<?php

/**
 * @file CaptchaDAO.inc.php
 *
 * Copyright (c) 2000-2008 John Willinsky
 * Distributed under the GNU GPL v2. For full terms see the file docs/COPYING.
 *
 * @package captcha
 * @class CaptchaDAO
 *
 * Class for Captcha DAO.
 * Operations for retrieving and modifying Captcha keys.
 *
 * $Id: CaptchaDAO.inc.php,v 1.5 2008/04/04 17:06:45 asmecher Exp $
 */

import('captcha.Captcha');

class CaptchaDAO extends DAO {
	/**
	 * Retrieve captchas by session id
	 * @param $userId int
	 * @return Captcha objects array
	 */
	function &getCaptchasBySessionId($sessionId) {
		$captchas = array();

		$result = &$this->retrieve('SELECT * FROM captchas WHERE session_id = ?', $sessionId);

		while (!$result->EOF) {
			$captchas[] = &$this->_returnCaptchaFromRow($result->GetRowAssoc(false));
			$result->moveNext();
		}

		$result->Close();
		unset($result);

		return $captchas;
	}

	/**
	 * Retrieve expired captchas
	 * @param $lifespan int optional number of seconds a captcha should last
	 * @return Captcha objects array
	 */
	function &getExpiredCaptchas($lifespan = 86400) {
		$captchas = array();
		$threshold = time() - $lifespan;

		$result = &$this->retrieve('SELECT c.* FROM captchas c LEFT JOIN sessions s ON (s.session_id = c.session_id) WHERE s.session_id IS NULL OR c.date_created <= ' . $this->datetimeToDB($threshold));

		while (!$result->EOF) {
			$captchas[] = &$this->_returnCaptchaFromRow($result->GetRowAssoc(false));
			$result->moveNext();
		}

		$result->Close();
		unset($result);

		return $captchas;
	}

	/**
	 * Retrieve Captcha by captcha id
	 * @param $captchaId int
	 * @return Captcha object
	 */
	function &getCaptcha($captchaId) {
		$result = &$this->retrieve(
			'SELECT * FROM captchas WHERE captcha_id = ?', $captchaId
		);

		$captcha = null;
		if ($result->RecordCount() != 0) {
			$captcha = &$this->_returnCaptchaFromRow($result->GetRowAssoc(false));
		}

		$result->Close();
		unset($result);

		return $captcha;
	}	

	/**
	 * Creates and returns an captcha object from a row
	 * @param $row array
	 * @return Captcha object
	 */
	function &_returnCaptchaFromRow($row) {
		$captcha = &new Captcha();
		$captcha->setCaptchaId($row['captcha_id']);
		$captcha->setSessionId($row['session_id']);
		$captcha->setValue($row['value']);
		$captcha->setDateCreated($this->datetimeFromDB($row['date_created']));

		HookRegistry::call('CaptchaDAO::_returnCaptchaFromRow', array(&$captcha, &$row));

		return $captcha;
	}

	/**
	 * inserts a new captcha into captchas table
	 * @param Captcha object
	 * @return int ID of new captcha
	 */
	function insertCaptcha(&$captcha) {
		$captcha->setDateCreated(Core::getCurrentDate());
		$this->update(
			sprintf('INSERT INTO captchas
				(session_id, value, date_created)
				VALUES
				(?, ?, %s)',
				$this->datetimeToDB($captcha->getDateCreated())),
			array(
				$captcha->getSessionId(),
				$captcha->getValue()
			)
		);

		$captcha->setCaptchaId($this->getInsertCaptchaId());
		return $captcha->getCaptchaId();
	}

	/**
	 * Get the ID of the last inserted captcha.
	 * @return int
	 */
	function getInsertCaptchaId() {
		return $this->getInsertId('captchas', 'captcha_id');
	}	

	/**
	 * removes an captcha from captchas table
	 * @param Captcha object
	 */
	function deleteCaptcha(&$captcha) {
		$result = $this->update('DELETE FROM captchas WHERE captcha_id = ?', $captcha->getCaptchaId());
	}

	/**
	 * updates a captcha
	 * @param Captcha object
	 */
	function updateCaptcha(&$captcha) {
		$this->update(
			sprintf('UPDATE captchas
				SET
					session_id = ?,
					value = ?,
					date_created = %s
				WHERE captcha_id = ?',
				$this->datetimeToDB($captcha->getDateCreated())),
			array(
				$captcha->getSessionId(),
				$captcha->getValue(),
				$captcha->getCaptchaId()
			)
		);
	}
}

?>