<?php

/*
 * This file is part of Composer.
 *
 * (c) Nils Adermann <naderman@naderman.de>
 *     Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/*
 * This file is copied from the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 */

namespace Composer\Autoload;

use Composer\IO\IOInterface;
use Symfony\Component\Finder\Finder;

/**
 * ClassMapGenerator
 *
 * @author Gyula Sallai <salla016@gmail.com>
 * @author Jordi Boggiano <j.boggiano@seld.be>
 */
class ClassMapGenerator
{
    /**
     * Generate a class map file
     *
     * @param \Traversable $dirs Directories or a single path to search in
     * @param string       $file The name of the class map file
     */
    public static function dump($dirs, $file)
    {
        $maps = [];

        foreach ($dirs as $dir) {
            $maps = array_merge($maps, static::createMap($dir));
        }

        file_put_contents($file, sprintf('<?php return %s;', var_export($maps, true)));
    }

    /**
     * Iterate over all files in the given directory searching for classes
     *
     * @param \Iterator|string $path      The path to search in or an iterator
     * @param string           $blacklist Regex that matches against the file path that exclude from the classmap.
     * @param IOInterface      $io        IO object
     * @param string           $namespace Optional namespace prefix to filter by
     *
     * @throws \RuntimeException When the path is neither an existing file nor directory
     * @return array             A class map array
     */
    public static function createMap($path, $blacklist = null, IOInterface $io = null, $namespace = null)
    {
        if (is_string($path)) {
            if (is_file($path)) {
                $path = [new \SplFileInfo($path)];
            } elseif (is_dir($path)) {
                $path = Finder::create()->files()->followLinks()->name('/\.(php|inc|hh)$/')->in($path);
            } else {
                throw new \RuntimeException(
                    'Could not scan for classes inside "' . $path .
                    '" which does not appear to be a file nor a folder',
                    1476049953
                );
            }
        }

        $map = [];

        foreach ($path as $file) {
            $filePath = $file->getRealPath();

            if (!in_array(pathinfo($filePath, PATHINFO_EXTENSION), ['php', 'inc', 'hh'])) {
                continue;
            }

            if ($blacklist && preg_match($blacklist, str_replace('\\', '/', $filePath))) {
                continue;
            }

            $classes = self::findClasses($filePath);

            foreach ($classes as $class) {
                // skip classes not within the given namespace prefix
                if ($namespace !== null && !str_starts_with($class, $namespace)) {
                    continue;
                }

                if (!isset($map[$class])) {
                    $map[$class] = $filePath;
                } elseif ($io && $map[$class] !== $filePath && !preg_match(
                    '{/(test|fixture|example|stub)s?/}i',
                    str_replace('\\', '/', $map[$class] . ' ' . $filePath)
                )) {
                    $io->writeError(
                        '<warning>Warning: Ambiguous class resolution, "' . $class . '"' .
                        ' was found in both "' . $map[$class] . '" and "' . $filePath . '", the first will be used.</warning>'
                    );
                }
            }
        }

        return $map;
    }

    /**
     * Extract the classes in the given file
     *
     * @param  string            $path The file to check
     * @throws \RuntimeException
     * @return array             The found classes
     */
    private static function findClasses($path)
    {
        try {
            $contents = @php_strip_whitespace($path);
            if (!$contents) {
                if (!file_exists($path)) {
                    throw new \Exception('File does not exist', 1476049981);
                }
                if (!is_readable($path)) {
                    throw new \Exception('File is not readable', 1476049990);
                }
            }
        } catch (\Exception $e) {
            throw new \RuntimeException('Could not scan for classes inside ' . $path . ": \n" . $e->getMessage(), 1476050009, $e);
        }

        // return early if there is no chance of matching anything in this file
        if (!preg_match('{\b(?:class|interface|trait)\s}i', $contents)) {
            return [];
        }

        // strip heredocs/nowdocs
        $contents = preg_replace('{<<<\s*(\'?)(\w+)\\1(?:\r\n|\n|\r)(?:.*?)(?:\r\n|\n|\r)\\2(?=\r\n|\n|\r|;)}s', 'null', $contents);
        // strip strings
        $contents = preg_replace('{"[^"\\\\]*+(\\\\.[^"\\\\]*+)*+"|\'[^\'\\\\]*+(\\\\.[^\'\\\\]*+)*+\'}s', 'null', $contents);
        // strip leading non-php code if needed
        if (!str_starts_with($contents, '<?')) {
            $contents = preg_replace('{^.+?<\?}s', '<?', $contents, 1, $replacements);
            if ($replacements === 0) {
                return [];
            }
        }
        // strip non-php blocks in the file
        $contents = preg_replace('{\?>.+<\?}s', '?><?', $contents);
        // strip trailing non-php code if needed
        $pos = strrpos($contents, '?>');
        if ($pos !== false && !str_contains(substr($contents, $pos), '<?')) {
            $contents = substr($contents, 0, $pos);
        }

        preg_match_all('{
            (?:
                 \b(?<![\$:>])(?P<type>class|interface|trait) \s++ (?P<name>[a-zA-Z_\x7f-\xff:][a-zA-Z0-9_\x7f-\xff:\-]*+)
               | \b(?<![\$:>])(?P<ns>namespace) (?P<nsname>\s++[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*+(?:\s*+\\\\\s*+[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*+)*+)? \s*+ [\{;]
            )
        }ix', $contents, $matches);

        $classes = [];
        $namespace = '';

        $typeCount = count($matches['type']);
        for ($i = 0, $len = $typeCount; $i < $len; $i++) {
            if (!empty($matches['ns'][$i])) {
                $namespace = str_replace([' ', "\t", "\r", "\n"], '', $matches['nsname'][$i]) . '\\';
            } else {
                $name = $matches['name'][$i];
                if ($name[0] === ':') {
                    // This is an XHP class, https://github.com/facebook/xhp
                    $name = 'xhp' . substr(str_replace(['-', ':'], ['_', '__'], $name), 1);
                } elseif ($matches['type'][$i] === 'enum') {
                    // In Hack, something like:
                    //   enum Foo: int { HERP = '123'; }
                    // The regex above captures the colon, which isn't part of
                    // the class name.
                    $name = rtrim($name, ':');
                }
                $classes[] = ltrim($namespace . $name, '\\');
            }
        }

        return $classes;
    }
}
