<?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\Extractor;
  
  /*
   * The following is derived from code at http://github.com/nikic/PHP-Parser
   *
   * Copyright (c) 2011 by Nikita Popov
   *
   * Some rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   *
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *
   *     * Redistributions in binary form must reproduce the above
   *       copyright notice, this list of conditions and the following
   *       disclaimer in the documentation and/or other materials provided
   *       with the distribution.
   *
   *     * The names of the contributors may not be used to endorse or
   *       promote products derived from this software without specific
   *       prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  class PhpStringTokenParser
  {
      protected static $replacements = [
          '\\' => '\\',
          '$' => '$',
          'n' => "
  ",
          'r' => "\r",
          't' => "\t",
          'f' => "\f",
          'v' => "\v",
          'e' => "\x1B",
      ];
  
      /**
       * Parses a string token.
       *
       * @param string $str String token content
       *
       * @return string
       */
      public static function parse(string $str)
      {
          $bLength = 0;
          if ('b' === $str[0]) {
              $bLength = 1;
          }
  
          if ('\'' === $str[$bLength]) {
              return str_replace(
                  ['\\\\', '\\\''],
                  ['\\', '\''],
                  substr($str, $bLength + 1, -1)
              );
          } else {
              return self::parseEscapeSequences(substr($str, $bLength + 1, -1), '"');
          }
      }
  
      /**
       * Parses escape sequences in strings (all string types apart from single quoted).
       *
       * @param string      $str   String without quotes
       * @param string|null $quote Quote type
       *
       * @return string
       */
      public static function parseEscapeSequences(string $str, ?string $quote = null)
      {
          if (null !== $quote) {
              $str = str_replace('\\'.$quote, $quote, $str);
          }
  
          return preg_replace_callback(
              '~\\\\([\\\\$nrtfve]|[xX][0-9a-fA-F]{1,2}|[0-7]{1,3})~',
              [__CLASS__, 'parseCallback'],
              $str
          );
      }
  
      private static function parseCallback(array $matches): string
      {
          $str = $matches[1];
  
          if (isset(self::$replacements[$str])) {
              return self::$replacements[$str];
          } elseif ('x' === $str[0] || 'X' === $str[0]) {
              return \chr(hexdec($str));
          } else {
              return \chr(octdec($str));
          }
      }
  
      /**
       * Parses a constant doc string.
       *
       * @param string $startToken Doc string start token content (<<<SMTHG)
       * @param string $str        String token content
       *
       * @return string
       */
      public static function parseDocString(string $startToken, string $str)
      {
          // strip last newline (thanks tokenizer for sticking it into the string!)
          $str = preg_replace('~(\r
  |
  |\r)$~', '', $str);
  
          // nowdoc string
          if (str_contains($startToken, '\'')) {
              return $str;
          }
  
          return self::parseEscapeSequences($str, null);
      }
  }