<?php
// $Id$

/**
 * @file
 * The drush module engine.
 *
 * Closely follows the equivalent Drupal core functions.
 *
 */

/**
 * Invoke a hook in all available modules that implement it.
 *
 * @param $hook
 *   The name of the hook to invoke.
 * @param ...
 *   Arguments to pass to the hook.
 * @return
 *   An array of return values of the hook implementations. If modules return
 *   arrays from their implementations, those are merged into one array.
 */
function drush_module_invoke_all() {
  $args = func_get_args();
  $hook = $args[0];
  unset($args[0]);
  $return = array();
  foreach (drush_module_implements($hook) as $module) {
    $function = $module .'_'. $hook;
    $result = call_user_func_array($function, $args);
    if (isset($result) && is_array($result)) {
      $return = array_merge_recursive($return, $result);
    }
    else if (isset($result)) {
      $return[] = $result;
    }
  }
  return $return;
}

/**
 * Determine which modules are implementing a hook.
 *
 * @param $hook
 *   The name of the hook (e.g. "help" or "menu").
 *
 * @return
 *   An array with the names of the modules which are implementing this hook.
 */
function drush_module_implements($hook) {
  static $implementations;

  if (!isset($implementations[$hook])) {
    $implementations[$hook] = array();
    $list = drush_module_list();
    foreach ($list as $module) {
      if (drush_module_hook($module, $hook)) {
        $implementations[$hook][] = $module;
      }
    }
  }
  return (array)$implementations[$hook];
}

/**
 * Collect a list of all available modules.
 *
 * @return
 *   An associative array whose keys and values are the names of all available
 *   modules.
 */
function drush_module_list() {
  static $list = array();
  if (empty($list)) {
    $dirs[] = dirname(__FILE__);
    if ($include = drush_get_option(array('i', 'include'), FALSE)) {
      $dirs = array_merge($dirs, explode(":", $include));
    }
    foreach ($dirs as $dir) {
      $files = drush_scan_directory($dir, '\.drush\.inc$');
      foreach ($files as $filename => $info) {
        require_once($filename);
        $list[] = basename($filename, '.drush.inc');
      }
    }
  }
  return $list;
}

/**
 * Determine whether a module implements a hook.
 *
 * @param $module
 *   The name of the module (without the .module extension).
 * @param $hook
 *   The name of the hook (e.g. "help" or "menu").
 * @return
 *   TRUE if the the hook is implemented.
 */
function drush_module_hook($module, $hook) {
  return function_exists($module .'_'. $hook);
}


/**
 * Finds all files that match a given mask in a given directory.
 * Directories and files beginning with a period are excluded; this
 * prevents hidden files and directories (such as SVN working directories)
 * from being scanned.
 *
 * @param $dir
 *   The base directory for the scan, without trailing slash.
 * @param $mask
 *   The regular expression of the files to find.
 * @param $nomask
 *   An array of files/directories to ignore.
 * @param $callback
 *   The callback function to call for each match.
 * @param $recurse
 *   When TRUE, the directory scan will recurse the entire tree
 *   starting at the provided directory.
 * @param $key
 *   The key to be used for the returned array of files. Possible
 *   values are "filename", for the path starting with $dir,
 *   "basename", for the basename of the file, and "name" for the name
 *   of the file without an extension.
 * @param $min_depth
 *   Minimum depth of directories to return files from.
 * @param $depth
 *   Current depth of recursion. This parameter is only used internally and should not be passed.
 *
 * @return
 *   An associative array (keyed on the provided key) of objects with
 *   "path", "basename", and "name" members corresponding to the
 *   matching files.
 */
function drush_scan_directory($dir, $mask, $nomask = array('.', '..', 'CVS'), $callback = 0, $recurse = TRUE, $key = 'filename', $min_depth = 0, $depth = 0) {
  $key = (in_array($key, array('filename', 'basename', 'name')) ? $key : 'filename');
  $files = array();

  if (is_dir($dir) && $handle = opendir($dir)) {
    while (FALSE !== ($file = readdir($handle))) {
      if (!in_array($file, $nomask) && $file[0] != '.') {
        if (is_dir("$dir/$file") && $recurse) {
          // Give priority to files in this folder by merging them in after any subdirectory files.
          $files = array_merge(drush_scan_directory("$dir/$file", $mask, $nomask, $callback, $recurse, $key, $min_depth, $depth + 1), $files);
        }
        elseif ($depth >= $min_depth && ereg($mask, $file)) {
          // Always use this match over anything already set in $files with the same $$key.
          $filename = "$dir/$file";
          $basename = basename($file);
          $name = substr($basename, 0, strrpos($basename, '.'));
          $files[$$key] = new stdClass();
          $files[$$key]->filename = $filename;
          $files[$$key]->basename = $basename;
          $files[$$key]->name = $name;
          if ($callback) {
            $callback($filename);
          }
        }
      }
    }

    closedir($handle);
  }

  return $files;
}