<?php
namespace Plugin;
use Hood\Session;
class Captcha {

    private static $V = array(
        "a",
        "e",
        "i",
        "o",
        "u",
        "y"
    );

    private static $VN = array(
        "a",
        "e",
        "i",
        "o",
        "u",
        "y",
        "2",
        "3",
        "4",
        "5",
        "6",
        "7",
        "8",
        "9"
    );

    private static $C = array(
        "b",
        "c",
        "d",
        "f",
        "g",
        "h",
        "j",
        "k",
        "m",
        "n",
        "p",
        "q",
        "r",
        "s",
        "t",
        "u",
        "v",
        "w",
        "x",
        "z"
    );

    private static $CN = array(
        "b",
        "c",
        "d",
        "f",
        "g",
        "h",
        "j",
        "k",
        "m",
        "n",
        "p",
        "q",
        "r",
        "s",
        "t",
        "u",
        "v",
        "w",
        "x",
        "z",
        "2",
        "3",
        "4",
        "5",
        "6",
        "7",
        "8",
        "9"
    );
    
    private $_width = 160;
    private $_height = 60;
    private $_fs = 28;
    private $_dotNoiseLevel = 50;
    private $_lineNoiseLevel = 5;
    private $_wordLen = 6;
    
    private $_useNumbers = true;
    /**
     * Generate new random word
     *
     * @return string
     */
    protected function _generateWord() {
        $word = '';
        $wordLen = $this->getWordLen ();
        $vowels = $this->_useNumbers ? self::$VN : self::$V;
        $consonants = $this->_useNumbers ? self::$CN : self::$C;
        
        for($i = 0; $i < $wordLen; $i = $i + 2) {
            $consonant = $consonants [array_rand ( $consonants )];
            $vowel = $vowels [array_rand ( $vowels )];
            $word .= $consonant . $vowel;
        }
        if (strlen ( $word ) > $wordLen) {
            $word = substr ( $word, 0, $wordLen );
        }
        return $word;
    }
    
    public function getWordLen() {
        return $this->_wordLen;
    }
    
    /**
     * 设置验证码长度
     * 
     * @param string $wordLen
     * @return \Plugin\Captcha
     */
    public function setWordLen($wordLen) {
        $this->_wordLen = $wordLen;
        return $this;
    }
    
    /**
     * 获取图像宽度
     * 
     * @return int
     */
    public function getWidth() {
        return $this->_width;
    }
    
    /**
     * 获取图像高度
     *
     * @return int
     */
    public function getHeight() {
        return $this->_height;
    }
    
    /**
     * 设置图像宽度
     * 
     * @param int $width
     * @return \Plugin\Captcha
     */
    public function setWidth($width) {
        $this->_width = $width;
        return $this;
    }
    
    /**
     * 设置图像高度
     * 
     * @param int $height
     * @return \Plugin\Captcha
     */
    public function setHeight($height) {
        $this->_height = $height;
        return $this;
    }
    /**
     * 
     */
    public function getFontSize() {
        return $this->_fs;
    }
    public function setFontSize($fs) {
        $this->_fs = $fs;
        return $this;
    }
    
    /**
     * 设置干扰点
     * 
     * @param string $noise
     * @return \Plugin\Captcha
     */
    public function setDotNoiseLevel($noise = 100) {
        $this->_dotNoiseLevel = $noise;
        return $this;
    }
    
    /**
     * 设置干扰线
     * 
     * @param string $noise
     * @return \Plugin\Captcha
     */
    public function setLineNoiseLevel($noise = 5) {
        $this->_lineNoiseLevel = $noise;
        return $this;
    }
    
    /**
     * 获取干扰点
     * 
     * @return string
     */
    public function getDotNoiseLevel() {
        return $this->_dotNoiseLevel;
    }
    
    /**
     * 获取干扰线
     * 
     * @return string
     */
    public function getLineNoiseLevel() {
        return $this->_lineNoiseLevel;
    }
    
    /**
     * Generate random frequency
     * 
     * @return float
     */
    protected function _randomFreq() {
        return mt_rand ( 700000, 1000000 ) / 15000000;
    }
    
    /**
     * Generate random phase
     * 
     * @return float
     */
    protected function _randomPhase() {
        // random phase from 0 to pi
        return mt_rand ( 0, 3141592 ) / 1000000;
    }
    
    /**
     * Generate random character size
     * 
     * @return int
     */
    protected function _randomSize() {
        return 0;
        return mt_rand ( 300, 700 ) / 100;
    }
    
    public function getFont() {
        return dirname ( __FILE__ ) . '/ttf/2.ttf';
    }
    /**
     * 将验证码存入Sessioin
     *
     * @param string $namespace
     * @param string $code
     * @return true
     */
    public static function setToSession($namespace, $code) {
        self::getSessionObject($namespace)->captcha = $code;
        return true;
    }
    
    /**
     * 从session中取出已经生成的验证码
     *
     * @param string $namespace
     * @return string|false
     */
    public static function getFromSession($namespace) {
        $code = self::getSessionObject($namespace)->captcha;
        if (!empty( $code )) {
            return $code;
        } else {
            return false;
        }
    }
    
    /**
     * Constructor
     *
     * @param  array $options 
     * @return void
     */
    public function __construct($options = null) {
        if (isset ( $options )) {
            foreach ( $options as $k => $v ) {
                call_user_func ( array ($this, 'set' . ucfirst ( $k ) ), $v );
            }
        }
    }
    public function generate($namespace) {
        $word = $this->_generateWord ();
        self::setToSession ( $namespace, $word );
        header ( "Content-type: image/png" );
        $this->_generateImage ( $word );
        return $word;
    }
    
