<?php

class JsonPatternMatcher {

private $patterns = [];

private $rateLimit = 10; // Max requests per minute

private $requestTimestamps = [];

public function __construct(array $patterns) {

$this->patterns = $patterns;

}

public function match(string $jsonPayload): ?string {

// Check Rate Limit

$now = time();

if (isset($this->requestTimestamps[$this->getTimestamp($jsonPayload)]) &&

$now - $this->requestTimestamps[$this->getTimestamp($jsonPayload)] < 60) {

return 'Rate limit exceeded.';

}

$this->requestTimestamps[$this->getTimestamp($jsonPayload)] = $now;

foreach ($this->patterns as $pattern => $regex) {

if (preg_match($regex, $jsonPayload)) {

return $pattern; // Return the matching pattern

}

}

return null; // No pattern matched

}

private function getTimestamp(string $jsonPayload): int {

// Use a hash of the JSON payload as a timestamp

return hash('sha256', $jsonPayload);

}

}

// Example Usage

$patterns = [

'user_creation' => '/{"action": "user_creation", "username": "[a-zA-Z0-9]+"/i',

'product_update' => '/{"action": "product_update", "product_id": \\d+}/i',

'order_placement' => '/{"action": "order_placement", "order_id": \\d+}/i'

];

$matcher = new JsonPatternMatcher($patterns);

//Test cases

$json1 = '{"action": "user_creation", "username": "john_doe"}';

$json2 = '{"action": "product_update", "product_id": 123}';

$json3 = '{"action": "order_placement", "order_id": 456}';

$json4 = '{"action": "unknown"}';

$json5 = '{"action": "user_creation", "username": "jane123"}'; //same as json1

echo "Testing JSON1: " . $matcher->match($json1) . "\n";

echo "Testing JSON2: " . $matcher->match($json2) . "\n";

echo "Testing JSON3: " . $matcher->match($json3) . "\n";

echo "Testing JSON4: " . $matcher->match($json4) . "\n";

echo "Testing JSON5: " . $matcher->match($json5) . "\n";

//Simulate rate limiting

for ($i = 0; $i < 12; $i++) {

echo "Testing JSON1 (rate limited): " . $matcher->match($json1) . "\n";

}

?>