<?php

namespace Symfony\Components\DependencyInjection\Loader;

/*
 * This file is part of the Symfony framework.
 *
 * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

/**
 * FileLoader is the abstract class used by all built-in loaders that are file based.
 *
 * @package    Symfony
 * @subpackage Components_DependencyInjection
 * @author     Fabien Potencier <fabien.potencier@symfony-project.com>
 */
abstract class FileLoader extends Loader
{
  protected $paths;

  /**
   * Constructor.
   *
   * @param string|array $paths A path or an array of paths where to look for resources
   */
  public function __construct($paths = array())
  {
    if (!is_array($paths))
    {
      $paths = array($paths);
    }

    $this->paths = $paths;
  }

  /**
   * @throws \InvalidArgumentException When provided file does not exist
   */
  protected function findFile($file)
  {
    $path = $this->getAbsolutePath($file);
    if (!file_exists($path))
    {
      throw new \InvalidArgumentException(sprintf('The file "%s" does not exist (in: %s).', $file, implode(', ', $this->paths)));
    }

    return $path;
  }

  protected function getAbsolutePath($file, $currentPath = null)
  {
    if (self::isAbsolutePath($file))
    {
      return $file;
    }
    else if (null !== $currentPath && file_exists($currentPath.DIRECTORY_SEPARATOR.$file))
    {
      return $currentPath.DIRECTORY_SEPARATOR.$file;
    }
    else
    {
      foreach ($this->paths as $path)
      {
        if (file_exists($path.DIRECTORY_SEPARATOR.$file))
        {
          return $path.DIRECTORY_SEPARATOR.$file;
        }
      }
    }

    return $file;
  }

  static protected function isAbsolutePath($file)
  {
    return
      '/' == $file[0]
      ||
      '\\' == $file[0]
      ||
      (
        3 < strlen($file)
        &&
        ctype_alpha($file[0])
        &&
        ':' == $file[1]
        &&
        (
          '\\' == $file[2]
          ||
          '/' == $file[2]
        )
      )
    ;
  }
}