<?php
/**
 * Error Protection API: WP_Recovery_Mode_Cookie_Service class
 *
 * @package WordPress
 * @since 5.2.0
 */

/**
 * Core class used to set, validate, and clear cookies that identify a Recovery Mode session.
 *
 * @since 5.2.0
 */
final class WP_Recovery_Mode_Cookie_Service {

	/**
	 * Checks whether the recovery mode cookie is set.
	 *
	 * @since 5.2.0
	 *
	 * @return bool True if the cookie is set, false otherwise.
	 */
	public function is_cookie_set() {
		return ! empty( $_COOKIE[ RECOVERY_MODE_COOKIE ] );
	}

	/**
	 * Sets the recovery mode cookie.
	 *
	 * This must be immediately followed by exiting the request.
	 *
	 * @since 5.2.0
	 */
	public function set_cookie() {

		$value = $this->generate_cookie();

		/**
		 * Filter the length of time a Recovery Mode cookie is valid for.
		 *
		 * @since 5.2.0
		 *
		 * @param int $length Length in seconds.
		 */
		$length = apply_filters( 'recovery_mode_cookie_length', WEEK_IN_SECONDS );
		$expire = time() + $length;

		setcookie( RECOVERY_MODE_COOKIE, $value, $expire, COOKIEPATH, COOKIE_DOMAIN, is_ssl(), true );

		if ( COOKIEPATH !== SITECOOKIEPATH ) {
			setcookie( RECOVERY_MODE_COOKIE, $value, $expire, SITECOOKIEPATH, COOKIE_DOMAIN, is_ssl(), true );
		}
	}

	/**
	 * Clears the recovery mode cookie.
	 *
	 * @since 5.2.0
	 */
	public function clear_cookie() {
		setcookie( RECOVERY_MODE_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
		setcookie( RECOVERY_MODE_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
	}

	/**
	 * Validates the recovery mode cookie.
	 *
	 * @since 5.2.0
	 *
	 * @param string $cookie Optionally specify the cookie string.
	 *                       If omitted, it will be retrieved from the super global.
	 * @return true|WP_Error True on success, error object on failure.
	 */
	public function validate_cookie( $cookie = '' ) {

		if ( ! $cookie ) {
			if ( empty( $_COOKIE[ RECOVERY_MODE_COOKIE ] ) ) {
				return new WP_Error( 'no_cookie', __( 'No cookie present.' ) );
			}

			$cookie = $_COOKIE[ RECOVERY_MODE_COOKIE ];
		}

		$parts = $this->parse_cookie( $cookie );

		if ( is_wp_error( $parts ) ) {
			return $parts;
		}

		list( , $created_at, $random, $signature ) = $parts;

		if ( ! ctype_digit( $created_at ) ) {
			return new WP_Error( 'invalid_created_at', __( 'Invalid cookie format.' ) );
		}

		/** This filter is documented in wp-includes/class-wp-recovery-mode-cookie-service.php */
		$length = apply_filters( 'recovery_mode_cookie_length', WEEK_IN_SECONDS );

		if ( time() > $created_at + $length ) {
			return new WP_Error( 'expired', __( 'Cookie expired.' ) );
		}

		$to_sign = sprintf( 'recovery_mode|%s|%s', $created_at, $random );
		$hashed  = $this->recovery_mode_hash( $to_sign );

		if ( ! hash_equals( $signature, $hashed ) ) {
			return new WP_Error( 'signature_mismatch', __( 'Invalid cookie.' ) );
		}

		return true;
	}

	/**
	 * Gets the session identifier from the cookie.
	 *
	 * The cookie should be validated before calling this API.
	 *
	 * @since 5.2.0
	 *
	 * @param string $cookie Optionally specify the cookie string.
	 *                       If omitted, it will be retrieved from the super global.
	 * @return string|WP_Error Session ID on success, or error object on failure.
	 */
	public function get_session_id_from_cookie( $cookie = '' ) {
		if ( ! $cookie ) {
			if ( empty( $_COOKIE[ RECOVERY_MODE_COOKIE ] ) ) {
				return new WP_Error( 'no_cookie', __( 'No cookie present.' ) );
			}

			$cookie = $_COOKIE[ RECOVERY_MODE_COOKIE ];
		}

		$parts = $this->parse_cookie( $cookie );
		if ( is_wp_error( $parts ) ) {
			return $parts;
		}

		list( , , $random ) = $parts;

		return sha1( $random );
	}

	/**
	 * Parses the cookie into its four parts.
	 *
	 * @since 5.2.0
	 *
	 * @param string $cookie Cookie content.
	 * @return array|WP_Error Cookie parts array, or error object on failure.
	 */
	private function parse_cookie( $cookie ) {
		$cookie = base64_decode( $cookie );
		$parts  = explode( '|', $cookie );

		if ( 4 !== count( $parts ) ) {
			return new WP_Error( 'invalid_format', __( 'Invalid cookie format.' ) );
		}

		return $parts;
	}

	/**
	 * Generates the recovery mode cookie value.
	 *
	 * The cookie is a base64 encoded string with the following format:
	 *
	 * recovery_mode|iat|rand|signature
	 *
	 * Where "recovery_mode" is a constant string,
	 * iat is the time the cookie was generated at,
	 * rand is a randomly generated password that is also used as a session identifier
	 * and signature is an hmac of the preceding 3 parts.
	 *
	 * @since 5.2.0
	 *
	 * @return string Generated cookie content.
	 */
	private function generate_cookie() {
		$to_sign = sprintf( 'recovery_mode|%s|%s', time(), wp_generate_password( 20, false ) );
		$signed  = $this->recovery_mode_hash( $to_sign );

		return base64_encode( sprintf( '%s|%s', $to_sign, $signed ) );
	}

	/**
	 * Gets a form of `wp_hash()` specific to Recovery Mode.
	 *
	 * We cannot use `wp_hash()` because it is defined in `pluggable.php` which is not loaded until after plugins are loaded,
	 * which is too late to verify the recovery mode cookie.
	 *
	 * This tries to use the `AUTH` salts first, but if they aren't valid specific salts will be generated and stored.
	 *
	 * @since 5.2.0
	 *
	 * @param string $data Data to hash.
	 * @return string|false The hashed $data, or false on failure.
	 */
	private function recovery_mode_hash( $data ) {
		if ( ! defined( 'AUTH_KEY' ) || AUTH_KEY === 'put your unique phrase here' ) {
			$auth_key = get_site_option( 'recovery_mode_auth_key' );

			if ( ! $auth_key ) {
				if ( ! function_exists( 'wp_generate_password' ) ) {
					require_once ABSPATH . WPINC . '/pluggable.php';
				}

				$auth_key = wp_generate_password( 64, true, true );
				update_site_option( 'recovery_mode_auth_key', $auth_key );
			}
		} else {
			$auth_key = AUTH_KEY;
		}

		if ( ! defined( 'AUTH_SALT' ) || AUTH_SALT === 'put your unique phrase here' || AUTH_SALT === $auth_key ) {
			$auth_salt = get_site_option( 'recovery_mode_auth_salt' );

			if ( ! $auth_salt ) {
				if ( ! function_exists( 'wp_generate_password' ) ) {
					require_once ABSPATH . WPINC . '/pluggable.php';
				}

				$auth_salt = wp_generate_password( 64, true, true );
				update_site_option( 'recovery_mode_auth_salt', $auth_salt );
			}
		} else {
			$auth_salt = AUTH_SALT;
		}

		$secret = $auth_key . $auth_salt;

		return hash_hmac( 'sha1', $data, $secret );
	}
}


<?php
/**
 * Error Protection API: WP_Recovery_Mode_Email_Link class
 *
 * @package WordPress
 * @since 5.2.0
 */

/**
 * Core class used to send an email with a link to begin Recovery Mode.
 *
 * @since 5.2.0
 */
final class WP_Recovery_Mode_Email_Service {

	const RATE_LIMIT_OPTION = 'recovery_mode_email_last_sent';

	/**
	 * Service to generate recovery mode URLs.
	 *
	 * @since 5.2.0
	 * @var WP_Recovery_Mode_Link_Service
	 */
	private $link_service;

	/**
	 * WP_Recovery_Mode_Email_Service constructor.
	 *
	 * @since 5.2.0
	 *
	 * @param WP_Recovery_Mode_Link_Service $link_service
	 */
	public function __construct( WP_Recovery_Mode_Link_Service $link_service ) {
		$this->link_service = $link_service;
	}

	/**
	 * Sends the recovery mode email if the rate limit has not been sent.
	 *
	 * @since 5.2.0
	 *
	 * @param int   $rate_limit Number of seconds before another email can be sent.
	 * @param array $error      Error details from {@see error_get_last()}
	 * @param array $extension {
	 *     The extension that caused the error.
	 *
	 *     @type string $slug The extension slug. The plugin or theme's directory.
	 *     @type string $type The extension type. Either 'plugin' or 'theme'.
	 * }
	 * @return true|WP_Error True if email sent, WP_Error otherwise.
	 */
	public function maybe_send_recovery_mode_email( $rate_limit, $error, $extension ) {

