<?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\Finder;
 
 /**
  * Gitignore matches against text.
  *
  * @author Ahmed Abdou <mail@ahmd.io>
  */
 class Gitignore
 {
     /**
      * Returns a regexp which is the equivalent of the gitignore pattern.
      *
      * @param string $gitignoreFileContent
      *
      * @return string The regexp
      */
     public static function toRegex(string $gitignoreFileContent): string
     {
         $gitignoreFileContent = preg_replace('/^[^\\\\]*#.*/', '', $gitignoreFileContent);
         $gitignoreLines = preg_split('/\r\n|\r|\n/', $gitignoreFileContent);
         $gitignoreLines = array_map('trim', $gitignoreLines);
         $gitignoreLines = array_filter($gitignoreLines);
 
         $ignoreLinesPositive = array_filter($gitignoreLines, function (string $line) {
             return !preg_match('/^!/', $line);
         });
 
         $ignoreLinesNegative = array_filter($gitignoreLines, function (string $line) {
             return preg_match('/^!/', $line);
         });
 
         $ignoreLinesNegative = array_map(function (string $line) {
             return preg_replace('/^!(.*)/', '${1}', $line);
         }, $ignoreLinesNegative);
         $ignoreLinesNegative = array_map([__CLASS__, 'getRegexFromGitignore'], $ignoreLinesNegative);
 
         $ignoreLinesPositive = array_map([__CLASS__, 'getRegexFromGitignore'], $ignoreLinesPositive);
         if (empty($ignoreLinesPositive)) {
             return '/^$/';
         }
 
         if (empty($ignoreLinesNegative)) {
             return sprintf('/%s/', implode('|', $ignoreLinesPositive));
         }
 
         return sprintf('/(?=^(?:(?!(%s)).)*$)(%s)/', implode('|', $ignoreLinesNegative), implode('|', $ignoreLinesPositive));
     }
 
     private static function getRegexFromGitignore(string $gitignorePattern): string
     {
         $regex = '(';
         if (0 === strpos($gitignorePattern, '/')) {
             $gitignorePattern = substr($gitignorePattern, 1);
             $regex .= '^';
         } else {
             $regex .= '(^|\/)';
         }
 
         if ('/' === $gitignorePattern[\strlen($gitignorePattern) - 1]) {
             $gitignorePattern = substr($gitignorePattern, 0, -1);
         }
 
         $iMax = \strlen($gitignorePattern);
         for ($i = 0; $i < $iMax; ++$i) {
             $doubleChars = substr($gitignorePattern, $i, 2);
             if ('**' === $doubleChars) {
                 $regex .= '.+';
                 ++$i;
                 continue;
             }
 
             $c = $gitignorePattern[$i];
             switch ($c) {
                 case '*':
                     $regex .= '[^\/]+';
                     break;
                 case '/':
                 case '.':
                 case ':':
                 case '(':
                 case ')':
                 case '{':
                 case '}':
                     $regex .= '\\'.$c;
                     break;
                 default:
                     $regex .= $c;
             }
         }
 
         $regex .= '($|\/)';
         $regex .= ')';
 
         return $regex;
     }
 }