Boolean-ish option value.
	 * @return string|null
	 */
	private function getBooleanOptionValue( $value ) {
		if ( is_array( $value ) || is_object( $value ) ) {
			return null;
		}

		$value = filter_var( $value, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE );

		if ( null === $value ) {
			return null;
		}

		return $value ? 'true' : 'false';
	}

	/**
	 * Returns the lazyload inline script
	 *
	 * @param array<string> $args Array of arguments to populate the lazyload script options.
	 * @return string
	 */
	public function getLazyloadScript( $args = [] ) {
		$defaults = [
			'base_url' => '',
			'version'  => '',
		];

		$args = wp_parse_args( $args, $defaults );
		$min  = ( defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ) ? '' : '.min';

		/**
		 * Filters the script tag for the lazyload script
		 *
		 * @since 2.2.6
		 *
		 * @param string $script_tag HTML tag for the lazyload script.
		 */
		return apply_filters( 'rocket_lazyload_script_tag', '<script data-no-minify="1" async src="' . $args['base_url'] . $args['version'] . '/lazyload' . $min . '.js"></script>' ); // phpcs:ignore WordPress.WP.EnqueuedResources.NonEnqueuedScript
	}

	/**
	 * Inserts in the HTML the script to replace the Youtube thumbnail by the iframe.
	 *
	 * @param array<string, bool> $args Array of arguments to populate the script options.
	 * @return void
	 */
	public function insertYoutubeThumbnailScript( $args = [] ) {
		echo $this->getYoutubeThumbnailScript( $args ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
	}

	/**
	 * Returns the Youtube Thumbnail inline script
	 *
	 * @param array<string, bool> $args Array of arguments to populate the script options.
	 * @return string
	 */
	public function getYoutubeThumbnailScript( $args = [] ) {
		$defaults = [
			'resolution'        => 'hqdefault',
			'lazy_image'        => false,
			'native'            => true,
			'extension'         => 'jpg',
			'button_aria_label' => 'play Youtube video',
		];

		$allowed_resolutions = [
			'default'       => [
				'width'  => 120,
				'height' => 90,
			],
			'mqdefault'     => [
				'width'  => 320,
				'height' => 180,
			],
			'hqdefault'     => [
				'width'  => 480,
				'height' => 360,
			],
			'sddefault'     => [
				'width'  => 640,
				'height' => 480,
			],

			'maxresdefault' => [
				'width'  => 1280,
				'height' => 720,
			],
		];

		$args['resolution'] = ( isset( $args['resolution'] ) && isset( $allowed_resolutions[ $args['resolution'] ] ) ) ? $args['resolution'] : 'hqdefault';

		$args = wp_parse_args( $args, $defaults );

		$extension_uri = 'webp' === $args['extension'] ? 'vi_webp' : 'vi';

		$image_url = esc_url( 'https://i.ytimg.com/' . $extension_uri . '/ID/' . $args['resolution'] . '.' . $args['extension'] ); // CL: escape thumbnail URL before inline-script output (XSS).

		$image = '<img src="' . $image_url . '" alt="" width="' . $allowed_resolutions[ $args['resolution'] ]['width'] . '" height="' . $allowed_resolutions[ $args['resolution'] ]['height'] . '">';

		if ( isset( $args['lazy_image'] ) && $args['lazy_image'] ) {
			$attributes = 'alt="" width="' . $allowed_resolutions[ $args['resolution'] ]['width'] . '" height="' . $allowed_resolutions[ $args['resolution'] ]['height'] . '"';

			$image = '<img data-lazy-src="' . $image_url . '" ' . $attributes . '><noscript><img src="' . $image_url . '" ' . $attributes . '></noscript>';

			if ( $args['native'] ) {
				$image = '<img loading="lazy" src="' . $image_url . '" ' . $attributes . '>';
			}
		}

		$button_aria_label = esc_attr( $args['button_aria_label'] ); // CL: escape aria-label before inline-script output (XSS).

		/**
		 * Filters the patterns excluded from lazyload for youtube thumbnails.
		 *
		 * @param array $excluded_patterns Array of excluded patterns.
		 */
		$excluded_patterns = apply_filters( 'rocket_lazyload_exclude_youtube_thumbnail', [] );

		if ( ! is_array( $excluded_patterns ) ) {
			$excluded_patterns = [];
		}

		$excluded_patterns = wp_json_encode( $excluded_patterns );

