this->preg_index( $num_toks + 1 );

			// Create query and regex for embeds.
			$embedmatch = $match . $embedregex;
			$embedquery = $embedindex . '?' . $query . '&embed=true';

			// If asked to, turn the feed queries into comment feed ones.
			if ( $forcomments ) {
				$feedquery  .= '&withcomments=1';
				$feedquery2 .= '&withcomments=1';
			}

			// Start creating the array of rewrites for this dir.
			$rewrite = array();

			// ...adding on /feed/ regexes => queries.
			if ( $feed ) {
				$rewrite = array(
					$feedmatch  => $feedquery,
					$feedmatch2 => $feedquery2,
					$embedmatch => $embedquery,
				);
			}

			// ...and /page/xx ones.
			if ( $paged ) {
				$rewrite = array_merge( $rewrite, array( $pagematch => $pagequery ) );
			}

			// Only on pages with comments add ../comment-page-xx/.
			if ( EP_PAGES & $ep_mask || EP_PERMALINK & $ep_mask ) {
				$rewrite = array_merge( $rewrite, array( $commentmatch => $commentquery ) );
			} elseif ( EP_ROOT & $ep_mask && get_option( 'page_on_front' ) ) {
				$rewrite = array_merge( $rewrite, array( $rootcommentmatch => $rootcommentquery ) );
			}

			// Do endpoints.
			if ( $endpoints ) {
				foreach ( (array) $ep_query_append as $regex => $ep ) {
					// Add the endpoints on if the mask fits.
					if ( $ep[0] & $ep_mask || $ep[0] & $ep_mask_specific ) {
						$rewrite[ $match . $regex ] = $index . '?' . $query . $ep[1] . $this->preg_index( $num_toks + 2 );
					}
				}
			}

			// If we've got some tags in this dir.
			if ( $num_toks ) {
				$post = false;
				$page = false;

				/*
				 * Check to see if this dir is permalink-level: i.e. the structure specifies an
				 * individual post. Do this by checking it contains at least one of 1) post name,
				 * 2) post ID, 3) page name, 4) timestamp (year, month, day, hour, second and
				 * minute all present). Set these flags now as we need them for the endpoints.
				 */
				if ( str_contains( $struct, '%postname%' )
					|| str_contains( $struct, '%post_id%' )
					|| str_contains( $struct, '%pagename%' )
					|| ( str_contains( $struct, '%year%' )
						&& str_contains( $struct, '%monthnum%' )
						&& str_contains( $struct, '%day%' )
						&& str_contains( $struct, '%hour%' )
						&& str_contains( $struct, '%minute%' )
						&& str_contains( $struct, '%second%' ) )
				) {
					$post = true;
					if ( str_contains( $struct, '%pagename%' ) ) {
						$page = true;
					}
				}

				if ( ! $post ) {
					// For custom post types, we need to add on endpoints as well.
					foreach ( get_post_types( array( '_builtin' => false ) ) as $ptype ) {
						if ( str_contains( $struct, "%$ptype%" ) ) {
							$post = true;

							// This is for page style attachment URLs.
							$page = is_post_type_hierarchical( $ptype );
							break;
						}
					}
				}

				// If creating rules for a permalink, do all the endpoints like attachments etc.
				if ( $post ) {
					// Create query and regex for trackback.
					$trackbackmatch = $match . $trackbackregex;
					$trackbackquery = $trackbackindex . '?' . $query . '&tb=1';

					// Create query and regex for embeds.
					$embedmatch = $match . $embedregex;
					$embedquery = $embedindex . '?' . $query . '&embed=true';

					// Trim slashes from the end of the regex for this dir.
					$match = rtrim( $match, '/' );

					// Get rid of brackets.
					$submatchbase = str_replace( array( '(', ')' ), '', $match );

					// Add a rule for at attachments, which take the form of <permalink>/some-text.
					$sub1 = $submatchbase . '/([^/]+)/';

					// Add trackback regex <permalink>/trackback/...
					$sub1tb = $sub1 . $trackbackregex;

					// And <permalink>/feed/(atom|...)
					$sub1feed = $sub1 . $feedregex;

					// And <permalink>/(feed|atom...)
					$sub1feed2 = $sub1 . $feedregex2;

					// And <permalink>/comment-page-xx
					$sub1comment = $sub1 . $commentregex;

					// And <permalink>/embed/...
					$sub1embed = $sub1 . $embedregex;

					/*
					 * Add another rule to match attachments in the explicit form:
					 * <permalink>/attachment/some-text
					 */
					$sub2 = $submatchbase . '/attachment/([^/]+)/';

					// And add trackbacks <permalink>/attachment/trackback.
					$sub2tb = $sub2 . $trackbackregex;

					// Feeds, <permalink>/attachment/feed/(atom|...)
					$sub2feed = $sub2 . $feedregex;

					// And feeds again on to this <permalink>/attachment/(feed|atom...)
					$sub2feed2 = $sub2 . $feedregex2;

					// And <permalink>/comment-page-xx
					$sub2comment = $sub2 . $commentregex;

					// And <permalink>/embed/...
					$sub2embed = $sub2 . $embedregex;

					// Create queries for these extra tag-ons we've just dealt with.
					$subquery        = $index . '?attachment=' . $this->preg_index( 1 );
					$subtbquery      = $subquery . '&tb=1';
					$subfeedquery    = $subquery . '&feed=' . $this->preg_index( 2 );
					$subcommentquery = $subquery . '&cpage=' . $this->preg_index( 2 );
					$subembedquery   = $subquery . '&embed=true';

					// Do endpoints for attachments.
					if ( ! empty( $endpoints ) ) {
						foreach ( (array) $ep_query_append as $regex => $ep ) {
							if ( $ep[0] & EP_ATTACHMENT ) {
								$rewrite[ $sub1 . $regex ] = $subquery . $ep[1] . $this->preg_index( 3 );
								$rewrite[ $sub2 . $regex ] = $subquery . $ep[1] . $this->preg_index( 3 );
							}
						}
					}