		$last_sent = get_option( self::RATE_LIMIT_OPTION );

		if ( ! $last_sent || time() > $last_sent + $rate_limit ) {
			if ( ! update_option( self::RATE_LIMIT_OPTION, time() ) ) {
				return new WP_Error( 'storage_error', __( 'Could not update the email last sent time.' ) );
			}

			$sent = $this->send_recovery_mode_email( $rate_limit, $error, $extension );

			if ( $sent ) {
				return true;
			}

			return new WP_Error(
				'email_failed',
				sprintf(
					/* translators: %s: mail() */
					__( 'The email could not be sent. Possible reason: your host may have disabled the %s function.' ),
					'mail()'
				)
			);
		}

		$err_message = sprintf(
			/* translators: 1. Last sent as a human time diff, 2. Wait time as a human time diff. */
			__( 'A recovery link was already sent %1$s ago. Please wait another %2$s before requesting a new email.' ),
			human_time_diff( $last_sent ),
			human_time_diff( $last_sent + $rate_limit )
		);

		return new WP_Error( 'email_sent_already', $err_message );
	}

	/**
	 * Clears the rate limit, allowing a new recovery mode email to be sent immediately.
	 *
	 * @since 5.2.0
	 *
	 * @return bool True on success, false on failure.
	 */
	public function clear_rate_limit() {
		return delete_option( self::RATE_LIMIT_OPTION );
	}

	/**
	 * Sends the Recovery Mode email to the site admin email address.
	 *
	 * @since 5.2.0
	 *
	 * @param int   $rate_limit Number of seconds before another email can be sent.
	 * @param array $error      Error details from {@see error_get_last()}
	 * @param array $extension  Extension that caused the error.
	 * @return bool Whether the email was sent successfully.
	 */
	private function send_recovery_mode_email( $rate_limit, $error, $extension ) {

		$url      = $this->link_service->generate_url();
		$blogname = wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES );

		$switched_locale = false;

		// The switch_to_locale() function is loaded before it can actually be used.
		if ( function_exists( 'switch_to_locale' ) && isset( $GLOBALS['wp_locale_switcher'] ) ) {
			$switched_locale = switch_to_locale( get_locale() );
		}

		if ( $extension ) {
			$cause   = $this->get_cause( $extension );
			$details = wp_strip_all_tags( wp_get_extension_error_description( $error ) );

			if ( $details ) {
				$header  = __( 'Error Details' );
				$details = "\n\n" . $header . "\n" . str_pad( '', strlen( $header ), '=' ) . "\n" . $details;
			}
		} else {
			$cause   = '';
			$details = '';
		}

		/**
		 * Filters the support message sent with the the fatal error protection email.
		 *
		 * @since 5.2.0
		 *
		 * @param string $message The Message to include in the email.
		 */
		$support = apply_filters( 'recovery_email_support_info', __( 'Please contact your host for assistance with investigating this issue further.' ) );

		/**
		 * Filters the debug information included in the fatal error protection email.
		 *
		 * @since 5.3.0
		 *
		 * @param array $message An associative array of debug information.
		 */
		$debug = apply_filters( 'recovery_email_debug_info', $this->get_debug( $extension ) );

		/* translators: Do not translate LINK, EXPIRES, CAUSE, DETAILS, SITEURL, PAGEURL, SUPPORT. DEBUG: those are placeholders. */
		$message = __(
			'Howdy!

Since WordPress 5.2 there is a built-in feature that detects when a plugin or theme causes a fatal error on your site, and notifies you with this automated email.
###CAUSE###
First, visit your website (###SITEURL###) and check for any visible issues. Next, visit the page where the error was caught (###PAGEURL###) and check for any visible issues.

###SUPPORT###

If your site appears broken and you can\'t access your dashboard normally, WordPress now has a special "recovery mode". This lets you safely login to your dashboard and investigate further.

###LINK###

To keep your site safe, this link will expire in ###EXPIRES###. Don\'t worry about that, though: a new link will be emailed to you if the error occurs again after it expires.

When seeking help with this issue, you may be asked for some of the following information:
###DEBUG###

###DETAILS###'
		);
		$message = str_replace(
			array(
				'###LINK###',
				'###EXPIRES###',
				'###CAUSE###',
				'###DETAILS###',
				'###SITEURL###',
				'###PAGEURL###',
				'###SUPPORT###',
				'###DEBUG###',
			),
			array(
				$url,
				human_time_diff( time() + $rate_limit ),
				$cause ? "\n{$cause}\n" : "\n",
				$details,
				home_url( '/' ),
				home_url( $_SERVER['REQUEST_URI'] ),
				$support,
				implode( "\r\n", $debug ),
			),
			$message
		);

		$email = array(
			'to'      => $this->get_recovery_mode_email_address(),
			/* translators: %s: Site title. */
			'subject' => __( '[%s] Your Site is Experiencing a Technical Issue' ),
			'message' => $message,
			'headers' => '',
		);

		/**
		 * Filter the contents of the Recovery Mode email.
		 *
		 * @since 5.2.0
		 *
		 * @param array  $email Used to build wp_mail().
		 * @param string $url   URL to enter recovery mode.
		 */
		$email = apply_filters( 'recovery_mode_email', $email, $url );

		$sent = wp_mail(
			$email['to'],
			wp_specialchars_decode( sprintf( $email['subject'], $blogname ) ),
			$email['message'],
			$email['headers']
		);

		if ( $switched_locale ) {
			restore_previous_locale();
		}

		return $sent;
	}

	/**
	 * Gets the email address to send the recovery mode link to.
	 *
	 * @since 5.2.0
	 *
	 * @return string Email address to send recovery mode link to.
	 */
	private function get_recovery_mode_email_address() {
		if ( defined( 'RECOVERY_MODE_EMAIL' ) && is_email( RECOVERY_MODE_EMAIL ) ) {
			return RECOVERY_MODE_EMAIL;
		}

		return get_option( 'admin_email' );
	}

	/**
	 * Gets the description indicating the possible cause for the error.
	 *
	 * @since 5.2.0
	 *
	 * @param array $extension The extension that caused the error.
	 * @return string Message about which extension caused the error.
	 */
	private function get_cause( $extension ) {

		if ( 'plugin' === $extension['type'] ) {
			$plugin = $this->get_plugin( $extension );

			if ( false === $plugin ) {
				$name = $extension['slug'];
			} else {
				$name = $plugin['Name'];
			}

			/* translators: %s: Plugin name. */
			$cause = sprintf( __( 'In this case, WordPress caught an error with one of your plugins, %s.' ), $name );
		} else {
			$theme = wp_get_theme( $extension['slug'] );
			$name  = $theme->exists() ? $theme->display( 'Name' ) : $extension['slug'];

			/* translators: %s: Theme name. */
			$cause = sprintf( __( 'In this case, WordPress caught an error with your theme, %s.' ), $name );
		}

		return $cause;
	}

	/**
	 * Return the details for a single plugin based on the extension data from an error.
	 *
	 * @since 5.3.0
	 *
	 * @param array $extension The extension that caused the error.
	 * @return bool|array A plugin array {@see get_plugins()} or `false` if no plugin was found.
	 */
	private function get_plugin( $extension ) {
		if ( ! function_exists( 'get_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}

		$plugins = get_plugins();

		// Assume plugin main file name first since it is a common convention.
		if ( isset( $plugins[ "{$extension['slug']}/{$extension['slug']}.php" ] ) ) {
			return $plugins[ "{$extension['slug']}/{$extension['slug']}.php" ];
		} else {
			foreach ( $plugins as $file => $plugin_data ) {
				if ( 0 === strpos( $file, "{$extension['slug']}/" ) || $file === $extension['slug'] ) {
					return $plugin_data;
				}
			}
		}

		return false;
	}

	/**
	 * Return debug information in an easy to manipulate format.
	 *
	 * @since 5.3.0
	 *
	 * @param array $extension The extension that caused the error.
	 * @return array An associative array of debug information.
	 */
	private function get_debug( $extension ) {
		$theme      = wp_get_theme();
		$wp_version = get_bloginfo( 'version' );

		if ( $extension ) {
			$plugin = $this->get_plugin( $extension );
		} else {
			$plugin = null;
		}

		$debug = array(
			/* translators: %s: Current WordPress version number. */
			'wp'    => sprintf(
				__( 'WordPress version %s' ),
				$wp_version
			),
			'theme' => sprintf(
				/* translators: 1: Current active theme name. 2: Current active theme version. */
				__( 'Current theme: %1$s (version %2$s)' ),
				$theme->get( 'Name' ),
				$theme->get( 'Version' )
			),
		);

		if ( null !== $plugin ) {
			$debug['plugin'] = sprintf(
				/* translators: 1: The failing plugins name. 2: The failing plugins version. */
				__( 'Current plugin: %1$s (version %2$s)' ),
				$plugin['Name'],
				$plugin['Version']
			);
		}

