Separate generation concerns into different services

Generator/CaptchaGenerator.php

@@ -22,57 +22,27 @@ class CaptchaGenerator
     protected $router;
 
     /**
-     * Name of folder for captcha images
+     * @var ImageBuilder
-     * @var string
      */
-    protected $imageFolder;
+    protected $builder;
 
     /**
-     * Absolute path to public web folder
+     * @var ImageFileHandler
-     * @var string
      */
-    protected $webPath;
+    protected $imageFileHandler;
-
-    /**
-     * Frequency of garbage collection in fractions of 1
-     * @var int
-     */
-    protected $gcFreq;
-
-    /**
-     * Maximum age of images in minutes
-     * @var int
-     */
-    protected $expiration;
-
-    /**
-     * The fingerprint used to generate the image details across requests
-     * @var array|null
-     */
-    protected $fingerprint;
-
-    /**
-     * Whether this instance should use the fingerprint
-     * @var bool
-     */
-    protected $useFingerprint;
 
     /**
      * @param \Symfony\Component\HttpFoundation\Session\SessionInterface $session
      * @param \Symfony\Component\Routing\RouterInterface $router
-     * @param string $imageFolder
+     * @param ImageBuilder $builder
-     * @param string $webPath
+     * @param ImageFileHandler $imageFileHandler
-     * @param int $gcFreq
-     * @param int $expiration
      */
-    public function __construct(SessionInterface $session, RouterInterface $router, $imageFolder, $webPath, $gcFreq, $expiration)
+    public function __construct(SessionInterface $session, RouterInterface $router, ImageBuilder $builder, ImageFileHandler $imageFileHandler)
     {
         $this->session          = $session;
         $this->router           = $router;
-        $this->imageFolder      = $imageFolder;
+        $this->builder          = $builder;
-        $this->webPath          = $webPath;
+        $this->imageFileHandler = $imageFileHandler;
-        $this->gcFreq           = $gcFreq;
-        $this->expiration       = $expiration;
     }
 
     /**
@@ -87,14 +57,12 @@ class CaptchaGenerator
     {
         // Randomly execute garbage collection and returns the image filename
         if ($options['as_file']) {
-            if (mt_rand(1, $this->gcFreq) == 1) {
+            $this->imageFileHandler->collectGarbage();
-                $this->garbageCollection();
-            }
 
             return $this->generate($key, $options);
         }
 
-        // Returns the configured URL for image generation
+        // Returns the image generation URL
         if ($options['as_url']) {
             return $this->router->generate('gregwar_captcha.generate_captcha', array('key' => $key));
         }
@@ -103,217 +71,75 @@ class CaptchaGenerator
     }
 
     /**
-     * Generate the image
+     * @param string $key
+     * @param array $options
+     *
+     * @return string
      */
     public function generate($key, array $options)
     {
-        $width  = $options['width'];
+        $fingerprint = $this->getFingerprint($key, $options);
-        $height = $options['height'];
 