					/*
					 * Now we've finished with endpoints, finish off the $sub1 and $sub2 matches
					 * add a ? as we don't have to match that last slash, and finally a $ so we
					 * match to the end of the URL
					 */
					$sub1 .= '?$';
					$sub2 .= '?$';

					/*
					 * Post pagination, e.g. <permalink>/2/
					 * Previously: '(/[0-9]+)?/?$', which produced '/2' for page.
					 * When cast to int, returned 0.
					 */
					$match = $match . '(?:/([0-9]+))?/?$';
					$query = $index . '?' . $query . '&page=' . $this->preg_index( $num_toks + 1 );

					// Not matching a permalink so this is a lot simpler.
				} else {
					// Close the match and finalize the query.
					$match .= '?$';
					$query  = $index . '?' . $query;
				}

				/*
				 * Create the final array for this dir by joining the $rewrite array (which currently
				 * only contains rules/queries for trackback, pages etc) to the main regex/query for
				 * this dir
				 */
				$rewrite = array_merge( $rewrite, array( $match => $query ) );

				// If we're matching a permalink, add those extras (attachments etc) on.
				if ( $post ) {
					// Add trackback.
					$rewrite = array_merge( array( $trackbackmatch => $trackbackquery ), $rewrite );

					// Add embed.
					$rewrite = array_merge( array( $embedmatch => $embedquery ), $rewrite );

					// Add regexes/queries for attachments, attachment trackbacks and so on.
					if ( ! $page ) {
						// Require <permalink>/attachment/stuff form for pages because of confusion with subpages.
						$rewrite = array_merge(
							$rewrite,
							array(
								$sub1        => $subquery,
								$sub1tb      => $subtbquery,
								$sub1feed    => $subfeedquery,
								$sub1feed2   => $subfeedquery,
								$sub1comment => $subcommentquery,
								$sub1embed   => $subembedquery,
							)
						);
					}

					$rewrite = array_merge(
						array(
							$sub2        => $subquery,
							$sub2tb      => $subtbquery,
							$sub2feed    => $subfeedquery,
							$sub2feed2   => $subfeedquery,
							$sub2comment => $subcommentquery,
							$sub2embed   => $subembedquery,
						),
						$rewrite
					);
				}
			}
			// Add the rules for this dir to the accumulating $post_rewrite.
			$post_rewrite = array_merge( $rewrite, $post_rewrite );
		}

		// The finished rules. phew!
		return $post_rewrite;
	}

	/**
	 * Generates rewrite rules with permalink structure and walking directory only.
	 *
	 * Shorten version of WP_Rewrite::generate_rewrite_rules() that allows for shorter
	 * list of parameters. See the method for longer description of what generating
	 * rewrite rules does.
	 *
	 * @since 1.5.0
	 *
	 * @see WP_Rewrite::generate_rewrite_rules() See for long description and rest of parameters.
	 *
	 * @param string $permalink_structure The permalink structure to generate rules.
	 * @param bool   $walk_dirs           Optional. Whether to create list of directories to walk over.
	 *                                    Default false.
	 * @return array An array of rewrite rules keyed by their regex pattern.
	 */
	public function generate_rewrite_rule( $permalink_structure, $walk_dirs = false ) {
		return $this->generate_rewrite_rules( $permalink_structure, EP_NONE, false, false, false, $walk_dirs );
	}

	/**
	 * Constructs rewrite matches and queries from permalink structure.
	 *
	 * Runs the action {@see 'generate_rewrite_rules'} with the parameter that is an
	 * reference to the current WP_Rewrite instance to further manipulate the
	 * permalink structures and rewrite rules. Runs the {@see 'rewrite_rules_array'}
	 * filter on the full rewrite rule array.
	 *
	 * There are two ways to manipulate the rewrite rules, one by hooking into
	 * the {@see 'generate_rewrite_rules'} action and gaining full control of the
	 * object or just manipulating the rewrite rule array before it is passed
	 * from the function.
	 *
	 * @since 1.5.0
	 *
	 * @return string[] An associative array of matches and queries.
	 */
	public function rewrite_rules() {
		$rewrite = array();

		if ( empty( $this->permalink_structure ) ) {
			return $rewrite;
		}

		// robots.txt -- only if installed at the root.
		$home_path      = parse_url( home_url() );
		$robots_rewrite = ( empty( $home_path['path'] ) || '/' === $home_path['path'] ) ? array( 'robots\.txt$' => $this->index . '?robots=1' ) : array();

		// favicon.ico -- only if installed at the root.
		$favicon_rewrite = ( empty( $home_path['path'] ) || '/' === $home_path['path'] ) ? array( 'favicon\.ico$' => $this->index . '?favicon=1' ) : array();

		// Old feed and service files.
		$deprecated_files = array(
			'.*wp-(atom|rdf|rss|rss2|feed|commentsrss2)\.php$' => $this->index . '?feed=old',
			'.*wp-app\.php(/.*)?$' => $this->index . '?error=403',
		);

		// Registration rules.
		$registration_pages = array();
		if ( is_multisite() && is_main_site() ) {
			$registration_pages['.*wp-signup.php$']   = $this->index . '?signup=true';
			$registration_pages['.*wp-activate.php$'] = $this->index . '?activate=true';
		}

		// Deprecated.
		$registration_pages['.*wp-register.php$'] = $this->index . '?register=true';

		// Post rewrite rules.
		$post_rewrite = $this->generate_rewrite_rules( $this->permalink_structure, EP_PERMALINK );

		/**
		 * Filters rewrite rules used for "post" archives.
		 *
		 * @since 1.5.0
		 *
		 * @param string[] $post_rewrite Array of rewrite rules for posts, keyed by their regex pattern.
		 */
		$post_rewrite = apply_filters( 'post_rewrite_rules', $post_rewrite );

		// Date rewrite rules.
		$date_rewrite = $this->generate_rewrite_rules( $this->get_date_permastruct(), EP_DATE );

