````
Concept: Behavioral Anti-Bot Checks with JS-Generated Tokens
Why?

Bots and scripts often submit forms immediately without any user interaction.
Humans almost always perform some interactions on the page: moving mouse, scrolling, typing, clicking.
Capturing these user events and generating a token or flag lets your server validate whether the form submission likely came from a real user or a bot.

How does it work?

At page load:
JavaScript binds listeners for user interactions — scroll, mousemove, keydown, click.
Upon the first such interaction, JS injects or enables a hidden input field with a token or sets a flag value in a hidden field.

Timing enforcement:
Additionally, measure time elapsed since the page was loaded.
Detect if a form was submitted too quickly (e.g., within 2 seconds), flag as suspicious.

On form submit:
The token or interaction flag is sent with the POST data.
The server validates:
Is the token present?
Was the token generated properly (optionally signed, timestamped)?
Has enough time passed before submission?

If validation fails:
Reject the submission or treat as bot.
Log, throttle, or challenge user further (captcha, etc.).

Implementation details
JavaScript snippet: generate interaction token

document.addEventListener("DOMContentLoaded", function() {
let interactionDetected = false;

function markInteraction() {
if (interactionDetected) return;
interactionDetected = true;

// Create hidden input if not exists
let form = document.querySelector('form');
if (!form) return;

let input = document.getElementById('user_interaction_token');
if (!input) {
    input = document.createElement('input');
    input.type = 'hidden';
    input.name = 'user_interaction_token';
    input.id = 'user_interaction_token';
    // Simple token: timestamp or randomized string, can be enhanced e.g. signed/tokenized
    input.value = Date.now();
    form.appendChild(input);
}

}

// Bind common interaction events
['scroll', 'mousemove', 'keydown', 'click'].forEach(eventType => {
window.addEventListener(eventType, markInteraction, { once: true });
});

});

Include this JS code on your form page (directly or via asset bundle).
Server-side validation (PHP)

In your controller action processing the form:

use Yii;

// Minimum time (e.g. 2 seconds) users must interact before submitting
define('MIN_FORM_TIME_MS', 2000);

$post = Yii::$app->request->post();

$userInteractionToken = $post['user_interaction_token'] ?? null;

if ($userInteractionToken === null) {
// No interaction token submitted - possible bot
Yii::$app->session->setFlash('error', 'Suspicious activity detected: no user interaction.');
return $this->refresh();
}

// Check time elapsed since token was created (assumes token is timestamp)
$now = round(microtime(true) * 1000);
$elapsedTime = $now - (int)$userInteractionToken;

if ($elapsedTime < MIN_FORM_TIME_MS) {
// Submitted too quickly - likely bot
Yii::$app->session->setFlash('error', 'Suspicious activity detected: form submitted too fast.');
return $this->refresh();
}

// Proceed with normal validation and processing

Enhancements for stronger security

Use a signed token with embedded timestamp instead of plain timestamp to avoid token tampering.

Track multiple events or rebuild interaction token if needed.

Use cookies or Web Storage for additional behavioral signals.

Implement progressive delays or challenges on suspicious submissions.

Benefits

Very low friction for legitimate users (token generated automatically on first interaction).

Bots that don’t simulate user events or submit immediately get blocked.

Can be combined with other techniques (honeypots, captchas, rate limits).

Summary

This approach lets you:

Track real user interactions client-side with minimal JS.

Require minimum time spent and interaction before submission server-side.

Reject or challenge suspicious fast/no-interaction submissions.

If you want, I can help you integrate this into your existing Yii2 forms with code examples, asset bundles, and demo!

help make this code better, more complete and how i intergrate it

Certainly! Your behavioral anti-bot check implementation is solid as a basic approach. I'll help you improve the JavaScript and server-side PHP code for better security, robustness, and integration with Yii2. Then, I'll outline how to properly integrate it into Yii2 forms and assets.
Enhanced Approach
Goals of Improvements:

Use a signed, timestamped token to prevent tampering.
Make the token unique per page load.
Add server-side token signature validation.
Support multiple forms on a page.
Track multiple interaction events or at least ensure the token only generated once.
Handle token expiration.
Ensure smooth integration into Yii2 flows (CSRF, client scripts, form inputs).

    Enhanced JavaScript

Generate a client-side token embedded with a page load timestamp, and then sign it server-side on page render — or, since JS can't sign securely, create a token with randomness only, send that and timestamp back to validate.