		$debug['php'] = sprintf(
			/* translators: %s: The currently used PHP version. */
			__( 'PHP version %s' ),
			PHP_VERSION
		);

		return $debug;
	}
}


<?php
/**
 * Error Protection API: WP_Recovery_Mode_Key_Service class
 *
 * @package WordPress
 * @since 5.2.0
 */

/**
 * Core class used to generate and validate keys used to enter Recovery Mode.
 *
 * @since 5.2.0
 */
final class WP_Recovery_Mode_Key_Service {

	/**
	 * The option name used to store the keys.
	 *
	 * @since 5.2.0
	 * @var string
	 */
	private $option_name = 'recovery_keys';

	/**
	 * Creates a recovery mode token.
	 *
	 * @since 5.2.0
	 *
	 * @return string A random string to identify its associated key in storage.
	 */
	public function generate_recovery_mode_token() {
		return wp_generate_password( 22, false );
	}

	/**
	 * Creates a recovery mode key.
	 *
	 * @since 5.2.0
	 *
	 * @global PasswordHash $wp_hasher
	 *
	 * @param string $token A token generated by {@see generate_recovery_mode_token()}.
	 * @return string Recovery mode key.
	 */
	public function generate_and_store_recovery_mode_key( $token ) {

		global $wp_hasher;

		$key = wp_generate_password( 22, false );

		if ( empty( $wp_hasher ) ) {
			require_once ABSPATH . WPINC . '/class-phpass.php';
			$wp_hasher = new PasswordHash( 8, true );
		}

		$hashed = $wp_hasher->HashPassword( $key );

		$records = $this->get_keys();

		$records[ $token ] = array(
			'hashed_key' => $hashed,
			'created_at' => time(),
		);

		$this->update_keys( $records );

		/**
		 * Fires when a recovery mode key is generated.
		 *
		 * @since 5.2.0
		 *
		 * @param string $token The recovery data token.
		 * @param string $key   The recovery mode key.
		 */
		do_action( 'generate_recovery_mode_key', $token, $key );

		return $key;
	}

	/**
	 * Verifies if the recovery mode key is correct.
	 *
	 * Recovery mode keys can only be used once; the key will be consumed in the process.
	 *
	 * @since 5.2.0
	 *
	 * @param string $token The token used when generating the given key.
	 * @param string $key   The unhashed key.
	 * @param int    $ttl   Time in seconds for the key to be valid for.
	 * @return true|WP_Error True on success, error object on failure.
	 */
	public function validate_recovery_mode_key( $token, $key, $ttl ) {

		$records = $this->get_keys();

		if ( ! isset( $records[ $token ] ) ) {
			return new WP_Error( 'token_not_found', __( 'Recovery Mode not initialized.' ) );
		}

		$record = $records[ $token ];

		$this->remove_key( $token );

		if ( ! is_array( $record ) || ! isset( $record['hashed_key'], $record['created_at'] ) ) {
			return new WP_Error( 'invalid_recovery_key_format', __( 'Invalid recovery key format.' ) );
		}

		if ( ! wp_check_password( $key, $record['hashed_key'] ) ) {
			return new WP_Error( 'hash_mismatch', __( 'Invalid recovery key.' ) );
		}

		if ( time() > $record['created_at'] + $ttl ) {
			return new WP_Error( 'key_expired', __( 'Recovery key expired.' ) );
		}

		return true;
	}

	/**
	 * Removes expired recovery mode keys.
	 *
	 * @since 5.2.0
	 *
	 * @param int $ttl Time in seconds for the keys to be valid for.
	 */
	public function clean_expired_keys( $ttl ) {

		$records = $this->get_keys();

		foreach ( $records as $key => $record ) {
			if ( ! isset( $record['created_at'] ) || time() > $record['created_at'] + $ttl ) {
				unset( $records[ $key ] );
			}
		}

		$this->update_keys( $records );
	}

	/**
	 * Removes a used recovery key.
	 *
	 * @since 5.2.0
	 *
	 * @param string $token The token used when generating a recovery mode key.
	 */
	private function remove_key( $token ) {

		$records = $this->get_keys();

		if ( ! isset( $records[ $token ] ) ) {
			return;
		}

		unset( $records[ $token ] );

		$this->update_keys( $records );
	}

	/**
	 * Gets the recovery key records.
	 *
	 * @since 5.2.0
	 *
	 * @return array Associative array of $token => $data pairs, where $data has keys 'hashed_key'
	 *               and 'created_at'.
	 */
	private function get_keys() {
		return (array) get_option( $this->option_name, array() );
	}

	/**
	 * Updates the recovery key records.
	 *
	 * @since 5.2.0
	 *
	 * @param array $keys Associative array of $token => $data pairs, where $data has keys 'hashed_key'
	 *                    and 'created_at'.
	 * @return bool True on success, false on failure.
	 */
	private function update_keys( array $keys ) {
		return update_option( $this->option_name, $keys );
	}
}


<?php
/**
 * Error Protection API: WP_Recovery_Mode_Link_Handler class
 *
 * @package WordPress
 * @since 5.2.0
 */

/**
 * Core class used to generate and handle recovery mode links.
 *
 * @since 5.2.0
 */
class WP_Recovery_Mode_Link_Service {
	const LOGIN_ACTION_ENTER   = 'enter_recovery_mode';
	const LOGIN_ACTION_ENTERED = 'entered_recovery_mode';

	/**
	 * Service to generate and validate recovery mode keys.
	 *
	 * @since 5.2.0
	 * @var WP_Recovery_Mode_Key_Service
	 */
	private $key_service;

	/**
	 * Service to handle cookies.
	 *
	 * @since 5.2.0
	 * @var WP_Recovery_Mode_Cookie_Service
	 */
	private $cookie_service;

	/**
	 * WP_Recovery_Mode_Link_Service constructor.
	 *
	 * @since 5.2.0
	 *
	 * @param WP_Recovery_Mode_Cookie_Service $cookie_service Service to handle setting the recovery mode cookie.
	 * @param WP_Recovery_Mode_Key_Service    $key_service    Service to handle generating recovery mode keys.
	 */
	public function __construct( WP_Recovery_Mode_Cookie_Service $cookie_service, WP_Recovery_Mode_Key_Service $key_service ) {
		$this->cookie_service = $cookie_service;
		$this->key_service    = $key_service;
	}

	/**
	 * Generates a URL to begin recovery mode.
	 *
	 * Only one recovery mode URL can may be valid at the same time.
	 *
	 * @since 5.2.0
	 *
	 * @return string Generated URL.
	 */
	public function generate_url() {
		$token = $this->key_service->generate_recovery_mode_token();
		$key   = $this->key_service->generate_and_store_recovery_mode_key( $token );

		return $this->get_recovery_mode_begin_url( $token, $key );
	}

	/**
	 * Enters recovery mode when the user hits wp-login.php with a valid recovery mode link.
	 *
	 * @since 5.2.0
	 *
	 * @param int $ttl Number of seconds the link should be valid for.
	 */
	public function handle_begin_link( $ttl ) {
		if ( ! isset( $GLOBALS['pagenow'] ) || 'wp-login.php' !== $GLOBALS['pagenow'] ) {
			return;
		}

		if ( ! isset( $_GET['action'], $_GET['rm_token'], $_GET['rm_key'] ) || self::LOGIN_ACTION_ENTER !== $_GET['action'] ) {
			return;
		}

		if ( ! function_exists( 'wp_generate_password' ) ) {
			require_once ABSPATH . WPINC . '/pluggable.php';
		}

		$validated = $this->key_service->validate_recovery_mode_key( $_GET['rm_token'], $_GET['rm_key'], $ttl );

		if ( is_wp_error( $validated ) ) {
			wp_die( $validated, '' );
		}

		$this->cookie_service->set_cookie();

		$url = add_query_arg( 'action', self::LOGIN_ACTION_ENTERED, wp_login_url() );
		wp_redirect( $url );
		die;
	}

	/**
	 * Gets a URL to begin recovery mode.
	 *
	 * @since 5.2.0
	 *
	 * @param string $token Recovery Mode token created by {@see generate_recovery_mode_token()}.
	 * @param string $key   Recovery Mode key created by {@see generate_and_store_recovery_mode_key()}.
	 * @return string Recovery mode begin URL.
	 */
	private function get_recovery_mode_begin_url( $token, $key ) {

		$url = add_query_arg(
			array(
				'action'   => self::LOGIN_ACTION_ENTER,
				'rm_token' => $token,
				'rm_key'   => $key,
			),
			wp_login_url()
		);

		/**
		 * Filter the URL to begin recovery mode.
		 *
		 * @since 5.2.0
		 *
		 * @param string $url   The generated recovery mode begin URL.
		 * @param string $token The token used to identify the key.
		 * @param string $key   The recovery mode key.
		 */
		return apply_filters( 'recovery_mode_begin_url', $url, $token, $key );
	}
}


<?php
/**
 * Error Protection API: WP_Recovery_Mode class
 *
 * @package WordPress
 * @since 5.2.0
 */