-        if ($options['keep_value'] && $this->session->has($key . '_fingerprint')) {
+        $content = $this->builder->build(
-            $this->fingerprint = $this->session->get($key . '_fingerprint');
+            $options['width'],
-            $this->useFingerprint = true;
+            $options['height'],
-        } else {
+            $options['font'],
-            $this->fingerprint = null;
+            $this->getPhrase($key, $options),
-            $this->useFingerprint = false;
+            $fingerprint
-        }
+        );
-
-        $captchaValue = $this->getCaptchaValue($key, $options['keep_value'], $options['charset'], $options['length']);
-
-        $i = imagecreatetruecolor($width,$height);
-        $col = imagecolorallocate($i, $this->rand(0,110), $this->rand(0,110), $this->rand(0,110));
-
-        imagefill($i, 0, 0, 0xFFFFFF);
-
-        // Draw random lines
-        for ($t=0; $t<10; $t++) {
-            $tcol = imagecolorallocate($i, 100+$this->rand(0,150), 100+$this->rand(0,150), 100+$this->rand(0,150));
-            $Xa = $this->rand(0, $width);
-            $Ya = $this->rand(0, $height);
-            $Xb = $this->rand(0, $width);
-            $Yb = $this->rand(0, $height);
-            imageline($i, $Xa, $Ya, $Xb, $Yb, $tcol);
-        }
-
-        // Write CAPTCHA text
-        $size       = $width / strlen($captchaValue);
-        $font       = $options['font'];
-        $box        = imagettfbbox($size, 0, $font, $captchaValue);
-        $textWidth  = $box[2] - $box[0];
-        $textHeight = $box[1] - $box[7];
-
-        imagettftext($i, $size, 0, ($width - $textWidth) / 2, ($height - $textHeight) / 2 + $size, $col, $font, $captchaValue);
-
-        // Distort the image
-        $X     = $this->rand(0, $width);
-        $Y     = $this->rand(0, $height);
-        $phase = $this->rand(0, 10);
-        $scale = 1.3 + $this->rand(0, 10000) / 30000;
-        $out   = imagecreatetruecolor($width, $height);
-
-        for ($x = 0; $x < $width; $x++) {
-            for ($y = 0; $y < $height; $y++) {
-                $Vx = $x - $X;
-                $Vy = $y - $Y;
-                $Vn = sqrt($Vx * $Vx + $Vy * $Vy);
-
-                if ($Vn != 0) {
-                    $Vn2 = $Vn + 4 * sin($Vn / 8);
-                    $nX  = $X + ($Vx * $Vn2 / $Vn);
-                    $nY  = $Y + ($Vy * $Vn2 / $Vn);
-                } else {
-                    $nX = $X;
-                    $nY = $Y;
-                }
-                $nY = $nY + $scale * sin($phase + $nX * 0.2);
-
-                $p = $this->bilinearInterpolate($nX - floor($nX), $nY - floor($nY),
-                    $this->getCol($i, floor($nX), floor($nY)),
-                    $this->getCol($i, ceil($nX), floor($nY)),
-                    $this->getCol($i, floor($nX), ceil($nY)),
-                    $this->getCol($i, ceil($nX), ceil($nY)));
-
-                if ($p == 0) {
-                    $p = 0xFFFFFF;
-                }
-
-                imagesetpixel($out, $x, $y, $p);
-            }
-        }
 
         if ($options['keep_value']) {
-            $this->session->set($key . '_fingerprint', $this->fingerprint);
+            $this->session->set($key . '_fingerprint', $this->builder->getFingerprint());
         }
 
-        // Renders it
         if (!$options['as_file']) {
             ob_start();
-            imagejpeg($out, null, $options['quality']);
+            imagejpeg($content, null, $options['quality']);
 
             return ob_get_clean();
         }
 
-        // Check if folder exists and create it if not
+        return $this->imageFileHandler->saveAsFile($content);
-        if (!file_exists($this->webPath . '/' . $this->imageFolder)) {
-            mkdir($this->webPath . '/' . $this->imageFolder, 0755);
-        }
-        
-        $filename = md5(uniqid()) . '.jpg';
-        $filepath = $this->webPath . '/' . $this->imageFolder . '/' . $filename;
-        imagejpeg($out, $filepath, 15);
-
-        return '/' . $this->imageFolder . '/' . $filename;
     }
 
     /**
-     * Generate a new captcha value or pull the existing one from the session
-     *
      * @param string $key
-     * @param bool $keepValue
+     * @param array $options
-     * @param string $charset
-     * @param int $length
      *
-     * @return mixed|string
+     * @return string
      */
-    protected function getCaptchaValue($key, $keepValue, $charset, $length)
+    protected function getPhrase($key, array $options)
     {
-        if ($keepValue && $this->session->has($key)) {
+        // Get the phrase that we'll use for this image
+        if ($options['keep_value'] && $this->session->has($key)) {
             return $this->session->get($key);
         }
 
-        $value = '';
+        $phrase = '';
-        $chars = str_split($charset);
+        $chars = str_split($options['charset']);
 
-        for ($i=0; $i < $length; $i++) {
+        for ($i = 0; $i < $options['length']; $i++) {
-            $value .= $chars[array_rand($chars)];
+            $phrase .= $chars[array_rand($chars)];
         }
 
-        $this->session->set($key, $value);
+        $this->session->set($key, $phrase);
 
-        return $value;
+        return $phrase;
     }
 
     /**
-     * Deletes all images in the configured folder
+     * @param string $key
-     * that are older than the configured number of minutes
+     * @param array $options
      *
-     * @return void
+     * @return array|null
      */
-    protected function garbageCollection()
+    protected function getFingerprint($key, array $options)
     {
-        $finder = new Finder();
+        if ($options['keep_value'] && $this->session->has($key . '_fingerprint')) {
-        $criteria = sprintf('<= now - %s minutes', $this->expiration);
+            return $this->session->get($key . '_fingerprint');
-        $finder->in($this->webPath . '/' . $this->imageFolder)
-            ->date($criteria);
-
-        foreach($finder->files() as $file) {
-            unlink($file->getPathname());
-        }
-    }
-
-    /**
-     * Returns a random number or the next number in the
-     * fingerprint
-     */
-    protected function rand($min, $max)
-    {
-        if (!is_array($this->fingerprint)) {
-            $this->fingerprint = array();
         }
 