For ease, you can send a random nonce (unique string) client side on interaction, and submit that. Then on server side, combine that with session state or secret key and check elapsed time.
Example: generate nonce on page load, inject token on first interaction

document.addEventListener("DOMContentLoaded", function() {
// Generate random nonce per page load (better than timestamp alone)
function generateNonce() {
return (Math.random().toString(36).substr(2, 9)) + (Date.now().toString(36));
}
const pageNonce = generateNonce();

let interactionDetected = false;

function markInteraction() {
    if (interactionDetected) return;
    interactionDetected = true;

    let forms = document.querySelectorAll("form");
    if (!forms || forms.length === 0) return;

    forms.forEach(form => {
        let input = form.querySelector('input[name="user_interaction_token"]');
        if (!input) {
            input = document.createElement('input');
            input.type = 'hidden';
            input.name = 'user_interaction_token';
            form.appendChild(input);
        }
        // Set value as nonce + "|" + timestamp of interaction for server validation
        input.value = pageNonce + "|" + Date.now();
    });
}

['scroll', 'mousemove', 'keydown', 'click'].forEach(eventType => {
    window.addEventListener(eventType, markInteraction, { once: true });
});

});

Explanation:

pageNonce is unique per page load.
When user first interacts, all forms have a hidden input named user_interaction_token set to nonce|timestamp.
On server, you can validate nonce (against session), validate elapsed time, etc.

    Server-Side PHP (Yii2) Validation
    Setup:

    On page generation (render), generate a nonce stored in session.
    On form submit, check:
    Token exists and format nonce|timestamp.
    Nonce matches session nonce.
    Time elapsed since timestamp ≥ minimum required.
    Optionally sign or encrypt nonce for stronger security.

Example in Yii2 Controller

use Yii;

define('MIN_FORM_TIME_MS', 2000);

class YourController extends \yii\web\Controller
{
public function actionYourForm()
{
// Generate and store nonce per page load, pass to view
$session = Yii::$app->session;
$interactionNonce = bin2hex(random_bytes(16)); // 32 character hex string
$session->set('interaction_nonce', $interactionNonce);

    return $this->render('your-form', [
        'interactionNonce' => $interactionNonce,
    ]);
}

public function actionSubmit()
{
    $post = Yii::$app->request->post();

    if (!Yii::$app->request->isPost) {
        return $this->redirect(['your-form']);
    }

    $session = Yii::$app->session;
    $sessionNonce = $session->get('interaction_nonce');

    $userInteractionToken = $post['user_interaction_token'] ?? null;
    if ($userInteractionToken === null) {
        Yii::$app->session->setFlash('error', 'Suspicious activity detected: no user interaction.');
        return $this->refresh();
    }

    // Expect format nonce|timestamp
    if (!preg_match('/^([a-f0-9]{32})\|(\d+)$/', $userInteractionToken, $matches)) {
        Yii::$app->session->setFlash('error', 'Invalid interaction token format.');
        return $this->refresh();
    }

    $nonce = $matches[1];
    $timestamp = (int)$matches[2];

    if (!$sessionNonce || $nonce !== $sessionNonce) {
        Yii::$app->session->setFlash('error', 'Invalid interaction nonce.');
        return $this->refresh();
    }

    // Check elapsed time
    $now = round(microtime(true) * 1000);
    $elapsed = $now - $timestamp;

    if ($elapsed < MIN_FORM_TIME_MS) {
        Yii::$app->session->setFlash('error', 'Suspicious activity detected: form submitted too fast.');
        return $this->refresh();
    }

    // Passed all checks -- proceed with normal validation and processing
    // ...
}

}

    Integrate into Yii2 Form Views
    Pass nonce to JS safely:

In your view file, e.g., your-form.php:
{ let input = form.querySelector('input[name="user_interaction_token"]'); if (!input) { input = document.createElement('input'); input.type = 'hidden'; input.name = 'user_interaction_token'; form.appendChild(input); } input.value = pageNonce + "|" + Date.now(); }); } ['scroll', 'mousemove', 'keydown', 'click'].forEach(eventType => { window.addEventListener(eventType, markInteraction, { once: true }); }); }); JS; $this->registerJs($js); ?> field($model, 'your_field')->textInput() ?>
'btn btn-primary']) ?>

    Additional Security Tips

    Regenerate nonce on every page load, store in session.
    Limit nonce lifespan (e.g., expire after 10 min).