		/**
		 * Filters rewrite rules used for date archives.
		 *
		 * Likely date archives would include `/yyyy/`, `/yyyy/mm/`, and `/yyyy/mm/dd/`.
		 *
		 * @since 1.5.0
		 *
		 * @param string[] $date_rewrite Array of rewrite rules for date archives, keyed by their regex pattern.
		 */
		$date_rewrite = apply_filters( 'date_rewrite_rules', $date_rewrite );

		// Root-level rewrite rules.
		$root_rewrite = $this->generate_rewrite_rules( $this->root . '/', EP_ROOT );

		/**
		 * Filters rewrite rules used for root-level archives.
		 *
		 * Likely root-level archives would include pagination rules for the homepage
		 * as well as site-wide post feeds (e.g. `/feed/`, and `/feed/atom/`).
		 *
		 * @since 1.5.0
		 *
		 * @param string[] $root_rewrite Array of root-level rewrite rules, keyed by their regex pattern.
		 */
		$root_rewrite = apply_filters( 'root_rewrite_rules', $root_rewrite );

		// Comments rewrite rules.
		$comments_rewrite = $this->generate_rewrite_rules( $this->root . $this->comments_base, EP_COMMENTS, false, true, true, false );

		/**
		 * Filters rewrite rules used for comment feed archives.
		 *
		 * Likely comments feed archives include `/comments/feed/` and `/comments/feed/atom/`.
		 *
		 * @since 1.5.0
		 *
		 * @param string[] $comments_rewrite Array of rewrite rules for the site-wide comments feeds, keyed by their regex pattern.
		 */
		$comments_rewrite = apply_filters( 'comments_rewrite_rules', $comments_rewrite );

		// Search rewrite rules.
		$search_structure = $this->get_search_permastruct();
		$search_rewrite   = $this->generate_rewrite_rules( $search_structure, EP_SEARCH );

		/**
		 * Filters rewrite rules used for search archives.
		 *
		 * Likely search-related archives include `/search/search+query/` as well as
		 * pagination and feed paths for a search.
		 *
		 * @since 1.5.0
		 *
		 * @param string[] $search_rewrite Array of rewrite rules for search queries, keyed by their regex pattern.
		 */
		$search_rewrite = apply_filters( 'search_rewrite_rules', $search_rewrite );

		// Author rewrite rules.
		$author_rewrite = $this->generate_rewrite_rules( $this->get_author_permastruct(), EP_AUTHORS );

		/**
		 * Filters rewrite rules used for author archives.
		 *
		 * Likely author archives would include `/author/author-name/`, as well as
		 * pagination and feed paths for author archives.
		 *
		 * @since 1.5.0
		 *
		 * @param string[] $author_rewrite Array of rewrite rules for author archives, keyed by their regex pattern.
		 */
		$author_rewrite = apply_filters( 'author_rewrite_rules', $author_rewrite );

		// Pages rewrite rules.
		$page_rewrite = $this->page_rewrite_rules();

		/**
		 * Filters rewrite rules used for "page" post type archives.
		 *
		 * @since 1.5.0
		 *
		 * @param string[] $page_rewrite Array of rewrite rules for the "page" post type, keyed by their regex pattern.
		 */
		$page_rewrite = apply_filters( 'page_rewrite_rules', $page_rewrite );

		// Extra permastructs.
		foreach ( $this->extra_permastructs as $permastructname => $struct ) {
			if ( is_array( $struct ) ) {
				if ( count( $struct ) === 2 ) {
					$rules = $this->generate_rewrite_rules( $struct[0], $struct[1] );
				} else {
					$rules = $this->generate_rewrite_rules( $struct['struct'], $struct['ep_mask'], $struct['paged'], $struct['feed'], $struct['forcomments'], $struct['walk_dirs'], $struct['endpoints'] );
				}
			} else {
				$rules = $this->generate_rewrite_rules( $struct );
			}

			/**
			 * Filters rewrite rules used for individual permastructs.
			 *
			 * The dynamic portion of the hook name, `$permastructname`, refers
			 * to the name of the registered permastruct.
			 *
			 * Possible hook names include:
			 *
			 *  - `category_rewrite_rules`
			 *  - `post_format_rewrite_rules`
			 *  - `post_tag_rewrite_rules`
			 *
			 * @since 3.1.0
			 *
			 * @param string[] $rules Array of rewrite rules generated for the current permastruct, keyed by their regex pattern.
			 */
			$rules = apply_filters( "{$permastructname}_rewrite_rules", $rules );

			if ( 'post_tag' === $permastructname ) {

				/**
				 * Filters rewrite rules used specifically for Tags.
				 *
				 * @since 2.3.0
				 * @deprecated 3.1.0 Use {@see 'post_tag_rewrite_rules'} instead.
				 *
				 * @param string[] $rules Array of rewrite rules generated for tags, keyed by their regex pattern.
				 */
				$rules = apply_filters_deprecated( 'tag_rewrite_rules', array( $rules ), '3.1.0', 'post_tag_rewrite_rules' );
			}

			$this->extra_rules_top = array_merge( $this->extra_rules_top, $rules );
		}

		// Put them together.
		if ( $this->use_verbose_page_rules ) {
			$this->rules = array_merge( $this->extra_rules_top, $robots_rewrite, $favicon_rewrite, $deprecated_files, $registration_pages, $root_rewrite, $comments_rewrite, $search_rewrite, $author_rewrite, $date_rewrite, $page_rewrite, $post_rewrite, $this->extra_rules );
		} else {
			$this->rules = array_merge( $this->extra_rules_top, $robots_rewrite, $favicon_rewrite, $deprecated_files, $registration_pages, $root_rewrite, $comments_rewrite, $search_rewrite, $author_rewrite, $date_rewrite, $post_rewrite, $page_rewrite, $this->extra_rules );
		}

		/**
		 * Fires after the rewrite rules are generated.
		 *
		 * @since 1.5.0
		 *
		 * @param WP_Rewrite $wp_rewrite Current WP_Rewrite instance (passed by reference).
		 */
		do_action_ref_array( 'generate_rewrite_rules', array( &$this ) );

