<?php
/**
* This file contains generate captcha code.
*
* @author  Tech Banker
* @package wp-captcha-booster/includes
* @version 1.0.0
*/

if(!defined("ABSPATH")) exit; //exit if accessed directly
global $wpdb,$captcha_array,$meta_data_array;

//defining the image type to be shown in browser window
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
header("Content-Type: image/png");

//Settings: You can customize the captcha here
if(file_exists(CAPTCHA_BOOSTER_DIR_PATH . "includes/captcha-setting.php"))
{
	include_once CAPTCHA_BOOSTER_DIR_PATH . "includes/captcha-setting.php";
}

switch($captcha_type)
{
	case "only_digits":
		$charset = "0123456789";
	break;

	case "only_alphabets":
		if($text_case == "random")
		{
			$charset = "ABCDEFGHKLMNPRSTUVWYZabcdefghklmnprstuvwyz";
		}
		elseif($text_case == "upper_case")
		{
			$charset = "ABCDEFGHKLMNPRSTUVWYZ";
		}
		else
		{
			$charset = "abcdefghklmnprstuvwyz";
		}
	break;

	case "alphabets_and_digits":
		if($text_case == "random")
		{
			$charset = "ABCDEFGHKLMNPRSTUVWYZabcdefghklmnprstuvwyz0123456789";
		}
		elseif($text_case == "upper_case")
		{
			$charset = "ABCDEFGHKLMNPRSTUVWYZ0123456789";
		}
		else
		{
			$charset = "abcdefghklmnprstuvwyz0123456789";
		}
	break;
}

$captcha_enable_space = 5;
$code = "";
$code_string = "";
$space = "";
$captcha_fonts = CAPTCHA_BOOSTER_DIR_PATH."fonts/font.ttf";
$signature_fonts = CAPTCHA_BOOSTER_DIR_PATH."fonts/font-signature.ttf";
if($captcha_enable_space == 1) $space = " ";
$count = 0;
while ($count < $captcha_character)
{
	$str = substr($charset, mt_rand(0, strlen($charset)-1), 1);
	$code_string .= $str.$space;
	$code .= $str;
	$count++;
}

/*create image*/
$size_font = $captcha_height * ($captcha_font_style[0]/50);
$image = imagecreatetruecolor($captcha_width, $captcha_height);
$tmpimg_distortion =imagecreate($captcha_width * 5, $captcha_height * 5);

/* setting the captcha text transparency*/
if($text_transparency>0)
{
	$alpha = intval($text_transparency / 100 * 127);
	$arr_text_color = hexrgb($captcha_font_style[1]);
	$image_text_color = imagecolorallocatealpha($image, $arr_text_color["red"], $arr_text_color["green"], $arr_text_color["blue"], $alpha);
}
else
{
	$arr_text_color = hexrgb($captcha_font_style[1]);
	$image_text_color = imagecolorallocate($image, $arr_text_color["red"], $arr_text_color["green"], $arr_text_color["blue"]);
}
/* Displaying background image for Captcha*/
set_background($image,$captcha_width, $captcha_height, $captcha_background);

$textbox = imagettfbbox($size_font, 0, $captcha_fonts, $code_string);
$width = ($captcha_width - $textbox[4])/2;
$height = ($captcha_height - $textbox[5])/2;
$width_shadow = ($captcha_width - $textbox[4])/2.5;

/* create shadow for captcha text*/
$arr_shadow_color = hexrgb($text_shadow_color);
$image_shadow_color = imagecolorallocate($image, $arr_shadow_color["red"], $arr_shadow_color["green"], $arr_shadow_color["blue"]);
imagettftext($image, $size_font, 2, $width_shadow, $height, $image_shadow_color, $captcha_fonts, $code_string);
imagettftext($image, $size_font, 2, $width, $height, $image_text_color, $captcha_fonts , $code_string);

/*generating lines randomly in background of image */
$arr_line_color = hexrgb($lines_color);
$image_line_color = imagecolorallocate($image, $arr_line_color["red"], $arr_line_color["green"], $arr_line_color["blue"]);
for( $count=0; $count<$lines; $count++ )
{
	imagesetthickness($image, rand(1,3));
	imageline($image, mt_rand(0,$captcha_width), mt_rand(0,$captcha_height),mt_rand(0,$captcha_width), mt_rand(0,$captcha_height), $image_line_color);
}

/* generating the dots randomly in background */

$arr_dots_color = hexrgb($noise_color);
$image_dots_color = imagecolorallocate($image, $arr_dots_color["red"], $arr_dots_color["green"], $arr_dots_color["blue"]);
for($count=0; $count<$noise_level; $count++ )
{
	imagefilledellipse($image, mt_rand(0,$captcha_width),	mt_rand(0,$captcha_height), 2, 3, $image_dots_color);
}

/* create signature on captcha */
$arr_signature_color = hexrgb($signature_style[1]);
$image_signature_color = imagecolorallocate($image, $arr_signature_color["red"], $arr_signature_color["green"], $arr_signature_color["blue"]);
if(trim($signature_text) != "")
{
	$bbox = imagettfbbox($signature_style[0], 0, $signature_fonts, $signature_text);
	$textlen = $bbox[2] - $bbox[0];
	$width = $captcha_width - $textlen - 5;
	$height = $captcha_height - 3;

	imagettftext($image, $signature_style[0], 0, $width, $height, $image_signature_color, $signature_fonts,  $signature_text);
}

/* generating background image for Captcha*/
function set_background($image,$captcha_width, $captcha_height, $captcha_background)
{
	$bg_img = CAPTCHA_BOOSTER_DIR_PATH . "/backgrounds/".$captcha_background;
	$dat = @getimagesize($bg_img);
	if($dat == false)
	{
		return;
	}
	switch($dat[2])
	{
		case 1:  $newim = @imagecreatefromgif($bg_img); break;
		case 2:  $newim = @imagecreatefromjpeg($bg_img); break;
		case 3:  $newim = @imagecreatefrompng($bg_img); break;
		default: return;
	}
	if(!$newim) return;
	imagecopyresampled($image, $newim, 0, 0, 0, 0,$captcha_width, $captcha_height, imagesx($newim), imagesy($newim));
}

/*Show captcha image in the page html page */
imagepng($image);
imagedestroy($image);
$_SESSION["captcha_code"][] = $code;

/*change hexa values into colors*/
function hexrgb ($hexstr)
{
	$int = hexdec($hexstr);
	return array("red" => 0xFF & ($int >> 0x10),"green" => 0xFF & ($int >> 0x8),"blue" => 0xFF & $int);
}
?>