<?php
/**
*
* @package VC
* @version $Id: $
* @copyright (c) 2008 phpBB Group
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
*
*/

/**
* @ignore
*/
if (!defined('IN_PHPBB'))
{
	exit;
}


class captcha
{
	var $width = 360;
	var $height = 96;

	/**
	* Create the image containing $code with a seed of $seed
	*/
	function execute($code, $seed)
	{
		global $phpbb_root_path, $config;
		srand($seed);
		mt_srand($seed);
		
		// Create image
		$capt = new yes_no_captcha();
		$capt->init($code, $this->width, $this->height, $phpbb_root_path . 'images/captcha/smilies');
		$img = $capt->paint();

		// Send image
		header('Content-Type: image/png');
		header('Cache-control: no-cache, no-store');
		imagepng($img);
		imagedestroy($img);
	}

	
}

/**
* @package VC
*/
class yes_no_captcha
{
	var $letter_img = array();
	var $path;
	var $img;
	var $width = 0;
	var $height = 0;
	var $x_per_letter;
	
	/** 
	* Init method
	* @param string $code The correct answer
	* @param int $width The number of pixels in the x direction
	* @param int $height The number of pixels in the y direction
	* @param string $path The path to load the images one. Needs to contain directories "correct" and "incorrect" with right respectively wrong pictures
	*/
	function init($code, $width, $height, $path)
	{
		global $phpbb_root_path, $phpEx;
		
		$this->width = $width;
		$this->height = $height;
		$this->path = $path;
		
		$this->img = imagecreatetruecolor($this->width, $this->height);
		if (!function_exists('filelist'))
		{
			include($phpbb_root_path . 'includes/functions_admin.' . $phpEx);
		}
		$images = filelist($phpbb_root_path . $path);
		$code_len = strlen($code);
		$anticode_len = mt_rand($code_len - 1, $code_len + 1);
		$rand_str = md5(mt_rand(0, 2000000000));
		$rand_str = str_replace('0', 'Z', strtoupper(base_convert($rand_str, 16, 35)));
		$anticode = substr($rand_str, 0, $anticode_len);
		$codes = array(
			'correct' => $code,
			'incorrect' => $anticode,
		);

		$letters_correct = 0;
		$letters_incorrect = 0;
		while($letters_correct < strlen($codes['correct']) || $letters_incorrect < strlen($codes['incorrect']))
		{
			$which = ($letters_correct < strlen($codes['correct']) && $letters_incorrect < strlen($codes['incorrect']) ? mt_rand(0,1) : ($letters_correct < strlen($codes['correct'])) ? 1 : 0);
			if ($which)
			{
				$name = 'correct';
				$i = $letters_correct++;

			}
			else
			{
				$name = 'incorrect';
				$i = $letters_incorrect++;
			}
			$this->letter_img[] = array(
								'letter'		=> $codes[$name][$i],
								'image'			=> $name . '/'. ($images[$name . '/'][mt_rand(0, count($images[$name . '/']) -1)]),
			);
		}
		
		
		$this->x_per_letter = floor($this->width / count($this->letter_img));
	}
	
	function paint()
	{
		$count = count($this->letter_img);
		for ($index = 0; $index < $count; $index ++)
		{
			$this->write_letter($index);
		}
		return $this->img;
	}
	
	function write_letter($index)
	{
		$imgfile = $this->path . '/' . $this->letter_img[$index]['image'];
		$imagedata = getimagesize($imgfile);
		switch ($imagedata[2])
		{
			case 1 : 
					$img = imagecreatefromgif($imgfile);
					break;
									
			case 2 : 
					$img = imagecreatefromjpeg($imgfile);
					break;
												
			case 3 : 
					$img = imagecreatefrompng($imgfile);
					break;
		
			default : return false;
		}
		$black = imagecolorallocate($this->img, 0, 0, 0);
		$img_rot = imagerotate($img, mt_rand(0, 30) - 15, $black);
		$position_x = $this->x_per_letter * $index;
		
		$color = imagecolorallocate($img_rot, 0, 10, 245);
		imagecopyresized($this->img, $img_rot, $position_x, 0, 0, 0, $this->x_per_letter, $this->height / 2, imagesx($img_rot), imagesy($img_rot));
		imagestring($this->img, 5, $position_x + mt_rand(5,10), $this->height / 2 + mt_rand(5,10), $this->letter_img[$index]['letter'], $color);
		imagedestroy($img);
		imagedestroy($img_rot);
	}
}

?>