<?php

/*
 * This file is copied from 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.
 *
 * @license MIT
 */

namespace Composer\Autoload;

/**
 * ClassMapGenerator
 *
 * @author Gyula Sallai <salla016@gmail.com>
 */
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 = array();

        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          $whitelist Regex that matches against the file path
     *
     * @return array A class map array
     *
     * @throws \RuntimeException When the path is neither an existing file nor directory
     */
    public static function createMap($path, $whitelist = null)
    {
        if (is_string($path)) {
            if (is_file($path)) {
                $path = array(new \SplFileInfo($path));
            } else if (is_dir($path)) {
                $path = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($path));
            } else {
                throw new \RuntimeException(
                    'Could not scan for classes inside "'.$path.
                    '" which does not appear to be a file nor a folder'
                );
            }
        }

        $map = array();

        foreach ($path as $file) {
            if (!$file->isFile()) {
                continue;
            }

            $filePath = $file->getRealPath();

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

            if ($whitelist && !preg_match($whitelist, strtr($filePath, '\\', '/'))) {
                continue;
            }

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

            foreach ($classes as $class) {
                $map[$class] = $filePath;
            }

        }

        return $map;
    }

    /**
     * Extract the classes in the given file
     *
     * @param string $path The file to check
     *
     * @return array The found classes
     */
    private static function findClasses($path)
    {
        $traits = version_compare(PHP_VERSION, '5.4', '<') ? '' : '|trait';

        try {
            $contents = php_strip_whitespace($path);
        } catch (\Exception $e) {
            throw new \RuntimeException('Could not scan for classes inside '.$path.": \n".$e->getMessage(), 0, $e);
        }

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

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

        preg_match_all('{
            (?:
                 \b(?<![\$:>])(?P<type>class|interface'.$traits.') \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 = array();
        $namespace = '';

        for ($i = 0, $len = count($matches['type']); $i < $len; $i++) {
            if (!empty($matches['ns'][$i])) {
                $namespace = str_replace(array(' ', "\t", "\r", "\n"), '', $matches['nsname'][$i]) . '\\';
            } else {
                $classes[] = ltrim($namespace . $matches['name'][$i], '\\');
            }
        }

        return $classes;
    }
}