    Invalidate nonce after one submission (to prevent replay).
    Combine interaction token with Yii2 CSRF tokens (they coexist).
    Log failed attempts to detect attack patterns.
    Optionally, integrate fallback CAPTCHA on repeated failures.

    Summary Checklist
    Step Description
    Generate nonce at page load On controller render, generate random nonce, store in session. Pass to view.
    Inject JS to listen to user interactions On first user interaction, set hidden `user_interaction_token = nonce
    Server validation On form submit, validate presence, format, nonce equality, elapsed time.
    Reject suspicious submissions Flash error and refresh if suspicious (no interaction or too fast).
    Proceed otherwise Normal validation and processing.

    Bonus: How to handle multiple forms and AJAX

If you have multiple forms or AJAX submissions, you can adapt:

For multiple forms: current code sets all forms' tokens on interaction.
For AJAX, ensure tokens are sent with requests and server validates similarly.
For SPA, consider tokens in JS stored and passed accordingly.

If you want, I can generate a Yii2 AssetBundle for this JS or provide a more advanced signed JWT token example instead.

Let me know if you want me to prepare that, or help with integrating in your specific Yii2 app code!

as of right now its not ideal, and would be better as a trait, behavior or something that I can plug and go. I dont have time to hardcode it into my app

Great point! Wrapping this logic as a reusable Yii2 behavior or trait makes perfect sense for quick plug-and-play integration without hardcoding. I’ll guide you through creating a solid Yii2 Behavior and a corresponding AssetBundle to inject the JS, plus controller code you just attach to any form controller or action.
1. Create the Yii2 Behavior for Anti-Bot Interaction Validation

File: components/Behavior/FormInteractionBehavior.php

<?php
namespace app\components\Behavior;

use Yii;
use yii\base\Behavior;
use yii\web\Controller;
use yii\web\Response;

class FormInteractionBehavior extends Behavior
{
    /**
     * Minimum elapsed time (ms) user must wait before submitting
     */
    public int $minFormTimeMs = 2000;

    /**
     * Session key to store the nonce
     */
    public string $sessionKey = '__form_interaction_nonce';

    /**
     * Attach to controller's beforeAction event to generate nonce per page load
     */
    public function events()
    {
        return [
            Controller::EVENT_BEFORE_ACTION => 'generateNonce',
        ];
    }

    /**
     * Generate/create nonce and store in session
     */
    public function generateNonce($event)
    {
        $session = Yii::$app->session;
        if (!$session->has($this->sessionKey)) {
            $nonce = bin2hex(random_bytes(16)); // secure 32 hex chars
            $session->set($this->sessionKey, $nonce);
        }
    }

    /**
     * Call this to validate the user interaction token on form submit
     * Example use in controller action:
     *   if (!$this->validateInteraction(Yii::$app->request->post())) {
     *       // handle failure (flash/redirect, etc)
     *   }
     *
     * @param array $post POST data from request
     * @return bool true if valid, false otherwise
     */
    public function validateInteraction(array $post): bool
    {
        $session = Yii::$app->session;
        $sessionNonce = $session->get($this->sessionKey);

        $token = $post['user_interaction_token'] ?? null;
        if ($token === null) {
            return false; // no token submitted
        }

        if (!preg_match('/^([a-f0-9]{32})\|(\d+)$/', $token, $matches)) {
            return false; // invalid format
        }

        $nonce = $matches[1];
        $timestamp = (int)$matches[2];

        if (!$sessionNonce || $nonce !== $sessionNonce) {
            return false; // invalid or missing nonce
        }

        $now = round(microtime(true) * 1000);
        $elapsed = $now - $timestamp;

        if ($elapsed < $this->minFormTimeMs) {
            return false; // submitted too fast
        }

        // Passed all checks: optionally remove nonce after one use to prevent replay
        $session->remove($this->sessionKey);

        return true;
    }
}

2. Create Yii2 AssetBundle to Inject JS Listening Code

File: assets/FormInteractionAsset.php

<?php
namespace app\assets;

use yii\web\AssetBundle;

class FormInteractionAsset extends AssetBundle
{
    public $js = [
        'form-interaction.js',
    ];

    public $depends = [
        'yii\web\YiiAsset', // For jQuery & yii.js (optional)
    ];

    public $sourcePath = '@app/assets/form-interaction';

    public $jsOptions = [
        'position' => \yii\web\View::POS_END,
    ];
}

3. JavaScript to Track User Interaction and Set Hidden Input

Place this file at:

