<?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

	 *

	 * @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() {

		/**

		 * 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 array $wp_theme_directories

	 *

	 * @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

	 *

	 * @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;

		}

	}