/**
 * Core class used to implement Recovery Mode.
 *
 * @since 5.2.0
 */
class WP_Recovery_Mode {

	const EXIT_ACTION = 'exit_recovery_mode';

	/**
	 * Service to handle cookies.
	 *
	 * @since 5.2.0
	 * @var WP_Recovery_Mode_Cookie_Service
	 */
	private $cookie_service;

	/**
	 * Service to generate a recovery mode key.
	 *
	 * @since 5.2.0
	 * @var WP_Recovery_Mode_Key_Service
	 */
	private $key_service;

	/**
	 * Service to generate and validate recovery mode links.
	 *
	 * @since 5.2.0
	 * @var WP_Recovery_Mode_Link_Service
	 */
	private $link_service;

	/**
	 * Service to handle sending an email with a recovery mode link.
	 *
	 * @since 5.2.0
	 * @var WP_Recovery_Mode_Email_Service
	 */
	private $email_service;

	/**
	 * Is recovery mode initialized.
	 *
	 * @since 5.2.0
	 * @var bool
	 */
	private $is_initialized = false;

	/**
	 * Is recovery mode active in this session.
	 *
	 * @since 5.2.0
	 * @var bool
	 */
	private $is_active = false;

	/**
	 * Get an ID representing the current recovery mode session.
	 *
	 * @since 5.2.0
	 * @var string
	 */
	private $session_id = '';

	/**
	 * WP_Recovery_Mode constructor.
	 *
	 * @since 5.2.0
	 */
	public function __construct() {
		$this->cookie_service = new WP_Recovery_Mode_Cookie_Service();
		$this->key_service    = new WP_Recovery_Mode_Key_Service();
		$this->link_service   = new WP_Recovery_Mode_Link_Service( $this->cookie_service, $this->key_service );
		$this->email_service  = new WP_Recovery_Mode_Email_Service( $this->link_service );
	}

	/**
	 * Initialize recovery mode for the current request.
	 *
	 * @since 5.2.0
	 */
	public function initialize() {
		$this->is_initialized = true;

		add_action( 'wp_logout', array( $this, 'exit_recovery_mode' ) );
		add_action( 'login_form_' . self::EXIT_ACTION, array( $this, 'handle_exit_recovery_mode' ) );
		add_action( 'recovery_mode_clean_expired_keys', array( $this, 'clean_expired_keys' ) );

		if ( ! wp_next_scheduled( 'recovery_mode_clean_expired_keys' ) && ! wp_installing() ) {
			wp_schedule_event( time(), 'daily', 'recovery_mode_clean_expired_keys' );
		}

		if ( defined( 'WP_RECOVERY_MODE_SESSION_ID' ) ) {
			$this->is_active  = true;
			$this->session_id = WP_RECOVERY_MODE_SESSION_ID;

			return;
		}

		if ( $this->cookie_service->is_cookie_set() ) {
			$this->handle_cookie();

			return;
		}

		$this->link_service->handle_begin_link( $this->get_link_ttl() );
	}

	/**
	 * Checks whether recovery mode is active.
	 *
	 * This will not change after recovery mode has been initialized. {@see WP_Recovery_Mode::run()}.
	 *
	 * @since 5.2.0
	 *
	 * @return bool True if recovery mode is active, false otherwise.
	 */
	public function is_active() {
		return $this->is_active;
	}

	/**
	 * Gets the recovery mode session ID.
	 *
	 * @since 5.2.0
	 *
	 * @return string The session ID if recovery mode is active, empty string otherwise.
	 */
	public function get_session_id() {
		return $this->session_id;
	}

	/**
	 * Checks whether recovery mode has been initialized.
	 *
	 * Recovery mode should not be used until this point. Initialization happens immediately before loading plugins.
	 *
	 * @since 5.2.0
	 *
	 * @return bool
	 */
	public function is_initialized() {
		return $this->is_initialized;
	}

	/**
	 * Handles a fatal error occurring.
	 *
	 * The calling API should immediately die() after calling this function.
	 *
	 * @since 5.2.0
	 *
	 * @param array $error Error details from {@see error_get_last()}
	 * @return true|WP_Error True if the error was handled and headers have already been sent.
	 *                       Or the request will exit to try and catch multiple errors at once.
	 *                       WP_Error if an error occurred preventing it from being handled.
	 */
	public function handle_error( array $error ) {

		$extension = $this->get_extension_for_error( $error );

		if ( ! $extension || $this->is_network_plugin( $extension ) ) {
			return new WP_Error( 'invalid_source', __( 'Error not caused by a plugin or theme.' ) );
		}

		if ( ! $this->is_active() ) {
			if ( ! is_protected_endpoint() ) {
				return new WP_Error( 'non_protected_endpoint', __( 'Error occurred on a non-protected endpoint.' ) );
			}

			if ( ! function_exists( 'wp_generate_password' ) ) {
				require_once ABSPATH . WPINC . '/pluggable.php';
			}

			return $this->email_service->maybe_send_recovery_mode_email( $this->get_email_rate_limit(), $error, $extension );
		}

		if ( ! $this->store_error( $error ) ) {
			return new WP_Error( 'storage_error', __( 'Failed to store the error.' ) );
		}

		if ( headers_sent() ) {
			return true;
		}

		$this->redirect_protected();
	}

	/**
	 * Ends the current recovery mode session.
	 *
	 * @since 5.2.0
	 *
	 * @return bool True on success, false on failure.
	 */
	public function exit_recovery_mode() {
		if ( ! $this->is_active() ) {
			return false;
		}

		$this->email_service->clear_rate_limit();
		$this->cookie_service->clear_cookie();

		wp_paused_plugins()->delete_all();
		wp_paused_themes()->delete_all();

		return true;
	}

	/**
	 * Handles a request to exit Recovery Mode.
	 *
	 * @since 5.2.0
	 */
	public function handle_exit_recovery_mode() {
		$redirect_to = wp_get_referer();

		// Safety check in case referrer returns false.
		if ( ! $redirect_to ) {
			$redirect_to = is_user_logged_in() ? admin_url() : home_url();
		}

		if ( ! $this->is_active() ) {
			wp_safe_redirect( $redirect_to );
			die;
		}

		if ( ! isset( $_GET['action'] ) || self::EXIT_ACTION !== $_GET['action'] ) {
			return;
		}

		if ( ! isset( $_GET['_wpnonce'] ) || ! wp_verify_nonce( $_GET['_wpnonce'], self::EXIT_ACTION ) ) {
			wp_die( __( 'Exit recovery mode link expired.' ), 403 );
		}

		if ( ! $this->exit_recovery_mode() ) {
			wp_die( __( 'Failed to exit recovery mode. Please try again later.' ) );
		}

		wp_safe_redirect( $redirect_to );
		die;
	}

	/**
	 * Cleans any recovery mode keys that have expired according to the link TTL.
	 *
	 * Executes on a daily cron schedule.
	 *
	 * @since 5.2.0
	 */
	public function clean_expired_keys() {
		$this->key_service->clean_expired_keys( $this->get_link_ttl() );
	}

	/**
	 * Handles checking for the recovery mode cookie and validating it.
	 *
	 * @since 5.2.0
	 */
	protected function handle_cookie() {
		$validated = $this->cookie_service->validate_cookie();

		if ( is_wp_error( $validated ) ) {
			$this->cookie_service->clear_cookie();

			$validated->add_data( array( 'status' => 403 ) );
			wp_die( $validated );
		}

		$session_id = $this->cookie_service->get_session_id_from_cookie();
		if ( is_wp_error( $session_id ) ) {
			$this->cookie_service->clear_cookie();

			$session_id->add_data( array( 'status' => 403 ) );
			wp_die( $session_id );
		}

		$this->is_active  = true;
		$this->session_id = $session_id;
	}

	/**
	 * Gets the rate limit between sending new recovery mode email links.
	 *
	 * @since 5.2.0
	 *
	 * @return int Rate limit in seconds.
	 */
	protected function get_email_rate_limit() {
		/**
		 * Filter the rate limit between sending new recovery mode email links.
		 *
		 * @since 5.2.0
		 *
		 * @param int $rate_limit Time to wait in seconds. Defaults to 1 day.
		 */
		return apply_filters( 'recovery_mode_email_rate_limit', DAY_IN_SECONDS );
	}

	/**
	 * Gets the number of seconds the recovery mode link is valid for.
	 *
	 * @since 5.2.0
	 *
	 * @return int Interval in seconds.
	 */
	protected function get_link_ttl() {

		$rate_limit = $this->get_email_rate_limit();
		$valid_for  = $rate_limit;