		// CL: escape dataset values (data-id, data-alt) before they are concatenated into the innerHTML'd thumbnail markup; browser dataset access HTML-decodes the esc_attr'd attribute, so a literal " or < would otherwise break out of alt="..."/src="..." -> DOM XSS. The escaped value is inserted via a String.replace REPLACEMENT FUNCTION (not a replacement string) so JS $-patterns ($`, $', $&, $n) in a dataset value are inserted literally instead of re-injecting raw pre/post-match template markup -> attribute breakout. Upstream this to the RocketLazyload package on re-vendor.
		return "<script>function lazyLoadThumbEsc(s){return String(s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/\"/g,'&quot;').replace(/'/g,'&#039;')}function lazyLoadThumb(e,alt,l){var t='{$image}',a='<button class=\"play\" aria-label=\"{$button_aria_label}\"></button>';if(l){t=t.replace('data-lazy-','');t=t.replace('loading=\"lazy\"','');t=t.replace(/<noscript>.*?<\/noscript>/g,'');}t=t.replace('alt=\"\"',function(){return 'alt=\"'+lazyLoadThumbEsc(alt)+'\"'});return t.replace(\"ID\",function(){return lazyLoadThumbEsc(e)})+a}function lazyLoadYoutubeIframe(){var e=document.createElement(\"iframe\"),s=this.parentNode.dataset.src,t=\"ID?autoplay=1\";t+=0===this.parentNode.dataset.query.length?\"\":\"&\"+this.parentNode.dataset.query;e.setAttribute(\"src\",t.replace(\"ID\",function(){return s})),e.setAttribute(\"frameborder\",\"0\"),e.setAttribute(\"allowfullscreen\",\"1\"),e.setAttribute(\"allow\",\"accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture\"),this.parentNode.parentNode.replaceChild(e,this.parentNode)}document.addEventListener(\"DOMContentLoaded\",function(){var exclusions={$excluded_patterns};var e,t,p,u,l,a=document.getElementsByClassName(\"rll-youtube-player\");for(t=0;t<a.length;t++)(e=document.createElement(\"div\")),(u='{$image_url}'),(u=u.replace('ID',function(){return a[t].dataset.id})),(l=exclusions.some(exclusion=>u.includes(exclusion))),e.setAttribute(\"data-id\",a[t].dataset.id),e.setAttribute(\"data-query\",a[t].dataset.query),e.setAttribute(\"data-src\",a[t].dataset.src),(e.innerHTML=lazyLoadThumb(a[t].dataset.id,a[t].dataset.alt,l)),a[t].appendChild(e),(p=e.querySelector(\".play\")),(p.onclick=lazyLoadYoutubeIframe)});</script>";
	}

	/**
	 * Inserts the CSS to style the Youtube thumbnail container
	 *
	 * @param array<string, bool> $args Array of arguments to populate the CSS.
	 * @return void
	 */
	public function insertYoutubeThumbnailCSS( $args = [] ) {
		wp_register_style( 'rocket-lazyload', false ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion
		wp_enqueue_style( 'rocket-lazyload' );
		wp_add_inline_style( 'rocket-lazyload', $this->getYoutubeThumbnailCSS( $args ) );
	}

	/**
	 * Returns the CSS for the Youtube Thumbnail
	 *
	 * @param array<string, bool> $args Array of arguments to populate the CSS.
	 * @return string
	 */
	public function getYoutubeThumbnailCSS( $args = [] ) {
		$defaults = [
			'base_url'          => '',
			'responsive_embeds' => true,
		];

		$args = wp_parse_args( $args, $defaults );

		$css = '.rll-youtube-player{position:relative;padding-bottom:56.23%;height:0;overflow:hidden;max-width:100%;}.rll-youtube-player:focus-within{outline: 2px solid currentColor;outline-offset: 5px;}.rll-youtube-player iframe{position:absolute;top:0;left:0;width:100%;height:100%;z-index:100;background:0 0}.rll-youtube-player img{bottom:0;display:block;left:0;margin:auto;max-width:100%;width:100%;position:absolute;right:0;top:0;border:none;height:auto;-webkit-transition:.4s all;-moz-transition:.4s all;transition:.4s all}.rll-youtube-player img:hover{-webkit-filter:brightness(75%)}.rll-youtube-player .play{height:100%;width:100%;left:0;top:0;position:absolute;background:url(' . $args['base_url'] . 'img/youtube.png) no-repeat center;background-color: transparent !important;cursor:pointer;border:none;}';

		if ( $args['responsive_embeds'] ) {
			$css .= '.wp-embed-responsive .wp-has-aspect-ratio .rll-youtube-player{position:absolute;padding-bottom:0;width:100%;height:100%;top:0;bottom:0;left:0;right:0}';
		}

		return $css;
	}

	/**
	 * Inserts the CSS needed when Javascript is not enabled to keep the display correct
	 *
	 * @return void
	 */
	public function insertNoJSCSS() {
		echo $this->getNoJSCSS(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
	}

	/**
	 * Returns the CSS to correctly display images when JavaScript is disabled
	 *
	 * @return string
	 */
	public function getNoJSCSS() {
		return '<noscript><style id="rocket-lazyload-nojs-css">.rll-youtube-player, [data-lazy-src]{display:none !important;}</style></noscript>';
	}
}