		/**
		 * Filters the full set of generated rewrite rules.
		 *
		 * @since 1.5.0
		 *
		 * @param string[] $rules The compiled array of rewrite rules, keyed by their regex pattern.
		 */
		$this->rules = apply_filters( 'rewrite_rules_array', $this->rules );

		return $this->rules;
	}

	/**
	 * Retrieves the rewrite rules.
	 *
	 * The difference between this method and WP_Rewrite::rewrite_rules() is that
	 * this method stores the rewrite rules in the 'rewrite_rules' option and retrieves
	 * it. This prevents having to process all of the permalinks to get the rewrite rules
	 * in the form of caching.
	 *
	 * @since 1.5.0
	 *
	 * @return string[] Array of rewrite rules keyed by their regex pattern.
	 */
	public function wp_rewrite_rules() {
		$this->rules = get_option( 'rewrite_rules' );
		if ( empty( $this->rules ) ) {
			$this->matches = 'matches';
			$this->rewrite_rules();
			if ( ! did_action( 'wp_loaded' ) ) {
				add_action( 'wp_loaded', array( $this, 'flush_rules' ) );
				return $this->rules;
			}
			update_option( 'rewrite_rules', $this->rules );
		}

		return $this->rules;
	}

	/**
	 * Retrieves mod_rewrite-formatted rewrite rules to write to .htaccess.
	 *
	 * Does not actually write to the .htaccess file, but creates the rules for
	 * the process that will.
	 *
	 * Will add the non_wp_rules property rules to the .htaccess file before
	 * the WordPress rewrite rules one.
	 *
	 * @since 1.5.0
	 *
	 * @return string
	 */
	public function mod_rewrite_rules() {
		if ( ! $this->using_permalinks() ) {
			return '';
		}

		$site_root = parse_url( site_url() );
		if ( isset( $site_root['path'] ) ) {
			$site_root = trailingslashit( $site_root['path'] );
		}

		$home_root = parse_url( home_url() );
		if ( isset( $home_root['path'] ) ) {
			$home_root = trailingslashit( $home_root['path'] );
		} else {
			$home_root = '/';
		}

		$rules  = "<IfModule mod_rewrite.c>\n";
		$rules .= "RewriteEngine On\n";
		$rules .= "RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]\n";
		$rules .= "RewriteBase $home_root\n";

		// Prevent -f checks on index.php.
		$rules .= "RewriteRule ^index\.php$ - [L]\n";

		// Add in the rules that don't redirect to WP's index.php (and thus shouldn't be handled by WP at all).
		foreach ( (array) $this->non_wp_rules as $match => $query ) {
			// Apache 1.3 does not support the reluctant (non-greedy) modifier.
			$match = str_replace( '.+?', '.+', $match );

			$rules .= 'RewriteRule ^' . $match . ' ' . $home_root . $query . " [QSA,L]\n";
		}

		if ( $this->use_verbose_rules ) {
			$this->matches = '';
			$rewrite       = $this->rewrite_rules();
			$num_rules     = count( $rewrite );
			$rules        .= "RewriteCond %{REQUEST_FILENAME} -f [OR]\n" .
				"RewriteCond %{REQUEST_FILENAME} -d\n" .
				"RewriteRule ^.*$ - [S=$num_rules]\n";

			foreach ( (array) $rewrite as $match => $query ) {
				// Apache 1.3 does not support the reluctant (non-greedy) modifier.
				$match = str_replace( '.+?', '.+', $match );

				if ( str_contains( $query, $this->index ) ) {
					$rules .= 'RewriteRule ^' . $match . ' ' . $home_root . $query . " [QSA,L]\n";
				} else {
					$rules .= 'RewriteRule ^' . $match . ' ' . $site_root . $query . " [QSA,L]\n";
				}
			}
		} else {
			$rules .= "RewriteCond %{REQUEST_FILENAME} !-f\n" .
				"RewriteCond %{REQUEST_FILENAME} !-d\n" .
				"RewriteRule . {$home_root}{$this->index} [L]\n";
		}

		$rules .= "</IfModule>\n";

		/**
		 * Filters the list of rewrite rules formatted for output to an .htaccess file.
		 *
		 * @since 1.5.0
		 *
		 * @param string $rules mod_rewrite Rewrite rules formatted for .htaccess.
		 */
		$rules = apply_filters( 'mod_rewrite_rules', $rules );

		/**
		 * Filters the list of rewrite rules formatted for output to an .htaccess file.
		 *
		 * @since 1.5.0
		 * @deprecated 1.5.0 Use the {@see 'mod_rewrite_rules'} filter instead.
		 *
		 * @param string $rules mod_rewrite Rewrite rules formatted for .htaccess.
		 */
		return apply_filters_deprecated( 'rewrite_rules', array( $rules ), '1.5.0', 'mod_rewrite_rules' );
	}

	/**
	 * Retrieves IIS7 URL Rewrite formatted rewrite rules to write to web.config file.
	 *
	 * Does not actually write to the web.config file, but creates the rules for
	 * the process that will.
	 *
	 * @since 2.8.0
	 *
	 * @param bool $add_parent_tags Optional. Whether to add parent tags to the rewrite rule sets.
	 *                              Default false.
	 * @return string IIS7 URL rewrite rule sets.
	 */
	public function iis7_url_rewrite_rules( $add_parent_tags = false ) {
		if ( ! $this->using_permalinks() ) {
			return '';
		}
		$rules = '';
		if ( $add_parent_tags ) {
			$rules .= '<configuration>
	<system.webServer>
		<rewrite>
			<rules>';
		}

		$rules .= '
			<rule name="WordPress: ' . esc_attr( home_url() ) . '" patternSyntax="Wildcard">
				<match url="*" />
					<conditions>
						<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
						<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
					</conditions>
				<action type="Rewrite" url="index.php" />
			</rule>';

		if ( $add_parent_tags ) {
			$rules .= '
			</rules>
		</rewrite>
	</system.webServer>
</configuration>';
		}

