<?php

class Authcode {

    var $CI;
    var $fontPath; //字体路径
    var $image;
    var $charLen = 4; //生成几位验证码
    var $arrChr = array("abcdefghigklmnopqrstuvwxyz1234567890"); //验证码字符
    var $width = 83; //图片宽
    var $height = 24; //图片高
    var $bgcolor = "#ffffff"; //背景色
    var $showNoisePix = false; //生成杂点
    var $noiseNumPix = 10; //生成杂点数量
    var $showNoiseLine = false; //生成杂线
    var $noiseNumLine = 2; //生成杂线数量
    var $showBorder = false; //边框，当杂点、线一起作用的时候，边框容易受干扰
    var $borderColor = "#000000";

    function __construct() {
        $this->CI = & get_instance();
        $this->fontPath = realpath(dirname(__FILE__) . '/fonts/');    //字体文件
        $this->arrChr = array_merge(range(1, 9), range('a', 'z')); //数字字母验证码
        //$this->arrChr         = range('A', 'Z');//纯字母验证码
        //$this->arrChr = range(0, 9);//纯数字验证码
    }

    /**
     * 显示验证码
     *
     */
    function show() {

        $this->image = imageCreate($this->width, $this->height);
        $this->back = $this->getColor($this->bgcolor);

        imageFilledRectangle($this->image, 0, 0, $this->width, $this->height, $this->back);

        $size = $this->width / $this->charLen - 4;
        if ($size > $this->height) {
            $size = $this->height;
        }
        $left = ($this->width - $this->charLen * ($size + $size / 10)) / $size + 5;
        $code = '';
        for ($i = 0; $i < $this->charLen; $i ++) {
            $randKey = rand(0, count($this->arrChr) - 1);
            $randText = $this->arrChr[$randKey];
            $code .= $randText;
            $textColor = imageColorAllocate($this->image, rand(0, 100), rand(0, 100), rand(0, 100));
            //$font = $this->fontPath . '/' . rand(1, 5) . ".ttf";
            $font = $this->fontPath . '/' . "arial" . ".ttf";
            $randsize = rand($size - $size / 10, $size + $size / 10);
            $location = $left + ($i * $size + $size / 10);
            @imagettftext($this->image, $randsize, rand(- 18, 18), $location, rand($size - $size / 10, $size + $size / 10) + 2, $textColor, $font, $randText);
        }

        if ($this->showNoisePix == true) {
            $this->setNoisePix();
        }
        if ($this->showNoiseLine == true) {
            $this->setNoiseLine();
        }
        if ($this->showBorder == true) {
            $this->borderColor = $this->getColor($this->borderColor);
            imageRectangle($this->image, 0, 0, $this->width - 1, $this->height - 1, $this->borderColor);
        }

        $this->CI->session->set_userdata('auth_code', $code);
        ob_clean();
        header("Content-type: image/jpeg");
        imagejpeg($this->image);
        imagedestroy($this->image);
    }

    /**
     * 显示验证码的JS调用
     *
     */
    function showScript() {
        //显示验证码
        echo "var img_src = '/imgauthcode/show/?';\n";
        echo "document.writeln('<img id=\"img_authcode\" src=\"' + img_src + Math.random() + '\" style=\"cursor:hand;\" onclick=\"this.src=img_src + Math.random();\" alt=\"点击更换图片\">');";
    }

    /**
     * 检查验证码是否正确
     *
     * @param string $auth_code
     * @return bool
     */
    function check($auth_code = null) {
        return ($this->CI->session->userdata('auth_code') && $auth_code) ? ($this->CI->session->userdata('auth_code') === $auth_code) : false;
    }

//eregi_replace()完美替代
    function eregirePlace_guy($a = '', $b = '', $c = '') {
        return preg_replace('/' . $a . '/', $b, $c);
    }

    function getColor($color) {
        $color = $this->eregirePlace_guy("^#", "", $color); //替代掉eregi_replace
        $r = $color[0] . $color[1];
        $r = hexdec($r);
        $b = $color[2] . $color[3];
        $b = hexdec($b);
        $g = $color[4] . $color[5];
        $g = hexdec($g);
        $color = imagecolorallocate($this->image, $r, $b, $g);
        return $color;
    }

    function setNoisePix() {
        for ($i = 0; $i < $this->noiseNumPix; $i ++) {
            $randColor = imageColorAllocate($this->image, rand(0, 255), rand(0, 255), rand(0, 255));
            imageSetPixel($this->image, rand(0, $this->width), rand(0, $this->height), $randColor);
        }
    }

    function setNoiseLine() {
        for ($i = 0; $i < $this->noiseNumLine; $i ++) {
            $randColor = imageColorAllocate($this->image, rand(0, 255), rand(0, 255), rand(0, 255));
            imageline($this->image, rand(1, $this->width), rand(1, $this->height), rand(1, $this->width), rand(1, $this->height), $randColor);
        }
    }

}

?>