From 851bad3ada29c04b4ac6e21f7582b917e5d898b5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?St=C3=A9phane=20Goetz?= <onigoetz@onigoetz.ch>
Date: Fri, 21 Sep 2018 23:41:49 +0200
Subject: [PATCH] Be more user friendly if the format is incorrect

---
 libs/Daux.php | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/libs/Daux.php b/libs/Daux.php
index f4637cf..0f99e63 100644
--- a/libs/Daux.php
+++ b/libs/Daux.php
@@ -293,6 +293,20 @@ class Daux
         return $class;
     }
 
+    protected function findAlternatives($input, $words) {
+        $alternatives = [];
+
+        foreach ($words as $word) {
+            $lev = levenshtein($input, $word);
+
+            if ($lev <= \strlen($word) / 3) {
+                $alternatives[] = $word;
+            }
+        }
+
+        return $alternatives;
+    }
+
     /**
      * @return \Todaymade\Daux\Format\Base\Generator
      */
@@ -307,7 +321,19 @@ class Daux
         $format = $this->getParams()->getFormat();
 
         if (!array_key_exists($format, $generators)) {
-            throw new \RuntimeException("The format '$format' doesn't exist, did you forget to set your processor ?");
+            $message = "The format '$format' doesn't exist, did you forget to set your processor ?";
+
+            $alternatives = $this->findAlternatives($format, array_keys($generators));
+
+            if (0 == \count($alternatives)) {
+                $message .= "\n\nAvailable formats are \n    " . implode("\n    ", array_keys($generators));
+            } elseif (1 == \count($alternatives)) {
+                $message .= "\n\nDid you mean this?\n    " . implode("\n    ", $alternatives);
+            } else {
+                $message .= "\n\nDid you mean one of these?\n    " . implode("\n    ", $alternatives);
+            }
+
+            throw new \RuntimeException($message);
         }
 
         $class = $generators[$format];