/assets/form-interaction/form-interaction.js

document.addEventListener("DOMContentLoaded", function() {
    // pageNonce will be set dynamically from PHP below when registering the asset
    
    // We’ll inject it from PHP view via window object
    if (!window.FormInteraction) {
        window.FormInteraction = {};
    }

    const pageNonce = window.FormInteraction.pageNonce || null;
    if (!pageNonce) return;

    let interactionDetected = false;

    function markInteraction() {
        if (interactionDetected) return;
        interactionDetected = true;

        let forms = document.querySelectorAll("form");
        forms.forEach(form => {
            let input = form.querySelector('input[name="user_interaction_token"]');
            if (!input) {
                input = document.createElement('input');
                input.type = 'hidden';
                input.name = 'user_interaction_token';
                form.appendChild(input);
            }
            input.value = pageNonce + "|" + Date.now();
        });
    }

    ['scroll', 'mousemove', 'keydown', 'click'].forEach(eventType => {
        window.addEventListener(eventType, markInteraction, { once: true });
    });
});

4. How To Integrate This Into Your Yii2 Controller and View
Example controller using the behavior:

<?php
namespace app\controllers;

use Yii;
use yii\web\Controller;
use app\components\Behavior\FormInteractionBehavior;

class SiteController extends Controller
{
    public function behaviors()
    {
        return [
            'formInteraction' => [
                'class' => FormInteractionBehavior::class,
                'minFormTimeMs' => 2000,  // adjust as needed
            ],
        ];
    }

    // Show form and pass nonce to view
    public function actionContact()
    {
        $session = Yii::$app->session;

        return $this->render('contact', [
            'interactionNonce' => $session->get('__form_interaction_nonce'),
        ]);
    }

    // Process form submit
    public function actionSubmitContact()
    {
        $post = Yii::$app->request->post();

        if (!$this->validateInteraction($post)) {
            Yii::$app->session->setFlash('error', 'Suspicious activity detected: no valid user interaction.');
            return $this->redirect(['contact']);
        }

        // Proceed with your normal validation and processing here
    }
}

Example view (views/site/contact.php):

<?php

use yii\helpers\Html;
use yii\widgets\ActiveForm;
use app\assets\FormInteractionAsset;

/* @var $this yii\web\View */
/* @var $interactionNonce string */
/* @var $model app\models\ContactForm */

FormInteractionAsset::register($this);

$js = <<<JS
window.FormInteraction = {
    pageNonce: '{$interactionNonce}'
};
JS;

$this->registerJs($js, \yii\web\View::POS_HEAD);
?>

<?php $form = ActiveForm::begin(['id' => 'contact-form']); ?>

<?= $form->field($model, 'name') ?>
<?= $form->field($model, 'email') ?>
<?= $form->field($model, 'subject') ?>
<?= $form->field($model, 'body')->textarea() ?>

<div class="form-group">
    <?= Html::submitButton('Submit', ['class' => 'btn btn-primary']) ?>
</div>

<?php ActiveForm::end(); ?>

5. Summary of Integration:

    Behavior generates and stores secure nonce in session automatically on any controller action.
    JS Asset generates hidden input with combined nonce + timestamp on first user interaction.
    On form submit, controller action calls $this->validateInteraction($post) to verify token presence, format, nonce matching, and elapsed time.
    If validation fails → treat as bot, flash error, reject.
    Works for multiple forms on page, reusable across your controllers/ actions by just attaching behavior.
    Nonces are single-use (removed on successful validation) to prevent replay attacks.
    Easy to adjust minFormTimeMs for spam-sensitivity.

Bonus: How to Further Improve?

    Use Yii2 Cache or DB to track multiple nonces for multi-tab usage.
    Add IP/user agent tying inside nonce/session for even better validation.
    Extend JS to handle AJAX forms, or integrate with captcha fallback on multiple failures.
    Add replay detection or nonce expiration after 10+ minutes.

If you want, I can prepare a full Composer-ready package for you or help setup CAPTCHA fallback or cache tracking next.

Would you like me to provide a full working example codebase with tests? Or a more advanced signed JWT token version?

"Would you like me to provide a full working example codebase with tests? Or a more advanced signed JWT token version?"
ok do this.

Great! I will provide you with a full working Yii2-compatible example of the behavioral anti-bot check that uses signed JWT tokens for higher security, along with basic PHPUnit tests. This example will include:

    Generating a signed JWT token client-side via server rendering.