-        if ($this->useFingerprint) {
+        return null;
-            $value = current($this->fingerprint);
-            next($this->fingerprint);
-        } else {
-            $value = mt_rand($min, $max);
-            $this->fingerprint[] = $value;
-        }
-
-        return $value;
-    }
-
-    protected function bilinearInterpolate($x, $y, $nw, $ne, $sw, $se)
-    {
-        list($r0, $g0, $b0) = $this->getRGB($nw);
-        list($r1, $g1, $b1) = $this->getRGB($ne);
-        list($r2, $g2, $b2) = $this->getRGB($sw);
-        list($r3, $g3, $b3) = $this->getRGB($se);
-
-        $cx = 1.0 - $x;
-        $cy = 1.0 - $y;
-
-        $m0 = $cx * $r0 + $x * $r1;
-        $m1 = $cx * $r2 + $x * $r3;
-        $r = (int)($cy * $m0 + $y * $m1);
-
-        $m0 = $cx * $g0 + $x * $g1;
-        $m1 = $cx * $g2 + $x * $g3;
-        $g = (int)($cy * $m0 + $y * $m1);
-
-        $m0 = $cx * $b0 + $x * $b1;
-        $m1 = $cx * $b2 + $x * $b3;
-        $b = (int)($cy * $m0 + $y * $m1);
-
-        return ($r << 16) | ($g << 8) | $b;
-    }
-
-    protected function getCol($image, $x, $y)
-    {
-        $L = imagesx($image);
-        $H = imagesy($image);
-        if ($x < 0 || $x >= $L || $y < 0 || $y >= $H) {
-            return 0xFFFFFF;
-        }
-
-        return imagecolorat($image, $x, $y);
-    }
-
-    protected function getRGB($col) {
-        return array(
-            (int)($col >> 16) & 0xff,
-            (int)($col >> 8) & 0xff,
-            (int)($col) & 0xff,
-        );
     }
 }
 

