<?php
/**
 * Copyright 2009-2014, Cake Development Corporation (http://cakedc.com)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright Copyright 2009-2014, Cake Development Corporation (http://cakedc.com)
 * @license MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

App::uses('HttpSocket', 'Network/Http');

/**
 * CakePHP Recaptcha component
 *
 * @package recaptcha
 * @subpackage recaptcha.controllers.components
 */

class RecaptchaComponent extends Component {

/**
 * Name
 *
 * @var string
 */
	public $Controller = null;

/**
 * Recaptcha API Url
 *
 * @var string
 */
	public $apiUrl = 'http://www.google.com/recaptcha/api/verify';

/**
 * Private API Key
 *
 * @var string
 */
	public $privateKey = '';

/**
 * Error coming back from Recaptcha
 *
 * @var string
 */
	public $error = null;

/**
 * Actions that should automatically checked for a recaptcha input
 *
 * @var array
 */
	public $actions = array();

/**
 * Settings
 *
 * @var array
 */
	public $settings = array();

/**
 * Default Options
 *
 * @var array
 */
	protected $_defaults = array(
		'errorField' => 'recaptcha',
		'actions' => array()
	);

 /**
 * Constructor
 *
 * @param ComponentCollection $collection A ComponentCollection this component can use to lazy load its components
 * @param array $settings Array of configuration settings
 * @return RecaptchaComponent
 */
	public function __construct(ComponentCollection $collection, $settings = array()) {
		parent::__construct($collection, $settings);
		$this->Controller = $collection->getController();
		$this->_defaults['modelClass'] = $this->Controller->modelClass;
		$this->settings = array_merge($this->_defaults, $settings);
		$this->actions = array_merge($this->actions, $this->settings['actions']);
		unset($this->settings['actions']);
	}

/**
 * Callback
 *
 * @param Controller $controller Controller with components to initialize
 * @param array $settings Array of configuration settings
 * @throws Exception Throws an exception if Recaptchas config is not present
 * @return void
 */
	public function initialize(Controller $controller, $settings = array()) {
		if ($controller->name === 'CakeError') {
			return;
		}
		$this->privateKey = Configure::read('Recaptcha.privateKey');
		$this->Controller = $controller;

		if (!isset($this->Controller->helpers['Recaptcha.Recaptcha'])) {
			$this->Controller->helpers[] = 'Recaptcha.Recaptcha';
		}

		if (empty($this->privateKey)) {
			throw new Exception(__d('recaptcha', "You must set your private Recaptcha key using Configure::write('Recaptcha.privateKey', 'your-key');!", true));
		}
	}

/**
 * Callback
 *
 * @param Controller $controller Controller with components to initialize
 * @return void
 */
	public function startup(Controller $controller) {
		extract($this->settings);
		$this->Controller->helpers[] = 'Recaptcha.Recaptcha';
		$this->Controller->{$modelClass}->Behaviors->load('Recaptcha.Recaptcha', array(
			'field' => $errorField
		));

		$this->Controller->{$modelClass}->recaptcha = true;
		if (in_array($this->Controller->action, $this->actions)) {
			if (!$this->verify()) {
				$this->Controller->{$modelClass}->recaptcha = false;
				$this->Controller->{$modelClass}->recaptchaError = $this->error;
			}
		}
	}

/**
 * Verifies the recaptcha input
 *
 * Please note that you still have to pass the result to the model and do
 * the validation there to make sure the data is not saved!
 *
 * @return boolean True if the response was correct
 */
	public function verify() {
		if (isset($this->Controller->request->data['recaptcha_challenge_field']) &&
			isset($this->Controller->request->data['recaptcha_response_field'])) {

			$response = $this->_getApiResponse();
			$response = explode("\n", $response->body());

			if (empty($response[0])) {
				$this->error = __d('recaptcha', 'Invalid API response, please contact the site admin.', true);
				return false;
			}

			if ($response[0] === 'true') {
				return true;
			}

			if ($response[1] === 'incorrect-captcha-sol') {
				$this->error = __d('recaptcha', 'Incorrect captcha', true);
			} else {
				$this->error = $response[1];
			}
		}
		return false;
	}

/**
 * Queries the Recaptcha API and and returns the raw response
 *
 * @return string
 */
	protected function _getApiResponse() {
		$Socket = new HttpSocket();
		return $Socket->post($this->apiUrl, array(
			'privatekey' => $this->privateKey,
			'remoteip' => env('REMOTE_ADDR'),
			'challenge' => $this->Controller->request->data['recaptcha_challenge_field'],
			'response' => $this->Controller->request->data['recaptcha_response_field']
		));
	}

}