<?php
/**
 * @file
 * Upload Path module; allows admins to specify a sub directory for uploaded files.
 */

/**
 * Implementation of hook_menu().
 */
function uploadpath_menu() {
    $items['admin/settings/uploadpath'] = array(
      'title' => 'File upload paths',
      'description' => 'Configure a prefix to apply to the path of uploaded files.',
      'access callback' => 'user_access',
      'access arguments' => array('administer site configuration'),
      'page callback' => 'drupal_get_form',
      'page arguments' => array('uploadpath_admin_settings'),
      'type' => MENU_NORMAL_ITEM,
      'file' => 'uploadpath.admin.inc',
    );
  return $items;
}

/**
 * Implementation of hook_nodeapi().
 */
function uploadpath_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  switch ($op) {
    case 'insert':
    case 'update':
    if( !in_array($node->type, variable_get('uploadpath_excluded_node_types',array())) ){
      if(isset($node->files) && user_access('upload files')) {
        foreach ($node->files as $key => $file) {
          if(is_object($file)){
            $file = (array)$file; // if object then type cast as array
          }
          // Only rewrite the path on new files to be saved
          if ($file['new'] && !$file['remove']){
            //get the token path pattern
            $pattern = variable_get('uploadpath_prefix_'.$node->type, false);
            if(!$pattern){ 
              //default pattern
              $pattern = variable_get('uploadpath_prefix', '[type]/[yyyy]/[mm]');
            }
            if(variable_get('uploadpath_clean_filenames', false) && $node->title){
              //convert filename into meaningful semantic name based on node title or file desc :-)
              //e.g: 'DC100_1.jpg' becomes 'the_quick_brown_fox_a3de.jpg'
              if($file['description'] && strlen($file['description']) > 3){
                $filename_root = $file['description']; //base filename on file desc
              }else{
                $filename_root = $node->title; //base filename on node title
              }
              //drupal_set_message($filename_root);
              //get path info of file
              $file_info = pathinfo($file['filename']);
              /*crop lowercase node title to max
              replace anything except numbers and letters with underscore
              add 10 digit unique id and file extension*/
              $file_name = substr($filename_root, 0, 50);
              //replace anything except numbers and letters with an underscore
              $file_name = preg_replace("/([^a-z0-9])/", '_', strtolower($file_name));
              //replace multiple underscores with a single one
              $file_name = preg_replace("/_+/", '_', $file_name);
              $file_name .= '_'. substr(uniqid(rand(), true),0,5). '.'. $file_info['extension'];
              // apply new, prefixed file name by token replacing the path pattern
              $file_path = token_replace($pattern . '/', 'node', $node);
              $file_name = $file_path . $file_name;
            }else{
              // apply new, prefixed file name by token replacing the path pattern
              $file_name = str_replace(array(' ', "\n", "\t"), '_', token_replace($pattern . '/', 'node', $node)) . $file['filename'];
            }
            // SECURITY NOTE:
            // Tokens include user supplied information and could provide an attack vector.
            // The current method of creating directories prevents the use of .. or other malicious
            // paths, but future developers should keep this in mind when modifying the following code	
            // Create the directory if it doesn't exist yet.
            $dirs = explode('/', dirname($file_name));
            $directory = file_directory_path();
            while (count($dirs)) {
              $directory .= '/' . array_shift($dirs);
              file_check_directory($directory, FILE_CREATE_DIRECTORY);
            }
            //move file to new subfolder
            if (file_move($file['filepath'], $file_name, FILE_EXISTS_RENAME)) {
              //update node file array with new path, if needed
              $node->files[$key]['filepath'] = $file_name; 
              // update file record in database
              db_query("UPDATE {files} SET filepath = '%s' WHERE fid = %d", $file['filepath'], $file['fid']);
            }
            //drupal_set_message('<pre>AFTER:'.print_r($node->files[$key],1).'</pre>');
          }
        }
      }
    }
    break;
  }
}