<?
/**
* CaptchaV2 File
* Generates CAPRCHA Numbers and Chars Image
* @author Albert Demeter <borex8@hotmail.com>
* @version 2.0
* GNU General Public License (Version 2, October 2nd, 2005)
*
* based on Hadar Porat's Captcha Numbers class v.1.5 <hpman28@gmail.com>
*
* This program is free software; you can redistribute
* it and/or modify it under the terms of the GNU
* General Public License as published by the Free
* Software Foundation; either version 2 of the License,
* or (at your option) any later version.
*
* This program is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/

/**
* CaptchaNumbersV2 Class
* @access public
* @author Albert Demeter <borex8@hotmail.com>
* @version 2.0
*/

class CaptchaNumbersV2 {
	var $length = 6;
	var $font = 'arial';
	var $size = 15;
	var $type = 'png';
	var $height = 40;
	var $width = 80;
	var $grid = 7;
	var $string = '';
	var $captchaType = 'mixed';

	/**
	* @return void
	* @param int $length string length
	* @param int $size font size
	* @param String $type image type
	* @param String $captchaType text contain digits, chars or mixed
	* @desc generate the main image
	*/	
	function CaptchaNumbersV2($length = '', $size = '', $type = '', $captchaType = '') {

		if ($length!='') $this -> length = $length;
		if ($size!='') $this -> size = $size;
		if ($type!='') $this -> type = $type;
		if ($captchaType!='') $this -> captchaType = $captchaType;

		$this -> width = $this -> length * $this -> size + $this -> grid + $this -> grid;
		$this -> height = $this -> size + (2 * $this -> grid);

		$this -> generateString();
	}

	/**
	* @return void
	* @desc display captcha image
	*/		
	function display() {
		$this -> sendHeader();
		$image = $this -> generate();

		switch ($this-> type) {
			case 'jpeg': imagejpeg($image); break;
			case 'png':  imagepng($image);  break;
			case 'gif':  imagegif($image);  break;
			default:     imagepng($image);  break;
		}
	}

	/**
	* @return Image
	* @desc generate the image
	*/		
	function generate() {
		$image = ImageCreate($this -> width, $this -> height) or die("Cannot Initialize new GD image stream");
		
		// colors
		$background_color = ImageColorAllocate($image, 240, 240, 240);
		$net_color_1 = ImageColorAllocate($image, 10, 200, 10);
		$net_color_2 = ImageColorAllocate($image, 200, 10, 10);
		$stringcolor_1 = ImageColorAllocate($image, 150, 150, 150);
		$stringcolor_2 = ImageColorAllocate($image, 120, 120, 250);


		for ($i = $this -> grid; $i < $this -> height; $i+=$this -> grid) 
		 	if ($i%2) ImageLine($image, 0, $i, $this -> width, $i, $net_color_1);
				 else ImageLine($image, 0, $i, $this -> width, $i, $net_color_2);

		// make the text
		$str = $this -> getString();
		for($i = 0, $n = strlen($str); $i < $n; $i++)
		{
		 	if ($i%2) ImageTTFText($image, $this -> size, 0, $this -> grid + $this -> size * $i, $this -> size + $this -> grid - rand(0, 5), $stringcolor_1, $this -> font, $str{$i} );
				 else ImageTTFText($image, $this -> size, 0, $this -> grid + $this -> size * $i, $this -> size + $this -> grid + rand(0, 5), $stringcolor_2, $this -> font, $str{$i} );
		}
		
		// grid
		for ($i = $this -> grid; $i < $this -> width; $i+=$this -> grid) 
		 	if ($i%2) ImageLine($image, $i, 0, $i, $this -> height, $net_color_1);
				 else ImageLine($image, $i, 0, $i, $this -> height, $net_color_2);

		return $image;
	}


	/**
	* @return String
	* @desc generate the string
	*/	
	function generateString() {
		$string = $this->create_random_value($this -> length, $this -> captchaType);
		$this -> string = $string;
		return true;
	}


	/**
	* @return void
	* @desc send image header
	*/
	function sendHeader() {
		header('Content-type: image/' . $this -> type);
	}
	
	/**
	* @return String
	* @desc return the string
	*/	
	function getString() {
		return $this -> string;
	}
	
	
  function create_random_value($length, $type = 'mixed') {
    if ( ($type != 'mixed') && ($type != 'chars') && ($type != 'digits')) return false;

    $rand_value = '';
    while (strlen($rand_value) < $length) {
      if ($type == 'digits') {
        $char = rand(0,9);
      } else {
        $char = chr(rand(0,255));
      }
      if ($type == 'mixed') {
        if (eregi('^[a-z0-9]$', $char)) $rand_value .= $char;
      } elseif ($type == 'chars') {
        if (eregi('^[a-z]$', $char)) $rand_value .= $char;
      } elseif ($type == 'digits') {
        if (ereg('^[0-9]$', $char)) $rand_value .= $char;
      }
    }

    return $rand_value;
  }	
}