<?php

/**

 * Sitemaps: WP_Sitemaps_Renderer class

 *

 * Responsible for rendering Sitemaps data to XML in accordance with sitemap protocol.

 *

 * @package WordPress

 * @subpackage Sitemaps

 * @since 5.5.0

 */

/**

 * Class WP_Sitemaps_Renderer

 *

 * @since 5.5.0

 */

class WP_Sitemaps_Renderer {

	/**

	 * XSL stylesheet for styling a sitemap for web browsers.

	 *

	 * @since 5.5.0

	 *

	 * @var string

	 */

	protected $stylesheet = '';

	/**

	 * XSL stylesheet for styling a sitemap for web browsers.

	 *

	 * @since 5.5.0

	 *

	 * @var string

	 */

	protected $stylesheet_index = '';

	/**

	 * WP_Sitemaps_Renderer constructor.

	 *

	 * @since 5.5.0

	 */

	public function __construct() {

		$stylesheet_url = $this->get_sitemap_stylesheet_url();

		if ( $stylesheet_url ) {

			$this->stylesheet = '<?xml-stylesheet type="text/xsl" href="' . esc_url( $stylesheet_url ) . '" ?>';

		}

		$stylesheet_index_url = $this->get_sitemap_index_stylesheet_url();

		if ( $stylesheet_index_url ) {

			$this->stylesheet_index = '<?xml-stylesheet type="text/xsl" href="' . esc_url( $stylesheet_index_url ) . '" ?>';

		}

	}

	/**

	 * Gets the URL for the sitemap stylesheet.

	 *

	 * @since 5.5.0

	 *

	 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.

	 *

	 * @return string The sitemap stylesheet URL.

	 */

	public function get_sitemap_stylesheet_url() {

		global $wp_rewrite;

		$sitemap_url = home_url( '/wp-sitemap.xsl' );

		if ( ! $wp_rewrite->using_permalinks() ) {

			$sitemap_url = home_url( '/?sitemap-stylesheet=sitemap' );

		}

		/**

		 * Filters the URL for the sitemap stylesheet.

		 *

		 * If a falsey value is returned, no stylesheet will be used and

		 * the "raw" XML of the sitemap will be displayed.

		 *

		 * @since 5.5.0

		 *

		 * @param string $sitemap_url Full URL for the sitemaps XSL file.

		 */

		return apply_filters( 'wp_sitemaps_stylesheet_url', $sitemap_url );

	}

	/**

	 * Gets the URL for the sitemap index stylesheet.

	 *

	 * @since 5.5.0

	 *

	 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.

	 *

	 * @return string The sitemap index stylesheet URL.

	 */

	public function get_sitemap_index_stylesheet_url() {

		global $wp_rewrite;

		$sitemap_url = home_url( '/wp-sitemap-index.xsl' );

		if ( ! $wp_rewrite->using_permalinks() ) {

			$sitemap_url = home_url( '/?sitemap-stylesheet=index' );

		}

		/**

		 * Filters the URL for the sitemap index stylesheet.

		 *

		 * If a falsey value is returned, no stylesheet will be used and

		 * the "raw" XML of the sitemap index will be displayed.

		 *

		 * @since 5.5.0

		 *

		 * @param string $sitemap_url Full URL for the sitemaps index XSL file.

		 */

		return apply_filters( 'wp_sitemaps_stylesheet_index_url', $sitemap_url );

	}

	/**

	 * Renders a sitemap index.

	 *

	 * @since 5.5.0

	 *

	 * @param array $sitemaps Array of sitemap URLs.

	 */

	public function render_index( $sitemaps ) {

		header( 'Content-type: application/xml; charset=UTF-8' );

		$this->check_for_simple_xml_availability();

		$index_xml = $this->get_sitemap_index_xml( $sitemaps );

		if ( ! empty( $index_xml ) ) {

			// All output is escaped within get_sitemap_index_xml().

			// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped

			echo $index_xml;

		}

	}

	/**

	 * Gets XML for a sitemap index.

