<?php
// $Id: libraries.module,v 1.2.2.3 2011/01/27 02:25:40 sun Exp $

/**
 * @file
 * External library handling for Drupal modules.
 */

/**
 * Gets the path of a library.
 *
 * @param $name
 *   The machine name of a library to return the path for.
 * @param $base_path
 *   Whether to prefix the resulting path with base_path().
 *
 * @return
 *   The path to the specified library.
 *
 * @ingroup libraries
 */
function libraries_get_path($name, $base_path = FALSE) {
  static $libraries;

  if (!isset($libraries)) {
    $libraries = libraries_get_libraries();
  }

  $path = ($base_path ? base_path() : '');
  if (!isset($libraries[$name])) {
    // Most often, external libraries can be shared across multiple sites, so
    // we return sites/all/libraries as the default path.
    $path .= 'sites/all/libraries/' . $name;
  }
  else {
    $path .= $libraries[$name];
  }

  return $path;
}

/**
 * Returns an array of library directories.
 *
 * Returns an array of library directories from the all-sites directory
 * (i.e. sites/all/libraries/), the profiles directory, and site-specific
 * directory (i.e. sites/somesite/libraries/). The returned array will be keyed
 * by the library name. Site-specific libraries are prioritized over libraries
 * in the default directories. That is, if a library with the same name appears
 * in both the site-wide directory and site-specific directory, only the
 * site-specific version will be listed.
 *
 * @return
 *   A list of library directories.
 *
 * @ingroup libraries
 */
function libraries_get_libraries() {
  global $profile;

  // When this function is called during Drupal's initial installation process,
  // the name of the profile that is about to be installed is stored in the
  // global $profile variable. At all other times, the regular system variable
  // contains the name of the current profile, and we can call variable_get()
  // to determine the profile.
  if (!isset($profile)) {
    $profile = variable_get('install_profile', 'default');
  }

  $directory = 'libraries';
  $searchdir = array();
  $config = conf_path();

  // Similar to 'modules' and 'themes' directories in the root directory,
  // certain distributions may want to place libraries into a 'libraries'
  // directory in Drupal's root directory.
  $searchdir[] = $directory;

  // The 'profiles' directory contains pristine collections of modules and
  // themes as organized by a distribution.  It is pristine in the same way
  // that /modules is pristine for core; users should avoid changing anything
  // there in favor of sites/all or sites/<domain> directories.
  if (file_exists("profiles/$profile/$directory")) {
    $searchdir[] = "profiles/$profile/$directory";
  }

  // Always search sites/all/*.
  $searchdir[] = 'sites/all/' . $directory;

  // Also search sites/<domain>/*.
  if (file_exists("$config/$directory")) {
    $searchdir[] = "$config/$directory";
  }

  // Retrieve list of directories.
  // @todo Core: Allow to scan for directories.
  $directories = array();
  $nomask = array('CVS');
  foreach ($searchdir as $dir) {
    if (is_dir($dir) && $handle = opendir($dir)) {
      while (FALSE !== ($file = readdir($handle))) {
        if (!in_array($file, $nomask) && $file[0] != '.') {
          if (is_dir("$dir/$file")) {
            $directories[$file] = "$dir/$file";
          }
        }
      }
      closedir($handle);
    }
  }

  return $directories;
}