Separate generation concerns into different services

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);
+        }
+    }
+}
+