		/**
		 * Filters the list of rewrite rules formatted for output to a web.config.
		 *
		 * @since 2.8.0
		 *
		 * @param string $rules Rewrite rules formatted for IIS web.config.
		 */
		return apply_filters( 'iis7_url_rewrite_rules', $rules );
	}

	/**
	 * Adds a rewrite rule that transforms a URL structure to a set of query vars.
	 *
	 * Any value in the $after parameter that isn't 'bottom' will result in the rule
	 * being placed at the top of the rewrite rules.
	 *
	 * @since 2.1.0
	 * @since 4.4.0 Array support was added to the `$query` parameter.
	 *
	 * @param string       $regex Regular expression to match request against.
	 * @param string|array $query The corresponding query vars for this rewrite rule.
	 * @param string       $after Optional. Priority of the new rule. Accepts 'top'
	 *                            or 'bottom'. Default 'bottom'.
	 */
	public function add_rule( $regex, $query, $after = 'bottom' ) {
		if ( is_array( $query ) ) {
			$external = false;
			$query    = add_query_arg( $query, 'index.php' );
		} else {
			$index = ! str_contains( $query, '?' ) ? strlen( $query ) : strpos( $query, '?' );
			$front = substr( $query, 0, $index );

			$external = $front !== $this->index;
		}

		// "external" = it doesn't correspond to index.php.
		if ( $external ) {
			$this->add_external_rule( $regex, $query );
		} else {
			if ( 'bottom' === $after ) {
				$this->extra_rules = array_merge( $this->extra_rules, array( $regex => $query ) );
			} else {
				$this->extra_rules_top = array_merge( $this->extra_rules_top, array( $regex => $query ) );
			}
		}
	}

	/**
	 * Adds a rewrite rule that doesn't correspond to index.php.
	 *
	 * @since 2.1.0
	 *
	 * @param string $regex Regular expression to match request against.
	 * @param string $query The corresponding query vars for this rewrite rule.
	 */
	public function add_external_rule( $regex, $query ) {
		$this->non_wp_rules[ $regex ] = $query;
	}

	/**
	 * Adds an endpoint, like /trackback/.
	 *
	 * @since 2.1.0
	 * @since 3.9.0 $query_var parameter added.
	 * @since 4.3.0 Added support for skipping query var registration by passing `false` to `$query_var`.
	 *
	 * @see add_rewrite_endpoint() for full documentation.
	 * @global WP $wp Current WordPress environment instance.
	 *
	 * @param string      $name      Name of the endpoint.
	 * @param int         $places    Endpoint mask describing the places the endpoint should be added.
	 *                               Accepts a mask of:
	 *                               - `EP_ALL`
	 *                               - `EP_NONE`
	 *                               - `EP_ALL_ARCHIVES`
	 *                               - `EP_ATTACHMENT`
	 *                               - `EP_AUTHORS`
	 *                               - `EP_CATEGORIES`
	 *                               - `EP_COMMENTS`
	 *                               - `EP_DATE`
	 *                               - `EP_DAY`
	 *                               - `EP_MONTH`
	 *                               - `EP_PAGES`
	 *                               - `EP_PERMALINK`
	 *                               - `EP_ROOT`
	 *                               - `EP_SEARCH`
	 *                               - `EP_TAGS`
	 *                               - `EP_YEAR`
	 * @param string|bool $query_var Optional. Name of the corresponding query variable. Pass `false` to
	 *                               skip registering a query_var for this endpoint. Defaults to the
	 *                               value of `$name`.
	 */
	public function add_endpoint( $name, $places, $query_var = true ) {
		global $wp;

		// For backward compatibility, if null has explicitly been passed as `$query_var`, assume `true`.
		if ( true === $query_var || null === $query_var ) {
			$query_var = $name;
		}
		$this->endpoints[] = array( $places, $name, $query_var );

		if ( $query_var ) {
			$wp->add_query_var( $query_var );
		}
	}

	/**
	 * Adds a new permalink structure.
	 *
	 * A permalink structure (permastruct) is an abstract definition of a set of rewrite rules;
	 * it is an easy way of expressing a set of regular expressions that rewrite to a set of
	 * query strings. The new permastruct is added to the WP_Rewrite::$extra_permastructs array.
	 *
	 * When the rewrite rules are built by WP_Rewrite::rewrite_rules(), all of these extra
	 * permastructs are passed to WP_Rewrite::generate_rewrite_rules() which transforms them
	 * into the regular expressions that many love to hate.
	 *
	 * The `$args` parameter gives you control over how WP_Rewrite::generate_rewrite_rules()
	 * works on the new permastruct.
	 *
	 * @since 2.5.0
	 *
	 * @param string $name   Name for permalink structure.
	 * @param string $struct Permalink structure (e.g. category/%category%)
	 * @param array  $args   {
	 *     Optional. Arguments for building rewrite rules based on the permalink structure.
	 *     Default empty array.
	 *
	 *     @type bool $with_front  Whether the structure should be prepended with `WP_Rewrite::$front`.
	 *                             Default true.
	 *     @type int  $ep_mask     The endpoint mask defining which endpoints are added to the structure.
	 *                             Accepts a mask of:
	 *                             - `EP_ALL`
	 *                             - `EP_NONE`
	 *                             - `EP_ALL_ARCHIVES`
	 *                             - `EP_ATTACHMENT`
	 *                             - `EP_AUTHORS`
	 *                             - `EP_CATEGORIES`
	 *                             - `EP_COMMENTS`
	 *                             - `EP_DATE`
	 *                             - `EP_DAY`
	 *                             - `EP_MONTH`
	 *                             - `EP_PAGES`
	 *                             - `EP_PERMALINK`
	 *                             - `EP_ROOT`
	 *                             - `EP_SEARCH`
	 *                             - `EP_TAGS`
	 *                             - `EP_YEAR`
	 *                             Default `EP_NONE`.
	 *     @type bool $paged       Whether archive pagination rules should be added for the structure.
	 *                             Default true.
	 *     @type bool $feed        Whether feed rewrite rules should be added for the structure. Default true.
	 *     @type bool $forcomments Whether the feed rules should be a query for a comments feed. Default false.
	 *     @type bool $walk_dirs   Whether the 'directories' making up the structure should be walked over
	 *                             and rewrite rules built for each in-turn. Default true.
	 *     @type bool $endpoints   Whether endpoints should be applied to the generated rules. Default true.
	 * }
	 */
	public function add_permastruct( $name, $struct, $args = array() ) {
		// Back-compat for the old parameters: $with_front and $ep_mask.
		if ( ! is_array( $args ) ) {
			$args = array( 'with_front' => $args );
		}

