<?php
/**
 * Multisite upgrade administration panel.
 *
 * @package WordPress
 * @subpackage Multisite
 * @since 3.0.0
 */

/** Load WordPress Administration Bootstrap */
require_once __DIR__ . '/admin.php';

require_once ABSPATH . WPINC . '/http.php';

/**
 * @global int $wp_db_version WordPress database version.
 */
global $wp_db_version;

// Used in the HTML title tag.
$title       = __( 'Upgrade Network' );
$parent_file = 'upgrade.php';

get_current_screen()->add_help_tab(
    array(
        'id'      => 'overview',
        'title'   => __( 'Overview' ),
        'content' =>
            '<p>' . __( 'Only use this screen once you have updated to a new version of WordPress through Updates/Available Updates (via the Network Administration navigation menu or the Toolbar). Clicking the Upgrade Network button will step through each site in the network, five at a time, and make sure any database updates are applied.' ) . '</p>' .
            '<p>' . __( 'If a version update to core has not happened, clicking this button will not affect anything.' ) . '</p>' .
            '<p>' . __( 'If this process fails for any reason, users logging in to their sites will force the same update.' ) . '</p>',
    )
);

get_current_screen()->set_help_sidebar(
    '<p><strong>' . __( 'For more information:' ) . '</strong></p>' .
    '<p>' . __( '<a href="https://developer.wordpress.org/advanced-administration/multisite/admin/#network-admin-updates-screen">Documentation on Upgrade Network</a>' ) . '</p>' .
    '<p>' . __( '<a href="https://wordpress.org/support/forums/">Support forums</a>' ) . '</p>'
);

require_once ABSPATH . 'wp-admin/admin-header.php';

if ( ! current_user_can( 'upgrade_network' ) ) {
    wp_die( __( 'Sorry, you are not allowed to access this page.' ), 403 );
}

echo '<div class="wrap">';
echo '<h1>' . __( 'Upgrade Network' ) . '</h1>';

$action = $_GET['action'] ?? 'show';

switch ( $action ) {
    case 'upgrade':
        $n = ( isset( $_GET['n'] ) ) ? (int) $_GET['n'] : 0;

        if ( $n < 5 ) {
            update_site_option( 'wpmu_upgrade_site', $wp_db_version );
        }

        $site_ids = get_sites(
            array(
                'spam'                   => 0,
                'deleted'                => 0,
                'archived'               => 0,
                'network_id'             => get_current_network_id(),
                'number'                 => 5,
                'offset'                 => $n,
                'fields'                 => 'ids',
                'order'                  => 'DESC',
                'orderby'                => 'id',
                'update_site_meta_cache' => false,
            )
        );
        if ( empty( $site_ids ) ) {
            echo '<p>' . __( 'All done!' ) . '</p>';
            break;
        }
        echo '<ul>';
        foreach ( (array) $site_ids as $site_id ) {
            switch_to_blog( $site_id );
            $siteurl     = site_url();
            $upgrade_url = admin_url( 'upgrade.php?step=upgrade_db' );
            restore_current_blog();

            echo "<li>$siteurl</li>";

            $response = wp_remote_get(
                $upgrade_url,
                array(
                    'timeout'     => 120,
                    'httpversion' => '1.1',
                    'sslverify'   => false,
                )
            );

            if ( is_wp_error( $response ) ) {
                wp_die(
                    sprintf(
                        /* translators: 1: Site URL, 2: Server error message. */
                        __( 'Warning! Problem updating %1$s. Your server may not be able to connect to sites running on it. Error message: %2$s' ),
                        $siteurl,
                        '<em>' . $response->get_error_message() . '</em>'
                    )
                );
            }

            /**
             * Fires after the Multisite DB upgrade for each site is complete.
             *
             * @since MU (3.0.0)
             *
             * @param array $response The upgrade response array.
             */
            do_action( 'after_mu_upgrade', $response );

            /**
             * Fires after each site has been upgraded.
             *
             * @since MU (3.0.0)
             *
             * @param int $site_id The Site ID.
             */
            do_action( 'wpmu_upgrade_site', $site_id );
        }
        echo '</ul>';
        ?><p><?php _e( 'If your browser does not start loading the next page automatically, click this link:' ); ?> <a class="button" href="upgrade.php?action=upgrade&amp;n=<?php echo ( $n + 5 ); ?>"><?php _e( 'Next Sites' ); ?></a></p>
        <script>
        <!--
        function nextpage() {
            location.href = "upgrade.php?action=upgrade&n=<?php echo ( $n + 5 ); ?>";
        }
        setTimeout( "nextpage()", 250 );
        //-->
        </script>
        <?php
        break;
    case 'show':
    default:
        if ( (int) get_site_option( 'wpmu_upgrade_site' ) !== $wp_db_version ) :
            ?>
        <h2><?php _e( 'Database Update Required' ); ?></h2>
        <p><?php _e( 'WordPress has been updated! Next and final step is to individually upgrade the sites in your network.' ); ?></p>
        <?php endif; ?>

        <p><?php _e( 'The database update process may take a little while, so please be patient.' ); ?></p>
        <p><a class="button button-primary" href="upgrade.php?action=upgrade"><?php _e( 'Upgrade Network' ); ?></a></p>
        <?php
        /**
         * Fires before the footer on the network upgrade screen.
         *
         * @since MU (3.0.0)
         */
        do_action( 'wpmu_upgrade_page' );
        break;
}
?>
</div>

<?php require_once ABSPATH . 'wp-admin/admin-footer.php'; ?>