		/**
		 * Filter the amount of time the recovery mode email link is valid for.
		 *
		 * The ttl must be at least as long as the email rate limit.
		 *
		 * @since 5.2.0
		 *
		 * @param int $valid_for The number of seconds the link is valid for.
		 */
		$valid_for = apply_filters( 'recovery_mode_email_link_ttl', $valid_for );

		return max( $valid_for, $rate_limit );
	}

	/**
	 * Gets the extension that the error occurred in.
	 *
	 * @since 5.2.0
	 *
	 * @global array $wp_theme_directories
	 *
	 * @param array $error Error that was triggered.
	 * @return array|false {
	 *     Extension details.
	 *
	 *     @type string $slug The extension slug. This is the plugin or theme's directory.
	 *     @type string $type The extension type. Either 'plugin' or 'theme'.
	 * }
	 */
	protected function get_extension_for_error( $error ) {
		global $wp_theme_directories;

		if ( ! isset( $error['file'] ) ) {
			return false;
		}

		if ( ! defined( 'WP_PLUGIN_DIR' ) ) {
			return false;
		}

		$error_file    = wp_normalize_path( $error['file'] );
		$wp_plugin_dir = wp_normalize_path( WP_PLUGIN_DIR );

		if ( 0 === strpos( $error_file, $wp_plugin_dir ) ) {
			$path  = str_replace( $wp_plugin_dir . '/', '', $error_file );
			$parts = explode( '/', $path );

			return array(
				'type' => 'plugin',
				'slug' => $parts[0],
			);
		}

		if ( empty( $wp_theme_directories ) ) {
			return false;
		}

		foreach ( $wp_theme_directories as $theme_directory ) {
			$theme_directory = wp_normalize_path( $theme_directory );

			if ( 0 === strpos( $error_file, $theme_directory ) ) {
				$path  = str_replace( $theme_directory . '/', '', $error_file );
				$parts = explode( '/', $path );

				return array(
					'type' => 'theme',
					'slug' => $parts[0],
				);
			}
		}

		return false;
	}

	/**
	 * Checks whether the given extension a network activated plugin.
	 *
	 * @since 5.2.0
	 *
	 * @param array $extension Extension data.
	 * @return bool True if network plugin, false otherwise.
	 */
	protected function is_network_plugin( $extension ) {
		if ( 'plugin' !== $extension['type'] ) {
			return false;
		}

		if ( ! is_multisite() ) {
			return false;
		}

		$network_plugins = wp_get_active_network_plugins();

		foreach ( $network_plugins as $plugin ) {
			if ( 0 === strpos( $plugin, $extension['slug'] . '/' ) ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Stores the given error so that the extension causing it is paused.
	 *
	 * @since 5.2.0
	 *
	 * @param array $error Error that was triggered.
	 * @return bool True if the error was stored successfully, false otherwise.
	 */
	protected function store_error( $error ) {
		$extension = $this->get_extension_for_error( $error );

		if ( ! $extension ) {
			return false;
		}

		switch ( $extension['type'] ) {
			case 'plugin':
				return wp_paused_plugins()->set( $extension['slug'], $error );
			case 'theme':
				return wp_paused_themes()->set( $extension['slug'], $error );
			default:
				return false;
		}
	}

	/**
	 * Redirects the current request to allow recovering multiple errors in one go.
	 *
	 * The redirection will only happen when on a protected endpoint.
	 *
	 * It must be ensured that this method is only called when an error actually occurred and will not occur on the
	 * next request again. Otherwise it will create a redirect loop.
	 *
	 * @since 5.2.0
	 */
	protected function redirect_protected() {
		// Pluggable is usually loaded after plugins, so we manually include it here for redirection functionality.
		if ( ! function_exists( 'wp_safe_redirect' ) ) {
			require_once ABSPATH . WPINC . '/pluggable.php';
		}

		$scheme = is_ssl() ? 'https://' : 'http://';

		$url = "{$scheme}{$_SERVER['HTTP_HOST']}{$_SERVER['REQUEST_URI']}";
		wp_safe_redirect( $url );
		exit;
	}
}


<?php
/**
 * Rewrite API: WP_Rewrite class
 *
 * @package WordPress
 * @subpackage Rewrite
 * @since 1.5.0
 */

/**
 * Core class used to implement a rewrite component API.
 *
 * The WordPress Rewrite class writes the rewrite module rules to the .htaccess
 * file. It also handles parsing the request to get the correct setup for the
 * WordPress Query class.
 *
 * The Rewrite along with WP class function as a front controller for WordPress.
 * You can add rules to trigger your page view and processing using this
 * component. The full functionality of a front controller does not exist,
 * meaning you can't define how the template files load based on the rewrite
 * rules.
 *
 * @since 1.5.0
 */
class WP_Rewrite {
	/**
	 * Permalink structure for posts.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	public $permalink_structure;

	/**
	 * Whether to add trailing slashes.
	 *
	 * @since 2.2.0
	 * @var bool
	 */
	public $use_trailing_slashes;

	/**
	 * Base for the author permalink structure (example.com/$author_base/authorname).
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $author_base = 'author';

	/**
	 * Permalink structure for author archives.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $author_structure;

	/**
	 * Permalink structure for date archives.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $date_structure;

	/**
	 * Permalink structure for pages.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $page_structure;

	/**
	 * Base of the search permalink structure (example.com/$search_base/query).
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $search_base = 'search';

	/**
	 * Permalink structure for searches.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $search_structure;

	/**
	 * Comments permalink base.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $comments_base = 'comments';

	/**
	 * Pagination permalink base.
	 *
	 * @since 3.1.0
	 * @var string
	 */
	public $pagination_base = 'page';

	/**
	 * Comments pagination permalink base.
	 *
	 * @since 4.2.0
	 * @var string
	 */
	var $comments_pagination_base = 'comment-page';

	/**
	 * Feed permalink base.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $feed_base = 'feed';

	/**
	 * Comments feed permalink structure.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $comment_feed_structure;

	/**
	 * Feed request permalink structure.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $feed_structure;

	/**
	 * The static portion of the post permalink structure.
	 *
	 * If the permalink structure is "/archive/%post_id%" then the front
	 * is "/archive/". If the permalink structure is "/%year%/%postname%/"
	 * then the front is "/".
	 *
	 * @since 1.5.0
	 * @var string
	 *
	 * @see WP_Rewrite::init()
	 */
	public $front;

	/**
	 * The prefix for all permalink structures.
	 *
	 * If PATHINFO/index permalinks are in use then the root is the value of
	 * `WP_Rewrite::$index` with a trailing slash appended. Otherwise the root
	 * will be empty.
	 *
	 * @since 1.5.0
	 * @var string
	 *
	 * @see WP_Rewrite::init()
	 * @see WP_Rewrite::using_index_permalinks()
	 */
	public $root = '';

	/**
	 * The name of the index file which is the entry point to all requests.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	public $index = 'index.php';

	/**
	 * Variable name to use for regex matches in the rewritten query.
	 *
	 * @since 1.5.0
	 * @var string
	 */
	var $matches = '';

	/**
	 * Rewrite rules to match against the request to find the redirect or query.
	 *
	 * @since 1.5.0
	 * @var array
	 */
	var $rules;

	/**
	 * Additional rules added external to the rewrite class.
	 *
	 * Those not generated by the class, see add_rewrite_rule().
	 *
	 * @since 2.1.0
	 * @var array
	 */
	var $extra_rules = array();

	/**
	 * Additional rules that belong at the beginning to match first.
	 *
	 * Those not generated by the class, see add_rewrite_rule().
	 *
	 * @since 2.3.0
	 * @var array
	 */
	var $extra_rules_top = array();

	/**
	 * Rules that don't redirect to WordPress' index.php.
	 *
	 * These rules are written to the mod_rewrite portion of the .htaccess,
	 * and are added by add_external_rule().
	 *
	 * @since 2.1.0
	 * @var array
	 */
	var $non_wp_rules = array();

	/**
	 * Extra permalink structures, e.g. categories, added by add_permastruct().
	 *
	 * @since 2.1.0
	 * @var array
	 */
	var $extra_permastructs = array();

	/**
	 * Endpoints (like /trackback/) added by add_rewrite_endpoint().
	 *
	 * @since 2.1.0
	 * @var array
	 */
	var $endpoints;

	/**
	 * Whether to write every mod_rewrite rule for WordPress into the .htaccess file.
	 *
	 * This is off by default, turning it on might print a lot of rewrite rules
	 * to the .htaccess file.
	 *
	 * @since 2.0.0
	 * @var bool
	 *
	 * @see WP_Rewrite::mod_rewrite_rules()
	 */
	public $use_verbose_rules = false;

	/**
	 * Could post permalinks be confused with those of pages?
	 *
	 * If the first rewrite tag in the post permalink structure is one that could
	 * also match a page name (e.g. %postname% or %author%) then this flag is
	 * set to true. Prior to WordPress 3.3 this flag indicated that every page
	 * would have a set of rules added to the top of the rewrite rules array.
	 * Now it tells WP::parse_request() to check if a URL matching the page
	 * permastruct is actually a page before accepting it.
	 *
	 * @since 2.5.0
	 * @var bool
	 *
	 * @see WP_Rewrite::init()
	 */
	public $use_verbose_page_rules = true;