    Storing & verifying the token signature server-side.
    Incorporating timestamp and nonce inside the token payload.
    Minimal dependencies (uses firebase/php-jwt composer library).
    Yii2 Behavior to manage the logic.
    AssetBundle and JS for interaction capture.
    Simple PHPUnit test to verify server-side validation logic.

Step-by-step Guide
1. Install JWT library

Use firebase/php-jwt:

composer require firebase/php-jwt

2. Create the Behavior with JWT signed token generation & validation

File: components/Behavior/FormInteractionJwtBehavior.php

<?php
namespace app\components\Behavior;

use Yii;
use yii\base\Behavior;
use yii\web\Controller;
use Firebase\JWT\JWT;
use Firebase\JWT\Key;
use Exception;

class FormInteractionJwtBehavior extends Behavior
{
    /**
     * Minimum elapsed time (ms) user must wait before submitting
     */
    public int $minFormTimeMs = 2000;

    /**
     * Secret key to sign JWT tokens (set via config, env, or generate dynamically)
     */
    public string $jwtSecret;

    /**
     * JWT algorithm
     */
    public string $jwtAlgo = 'HS256';

    /**
     * Session key for replay protection nonce
     */
    public string $sessionKey = '__form_interaction_nonce';

    public function __construct($config = [])
    {
        parent::__construct($config);
        if (empty($this->jwtSecret)) {
            throw new \InvalidArgumentException("jwtSecret must be set for " . static::class);
        }
    }

    /**
     * Events: generate nonce and store in session before controller action executes
     */
    public function events()
    {
        return [
            Controller::EVENT_BEFORE_ACTION => 'beforeAction',
        ];
    }

    /**
     * Generate nonce for replay protection — one per page load
     */
    public function beforeAction($event)
    {
        $session = Yii::$app->session;

        if (!$session->has($this->sessionKey)) {
            $session->set($this->sessionKey, bin2hex(random_bytes(16)));
        }
    }

    /**
     * Generate a signed JWT token string embedding nonce and current timestamp.
     * Call this from controller when rendering the form.
     */
    public function generateInteractionToken(): string
    {
        $session = Yii::$app->session;
        $nonce = $session->get($this->sessionKey);

        $payload = [
            'nonce' => $nonce,
            'iat' => time(),        // issued at (seconds)
            'ts_ms' => round(microtime(true) * 1000), // issued timestamp in ms for elapsed time calc
        ];

        return JWT::encode($payload, $this->jwtSecret, $this->jwtAlgo);
    }

    /**
     * Validate the JWT token submitted by client form
     * @param string|null $token JWT string from user_interaction_token POST field
     * @return bool true if valid, false otherwise
     */
    public function validateInteraction(?string $token): bool
    {
        if (empty($token)) {
            return false;
        }

        $session = Yii::$app->session;
        $expectedNonce = $session->get($this->sessionKey);

        try {
            $decoded = JWT::decode($token, new Key($this->jwtSecret, $this->jwtAlgo));
        } catch (Exception $e) {
            // Invalid token, signature failed, expired, etc.
