Let Members Deactivate Their Own Account

add_action( 'template_redirect', function () {
    if ( empty( $_POST['wpide_deactivate_nonce'] ) || ! is_user_logged_in() ) {
        return;
    }

    if ( ! wp_verify_nonce( sanitize_key( $_POST['wpide_deactivate_nonce'] ), 'wpide_deactivate' ) || current_user_can( 'manage_options' ) ) {
        wp_die( 'This request could not be completed.' );
    }

    $user_id = get_current_user_id();
    update_user_meta( $user_id, 'wpide_deactivated', time() );
    WP_Session_Tokens::get_instance( $user_id )->destroy_all();
    wp_clear_auth_cookie();

    wp_mail(
        get_option( 'admin_email' ),
        'A member deactivated their account',
        sprintf( "%s deactivated their account.\n%s", wp_get_current_user()->user_email, admin_url( 'user-edit.php?user_id=' . $user_id ) )
    );

    wp_safe_redirect( add_query_arg( 'account-closed', 1, home_url( '/' ) ) );
    exit;
} );

add_shortcode( 'wpide_deactivate_account', function () {
    if ( ! is_user_logged_in() || current_user_can( 'manage_options' ) ) {
        return '';
    }

    return '<form method="post" class="wpide-deactivate" onsubmit="return confirm(\'Close your account? You will be logged out.\');">'
        . wp_nonce_field( 'wpide_deactivate', 'wpide_deactivate_nonce', true, false )
        . '<p><button type="submit">Close my account</button></p></form>';
} );

add_filter( 'authenticate', function ( $user ) {
    if ( $user instanceof WP_User && get_user_meta( $user->ID, 'wpide_deactivated', true ) ) {
        return new WP_Error( 'wpide_deactivated', '<strong>This account has been closed.</strong> Contact us if you would like to reopen it.' );
    }

    return $user;
}, 60 );

add_filter( 'user_row_actions', function ( $actions, $user ) {
    if ( get_user_meta( $user->ID, 'wpide_deactivated', true ) && current_user_can( 'edit_user', $user->ID ) ) {
        $url = wp_nonce_url( admin_url( 'admin-post.php?action=wpide_reactivate&user_id=' . $user->ID ), 'wpide_reactivate_' . $user->ID );
        $actions['wpide_reactivate'] = '<strong>Deactivated</strong> · <a href="' . esc_url( $url ) . '">Reactivate</a>';
    }

    return $actions;
}, 10, 2 );

add_action( 'admin_post_wpide_reactivate', function () {
    $user_id = isset( $_GET['user_id'] ) ? absint( $_GET['user_id'] ) : 0;

    if ( ! $user_id || ! current_user_can( 'edit_user', $user_id ) ) {
        wp_die( 'You are not allowed to do this.' );
    }

    check_admin_referer( 'wpide_reactivate_' . $user_id );
    delete_user_meta( $user_id, 'wpide_deactivated' );

    wp_safe_redirect( admin_url( 'users.php' ) );
    exit;
} );