<?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
 */
#[AllowDynamicProperties]
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().
            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().
            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 &rsaquo; Error' ) ),
                array(
                    'response' => 501, // "Not implemented".
                )
            );
        }
    }
}