<?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', __( 'The email could not be sent. Possible reason: your host may have disabled the mail() function.' ) );

		}

		$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 $message string 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.' ) );

		/* translators: Do not translate LINK, EXPIRES, CAUSE, DETAILS, SITEURL, PAGEURL, SUPPORT: 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.

###DETAILS###'

		);

		$message = str_replace(

			array(

				'###LINK###',

				'###EXPIRES###',

				'###CAUSE###',

				'###DETAILS###',

				'###SITEURL###',

				'###PAGEURL###',

				'###SUPPORT###',

			),

			array(

				$url,

				human_time_diff( time() + $rate_limit ),

				$cause ? "\n{$cause}\n" : "\n",

				$details,

				home_url( '/' ),

				home_url( $_SERVER['REQUEST_URI'] ),

				$support,

			),

			$message

		);

		$email = array(

			'to'      => $this->get_recovery_mode_email_address(),

			/* translators: %s: site name */

			'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'] ) {

			if ( ! function_exists( 'get_plugins' ) ) {

				require_once ABSPATH . 'wp-admin/includes/plugin.php';

			}

			$plugins = get_plugins();

			$name = '';

			// Assume plugin main file name first since it is a common convention.

			if ( isset( $plugins[ "{$extension['slug']}/{$extension['slug']}.php" ] ) ) {

				$name = $plugins[ "{$extension['slug']}/{$extension['slug']}.php" ]['Name'];

			} else {

				foreach ( $plugins as $file => $plugin_data ) {

					if ( 0 === strpos( $file, "{$extension['slug']}/" ) || $file === $extension['slug'] ) {

						$name = $plugin_data['Name'];

						break;

					}

				}

			}

			if ( empty( $name ) ) {

				$name = $extension['slug'];

			}

			/* 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;

	}

}