<?php
/**
 * Class AMP_Content_Sanitizer
 *
 * @package AMP
 */

/**
 * Class AMP_Content_Sanitizer
 *
 * @since 0.4.1
 */
class AMP_Content_Sanitizer {

	/**
	 * Sanitize _content_.
	 *
	 * @since 0.4.1
	 * @since 0.7 Passing return_styles=false in $global_args causes stylesheets to be returned instead of styles.
	 * @deprecated Since 1.0
	 *
	 * @param string   $content HTML content string or DOM document.
	 * @param string[] $sanitizer_classes Sanitizer classes.
	 * @param array    $global_args       Global args.
	 * @return array Tuple containing sanitized HTML, scripts array, and styles array (or stylesheets, if return_styles=false is passed in $global_args).
	 */
	public static function sanitize( $content, array $sanitizer_classes, $global_args = array() ) {
		$dom = AMP_DOM_Utils::get_dom_from_content( $content );

		// For back-compat.
		if ( ! isset( $global_args['return_styles'] ) ) {
			$global_args['return_styles'] = true;
		}

		$results = self::sanitize_document( $dom, $sanitizer_classes, $global_args );
		return array(
			AMP_DOM_Utils::get_content_from_dom( $dom ),
			$results['scripts'],
			empty( $global_args['return_styles'] ) ? $results['stylesheets'] : $results['styles'],
		);
	}

	/**
	 * Sanitize document.
	 *
	 * @since 0.7
	 *
	 * @param DOMDocument $dom               HTML document.
	 * @param string[]    $sanitizer_classes Sanitizer classes.
	 * @param array       $args              Global args passed into sanitizers.
	 * @return array {
	 *     Scripts and stylesheets needed by sanitizers.
	 *
	 *     @type array $scripts     Scripts.
	 *     @type array $stylesheets Stylesheets. If $args['return_styles'] is empty.
	 *     @type array $styles      Styles. If $args['return_styles'] is not empty. For legacy purposes.
	 * }
	 */
	public static function sanitize_document( &$dom, $sanitizer_classes, $args ) {
		$scripts     = array();
		$stylesheets = array();
		$styles      = array();

		$return_styles = ! empty( $args['return_styles'] );
		unset( $args['return_styles'] );

		/**
		 * Sanitizers.
		 *
		 * @var AMP_Base_Sanitizer[] $sanitizers
		 */
		$sanitizers = array();

		// Instantiate the sanitizers.
		foreach ( $sanitizer_classes as $sanitizer_class => $sanitizer_args ) {
			if ( ! class_exists( $sanitizer_class ) ) {
				/* translators: %s is sanitizer class */
				_doing_it_wrong( __METHOD__, sprintf( esc_html__( 'Sanitizer (%s) class does not exist', 'amp' ), esc_html( $sanitizer_class ) ), '0.4.1' );
				continue;
			}

			/**
			 * Sanitizer.
			 *
			 * @type AMP_Base_Sanitizer $sanitizer
			 */
			$sanitizer = new $sanitizer_class( $dom, array_merge( $args, $sanitizer_args ) );

			if ( ! is_subclass_of( $sanitizer, 'AMP_Base_Sanitizer' ) ) {
				_doing_it_wrong(
					__METHOD__,
					esc_html(
						sprintf(
							/* translators: 1: sanitizer class. 2: AMP_Base_Sanitizer */
							__( 'Sanitizer (%1$s) must extend `%2$s`', 'amp' ),
							esc_html( $sanitizer_class ),
							'AMP_Base_Sanitizer'
						)
					),
					'0.1'
				);
				continue;
			}

			$sanitizers[ $sanitizer_class ] = $sanitizer;
		}

		// Let the sanitizers know about each other prior to sanitizing.
		foreach ( $sanitizers as $sanitizer ) {
			$sanitizer->init( $sanitizers );
		}

		// Sanitize.
		foreach ( $sanitizers as $sanitizer_class => $sanitizer ) {
			$sanitize_class_start = microtime( true );

			$sanitizer->sanitize();

			$scripts = array_merge( $scripts, $sanitizer->get_scripts() );
			if ( $return_styles ) {
				$styles = array_merge( $styles, $sanitizer->get_styles() );
			} else {
				$stylesheets = array_merge( $stylesheets, $sanitizer->get_stylesheets() );
			}

			AMP_HTTP::send_server_timing( 'amp_sanitize', -$sanitize_class_start, $sanitizer_class );
		}

		return compact( 'scripts', 'styles', 'stylesheets' );
	}
}