[Generator] Renaming, and separating the PhraseBuilder

Generator/PhraseBuilder.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Gregwar\CaptchaBundle\Generator;
+
+use Symfony\Component\Finder\Finder;
+use Symfony\Component\HttpFoundation\Session\SessionInterface;
+use Symfony\Component\Routing\RouterInterface;
+
+/**
+ * Generates random phrase
+ *
+ * @author Gregwar <g.passault@gmail.com>
+ */
+class PhraseBuilder
+{
+    public function build($length = 5, $charset = 'abcdefghijklmnopqrstuvwxyz0123456789')
+    {
+        $phrase = '';
+        $chars = str_split($charset);
+
+        for ($i = 0; $i < $length; $i++) {
+            $phrase .= $chars[array_rand($chars)];
+        }
+
+        return $phrase;
+    }
+}