	/**
	 * Rewrite tags that can be used in permalink structures.
	 *
	 * These are translated into the regular expressions stored in
	 * `WP_Rewrite::$rewritereplace` and are rewritten to the query
	 * variables listed in WP_Rewrite::$queryreplace.
	 *
	 * Additional tags can be added with add_rewrite_tag().
	 *
	 * @since 1.5.0
	 * @var array
	 */
	var $rewritecode = array(
		'%year%',
		'%monthnum%',
		'%day%',
		'%hour%',
		'%minute%',
		'%second%',
		'%postname%',
		'%post_id%',
		'%author%',
		'%pagename%',
		'%search%',
	);

	/**
	 * Regular expressions to be substituted into rewrite rules in place
	 * of rewrite tags, see WP_Rewrite::$rewritecode.
	 *
	 * @since 1.5.0
	 * @var array
	 */
	var $rewritereplace = array(
		'([0-9]{4})',
		'([0-9]{1,2})',
		'([0-9]{1,2})',
		'([0-9]{1,2})',
		'([0-9]{1,2})',
		'([0-9]{1,2})',
		'([^/]+)',
		'([0-9]+)',
		'([^/]+)',
		'([^/]+?)',
		'(.+)',
	);

	/**
	 * Query variables that rewrite tags map to, see WP_Rewrite::$rewritecode.
	 *
	 * @since 1.5.0
	 * @var array
	 */
	var $queryreplace = array(
		'year=',
		'monthnum=',
		'day=',
		'hour=',
		'minute=',
		'second=',
		'name=',
		'p=',
		'author_name=',
		'pagename=',
		's=',
	);

	/**
	 * Supported default feeds.
	 *
	 * @since 1.5.0
	 * @var array
	 */
	public $feeds = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );

	/**
	 * Determines whether permalinks are being used.
	 *
	 * This can be either rewrite module or permalink in the HTTP query string.
	 *
	 * @since 1.5.0
	 *
	 * @return bool True, if permalinks are enabled.
	 */
	public function using_permalinks() {
		return ! empty( $this->permalink_structure );
	}

	/**
	 * Determines whether permalinks are being used and rewrite module is not enabled.
	 *
	 * Means that permalink links are enabled and index.php is in the URL.
	 *
	 * @since 1.5.0
	 *
	 * @return bool Whether permalink links are enabled and index.php is in the URL.
	 */
	public function using_index_permalinks() {
		if ( empty( $this->permalink_structure ) ) {
			return false;
		}

		// If the index is not in the permalink, we're using mod_rewrite.
		return preg_match( '#^/*' . $this->index . '#', $this->permalink_structure );
	}

	/**
	 * Determines whether permalinks are being used and rewrite module is enabled.
	 *
	 * Using permalinks and index.php is not in the URL.
	 *
	 * @since 1.5.0
	 *
	 * @return bool Whether permalink links are enabled and index.php is NOT in the URL.
	 */
	public function using_mod_rewrite_permalinks() {
		return $this->using_permalinks() && ! $this->using_index_permalinks();
	}

	/**
	 * Indexes for matches for usage in preg_*() functions.
	 *
	 * The format of the string is, with empty matches property value, '$NUM'.
	 * The 'NUM' will be replaced with the value in the $number parameter. With
	 * the matches property not empty, the value of the returned string will
	 * contain that value of the matches property. The format then will be
	 * '$MATCHES[NUM]', with MATCHES as the value in the property and NUM the
	 * value of the $number parameter.
	 *
	 * @since 1.5.0
	 *
	 * @param int $number Index number.
	 * @return string
	 */
	public function preg_index( $number ) {
		$match_prefix = '$';
		$match_suffix = '';

		if ( ! empty( $this->matches ) ) {
			$match_prefix = '$' . $this->matches . '[';
			$match_suffix = ']';
		}

		return "$match_prefix$number$match_suffix";
	}

	/**
	 * Retrieves all page and attachments for pages URIs.
	 *
	 * The attachments are for those that have pages as parents and will be
	 * retrieved.
	 *
	 * @since 2.5.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @return array Array of page URIs as first element and attachment URIs as second element.
	 */
	public function page_uri_index() {
		global $wpdb;

		// Get pages in order of hierarchy, i.e. children after parents.
		$pages = $wpdb->get_results( "SELECT ID, post_name, post_parent FROM $wpdb->posts WHERE post_type = 'page' AND post_status != 'auto-draft'" );
		$posts = get_page_hierarchy( $pages );

		// If we have no pages get out quick.
		if ( ! $posts ) {
			return array( array(), array() );
		}

		// Now reverse it, because we need parents after children for rewrite rules to work properly.
		$posts = array_reverse( $posts, true );

		$page_uris            = array();
		$page_attachment_uris = array();

		foreach ( $posts as $id => $post ) {
			// URL => page name.
			$uri         = get_page_uri( $id );
			$attachments = $wpdb->get_results( $wpdb->prepare( "SELECT ID, post_name, post_parent FROM $wpdb->posts WHERE post_type = 'attachment' AND post_parent = %d", $id ) );
			if ( ! empty( $attachments ) ) {
				foreach ( $attachments as $attachment ) {
					$attach_uri                          = get_page_uri( $attachment->ID );
					$page_attachment_uris[ $attach_uri ] = $attachment->ID;
				}
			}

			$page_uris[ $uri ] = $id;
		}

		return array( $page_uris, $page_attachment_uris );
	}

	/**
	 * Retrieves all of the rewrite rules for pages.
	 *
	 * @since 1.5.0
	 *
	 * @return string[] Page rewrite rules.
	 */
	public function page_rewrite_rules() {
		// The extra .? at the beginning prevents clashes with other regular expressions in the rules array.
		$this->add_rewrite_tag( '%pagename%', '(.?.+?)', 'pagename=' );

		return $this->generate_rewrite_rules( $this->get_page_permastruct(), EP_PAGES, true, true, false, false );
	}

	/**
	 * Retrieves date permalink structure, with year, month, and day.
	 *
	 * The permalink structure for the date, if not set already depends on the
	 * permalink structure. It can be one of three formats. The first is year,
	 * month, day; the second is day, month, year; and the last format is month,
	 * day, year. These are matched against the permalink structure for which
	 * one is used. If none matches, then the default will be used, which is
	 * year, month, day.
	 *
	 * Prevents post ID and date permalinks from overlapping. In the case of
	 * post_id, the date permalink will be prepended with front permalink with
	 * 'date/' before the actual permalink to form the complete date permalink
	 * structure.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Date permalink structure on success, false on failure.
	 */
	public function get_date_permastruct() {
		if ( isset( $this->date_structure ) ) {
			return $this->date_structure;
		}

		if ( empty( $this->permalink_structure ) ) {
			$this->date_structure = '';
			return false;
		}

		// The date permalink must have year, month, and day separated by slashes.
		$endians = array( '%year%/%monthnum%/%day%', '%day%/%monthnum%/%year%', '%monthnum%/%day%/%year%' );

		$this->date_structure = '';
		$date_endian          = '';

		foreach ( $endians as $endian ) {
			if ( false !== strpos( $this->permalink_structure, $endian ) ) {
				$date_endian = $endian;
				break;
			}
		}

		if ( empty( $date_endian ) ) {
			$date_endian = '%year%/%monthnum%/%day%';
		}

		/*
		 * Do not allow the date tags and %post_id% to overlap in the permalink
		 * structure. If they do, move the date tags to $front/date/.
		 */
		$front = $this->front;
		preg_match_all( '/%.+?%/', $this->permalink_structure, $tokens );
		$tok_index = 1;
		foreach ( (array) $tokens[0] as $token ) {
			if ( '%post_id%' === $token && ( $tok_index <= 3 ) ) {
				$front = $front . 'date/';
				break;
			}
			$tok_index++;
		}

		$this->date_structure = $front . $date_endian;

		return $this->date_structure;
	}

	/**
	 * Retrieves the year permalink structure without month and day.
	 *
	 * Gets the date permalink structure and strips out the month and day
	 * permalink structures.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Year permalink structure on success, false on failure.
	 */
	public function get_year_permastruct() {
		$structure = $this->get_date_permastruct();

		if ( empty( $structure ) ) {
			return false;
		}

		$structure = str_replace( '%monthnum%', '', $structure );
		$structure = str_replace( '%day%', '', $structure );
		$structure = preg_replace( '#/+#', '/', $structure );

		return $structure;
	}

	/**
	 * Retrieves the month permalink structure without day and with year.
	 *
	 * Gets the date permalink structure and strips out the day permalink
	 * structures. Keeps the year permalink structure.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Year/Month permalink structure on success, false on failure.
	 */
	public function get_month_permastruct() {
		$structure = $this->get_date_permastruct();

		if ( empty( $structure ) ) {
			return false;
		}

		$structure = str_replace( '%day%', '', $structure );
		$structure = preg_replace( '#/+#', '/', $structure );

		return $structure;
	}

	/**
	 * Retrieves the day permalink structure with month and year.
	 *
	 * Keeps date permalink structure with all year, month, and day.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Year/Month/Day permalink structure on success, false on failure.
	 */
	public function get_day_permastruct() {
		return $this->get_date_permastruct();
	}