		if ( func_num_args() === 4 ) {
			$args['ep_mask'] = func_get_arg( 3 );
		}

		$defaults = array(
			'with_front'  => true,
			'ep_mask'     => EP_NONE,
			'paged'       => true,
			'feed'        => true,
			'forcomments' => false,
			'walk_dirs'   => true,
			'endpoints'   => true,
		);

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

		if ( $args['with_front'] ) {
			$struct = $this->front . $struct;
		} else {
			$struct = $this->root . $struct;
		}

		$args['struct'] = $struct;

		$this->extra_permastructs[ $name ] = $args;
	}

	/**
	 * Removes a permalink structure.
	 *
	 * @since 4.5.0
	 *
	 * @param string $name Name for permalink structure.
	 */
	public function remove_permastruct( $name ) {
		unset( $this->extra_permastructs[ $name ] );
	}

	/**
	 * Removes rewrite rules and then recreate rewrite rules.
	 *
	 * Calls WP_Rewrite::wp_rewrite_rules() after removing the 'rewrite_rules' option.
	 * If the function named 'save_mod_rewrite_rules' exists, it will be called.
	 *
	 * @since 2.0.1
	 *
	 * @param bool $hard Whether to update .htaccess (hard flush) or just update rewrite_rules option (soft flush). Default is true (hard).
	 */
	public function flush_rules( $hard = true ) {
		static $do_hard_later = null;

		// Prevent this action from running before everyone has registered their rewrites.
		if ( ! did_action( 'wp_loaded' ) ) {
			add_action( 'wp_loaded', array( $this, 'flush_rules' ) );
			$do_hard_later = ( isset( $do_hard_later ) ) ? $do_hard_later || $hard : $hard;
			return;
		}

		if ( isset( $do_hard_later ) ) {
			$hard = $do_hard_later;
			unset( $do_hard_later );
		}

		update_option( 'rewrite_rules', '' );
		$this->wp_rewrite_rules();

		/**
		 * Filters whether a "hard" rewrite rule flush should be performed when requested.
		 *
		 * A "hard" flush updates .htaccess (Apache) or web.config (IIS).
		 *
		 * @since 3.7.0
		 *
		 * @param bool $hard Whether to flush rewrite rules "hard". Default true.
		 */
		if ( ! $hard || ! apply_filters( 'flush_rewrite_rules_hard', true ) ) {
			return;
		}
		if ( function_exists( 'save_mod_rewrite_rules' ) ) {
			save_mod_rewrite_rules();
		}
		if ( function_exists( 'iis7_save_url_rewrite_rules' ) ) {
			iis7_save_url_rewrite_rules();
		}
	}

	/**
	 * Sets up the object's properties.
	 *
	 * The 'use_verbose_page_rules' object property will be set to true if the
	 * permalink structure begins with one of the following: '%postname%', '%category%',
	 * '%tag%', or '%author%'.
	 *
	 * @since 1.5.0
	 */
	public function init() {
		$this->extra_rules         = array();
		$this->non_wp_rules        = array();
		$this->endpoints           = array();
		$this->permalink_structure = get_option( 'permalink_structure' );
		$this->front               = substr( $this->permalink_structure, 0, strpos( $this->permalink_structure, '%' ) );
		$this->root                = '';

		if ( $this->using_index_permalinks() ) {
			$this->root = $this->index . '/';
		}

		unset( $this->author_structure );
		unset( $this->date_structure );
		unset( $this->page_structure );
		unset( $this->search_structure );
		unset( $this->feed_structure );
		unset( $this->comment_feed_structure );

		$this->use_trailing_slashes = str_ends_with( $this->permalink_structure, '/' );

		// Enable generic rules for pages if permalink structure doesn't begin with a wildcard.
		if ( preg_match( '/^[^%]*%(?:postname|category|tag|author)%/', $this->permalink_structure ) ) {
			$this->use_verbose_page_rules = true;
		} else {
			$this->use_verbose_page_rules = false;
		}
	}

	/**
	 * Sets the main permalink structure for the site.
	 *
	 * Will update the 'permalink_structure' option, if there is a difference
	 * between the current permalink structure and the parameter value. Calls
	 * WP_Rewrite::init() after the option is updated.
	 *
	 * Fires the {@see 'permalink_structure_changed'} action once the init call has
	 * processed passing the old and new values
	 *
	 * @since 1.5.0
	 *
	 * @param string $permalink_structure Permalink structure.
	 */
	public function set_permalink_structure( $permalink_structure ) {
		if ( $this->permalink_structure !== $permalink_structure ) {
			$old_permalink_structure = $this->permalink_structure;
			update_option( 'permalink_structure', $permalink_structure );

			$this->init();

			/**
			 * Fires after the permalink structure is updated.
			 *
			 * @since 2.8.0
			 *
			 * @param string $old_permalink_structure The previous permalink structure.
			 * @param string $permalink_structure     The new permalink structure.
			 */
			do_action( 'permalink_structure_changed', $old_permalink_structure, $permalink_structure );
		}
	}

	/**
	 * Sets the category base for the category permalink.
	 *
	 * Will update the 'category_base' option, if there is a difference between
	 * the current category base and the parameter value. Calls WP_Rewrite::init()
	 * after the option is updated.
	 *
	 * @since 1.5.0
	 *
	 * @param string $category_base Category permalink structure base.
	 */
	public function set_category_base( $category_base ) {
		if ( get_option( 'category_base' ) !== $category_base ) {
			update_option( 'category_base', $category_base );
			$this->init();
		}
	}