	 *

	 * @since 5.5.0

	 *

	 * @param array $sitemaps Array of sitemap URLs.

	 * @return string|false A well-formed XML string for a sitemap index. False on error.

	 */

	public function get_sitemap_index_xml( $sitemaps ) {

		$sitemap_index = new SimpleXMLElement(

			sprintf(

				'%1$s%2$s%3$s',

				'<?xml version="1.0" encoding="UTF-8" ?>',

				$this->stylesheet_index,

				'<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" />'

			)

		);

		foreach ( $sitemaps as $entry ) {

			$sitemap = $sitemap_index->addChild( 'sitemap' );

			// Add each element as a child node to the <sitemap> entry.

			foreach ( $entry as $name => $value ) {

				if ( 'loc' === $name ) {

					$sitemap->addChild( $name, esc_url( $value ) );

				} elseif ( 'lastmod' === $name ) {

					$sitemap->addChild( $name, esc_xml( $value ) );

				} else {

					_doing_it_wrong(

						__METHOD__,

						sprintf(

							/* translators: %s: List of element names. */

							__( 'Fields other than %s are not currently supported for the sitemap index.' ),

							implode( ',', array( 'loc', 'lastmod' ) )

						),

						'5.5.0'

					);

				}

			}

		}

		return $sitemap_index->asXML();

	}

	/**

	 * Renders a sitemap.

	 *

	 * @since 5.5.0

	 *

	 * @param array $url_list Array of URLs for a sitemap.

	 */

	public function render_sitemap( $url_list ) {

		header( 'Content-type: application/xml; charset=UTF-8' );

		$this->check_for_simple_xml_availability();

		$sitemap_xml = $this->get_sitemap_xml( $url_list );

		if ( ! empty( $sitemap_xml ) ) {

			// All output is escaped within get_sitemap_xml().

			// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped

			echo $sitemap_xml;

		}

	}

	/**

	 * Gets XML for a sitemap.

	 *

	 * @since 5.5.0

	 *

	 * @param array $url_list Array of URLs for a sitemap.

	 * @return string|false A well-formed XML string for a sitemap index. False on error.

	 */

	public function get_sitemap_xml( $url_list ) {

		$urlset = new SimpleXMLElement(

			sprintf(

				'%1$s%2$s%3$s',

				'<?xml version="1.0" encoding="UTF-8" ?>',

				$this->stylesheet,

				'<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" />'

			)

		);

		foreach ( $url_list as $url_item ) {

			$url = $urlset->addChild( 'url' );

			// Add each element as a child node to the <url> entry.

			foreach ( $url_item as $name => $value ) {

				if ( 'loc' === $name ) {

					$url->addChild( $name, esc_url( $value ) );

				} elseif ( in_array( $name, array( 'lastmod', 'changefreq', 'priority' ), true ) ) {

					$url->addChild( $name, esc_xml( $value ) );

				} else {

					_doing_it_wrong(

						__METHOD__,

						sprintf(

							/* translators: %s: List of element names. */

							__( 'Fields other than %s are not currently supported for sitemaps.' ),

							implode( ',', array( 'loc', 'lastmod', 'changefreq', 'priority' ) )

						),

						'5.5.0'

					);

				}

			}

		}

		return $urlset->asXML();

	}

	/**

	 * Checks for the availability of the SimpleXML extension and errors if missing.

	 *

	 * @since 5.5.0

	 */

	private function check_for_simple_xml_availability() {

		if ( ! class_exists( 'SimpleXMLElement' ) ) {

			add_filter(

				'wp_die_handler',

				static function () {

					return '_xml_wp_die_handler';

				}

			);

			wp_die(

				sprintf(

					/* translators: %s: SimpleXML */

					esc_xml( __( 'Could not generate XML sitemap due to missing %s extension' ) ),

					'SimpleXML'

				),

				esc_xml( __( 'WordPress › Error' ) ),

				array(

					'response' => 501, // "Not implemented".

				)

			);

		}

	}

}