s' === $ext ) {
			$zones[] = 'css';
		}

		if ( 'js' === $ext ) {
			$zones[] = 'js';
		}

		if ( in_array( $ext, $image_types, true ) ) {
			$zones[] = 'images';
		}

		return $zones;
	}

	/**
	 * Get all files we don't allow to get in CDN.
	 *
	 * @since 2.5
	 *
	 * @param string $delimiter RegEx delimiter.
	 * @return string A pipe-separated list of excluded files.
	 */
	private function get_excluded_files( $delimiter ) {
		$files = $this->options->get( 'cdn_reject_files', [] );

		/**
			* Filter the excluded files.
			*
			* @since 2.5
			*
			* @param array $files List of excluded files.
		*/
		$files = (array) apply_filters( 'rocket_cdn_reject_files', $files );
		$files = array_filter( $files );

		if ( ! $files ) {
			return '';
		}

		$files = array_flip( array_flip( $files ) );
		$files = array_map(
			function ( $file ) use ( $delimiter ) {
				return str_replace( $delimiter, '\\' . $delimiter, $file );
			},
			$files
		);

		return implode( '|', $files );
	}

	/**
	 * Get srcset attributes to rewrite to the CDN.
	 *
	 * @since 3.8.7
	 *
	 * @return string A pipe-separated list of srcset attributes.
	 */
	private function get_srcset_attributes() {
		/**
		 * Filter the srcset attributes.
		 *
		 * @since 3.8.7
		 *
		 * @param array $srcset_attributes List of srcset attributes.
		 */
		$srcset_attributes = (array) apply_filters(
			'rocket_cdn_srcset_attributes',
			[
				'data-lazy-',
				'data-',
			]
		);
		return implode( '|', $srcset_attributes );
	}

	/**
	 * Removes inline scripts from the HTML
	 *
	 * @since 3.10.5
	 *
	 * @param string $html HTML content.
	 *
	 * @return string
	 */
	private function remove_inline_scripts( $html ): string {
		if ( ! preg_match_all( '#<script(?:[^>]*)>(?<content>[\s\S]*?)</script>#msi', $html, $matches, PREG_SET_ORDER ) ) {
			return $html;
		}

		if ( empty( $matches ) ) {
			return $html;
		}

		foreach ( $matches as $inline_js ) {
			if ( empty( $inline_js['content'] ) ) {
				continue;
			}

			$html = str_replace( $inline_js[0], '', $html );
		}

		return $html;
	}
}