	/**
	 * Sets the tag base for the tag permalink.
	 *
	 * Will update the 'tag_base' option, if there is a difference between the
	 * current tag base and the parameter value. Calls WP_Rewrite::init() after
	 * the option is updated.
	 *
	 * @since 2.3.0
	 *
	 * @param string $tag_base Tag permalink structure base.
	 */
	public function set_tag_base( $tag_base ) {
		if ( get_option( 'tag_base' ) !== $tag_base ) {
			update_option( 'tag_base', $tag_base );
			$this->init();
		}
	}

	/**
	 * Constructor - Calls init(), which runs setup.
	 *
	 * @since 1.5.0
	 */
	public function __construct() {
		$this->init();
	}
}
tion(): void {
		$pending_processes = $this->get_enqueued_processors();
		if ( empty( $pending_processes ) ) {
			return;
		}
		foreach ( $pending_processes as $process_name ) {
			if ( ! $this->is_scheduled( $process_name ) ) {
				$this->schedule_batch_processing( $process_name );
			}
		}
		$this->schedule_watchdog_action( true );
	}

	/**
	 * Process a batch for a single processor, and handle any required rescheduling or state cleanup.
	 *
	 * @param string $processor_class_name Fully qualified class name of the processor.
	 *
	 * @throws \Exception If error occurred during batch processing.
	 */
	private function process_next_batch_for_single_processor( string $processor_class_name ): void {
		if ( ! $this->is_enqueued( $processor_class_name ) ) {
			return;
		}

		$batch_processor      = $this->get_processor_instance( $processor_class_name );
		$pending_count_before = $batch_processor->get_total_pending_count();
		$error                = $this->process_next_batch_for_single_processor_core( $batch_processor );
		$pending_count_after  = $batch_processor->get_total_pending_count();
		if ( ( $error instanceof \Exception ) && $pending_count_before === $pending_count_after ) {
			// The batch processing failed and no items were processed:
			// reschedule the processing with a delay, and also throw the error
			// so Action Scheduler will ignore the rescheduling if this happens repeatedly.
			$this->schedule_batch_processing( $processor_class_name, true );
			throw $error;
		}
		if ( $pending_count_after > 0 ) {
			$this->schedule_batch_processing( $processor_class_name );
		} else {
			$this->dequeue_processor( $processor_class_name );
		}
	}

	/**
	 * Process a batch for a single processor, updating state and logging any error.
	 *
	 * @param BatchProcessorInterface $batch_processor Batch processor instance.
	 *
	 * @return null|\Exception Exception if error occurred, null otherwise.
	 */
	private function process_next_batch_for_single_processor_core( BatchProcessorInterface $batch_processor ): ?\Exception {
		$details    = $this->get_process_details( $batch_processor );
		$time_start = microtime( true );
		$batch      = $batch_processor->get_next_batch_to_process( $details['current_batch_size'] );
		if ( empty( $batch ) ) {
			return null;
		}
		try {
			$batch_processor->process_batch( $batch );
			$time_taken = microtime( true ) - $time_start;
			$this->update_processor_state( $batch_processor, $time_taken );
		} catch ( \Exception $exception ) {
			$time_taken = microtime( true ) - $time_start;
			$this->log_error( $exception, $batch_processor, $batch );
			$this->update_processor_state( $batch_processor, $time_taken, $exception );
			return $exception;
		}
		return null;
	}

	/**
	 * Get the current state for a given enqueued processor.
	 *
	 * @param BatchProcessorInterface $batch_processor Batch processor instance.
	 *
	 * @return array Current state for the processor, or a "blank" state if none exists yet.
	 */
	private function get_process_details( BatchProcessorInterface $batch_processor ): array {
		return get_option(
			$this->get_processor_state_option_name( $batch_processor ),
			array(
				'total_time_spent'   => 0,
				'current_batch_size' => $batch_processor->get_default_batch_size(),
				'last_error'         => null,
			)
		);
	}

	/**
	 * Get the name of the option where we will be saving state for a given processor.
	 *
	 * @param BatchProcessorInterface $batch_processor Batch processor instance.
	 *
	 * @return string Option name.
	 */
	private function get_processor_state_option_name( BatchProcessorInterface $batch_processor ): string {
		$class_name = get_class( $batch_processor );
		$class_md5  = md5( $class_name );
		// truncate the class name so we know that it will fit in the option name column along with md5 hash and prefix.
		$class_name = substr( $class_name, 0, 140 );
		return 'wc_batch_' . $class_name . '_' . $class_md5;
	}

	/**
	 * Update the state for a processor after a batch has completed processing.
	 *
	 * @param BatchProcessorInterface $batch_processor Batch processor instance.
	 * @param float                   $time_taken Time take by the batch to complete processing.
	 * @param \Exception|null         $last_error Exception object in processing the batch, if there was one.
	 */
	private function update_processor_state( BatchProcessorInterface $batch_processor, float $time_taken, \Exception $last_error = null ): void {
		$current_status                      = $this->get_process_details( $batch_processor );
		$current_status['total_time_spent'] += $time_taken;
		$current_status['last_error']        = null !== $last_error ? $last_error->getMessage() : null;
		update_option( $this->get_processor_state_option_name( $batch_processor ), $current_status, false );
	}

	/**
	 * Schedule a processing action for a single processor.
	 *
	 * @param string $processor_class_name Fully qualified class name of the processor.
	 * @param bool   $with_delay   Whether to schedule the action for immediate execution or for later.
	 */
	private function schedule_batch_processing( string $processor_class_name, bool $with_delay = false ) : void {
		$time = $with_delay ? time() + MINUTE_IN_SECONDS : time();
		as_schedule_single_action( $time, self::PROCESS_SINGLE_BATCH_ACTION_NAME, array( $processor_class_name ) );
	}