Generator/ImageBuilder.php

@@ -0,0 +1,192 @@
+<?php
+
+namespace Gregwar\CaptchaBundle\Generator;
+
+use Symfony\Component\Finder\Finder;
+
+
+class ImageBuilder
+{
+    /**
+     * @var array
+     */
+    protected $fingerprint = array();
+
+    /**
+     * @var bool
+     */
+    protected $useFingerprint = false;
+
+    /**
+     * Generate the image
+     */
+    public function build($width, $height, $font, $phrase, $fingerprint = null)
+    {
+        if (null !== $fingerprint) {
+            $this->fingerprint = $fingerprint;
+            $this->useFingerprint = true;
+        } else {
+            $this->fingerprint = array();
+            $this->useFingerprint = false;
+        }
+
+        $i   = imagecreatetruecolor($width, $height);
+        $col = imagecolorallocate($i, $this->rand(0, 110), $this->rand(0, 110), $this->rand(0, 110));
+
+        imagefill($i, 0, 0, 0xFFFFFF);
+
+        // Draw random lines
+        for ($t = 0; $t < 10; $t++) {
+            $tcol = imagecolorallocate($i, 100 + $this->rand(0, 150), 100 + $this->rand(0, 150), 100 + $this->rand(0, 150));
+            $Xa   = $this->rand(0, $width);
+            $Ya   = $this->rand(0, $height);
+            $Xb   = $this->rand(0, $width);
+            $Yb   = $this->rand(0, $height);
+            imageline($i, $Xa, $Ya, $Xb, $Yb, $tcol);
+        }
+
+        // Write CAPTCHA text
+        $size       = $width / strlen($phrase);
+        $box        = imagettfbbox($size, 0, $font, $phrase);
+        $textWidth  = $box[2] - $box[0];
+        $textHeight = $box[1] - $box[7];
+
+        imagettftext($i, $size, 0, ($width - $textWidth) / 2, ($height - $textHeight) / 2 + $size, $col, $font, $phrase);
+
+        // Distort the image
+        $X          = $this->rand(0, $width);
+        $Y          = $this->rand(0, $height);
+        $phase      = $this->rand(0, 10);
+        $scale      = 1.3 + $this->rand(0, 10000) / 30000;
+        $contents   = imagecreatetruecolor($width, $height);
+
+        for ($x = 0; $x < $width; $x++) {
+            for ($y = 0; $y < $height; $y++) {
+                $Vx = $x - $X;
+                $Vy = $y - $Y;
+                $Vn = sqrt($Vx * $Vx + $Vy * $Vy);
+
+                if ($Vn != 0) {
+                    $Vn2 = $Vn + 4 * sin($Vn / 8);
+                    $nX  = $X + ($Vx * $Vn2 / $Vn);
+                    $nY  = $Y + ($Vy * $Vn2 / $Vn);
+                } else {
+                    $nX = $X;
+                    $nY = $Y;
+                }
+                $nY = $nY + $scale * sin($phase + $nX * 0.2);
+
+                $p = $this->bilinearInterpolate($nX - floor($nX), $nY - floor($nY),
+                    $this->getCol($i, floor($nX), floor($nY)),
+                    $this->getCol($i, ceil($nX), floor($nY)),
+                    $this->getCol($i, floor($nX), ceil($nY)),
+                    $this->getCol($i, ceil($nX), ceil($nY)));
+
+                if ($p == 0) {
+                    $p = 0xFFFFFF;
+                }
+
+                imagesetpixel($contents, $x, $y, $p);
+            }
+        }
+
+        return $contents;
+    }
+
+    /**
+     * @return array
+     */
+    public function getFingerprint()
+    {
+        return $this->fingerprint;
+    }
+
+    /**
+     * Returns a random number or the next number in the
+     * fingerprint
+     */
+    protected function rand($min, $max)
+    {
+        if (!is_array($this->fingerprint)) {
+            $this->fingerprint = array();
+        }
+
+        if ($this->useFingerprint) {
+            $value = current($this->fingerprint);
+            next($this->fingerprint);
+        } else {
+            $value = mt_rand($min, $max);
+            $this->fingerprint[] = $value;
+        }
+
+        return $value;
+    }
+
+    /**
+     * @param $x
+     * @param $y
+     * @param $nw
+     * @param $ne
+     * @param $sw
+     * @param $se
+     *
+     * @return int
+     */
+    protected function bilinearInterpolate($x, $y, $nw, $ne, $sw, $se)
+    {
+        list($r0, $g0, $b0) = $this->getRGB($nw);
+        list($r1, $g1, $b1) = $this->getRGB($ne);
+        list($r2, $g2, $b2) = $this->getRGB($sw);
+        list($r3, $g3, $b3) = $this->getRGB($se);
+
+        $cx = 1.0 - $x;
+        $cy = 1.0 - $y;
+
+        $m0 = $cx * $r0 + $x * $r1;
+        $m1 = $cx * $r2 + $x * $r3;
+        $r  = (int)($cy * $m0 + $y * $m1);
+
+        $m0 = $cx * $g0 + $x * $g1;
+        $m1 = $cx * $g2 + $x * $g3;
+        $g  = (int)($cy * $m0 + $y * $m1);
+
+        $m0 = $cx * $b0 + $x * $b1;
+        $m1 = $cx * $b2 + $x * $b3;
+        $b  = (int)($cy * $m0 + $y * $m1);
+
+        return ($r << 16) | ($g << 8) | $b;
+    }
+
+    /**
+     * @param $image
+     * @param $x
+     * @param $y
+     *
+     * @return int
+     */
+    protected function getCol($image, $x, $y)
+    {
+        $L = imagesx($image);
+        $H = imagesy($image);
+        if ($x < 0 || $x >= $L || $y < 0 || $y >= $H) {
+            return 0xFFFFFF;
+        }
+
+        return imagecolorat($image, $x, $y);
+    }
+
+    /**
+     * @param $col
+     *
+     * @return array
+     */
+    protected function getRGB($col)
+    {
+        return array(
+            (int)($col >> 16) & 0xff,
+            (int)($col >> 8) & 0xff,
+            (int)($col) & 0xff,
+        );
+    }
+}
+