            return false;
        }

        if (empty($decoded->nonce) || $decoded->nonce !== $expectedNonce) {
            return false; // nonce mismatch or missing (replay protection)
        }

        if (empty($decoded->ts_ms) || !is_numeric($decoded->ts_ms)) {
            return false; // missing timestamp
        }

        $elapsed = round(microtime(true) * 1000) - (int)$decoded->ts_ms;

        if ($elapsed < $this->minFormTimeMs) {
            return false; // submitted too quickly
        }

        // Passed validation — remove nonce to prevent replay
        $session->remove($this->sessionKey);

        return true;
    }
}

3. Create AssetBundle and JS for placing token on interaction

File: assets/FormInteractionJwtAsset.php

<?php
namespace app\assets;

use yii\web\AssetBundle;

class FormInteractionJwtAsset extends AssetBundle
{
    public $js = [
        'form-interaction.jwt.js',
    ];

    public $depends = [
        'yii\web\YiiAsset',
    ];

    public $sourcePath = '@app/assets/form-interaction';
    public $jsOptions = [
        'position' => \yii\web\View::POS_END,
    ];
}

4. JavaScript to listen for first user interaction and set signed token

File: assets/form-interaction/form-interaction.jwt.js

document.addEventListener("DOMContentLoaded", function () {
    if (!window.FormInteractionJwt) {
        window.FormInteractionJwt = {};
    }

    const jwtToken = window.FormInteractionJwt.token || null;
    if (!jwtToken) return;

    let interactionDetected = false;

    function markInteraction() {
        if (interactionDetected) return;
        interactionDetected = true;

        document.querySelectorAll('form').forEach(form => {
            let input = form.querySelector('input[name="user_interaction_token"]');
            if (!input) {
                input = document.createElement('input');
                input.type = 'hidden';
                input.name = 'user_interaction_token';
                form.appendChild(input);
            }
            // Set JWT token generated on page load — it encodes nonce and page load timestamp
            input.value = jwtToken;
        });
    }

    ['scroll', 'mousemove', 'keydown', 'click'].forEach(evt => {
        window.addEventListener(evt, markInteraction, { once: true });
    });
});

5. Controller example using behavior and passing token to view

<?php
namespace app\controllers;

use Yii;
use yii\web\Controller;
use app\components\Behavior\FormInteractionJwtBehavior;

class SiteController extends Controller
{
    public function behaviors()
    {
        return [
            'formInteractionJwt' => [
                'class' => FormInteractionJwtBehavior::class,
                'jwtSecret' => Yii::$app->params['formInteractionJwtSecret'],
                'minFormTimeMs' => 2000,
            ],
        ];
    }

    public function actionContact()
    {
        /** @var FormInteractionJwtBehavior $beh */
        $beh = $this->getBehavior('formInteractionJwt');
        $jwtToken = $beh->generateInteractionToken();

        return $this->render('contact', ['jwtToken' => $jwtToken]);
    }

    public function actionSubmitContact()
    {
        $post = Yii::$app->request->post();
        /** @var FormInteractionJwtBehavior $beh */
        $beh = $this->getBehavior('formInteractionJwt');

        if (!$beh->validateInteraction($post['user_interaction_token'] ?? null)) {
            Yii::$app->session->setFlash('error', 'Suspicious activity detected: no valid user interaction.');
            return $this->redirect(['contact']);
        }

        // Process normal form submit here...

        Yii::$app->session->setFlash('success', 'Form submitted successfully!');
        return $this->redirect(['contact']);
    }
}

6. View file example (views/site/contact.php):

<?php

use yii\helpers\Html;
use yii\widgets\ActiveForm;
use app\assets\FormInteractionJwtAsset;

/* @var $this yii\web\View */
/* @var $jwtToken string */

FormInteractionJwtAsset::register($this);

$js = <<<JS
window.FormInteractionJwt = {
    token: '{$jwtToken}'
};
JS;

$this->registerJs($js, \yii\web\View::POS_HEAD);
?>

<h1>Contact</h1>

<?php $form = ActiveForm::begin(['id' => 'contact-form']); ?>

<?= $form->field($model ?? null, 'name')->textInput() ?>
<?= $form->field($model ?? null, 'email')->input('email') ?>
<?= $form->field($model ?? null, 'subject')->textInput() ?>
<?= $form->field($model ?? null, 'body')->textarea() ?>

<!-- No input needed for user_interaction_token - injected by JS -->

<div class="form-group">
    <?= Html::submitButton('Submit', ['class' => 'btn btn-primary']) ?>
</div>

<?php ActiveForm::end(); ?>

7. Yii2 configuration

In config/web.php or params.php add a strong secret key:

return [
    // ...
