<?php
function _xmp_import_getXmpData($filename){
   $chunk_size = 1024;
   $buffer = NULL;

   if (($file_pointer = fopen($filename, 'r')) === FALSE){
      throw new RuntimeException('Could not open file for reading');
   }
   else{
       $found_start = FALSE;
       $i = 0;
       while (($chunk = fread($file_pointer, $chunk_size)) !== FALSE) {
          $i++;
          //if($i>=50){//avoid too much recursion
          //    return $buffer;
          //}
          if (($pos = strpos($chunk, '<x:xmpmeta')) !== FALSE){
             $found_start = TRUE;
             $buffer .= substr($chunk, $pos);
          }
          else if (($pos = strpos($buffer, '</x:xmpmeta>')) !== FALSE){
             //var_dump(($pos = strpos($finetag, '</x:xmpmeta>')));
             $buffer .= substr($chunk, 0, $pos + 12);
             //echo "found";
             break;
          }
          else if ($found_start){
              $buffer .= $chunk;
          }
          // end elseif // ($found_start) //
       }
       // end while // (($chunk = fread($file_pointer, $chunk_size) !== FALSE) //

       fclose($file_pointer);

       return $buffer;
   }
}
function _xmp_import_readXmpFromImage($filename){
    $buffer = _xmp_import_getXmpData($filename);
    $xmlDoc = new DOMDocument();
    $xmlDoc->loadXML($buffer);
    $children = $xmlDoc->childNodes;
    //print $xmlDoc->saveXML();
    foreach ($children as $child){
        $root = $child;
    }
    $bags = $root->getElementsByTagName("Bag");
    foreach($bags as $bag){
        $bagger = $bag;
    }
    $tags = $bagger->childNodes;
    foreach($tags as $tag){
        if(trim($tag->textContent)!=""){
            $gotTags[]=trim($tag->textContent);
        }
    }
    return $gotTags;
}
/**
 * From a given node we are going to get the imagepath of the image. if it's an image node
 * it's just going to be images[IMAGE_ORIGINAL]. If it's an imagefield node, we have to go
 * through the fields and look if there is an imagefield and then return the path
 *
 * @param $fields
 * @param $node
 * @return unknown_type
 */
function _xmp_import_get_image_path($fields, &$node) {
  if ($node->type == 'image') {
    return $node->images[IMAGE_ORIGINAL];
  }

  foreach ($fields as $field) {
    if ($field['type'] == 'filefield') {
      $tmp = $node->$field['field_name'];
      return $tmp[0]['filepath'];
    }
  }
  return NULL;
}
/*getting the image field in order to set alt and title*/
function _xmp_import_get_image_field_data($fields, &$node){
  if ($node->type == 'image') {
    //return $node->images[IMAGE_ORIGINAL];
      //dunno what to return
    return;
  }

  foreach ($fields as $field) {
    if ($field['type'] == 'filefield') {
      $tmp = $node->$field['field_name'];
      return $field['field_name'];
    }
  }
  return NULL;
}
/*hook_nodeapi*/
function xmp_import_nodeapi(&$node, $op, $teaser = NULL, $page = NULL){
    if ($teaser) {
        return;
    }
    switch ($op) {

    case 'update':
      //we just create nodes.
      break;

    case 'presave':
      $info = content_types($node->type);
      $fields = $info['fields'];
      $image_path = _xmp_import_get_image_path($fields, $node);
      $fid = db_result(db_query("SELECT fid FROM {files} WHERE filepath = '%s'", $image_path));
      $file = file_create_path($image_path);

      $tags = _xmp_import_readXmpFromImage($file);
      foreach($tags as $tag){
          $taxonomy[] = $tag;
      }
      if(strlen($node->taxonomy['tags'][2])>0){
          $taxterms = ", ".implode(", ", $taxonomy);
      }
      else $taxterms = implode(", ", $taxonomy);
      $node->taxonomy['tags'][2] .= $taxterms;

      //setting up field data
      $data = _xmp_import_get_image_field_data($fields, $node);
      $field = $data;
      //var_dump($data);
      $fielder = $node->$field;
      $fielder[0]['data']['alt'] = implode(", ", $taxonomy);
      $fielder[0]['data']['title'] = implode(", ", $taxonomy);
      $node->$field = $fielder;
      break;
    }
      //break;
}

?>