	/**
	 * Retrieves the permalink structure for categories.
	 *
	 * If the category_base property has no value, then the category structure
	 * will have the front property value, followed by 'category', and finally
	 * '%category%'. If it does, then the root property will be used, along with
	 * the category_base property value.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Category permalink structure on success, false on failure.
	 */
	public function get_category_permastruct() {
		return $this->get_extra_permastruct( 'category' );
	}

	/**
	 * Retrieve the permalink structure for tags.
	 *
	 * If the tag_base property has no value, then the tag structure will have
	 * the front property value, followed by 'tag', and finally '%tag%'. If it
	 * does, then the root property will be used, along with the tag_base
	 * property value.
	 *
	 * @since 2.3.0
	 *
	 * @return string|false Tag permalink structure on success, false on failure.
	 */
	public function get_tag_permastruct() {
		return $this->get_extra_permastruct( 'post_tag' );
	}

	/**
	 * Retrieves an extra permalink structure by name.
	 *
	 * @since 2.5.0
	 *
	 * @param string $name Permalink structure name.
	 * @return string|false Permalink structure string on success, false on failure.
	 */
	public function get_extra_permastruct( $name ) {
		if ( empty( $this->permalink_structure ) ) {
			return false;
		}

		if ( isset( $this->extra_permastructs[ $name ] ) ) {
			return $this->extra_permastructs[ $name ]['struct'];
		}

		return false;
	}

	/**
	 * Retrieves the author permalink structure.
	 *
	 * The permalink structure is front property, author base, and finally
	 * '/%author%'. Will set the author_structure property and then return it
	 * without attempting to set the value again.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Author permalink structure on success, false on failure.
	 */
	public function get_author_permastruct() {
		if ( isset( $this->author_structure ) ) {
			return $this->author_structure;
		}

		if ( empty( $this->permalink_structure ) ) {
			$this->author_structure = '';
			return false;
		}

		$this->author_structure = $this->front . $this->author_base . '/%author%';

		return $this->author_structure;
	}

	/**
	 * Retrieves the search permalink structure.
	 *
	 * The permalink structure is root property, search base, and finally
	 * '/%search%'. Will set the search_structure property and then return it
	 * without attempting to set the value again.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Search permalink structure on success, false on failure.
	 */
	public function get_search_permastruct() {
		if ( isset( $this->search_structure ) ) {
			return $this->search_structure;
		}

		if ( empty( $this->permalink_structure ) ) {
			$this->search_structure = '';
			return false;
		}

		$this->search_structure = $this->root . $this->search_base . '/%search%';

		return $this->search_structure;
	}

	/**
	 * Retrieves the page permalink structure.
	 *
	 * The permalink structure is root property, and '%pagename%'. Will set the
	 * page_structure property and then return it without attempting to set the
	 * value again.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Page permalink structure on success, false on failure.
	 */
	public function get_page_permastruct() {
		if ( isset( $this->page_structure ) ) {
			return $this->page_structure;
		}

		if ( empty( $this->permalink_structure ) ) {
			$this->page_structure = '';
			return false;
		}

		$this->page_structure = $this->root . '%pagename%';

		return $this->page_structure;
	}

	/**
	 * Retrieves the feed permalink structure.
	 *
	 * The permalink structure is root property, feed base, and finally
	 * '/%feed%'. Will set the feed_structure property and then return it
	 * without attempting to set the value again.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Feed permalink structure on success, false on failure.
	 */
	public function get_feed_permastruct() {
		if ( isset( $this->feed_structure ) ) {
			return $this->feed_structure;
		}

		if ( empty( $this->permalink_structure ) ) {
			$this->feed_structure = '';
			return false;
		}

		$this->feed_structure = $this->root . $this->feed_base . '/%feed%';

		return $this->feed_structure;
	}

	/**
	 * Retrieves the comment feed permalink structure.
	 *
	 * The permalink structure is root property, comment base property, feed
	 * base and finally '/%feed%'. Will set the comment_feed_structure property
	 * and then return it without attempting to set the value again.
	 *
	 * @since 1.5.0
	 *
	 * @return string|false Comment feed permalink structure on success, false on failure.
	 */
	public function get_comment_feed_permastruct() {
		if ( isset( $this->comment_feed_structure ) ) {
			return $this->comment_feed_structure;
		}

		if ( empty( $this->permalink_structure ) ) {
			$this->comment_feed_structure = '';
			return false;
		}

		$this->comment_feed_structure = $this->root . $this->comments_base . '/' . $this->feed_base . '/%feed%';

		return $this->comment_feed_structure;
	}

	/**
	 * Adds or updates existing rewrite tags (e.g. %postname%).
	 *
	 * If the tag already exists, replace the existing pattern and query for
	 * that tag, otherwise add the new tag.
	 *
	 * @since 1.5.0
	 *
	 * @see WP_Rewrite::$rewritecode
	 * @see WP_Rewrite::$rewritereplace
	 * @see WP_Rewrite::$queryreplace
	 *
	 * @param string $tag   Name of the rewrite tag to add or update.
	 * @param string $regex Regular expression to substitute the tag for in rewrite rules.
	 * @param string $query String to append to the rewritten query. Must end in '='.
	 */
	public function add_rewrite_tag( $tag, $regex, $query ) {
		$position = array_search( $tag, $this->rewritecode, true );
		if ( false !== $position && null !== $position ) {
			$this->rewritereplace[ $position ] = $regex;
			$this->queryreplace[ $position ]   = $query;
		} else {
			$this->rewritecode[]    = $tag;
			$this->rewritereplace[] = $regex;
			$this->queryreplace[]   = $query;
		}
	}

	/**
	 * Removes an existing rewrite tag.
	 *
	 * @since 4.5.0
	 *
	 * @see WP_Rewrite::$rewritecode
	 * @see WP_Rewrite::$rewritereplace
	 * @see WP_Rewrite::$queryreplace
	 *
	 * @param string $tag Name of the rewrite tag to remove.
	 */
	public function remove_rewrite_tag( $tag ) {
		$position = array_search( $tag, $this->rewritecode, true );
		if ( false !== $position && null !== $position ) {
			unset( $this->rewritecode[ $position ] );
			unset( $this->rewritereplace[ $position ] );
			unset( $this->queryreplace[ $position ] );
		}
	}

	/**
	 * Generates rewrite rules from a permalink structure.
	 *
	 * The main WP_Rewrite function for building the rewrite rule list. The
	 * contents of the function is a mix of black magic and regular expressions,
	 * so best just ignore the contents and move to the parameters.
	 *
	 * @since 1.5.0
	 *
	 * @param string $permalink_structure The permalink structure.
	 * @param int    $ep_mask             Optional. Endpoint mask defining what endpoints are added to the structure.
	 *                                    Accepts `EP_NONE`, `EP_PERMALINK`, `EP_ATTACHMENT`, `EP_DATE`, `EP_YEAR`,
	 *                                    `EP_MONTH`, `EP_DAY`, `EP_ROOT`, `EP_COMMENTS`, `EP_SEARCH`, `EP_CATEGORIES`,
	 *                                    `EP_TAGS`, `EP_AUTHORS`, `EP_PAGES`, `EP_ALL_ARCHIVES`, and `EP_ALL`.
	 *                                    Default `EP_NONE`.
	 * @param bool   $paged               Optional. Whether archive pagination rules should be added for the structure.
	 *                                    Default true.
	 * @param bool   $feed                Optional Whether feed rewrite rules should be added for the structure.
	 *                                    Default true.
	 * @param bool   $forcomments         Optional. Whether the feed rules should be a query for a comments feed.
	 *                                    Default false.
	 * @param bool   $walk_dirs           Optional. Whether the 'directories' making up the structure should be walked
	 *                                    over and rewrite rules built for each in-turn. Default true.
	 * @param bool   $endpoints           Optional. Whether endpoints should be applied to the generated rewrite rules.
	 *                                    Default true.
	 * @return string[] Array of rewrite rules keyed by their regex pattern.
	 */
	public function generate_rewrite_rules( $permalink_structure, $ep_mask = EP_NONE, $paged = true, $feed = true, $forcomments = false, $walk_dirs = true, $endpoints = true ) {
		// Build a regex to match the feed section of URLs, something like (feed|atom|rss|rss2)/?
		$feedregex2 = '';
		foreach ( (array) $this->feeds as $feed_name ) {
			$feedregex2 .= $feed_name . '|';
		}
		$feedregex2 = '(' . trim( $feedregex2, '|' ) . ')/?$';

		/*
		 * $feedregex is identical but with /feed/ added on as well, so URLs like <permalink>/feed/atom
		 * and <permalink>/atom are both possible
		 */
		$feedregex = $this->feed_base . '/' . $feedregex2;

		// Build a regex to match the trackback and page/xx parts of URLs.
		$trackbackregex = 'trackback/?$';
		$pageregex      = $this->pagination_base . '/?([0-9]{1,})/?$';
		$commentregex   = $this->comments_pagination_base . '-([0-9]{1,})/?$';
		$embedregex     = 'embed/?$';