    'params' => [
        'formInteractionJwtSecret' => 'change-this-to-a-very-long-random-secret-key-you-generate',
    ],
];

8. Basic PHPUnit test for behavior validation

File: tests/unit/components/Behavior/FormInteractionJwtBehaviorTest.php

<?php
namespace tests\unit\components\Behavior;

use app\components\Behavior\FormInteractionJwtBehavior;
use Yii;
use PHPUnit\Framework\TestCase;

class FormInteractionJwtBehaviorTest extends TestCase
{
    protected $behavior;

    protected function setUp(): void
    {
        parent::setUp();

        // Mock Yii::$app->session
        $session = new \yii\web\Session();
        $session->open();
        Yii::$app->set('session', $session);

        $this->behavior = new FormInteractionJwtBehavior([
            'jwtSecret' => 'test-secret-key',
            'minFormTimeMs' => 1000,
        ]);

        // simulate nonce generation
        $session->set($this->behavior->sessionKey, '1234567890abcdef1234567890abcdef');
    }

    public function testTokenGenerationAndValidation()
    {
        $jwt = $this->behavior->generateInteractionToken();

        $this->assertIsString($jwt);

        // Call valid immediately should fail (too fast)
        $valid = $this->behavior->validateInteraction($jwt);
        $this->assertFalse($valid);

        // Sleep for 1.1 second to pass minFormTimeMs = 1000
        usleep(1100000);

        // Token should still be valid now (re-generate session key for replay)
        \Yii::$app->session->set($this->behavior->sessionKey, '1234567890abcdef1234567890abcdef');
        $valid = $this->behavior->validateInteraction($jwt);
        $this->assertTrue($valid);

        // Second attempt should fail because nonce removed on success
        $valid = $this->behavior->validateInteraction($jwt);
        $this->assertFalse($valid);
    }

    public function testInvalidTokens()
    {
        $invalidToken = 'invalid.token.string';
        $this->assertFalse($this->behavior->validateInteraction($invalidToken));
        $this->assertFalse($this->behavior->validateInteraction(null));
        $this->assertFalse($this->behavior->validateInteraction(''));
    }
}

Summary

    Uses JWT signed tokens with nonce + timestamp for strong tamper-proof anti-bot check.
    Signed token generated server side and sent to client on page load.
    Client sets hidden token field on first interaction.
    Server verifies token signature, nonce matching, and elapsed time before accepting form.
    Behavior + Asset bundle + JS are reusable and clean for Yii2.
    PHPUnit test demonstrates validation logic and replay protection.

If you want, I can also share a GitHub repo with this fully integrated for easy cloning and running out-of-the-box. Would you like that next?
```
Do you think you can take this conversation and write a complete proof of concept for helping to prevent bots and ai agents from abusing my systems/app?

could use:
```
declare(strict_types=1);

namespace app\helpers;

use Firebase\JWT\JWT;
use Firebase\JWT\Key;
use stdClass;// stdClass stands for "standard class". It is PHP’s generic, empty class.

use yii\base\UnknownPropertyException;
use \yii\base\InvalidArgumentException;

use app\helpers\ExceptionLogger;

/**
* PHP-JWT helper class for generating and validating JWT tokens
* @url https://jwt.io/
* @url https://github.com/firebase/php-jwt
*/
class JwtHelper
{
	private const ALGORITHM = 'HS256';
	
	/**
	* Retrieve the JWT secret key from environment variables
	* @return string
	* @throws \RuntimeException if key not set
	*/
	private static function getKey(): string
	{
		$key = $_ENV['JWT_SECRET_KEY'] ?? '';
		if ($key === false || empty($key))
		{
			throw new UnknownPropertyException('JWT_SECRET_KEY environment variable not set');
		}
		
		return $key;
	}
	
	/**
	* Generate JWT token for given user ID
	* @param int $userId
	* @return string
	*
	* Expiration time:
	* 7 days (604800)
	* 24 hours (86400)
	* 1 hour (3600)
	* 15 mins (900)
	*
	* Note: 15 mins x 60 sec = 900 seconds
	*/
	public static function generateToken(string $userKey, int $expireSeconds = 3600): string
	{
		$now = time();
		$payload = [
			'iss' => $_ENV['JWT_ISS'] ?? 'card-app',// Issuer
			'aud' => $_ENV['JWT_AUD'] ?? 'card-app-users',// Audience
			'iat' => $now,
			'nbf' => $now,
			'exp' => $now + $expireSeconds,
			'sub' => $userKey,
		];
		
		return JWT::encode($payload, self::getKey(), self::ALGORITHM);
	}
	
	/**
	* Validate JWT token string
	* @param string $token
	* @return stdClass|false Returns decoded token object or false if invalid
	*/
	public static function validateToken(string $token): stdClass|false
	{
		try
		{
			// Quick check for correct JWT format (3 parts separated by 2 dots)
			if (substr_count($token, '.') !== 2)
			{
				throw new InvalidArgumentException('Token format is invalid.');
			}
		
			/** @var stdClass $decoded */
			$decoded = JWT::decode($token, new Key(self::getKey(), self::ALGORITHM));
			
			return $decoded;
		}
		catch (\Throwable $e)
		{
			ExceptionLogger::log($e, 'helpers_jwtHelper_error_');
			
			return false;
		}
	}
}
```
with it. And fully explain how it will prevent bots and ai agents. pros/cons, etc.