<?php
/**
 * SMTP test email.
 *
 * @package Adminkeep
 */

namespace Adminkeep\Service;

use Adminkeep\Feature\Smtp;

defined( 'ABSPATH' ) || exit;

/**
 * Sends the test email and reports what the server said.
 *
 * One sender for the SMTP screen, its AJAX route and WP-CLI. Nothing about the conversation is
 * stored: it is returned, scrubbed of the username and password, and forgotten.
 */
class SmtpTester {

	/**
	 * Send a test email.
	 *
	 * @param string     $to     Recipient, as given. Anything that is not an address sends nothing.
	 * @param SmtpConfig $config The configuration in force, used to scrub the result.
	 * @return array {
	 *     @type bool   $sent  Whether wp_mail() reported success.
	 *     @type string $to    The recipient, or '' when it was not a valid address.
	 *     @type string $error Scrubbed error message, '' when none.
	 *     @type string $log   Scrubbed SMTP conversation, '' when none.
	 * }
	 */
	public static function send( $to, SmtpConfig $config ) {
		$to = is_string( $to ) ? sanitize_email( $to ) : '';

		if ( ! is_email( $to ) ) {
			return array(
				'sent'  => false,
				'to'    => '',
				'error' => __( 'That is not a valid email address.', 'adminkeep' ),
				'log'   => '',
			);
		}

		$log   = '';
		$error = '';

		// After Smtp::configure_mailer(), so the conversation being recorded is the real one.
		$debug = static function ( $phpmailer ) use ( &$log ) {
			// phpcs:disable WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase -- PHPMailer's own property names.
			$phpmailer->SMTPDebug   = 2;
			$phpmailer->Debugoutput = static function ( $line ) use ( &$log ) {
				$log .= rtrim( (string) $line ) . "\n";
			};
			// phpcs:enable WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
		};

		$failed = static function ( $wp_error ) use ( &$error ) {
			$error = $wp_error instanceof \WP_Error ? $wp_error->get_error_message() : '';
		};

		add_action( 'phpmailer_init', $debug, Smtp::MAILER_PRIORITY + 1 );
		add_action( 'wp_mail_failed', $failed );

		// The debug hook must never outlive this request's test, whatever wp_mail() does.
		try {
			$sent = wp_mail(
				$to,
				/* translators: %s: site name. */
				sprintf( __( 'Test email from %s', 'adminkeep' ), wp_specialchars_decode( get_bloginfo( 'name' ), ENT_QUOTES ) ),
				__( "This is a test email sent from Adminkeep's SMTP settings. If you are reading it, your site can send email.", 'adminkeep' )
			);
		} finally {
			remove_action( 'phpmailer_init', $debug, Smtp::MAILER_PRIORITY + 1 );
			remove_action( 'wp_mail_failed', $failed );

			// wp_mail() reuses one global PHPMailer, so the debug settings this test turned on
			// would still be on for anything else the request sends, writing that conversation
			// into a closure this screen is done with.
			global $phpmailer;

			if ( $phpmailer instanceof \PHPMailer\PHPMailer\PHPMailer ) {
				// phpcs:disable WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase -- PHPMailer's own property names.
				$phpmailer->SMTPDebug   = 0;
				$phpmailer->Debugoutput = 'error_log';
				// phpcs:enable WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase
			}
		}

		$password = $config->password();

		return array(
			'sent'  => (bool) $sent,
			'to'    => $to,
			'error' => SmtpScrubber::scrub( $error, (string) $config->get( 'username' ), (string) $password ),
			'log'   => SmtpScrubber::scrub( $log, (string) $config->get( 'username' ), (string) $password ),
		);
	}
}