<?php
 
 /*
  * This file is part of the Symfony package.
  *
  * (c) Fabien Potencier <fabien@symfony.com>
  *
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
 
 namespace Symfony\Component\Translation\Loader;
 
 /**
  * @copyright Copyright (c) 2010, Union of RAD https://github.com/UnionOfRAD/lithium
  * @copyright Copyright (c) 2012, Clemens Tolboom
  */
 class PoFileLoader extends FileLoader
 {
     /**
      * Parses portable object (PO) format.
      *
      * From https://www.gnu.org/software/gettext/manual/gettext.html#PO-Files
      * we should be able to parse files having:
      *
      * white-space
      * #  translator-comments
      * #. extracted-comments
      * #: reference...
      * #, flag...
      * #| msgid previous-untranslated-string
      * msgid untranslated-string
      * msgstr translated-string
      *
      * extra or different lines are:
      *
      * #| msgctxt previous-context
      * #| msgid previous-untranslated-string
      * msgctxt context
      *
      * #| msgid previous-untranslated-string-singular
      * #| msgid_plural previous-untranslated-string-plural
      * msgid untranslated-string-singular
      * msgid_plural untranslated-string-plural
      * msgstr[0] translated-string-case-0
      * ...
      * msgstr[N] translated-string-case-n
      *
      * The definition states:
      * - white-space and comments are optional.
      * - msgid "" that an empty singleline defines a header.
      *
      * This parser sacrifices some features of the reference implementation the
      * differences to that implementation are as follows.
      * - No support for comments spanning multiple lines.
      * - Translator and extracted comments are treated as being the same type.
      * - Message IDs are allowed to have other encodings as just US-ASCII.
      *
      * Items with an empty id are ignored.
      *
      * {@inheritdoc}
      */
     protected function loadResource($resource)
     {
         $stream = fopen($resource, 'r');
 
         $defaults = [
             'ids' => [],
             'translated' => null,
         ];
 
         $messages = [];
         $item = $defaults;
         $flags = [];
 
         while ($line = fgets($stream)) {
             $line = trim($line);
 
             if ('' === $line) {
                 // Whitespace indicated current item is done
                 if (!\in_array('fuzzy', $flags)) {
                     $this->addMessage($messages, $item);
                 }
                 $item = $defaults;
                 $flags = [];
             } elseif ('#,' === substr($line, 0, 2)) {
                 $flags = array_map('trim', explode(',', substr($line, 2)));
             } elseif ('msgid "' === substr($line, 0, 7)) {
                 // We start a new msg so save previous
                 // TODO: this fails when comments or contexts are added
                 $this->addMessage($messages, $item);
                 $item = $defaults;
                 $item['ids']['singular'] = substr($line, 7, -1);
             } elseif ('msgstr "' === substr($line, 0, 8)) {
                 $item['translated'] = substr($line, 8, -1);
             } elseif ('"' === $line[0]) {
                 $continues = isset($item['translated']) ? 'translated' : 'ids';
 
                 if (\is_array($item[$continues])) {
                     end($item[$continues]);
                     $item[$continues][key($item[$continues])] .= substr($line, 1, -1);
                 } else {
                     $item[$continues] .= substr($line, 1, -1);
                 }
             } elseif ('msgid_plural "' === substr($line, 0, 14)) {
                 $item['ids']['plural'] = substr($line, 14, -1);
             } elseif ('msgstr[' === substr($line, 0, 7)) {
                 $size = strpos($line, ']');
                 $item['translated'][(int) substr($line, 7, 1)] = substr($line, $size + 3, -1);
             }
         }
         // save last item
         if (!\in_array('fuzzy', $flags)) {
             $this->addMessage($messages, $item);
         }
         fclose($stream);
 
         return $messages;
     }
 
     /**
      * Save a translation item to the messages.
      *
      * A .po file could contain by error missing plural indexes. We need to
      * fix these before saving them.
      */
     private function addMessage(array &$messages, array $item)
     {
         if (!empty($item['ids']['singular'])) {
             $id = stripcslashes($item['ids']['singular']);
             if (isset($item['ids']['plural'])) {
                 $id .= '|'.stripcslashes($item['ids']['plural']);
             }
 
             $translated = (array) $item['translated'];
             // PO are by definition indexed so sort by index.
             ksort($translated);
             // Make sure every index is filled.
             end($translated);
             $count = key($translated);
             // Fill missing spots with '-'.
             $empties = array_fill(0, $count + 1, '-');
             $translated += $empties;
             ksort($translated);
 
             $messages[$id] = stripcslashes(implode('|', $translated));
         }
     }
 }