Generator/ImageFileHandler.php

@@ -0,0 +1,103 @@
+<?php
+
+namespace Gregwar\CaptchaBundle\Generator;
+
+use Symfony\Component\Finder\Finder;
+
+/**
+ * @author Jeremy Livingston <jeremy@quizzle.com>
+ */
+class ImageFileHandler
+{
+    /**
+     * Name of folder for captcha images
+     * @var string
+     */
+    protected $imageFolder;
+
+    /**
+     * Absolute path to public web folder
+     * @var string
+     */
+    protected $webPath;
+
+    /**
+     * Frequency of garbage collection in fractions of 1
+     * @var int
+     */
+    protected $gcFreq;
+
+    /**
+     * Maximum age of images in minutes
+     * @var int
+     */
+    protected $expiration;
+
+    /**
+     * @param $imageFolder
+     * @param $webPath
+     * @param $gcFreq
+     * @param $expiration
+     */
+    public function __construct($imageFolder, $webPath, $gcFreq, $expiration)
+    {
+        $this->imageFolder      = $imageFolder;
+        $this->webPath          = $webPath;
+        $this->gcFreq           = $gcFreq;
+        $this->expiration       = $expiration;
+    }
+
+    /**
+     * Saves the provided image content as a file
+     *
+     * @param string $contents
+     *
+     * @return string
+     */
+    public function saveAsFile($contents)
+    {
+        $this->createFolderIfMissing();
+
+        $filename = md5(uniqid()) . '.jpg';
+        $filePath = $this->webPath . '/' . $this->imageFolder . '/' . $filename;
+        imagejpeg($contents, $filePath, 15);
+
+        return '/' . $this->imageFolder . '/' . $filename;
+    }
+
+    /**
+     * Randomly runs garbage collection on the image directory
+     *
+     * @return bool
+     */
+    public function collectGarbage()
+    {
+        if (!mt_rand(1, $this->gcFreq) == 1) {
+            return false;
+        }
+
+        $this->createFolderIfMissing();
+
+        $finder = new Finder();
+        $criteria = sprintf('<= now - %s minutes', $this->expiration);
+        $finder->in($this->webPath . '/' . $this->imageFolder)
+            ->date($criteria);
+
+        foreach($finder->files() as $file) {
+            unlink($file->getPathname());
+        }
+
+        return true;
+    }
+
+    /**
+     * Creates the folder if it doesn't exist
+     */
+    protected function createFolderIfMissing()
+    {
+        if (!file_exists($this->webPath . '/' . $this->imageFolder)) {
+            mkdir($this->webPath . '/' . $this->imageFolder, 0755);
+        }
+    }
+}
+

Resources/config/services.yml

@@ -1,6 +1,4 @@
-
 services:
-    # captcha type
     captcha.type:
         class: Gregwar\CaptchaBundle\Type\CaptchaType
         arguments:
@@ -15,7 +13,16 @@ services:
         arguments:
             - @session
             - @router
+            - @gregwar_captcha.image_builder
+            - @gregwar_captcha.image_file_handler
+
+    gregwar_captcha.image_file_handler:
+        class: Gregwar\CaptchaBundle\Generator\ImageFileHandler
+        arguments:
             - %gregwar_captcha.config.image_folder%
             - %gregwar_captcha.config.web_path%
             - %gregwar_captcha.config.gc_freq%
             - %gregwar_captcha.config.expiration%
+
+    gregwar_captcha.image_builder:
+        class: Gregwar\CaptchaBundle\Generator\ImageBuilder

Type/CaptchaType.php

@@ -36,12 +36,6 @@ class CaptchaType extends AbstractType
      */
     private $options = array();
 
-    /**
-     * Session key
-     * @var string
-     */
-    private $key = 'captcha';
-
     /**
      * @param \Symfony\Component\HttpFoundation\Session\SessionInterface $session
      * @param \Gregwar\CaptchaBundle\Generator\CaptchaGenerator $generator
@@ -60,9 +54,13 @@ class CaptchaType extends AbstractType
      */
     public function buildForm(FormBuilderInterface $builder, array $options)
     {
-        $this->key = $builder->getForm()->getName();
+        $validator = new CaptchaValidator(
+            $this->session,
+            $builder->getForm()->getName(),
+            $options['invalid_message'],
+            $options['bypass_code']
+        );
 
-        $validator = new CaptchaValidator($this->session, $this->key, $options['invalid_message'], $options['bypass_code']);
         $builder->addEventListener(FormEvents::POST_BIND, array($validator, 'validate'));
     }
 
@@ -76,7 +74,7 @@ class CaptchaType extends AbstractType
         $view->vars = array_merge($view->vars, array(
             'captcha_width'     => $options['width'],
             'captcha_height'    => $options['height'],
-            'captcha_code'      => $this->generator->getCaptchaCode($this->key, $options),
+            'captcha_code'      => $this->generator->getCaptchaCode($form->getName(), $options),
             'value'             => '',
         ));
     }