    /**
     * 生成验证码
     * 
     * @param string $word
     */
    protected function _generateImage($word) {
        if (! extension_loaded("gd")) {
            exit("Image CAPTCHA requires GD extension");
        }
        if (! function_exists("imagepng")) {
            exit("Image CAPTCHA requires PNG support");
        }
        if (! function_exists("imageftbbox")) {
            exit("Image CAPTCHA requires FT fonts support");
        }
        $font = $this->getFont();
        if (empty($font)) {
            exit("Image CAPTCHA requires font");
        }
        $w = $this->getWidth ();
        $h = $this->getHeight ();
        $fsize = $this->getFontSize ();
        
        $img = imagecreatetruecolor ( $w, $h );
        $text_color = imagecolorallocate ( $img, 0, 0, 0 );
        $bg_color = imagecolorallocate ( $img, 255, 255, 255 );
        imagefilledrectangle ( $img, 0, 0, $w - 1, $h - 1, $bg_color );
        $textbox = imageftbbox ( $fsize, 0, $font, $word );
        $x = ($w - ($textbox [2] - $textbox [0])) / 2;
        $y = ($h - ($textbox [7] - $textbox [1])) / 2;
        imagefttext ( $img, $fsize, 0, $x, $y, $text_color, $font, $word );
        
        // generate noise
        for($i = 0; $i < $this->_dotNoiseLevel; $i ++) {
            imagefilledellipse ( $img, mt_rand ( 0, $w ), mt_rand ( 0, $h ), 2, 2, $text_color );
        }
        for($i = 0; $i < $this->_lineNoiseLevel; $i ++) {
            imageline ( $img, mt_rand ( 0, $w ), mt_rand ( 0, $h ), mt_rand ( 0, $w ), mt_rand ( 0, $h ), $text_color );
        }
        
        // transformed image
        $img2 = imagecreatetruecolor ( $w, $h );
        $bg_color = imagecolorallocate ( $img2, 255, 255, 255 );
        imagefilledrectangle ( $img2, 0, 0, $w - 1, $h - 1, $bg_color );
        // apply wave transforms
        $freq1 = $this->_randomFreq ();
        $freq2 = $this->_randomFreq ();
        $freq3 = $this->_randomFreq ();
        $freq4 = $this->_randomFreq ();
        
        $ph1 = $this->_randomPhase ();
        $ph2 = $this->_randomPhase ();
        $ph3 = $this->_randomPhase ();
        $ph4 = $this->_randomPhase ();
        
        $szx = $this->_randomSize ();
        $szy = $this->_randomSize ();
        
        for($x = 0; $x < $w; $x ++) {
            for($y = 0; $y < $h; $y ++) {
                $sx = $x + (sin ( $x * $freq1 + $ph1 ) + sin ( $y * $freq3 + $ph3 )) * $szx;
                $sy = $y + (sin ( $x * $freq2 + $ph2 ) + sin ( $y * $freq4 + $ph4 )) * $szy;
                
                if ($sx < 0 || $sy < 0 || $sx >= $w - 1 || $sy >= $h - 1) {
                    continue;
                } else {
                    $color = (imagecolorat ( $img, $sx, $sy ) >> 16) & 0xFF;
                    $color_x = (imagecolorat ( $img, $sx + 1, $sy ) >> 16) & 0xFF;
                    $color_y = (imagecolorat ( $img, $sx, $sy + 1 ) >> 16) & 0xFF;
                    $color_xy = (imagecolorat ( $img, $sx + 1, $sy + 1 ) >> 16) & 0xFF;
                }
                if ($color == 255 && $color_x == 255 && $color_y == 255 && $color_xy == 255) {
                    // ignore background
                    continue;
                } elseif ($color == 0 && $color_x == 0 && $color_y == 0 && $color_xy == 0) {
                    // transfer inside of the image as-is
                    $newcolor = 0;
                } else {
                    // do antialiasing for border items
                    $frac_x = $sx - floor ( $sx );
                    $frac_y = $sy - floor ( $sy );
                    $frac_x1 = 1 - $frac_x;
                    $frac_y1 = 1 - $frac_y;
                    
                    $newcolor = $color * $frac_x1 * $frac_y1 + $color_x * $frac_x * $frac_y1 + $color_y * $frac_x1 * $frac_y + $color_xy * $frac_x * $frac_y;
                }
                imagesetpixel ( $img2, $x, $y, imagecolorallocate ( $img2, $newcolor, $newcolor, $newcolor ) );
            }
        }
        
        // generate noise
        for($i = 0; $i < $this->_dotNoiseLevel; $i ++) {
            imagefilledellipse ( $img2, mt_rand ( 0, $w ), mt_rand ( 0, $h ), 2, 2, $text_color );
        }
        for($i = 0; $i < $this->_lineNoiseLevel; $i ++) {
            imageline ( $img2, mt_rand ( 0, $w ), mt_rand ( 0, $h ), mt_rand ( 0, $w ), mt_rand ( 0, $h ), $text_color );
        }
        imagepng ( $img2 );
        imagedestroy ( $img );
        imagedestroy ( $img2 );
    }
    
    /**
     * 获取session对象
     * 
     * @param string $namespace
     * @return object
     */
    public static function getSessionObject($namespace)
    {
        if(strtoupper(substr(PHP_OS,0,3)) === 'WIN')
        {
            return Session::fileStart($namespace);
        }
        else
        {
            return Session::start($namespace, null, 'yohobuy.com');
        }
    }
}