Extract a ReCapcha challenge to be presented to a external user

BustRecapcha.php

<?php 
/*

PHP template to ask a recapcha challenge, present it to a user.

*/
<?php


class BustRecapcha {

	public function __construct(){
		$this->recapcha_key = "EDIT_HERE_WITH_OBSERVED_KEY";

		if (!isset($_GET['recaptcha_response_field']) && !isset($_POST['recaptcha_response_field'])){
			$r = $this->callNoScriptPage();
			if (is_array($r) && !empty($r)){
				$this->makeForm($r);
			}
		}else{
			// info will be in
		}

	}

	function callNoScriptPage(){

		$result = array();

		$url = "https://www.google.com/recaptcha/api/noscript?k=".$this->recapcha_key;

		$html = file_get_contents($url);

		preg_match('/src\="(.*)"/', $html, $matches);

		$result['image_url'] = "https://www.google.com/recaptcha/api/".$matches[1];

		preg_match('/value\="(.*)"/', $html, $matches);

		$result['recaptcha_challenge_field'] = $matches[1];

		return $result;
	}

	function makeForm($challenge_data){
?>
			<img src="<?php echo $challenge_data['image_url'] ?>">

			<input name="recaptcha_challenge_field" id="recaptcha_challenge_field" type="hidden" value="<?php echo $challenge_data['recaptcha_challenge_field']; ?>">

			<input name="recaptcha_response_field" id="recaptcha_response_field" type="text" autocomplete="off">

			<script>
			$("#recaptcha_response_field").keyup(function (e){
			    if (e.keyCode == 13) {
				//console.log($("#recaptcha_challenge_field").val());
				//console.log($("#recaptcha_response_field").val());
				// RE DO REQUEST HERE, WITH recaptcha_challenge_field and recaptcha_response_field POST FIELDS
			    }
			});
			</script>


		<?php
		die();
	}

}