	/**
	 * Check if a batch processing action is already scheduled for a given processor.
	 * Differs from `as_has_scheduled_action` in that this excludes actions in progress.
	 *
	 * @param string $processor_class_name Fully qualified class name of the batch processor.
	 *
	 * @return bool True if a batch processing action is already scheduled for the processor.
	 */
	public function is_scheduled( string $processor_class_name ): bool {
		return as_has_scheduled_action( self::PROCESS_SINGLE_BATCH_ACTION_NAME, array( $processor_class_name ) );
	}

	/**
	 * Get an instance of a processor given its class name.
	 *
	 * @param string $processor_class_name Full class name of the batch processor.
	 *
	 * @return BatchProcessorInterface Instance of batch processor for the given class.
	 * @throws \Exception If it's not possible to get an instance of the class.
	 */
	private function get_processor_instance( string $processor_class_name ) : BatchProcessorInterface {
		$processor = wc_get_container()->get( $processor_class_name );

		/**
		 * Filters the instance of a processor for a given class name.
		 *
		 * @param object|null $processor The processor instance given by the dependency injection container, or null if none was obtained.
		 * @param string $processor_class_name The full class name of the processor.
		 * @return BatchProcessorInterface|null The actual processor instance to use, or null if none could be retrieved.
		 *
		 * @since 6.8.0.
		 */
		$processor = apply_filters( 'woocommerce_get_batch_processor', $processor, $processor_class_name );
		if ( ! isset( $processor ) && class_exists( $processor_class_name ) ) {
			// This is a fallback for when the batch processor is not registered in the container.
			$processor = new $processor_class_name();
		}
		if ( ! is_a( $processor, BatchProcessorInterface::class ) ) {
			throw new \Exception( "Unable to initialize batch processor instance for $processor_class_name" );
		}
		return $processor;
	}

	/**
	 * Helper method to get list of all the enqueued processors.
	 *
	 * @return array List (of string) of the class names of the enqueued processors.
	 */
	public function get_enqueued_processors() : array {
		return get_option( self::ENQUEUED_PROCESSORS_OPTION_NAME, array() );
	}

	/**
	 * Dequeue a processor once it has no more items pending processing.
	 *
	 * @param string $processor_class_name Full processor class name.
	 */
	private function dequeue_processor( string $processor_class_name ): void {
		$pending_processes = $this->get_enqueued_processors();
		if ( in_array( $processor_class_name, $pending_processes, true ) ) {
			$pending_processes = array_diff( $pending_processes, array( $processor_class_name ) );
			$this->set_enqueued_processors( $pending_processes );
		}
	}

	/**
	 * Helper method to set the enqueued processor class names.
	 *
	 * @param array $processors List of full processor class names.
	 */
	private function set_enqueued_processors( array $processors ): void {
		update_option( self::ENQUEUED_PROCESSORS_OPTION_NAME, $processors, false );
	}

	/**
	 * Check if a particular processor is enqueued.
	 *
	 * @param string $processor_class_name Fully qualified class name of the processor.
	 *
	 * @return bool True if the processor is enqueued.
	 */
	public function is_enqueued( string $processor_class_name ) : bool {
		return in_array( $processor_class_name, $this->get_enqueued_processors(), true );
	}

	/**
	 * Dequeue and de-schedule a processor instance so that it won't be processed anymore.
	 *
	 * @param string $processor_class_name Fully qualified class name of the processor.
	 * @return bool True if the processor has been dequeued, false if the processor wasn't enqueued (so nothing has been done).
	 */
	public function remove_processor( string $processor_class_name ): bool {
		$enqueued_processors = $this->get_enqueued_processors();
		if ( ! in_array( $processor_class_name, $enqueued_processors, true ) ) {
			return false;
		}

		$enqueued_processors = array_diff( $enqueued_processors, array( $processor_class_name ) );
		if ( empty( $enqueued_processors ) ) {
			$this->force_clear_all_processes();
		} else {
			update_option( self::ENQUEUED_PROCESSORS_OPTION_NAME, $enqueued_processors, false );
			as_unschedule_all_actions( self::PROCESS_SINGLE_BATCH_ACTION_NAME, array( $processor_class_name ) );
		}

		return true;
	}

	/**
	 * Dequeues and de-schedules all the processors.
	 */
	public function force_clear_all_processes(): void {
		as_unschedule_all_actions( self::PROCESS_SINGLE_BATCH_ACTION_NAME );
		as_unschedule_all_actions( self::WATCHDOG_ACTION_NAME );
		update_option( self::ENQUEUED_PROCESSORS_OPTION_NAME, array(), false );
	}

	/**
	 * Log an error that happened while processing a batch.
	 *
	 * @param \Exception              $error Exception object to log.
	 * @param BatchProcessorInterface $batch_processor Batch processor instance.
	 * @param array                   $batch Batch that was being processed.
	 */
	protected function log_error( \Exception $error, BatchProcessorInterface $batch_processor, array $batch ) : void {
		$batch_detail_string = '';
		// Log only first and last, as the entire batch may be too big.
		if ( count( $batch ) > 0 ) {
			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_print_r -- Logging is for debugging.
			$batch_detail_string = '\n' . print_r(
				array(
					'batch_start' => $batch[0],
					'batch_end'   => end( $batch ),
				),
				true
			);
		}
		$error_message = "Error processing batch for {$batch_processor->get_name()}: {$error->getMessage()}" . $batch_detail_string;

		/**
		 * Filters the error message for a batch processing.
		 *
		 * @param string $error_message The error message that will be logged.
		 * @param \Exception $error The exception that was thrown by the processor.
		 * @param BatchProcessorInterface $batch_processor The processor that threw the exception.
		 * @param array $batch The batch that was being processed.
		 * @return string The actual error message that will be logged.
		 *
		 * @since 6.8.0
		 */
		$error_message = apply_filters( 'wc_batch_processing_log_message', $error_message, $error, $batch_processor, $batch );

		$this->logger->error( $error_message, array( 'exception' => $error ) );
	}
}