		// Build up an array of endpoint regexes to append => queries to append.
		if ( $endpoints ) {
			$ep_query_append = array();
			foreach ( (array) $this->endpoints as $endpoint ) {
				// Match everything after the endpoint name, but allow for nothing to appear there.
				$epmatch = $endpoint[1] . '(/(.*))?/?$';

				// This will be appended on to the rest of the query for each dir.
				$epquery                     = '&' . $endpoint[2] . '=';
				$ep_query_append[ $epmatch ] = array( $endpoint[0], $epquery );
			}
		}

		// Get everything up to the first rewrite tag.
		$front = substr( $permalink_structure, 0, strpos( $permalink_structure, '%' ) );

		// Build an array of the tags (note that said array ends up being in $tokens[0]).
		preg_match_all( '/%.+?%/', $permalink_structure, $tokens );

		$num_tokens = count( $tokens[0] );

		$index          = $this->index; // Probably 'index.php'.
		$feedindex      = $index;
		$trackbackindex = $index;
		$embedindex     = $index;

		/*
		 * Build a list from the rewritecode and queryreplace arrays, that will look something
		 * like tagname=$matches[i] where i is the current $i.
		 */
		$queries = array();
		for ( $i = 0; $i < $num_tokens; ++$i ) {
			if ( 0 < $i ) {
				$queries[ $i ] = $queries[ $i - 1 ] . '&';
			} else {
				$queries[ $i ] = '';
			}

			$query_token    = str_replace( $this->rewritecode, $this->queryreplace, $tokens[0][ $i ] ) . $this->preg_index( $i + 1 );
			$queries[ $i ] .= $query_token;
		}

		// Get the structure, minus any cruft (stuff that isn't tags) at the front.
		$structure = $permalink_structure;
		if ( '/' !== $front ) {
			$structure = str_replace( $front, '', $structure );
		}

		/*
		 * Create a list of dirs to walk over, making rewrite rules for each level
		 * so for example, a $structure of /%year%/%monthnum%/%postname% would create
		 * rewrite rules for /%year%/, /%year%/%monthnum%/ and /%year%/%monthnum%/%postname%
		 */
		$structure = trim( $structure, '/' );
		$dirs      = $walk_dirs ? explode( '/', $structure ) : array( $structure );
		$num_dirs  = count( $dirs );

		// Strip slashes from the front of $front.
		$front = preg_replace( '|^/+|', '', $front );

		// The main workhorse loop.
		$post_rewrite = array();
		$struct       = $front;
		for ( $j = 0; $j < $num_dirs; ++$j ) {
			// Get the struct for this dir, and trim slashes off the front.
			$struct .= $dirs[ $j ] . '/'; // Accumulate. see comment near explode('/', $structure) above.
			$struct  = ltrim( $struct, '/' );

			// Replace tags with regexes.
			$match = str_replace( $this->rewritecode, $this->rewritereplace, $struct );

			// Make a list of tags, and store how many there are in $num_toks.
			$num_toks = preg_match_all( '/%.+?%/', $struct, $toks );

			// Get the 'tagname=$matches[i]'.
			$query = ( ! empty( $num_toks ) && isset( $queries[ $num_toks - 1 ] ) ) ? $queries[ $num_toks - 1 ] : '';

			// Set up $ep_mask_specific which is used to match more specific URL types.
			switch ( $dirs[ $j ] ) {
				case '%year%':
					$ep_mask_specific = EP_YEAR;
					break;
				case '%monthnum%':
					$ep_mask_specific = EP_MONTH;
					break;
				case '%day%':
					$ep_mask_specific = EP_DAY;
					break;
				default:
					$ep_mask_specific = EP_NONE;
			}

			// Create query for /page/xx.
			$pagematch = $match . $pageregex;
			$pagequery = $index . '?' . $query . '&paged=' . $this->preg_index( $num_toks + 1 );

			// Create query for /comment-page-xx.
			$commentmatch = $match . $commentregex;
			$commentquery = $index . '?' . $query . '&cpage=' . $this->preg_index( $num_toks + 1 );

			if ( get_option( 'page_on_front' ) ) {
				// Create query for Root /comment-page-xx.
				$rootcommentmatch = $match . $commentregex;
				$rootcommentquery = $index . '?' . $query . '&page_id=' . get_option( 'page_on_front' ) . '&cpage=' . $this->preg_index( $num_toks + 1 );
			}

			// Create query for /feed/(feed|atom|rss|rss2|rdf).
			$feedmatch = $match . $feedregex;
			$feedquery = $feedindex . '?' . $query . '&feed=' . $this->preg_index( $num_toks + 1 );

			// Create query for /(feed|atom|rss|rss2|rdf) (see comment near creation of $feedregex).
			$feedmatch2 = $match . $feedregex2;
			$feedquery2 = $feedindex . '?' . $query . '&feed=' . $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 ( strpos( $struct, '%postname%' ) !== false
						|| strpos( $struct, '%post_id%' ) !== false
						|| strpos( $struct, '%pagename%' ) !== false
						|| ( strpos( $struct, '%year%' ) !== false && strpos( $struct, '%monthnum%' ) !== false && strpos( $struct, '%day%' ) !== false && strpos( $struct, '%hour%' ) !== false && strpos( $struct, '%minute%' ) !== false && strpos( $struct, '%second%' ) !== false )
						) {
					$post = true;
					if ( strpos( $struct, '%pagename%' ) !== false ) {
						$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 ( strpos( $struct, "%$ptype%" ) !== false ) {
							$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 finalise 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
	 */
	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, e.g. 'post_tag' (tags),
			 * 'category' (categories), etc.
			 *
			 * @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 $this Current WP_Rewrite instance (passed by reference).
		 */
		do_action_ref_array( 'generate_rewrite_rules', array( &$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 .= "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 ( strpos( $query, $this->index ) !== false ) {
					$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 = false === strpos( $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.
	 * @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 `EP_NONE`, `EP_PERMALINK`, `EP_ATTACHMENT`, `EP_DATE`, `EP_YEAR`,
	 *                             `EP_MONTH`, `EP_DAY`, `EP_ROOT`, `EP_COMMENTS`, `EP_SEARCH`, `EP_CATEGORIES`,
	 *                             `EP_TAGS`, `EP_AUTHORS`, `EP_PAGES`, `EP_ALL_ARCHIVES`, and `EP_ALL`.
	 *                             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 = ( '/' === substr( $this->permalink_structure, -1, 1 ) );

		// 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 ( $permalink_structure != $this->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();
	}
}


<?php
/**
 * User API: WP_Role class
 *
 * @package WordPress
 * @subpackage Users
 * @since 4.4.0
 */

/**
 * Core class used to extend the user roles API.
 *
 * @since 2.0.0
 */
class WP_Role {
	/**
	 * Role name.
	 *
	 * @since 2.0.0
	 * @var string
	 */
	public $name;

	/**
	 * List of capabilities the role contains.
	 *
	 * @since 2.0.0
	 * @var bool[] Array of key/value pairs where keys represent a capability name and boolean values
	 *             represent whether the role has that capability.
	 */
	public $capabilities;

	/**
	 * Constructor - Set up object properties.
	 *
	 * The list of capabilities must have the key as the name of the capability
	 * and the value a boolean of whether it is granted to the role.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role         Role name.
	 * @param bool[] $capabilities Array of key/value pairs where keys represent a capability name and boolean values
	 *                             represent whether the role has that capability.
	 */
	public function __construct( $role, $capabilities ) {
		$this->name         = $role;
		$this->capabilities = $capabilities;
	}

	/**
	 * Assign role a capability.
	 *
	 * @since 2.0.0
	 *
	 * @param string $cap   Capability name.
	 * @param bool   $grant Whether role has capability privilege.
	 */
	public function add_cap( $cap, $grant = true ) {
		$this->capabilities[ $cap ] = $grant;
		wp_roles()->add_cap( $this->name, $cap, $grant );
	}

	/**
	 * Removes a capability from a role.
	 *
	 * @since 2.0.0
	 *
	 * @param string $cap Capability name.
	 */
	public function remove_cap( $cap ) {
		unset( $this->capabilities[ $cap ] );
		wp_roles()->remove_cap( $this->name, $cap );
	}

	/**
	 * Determines whether the role has the given capability.
	 *
	 * @since 2.0.0
	 *
	 * @param string $cap Capability name.
	 * @return bool Whether the role has the given capability.
	 */
	public function has_cap( $cap ) {
		/**
		 * Filters which capabilities a role has.
		 *
		 * @since 2.0.0
		 *
		 * @param bool[] $capabilities Array of key/value pairs where keys represent a capability name and boolean values
		 *                             represent whether the role has that capability.
		 * @param string $cap          Capability name.
		 * @param string $name         Role name.
		 */
		$capabilities = apply_filters( 'role_has_cap', $this->capabilities, $cap, $this->name );

		if ( ! empty( $capabilities[ $cap ] ) ) {
			return $capabilities[ $cap ];
		} else {
			return false;
		}
	}

}