<?php

/**
 * 验证码驱动
 * @author  Devil
 * @version v_1.0.0
 */
class VerifyLibrary
{
    private $rand_string;
    private $img;

    /**
     * [__construct 构造方法]
     */
    public function __construct()
    {
        /* 验证码生成 */
        $this->rand_string = $this->GetRandString();
    }

    /**
     * [GetVerify 获取当前验证码]
     */
    public function GetVerify()
    {
        return $this->rand_string;
    }

    /**
     * [GetVerifyImg 验证码生成]
     * @return [string] [验证码]
     */
    public function GetVerifyImg() {
        $this->img = imagecreatetruecolor(63, 22); //创建一个画布（真色彩）

        // 画背景
        $back_color = imagecolorallocate($this->img, 235, 236, 237); 
        imagefilledrectangle($this->img,0,0,63,22,$back_color);

        //加入干扰，画出多条线
        $this->InterferenceLine();

        //加入干扰，画出点    
        $this->InterferencePoint();

        //将生成好的字符串写入图像
        $fgcolor = imagecolorallocate($this->img, rand(0,200), rand(0,255), rand(0,255));
        imagestring($this->img, 5, 5, 5, strtoupper($this->rand_string), $fgcolor);

        //输出图像
        header('Content-Type: image/gif');
        imagegif($this->img);

        //销毁图像
        imagedestroy($this->img);
    }

    /**
     * [InterferencePoint 加入干扰，画点]
     */
    private function InterferencePoint()
    {
        for($i=0; $i<200; $i++){ 
            $bgcolor = imagecolorallocate($this->img, rand(0,255), rand(0,255), rand(0,255));  //产生随机的颜色
            imagesetpixel($this->img, rand()%90, rand()%30, $bgcolor); 
        }
    }

    /**
     * [InterferenceLine 加入干扰，画出多条线]
     */
    private function InterferenceLine()
    {
        for($i=0; $i<5; $i++)
        {
            $bgcolor=imagecolorallocate($this->img, rand(0,255), rand(0,255), rand(0,255));  //产生随机的颜色
            imageline($this->img, rand(10,90), 0, rand(10,90), 20, $bgcolor);
        }
    }

    /**
     * [GetRandString 生成随机数值]
     * @param [int]     $number [随机数位数]
     * @return[string]          [返回小写的随机数值]
     */
    private function GetRandString($number = 6)
    {
        $origstr = '3456789abxdefghijkmnprstuvwxy';
        $verifystring = '';
        $len = strlen($origstr);
        for($i=0; $i<$number; $i++) {
            $index = mt_rand(0, $len-1);
            $char = $origstr[$index];
            $verifystring .= $char;
        }
        return $verifystring;
    }

}
?>