<?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
*/
#[AllowDynamicProperties]
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 `error_get_last()`.
* @return true|WP_Error|void 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() {
/**
* Filters 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;

/**
* Filters 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 string[] $wp_theme_directories
*
* @param array $error Error details from `error_get_last()`.
* @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 ( str_starts_with( $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 ( str_starts_with( $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 ( str_starts_with( $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 details from `error_get_last()`.
* @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;
}
}