Temporary FluentCommunity workaround to generate friendly anonymous WordPress usernames during default signup, helping prevent email-derived usernames from being exposed in mentions or profile UI.

fluentcommunity-friendly-anonymous-usernames.php

<?php

defined('ABSPATH') || exit;

/**
 * Modify FluentCommunity signup fields.
 */
add_filter('fluent_community/auth/signup_fields', function ($fields) {

    if (isset($fields['full_name'])) {
        $fields['full_name']['label'] = 'Public Display Name';
        $fields['full_name']['placeholder'] = 'Example: Optimisticflamingo24';
    }

    if (isset($fields['username'])) {
        // Do not disable/remove this field. FluentCommunity still validates username.
        unset($fields['username']['disabled']);
        unset($fields['username']['readonly']);

        $fields['username']['required'] = false;
        $fields['username']['label'] = '';
        $fields['username']['placeholder'] = '';
        $fields['username']['value'] = '';
        $fields['username']['input_class'] = 'fcom-anonymous-generated-username';
    }

    return $fields;

}, 20);


/**
 * Server-side enforcement.
 * This replaces the submitted username before FluentCommunity creates the WP user.
 */
add_action('wp_ajax_nopriv_fcom_user_registration', 'fcom_force_friendly_anonymous_signup_username', 0);
add_action('wp_ajax_fcom_user_registration', 'fcom_force_friendly_anonymous_signup_username', 0);

function fcom_force_friendly_anonymous_signup_username()
{
    $username = fcom_generate_friendly_anonymous_username();

    $_POST['username'] = $username;
    $_REQUEST['username'] = $username;
}


/**
 * Frontend CSS/JS for FluentCommunity registration form.
 */
add_action('wp_footer', 'fcom_anonymous_signup_frontend_script', 999);
add_action('fluent_community/headless/footer', 'fcom_anonymous_signup_frontend_script', 999);

function fcom_anonymous_signup_frontend_script()
{
    static $printed = false;

    if ($printed) {
        return;
    }

    $printed = true;

    ?>
    <style>
        #fcom_group_username,
        .fcom-anonymous-generated-username {
            display: none !important;
        }
    </style>

    <script>
        (function () {
            var adjectives = [
                'bright', 'calm', 'gentle', 'happy', 'kind',
                'lucky', 'quiet', 'sunny', 'clever', 'brave',
                'cozy', 'wise', 'merry', 'fresh', 'soft',
                'hopeful', 'peaceful', 'steady', 'warm', 'bold'
            ];

            var animals = [
                'panda', 'otter', 'robin', 'turtle', 'owl',
                'fox', 'koala', 'dolphin', 'sparrow', 'rabbit',
                'beaver', 'badger', 'falcon', 'penguin', 'whale',
                'deer', 'lynx', 'swan', 'seal', 'wren'
            ];

            function randomItem(items) {
                return items[Math.floor(Math.random() * items.length)];
            }

            function friendlyUsername() {
                var number = Math.floor(Math.random() * 990) + 10;
                return randomItem(adjectives) + '_' + randomItem(animals) + '_' + number;
            }

            function ensureAnonymousUsername(form) {
                if (!form) {
                    return;
                }

                var input = form.querySelector('input[name="username"]');

                if (!input) {
                    input = document.createElement('input');
                    input.type = 'hidden';
                    input.name = 'username';
                    form.appendChild(input);
                }

                input.disabled = false;

                if (!input.value || input.value.length < 4) {
                    input.value = friendlyUsername();
                }
            }

            document.addEventListener('DOMContentLoaded', function () {
                var form = document.getElementById('fcom_user_registration_form');
                ensureAnonymousUsername(form);
            });

            document.addEventListener('submit', function (event) {
                var form = event.target && event.target.closest
                    ? event.target.closest('#fcom_user_registration_form')
                    : null;

                ensureAnonymousUsername(form);
            }, true);
        })();
    </script>
    <?php
}


/**
 * Generate friendly anonymous usernames.
 *
 * Example:
 * calm_panda_42
 * bright_otter_317
 * gentle_robin_88
 */
function fcom_generate_friendly_anonymous_username()
{
    $adjectives = [
        'bright', 'calm', 'gentle', 'happy', 'kind',
        'lucky', 'quiet', 'sunny', 'clever', 'brave',
        'cozy', 'wise', 'merry', 'fresh', 'soft',
        'hopeful', 'peaceful', 'steady', 'warm', 'bold'
    ];

    $animals = [
        'panda', 'otter', 'robin', 'turtle', 'owl',
        'fox', 'koala', 'dolphin', 'sparrow', 'rabbit',
        'beaver', 'badger', 'falcon', 'penguin', 'whale',
        'deer', 'lynx', 'swan', 'seal', 'wren'
    ];

    for ($i = 0; $i < 100; $i++) {
        $adjective = $adjectives[array_rand($adjectives)];
        $animal = $animals[array_rand($animals)];
        $number = wp_rand(10, 999);

        $username = sanitize_user($adjective . '_' . $animal . '_' . $number, true);

        // Keep it FluentCommunity-friendly.
        $username = substr($username, 0, 30);

        if (fcom_friendly_anonymous_username_is_available($username)) {
            return $username;
        }
    }

    // Fallback.
    for ($i = 0; $i < 20; $i++) {
        $username = sanitize_user('member_' . wp_rand(100000, 999999), true);

        if (fcom_friendly_anonymous_username_is_available($username)) {
            return $username;
        }
    }

    return sanitize_user('member_' . time() . wp_rand(100, 999), true);
}


/**
 * Check username availability in WordPress and FluentCommunity.
 */
function fcom_friendly_anonymous_username_is_available($username)
{
    if (!$username || strlen($username) < 4) {
        return false;
    }

    if (username_exists($username)) {
        return false;
    }

    if (class_exists('\FluentCommunity\App\Services\ProfileHelper')) {
        try {
            if (!\FluentCommunity\App\Services\ProfileHelper::isUsernameAvailable($username)) {
                return false;
            }
        } catch (Throwable $e) {
            // If FluentCommunity check fails, continue with WordPress username check.
        }
    }

    return true;
}