<?php
// $Id:$

/**
 * On behalf implementation of hook_feedapi_mapper() for imagefield module.
 *
 * @see hook_feedapi_mapper()
 *
 * @todo:
 * - TODO: limit available fields to imagefields only
 * - TODO: fix detection of feed_element data
 * - TODO: fix temporary upload location / method
 * - TODO: batch-process images so to reduce php- / network timeout issues
 * - TODO: security audit
 *
 * Mapping flow
 *
 * 1) hook_feedapi_mapper('list')
 *
 * This operation is invoked when the mapper is about to present mapping
 * options to the user. When $op is 'list' the $node parameter contains the
 * type of the node at $node->type, all other parameters are not present.
 * Examine $node->type and determine which mapping targets are available.
 *
 * If no mapping target is available return FALSE.
 *
 * If a single mapping target is available return:
 * array(
 *   'single_target' => t('Single target'), // 'single_target' will be the value of $field_name on 'map'
 * )
 *
 * If multiple mapping targets are available return:
 * array(
 *   'target1' => t('Target 1'), // 'target1' will be the field name on 'map'
 *   'target2' => t('Target 2'), // 'target2' will be the field name on 'map'
 * )
 *
 * Feed Element Mapper also supports sub fields:
 * array(
 *   'multiple_targets' => array( // 'multiple_targets' will be the value of $field_name on 'map'
 *     'target1' => t('Target 1'), // 'target1' will be the value of $sub_field on 'map'
 *     'target2' => t('Target 2'), // 'target2' will be the value of $sub_field on 'map'
 *   )
 * )
 *
 *
 * 2) hook_feedapi_mapper('map')
 *
 * This operation is invoked when the actual mapping happens. If a user
 * selected the mapping functionality exposed on 'list' hook_feedapi_mapper
 * will be called on node prepare with $op == 'map', $node = feed item node the
 * mapping is performed on, $feed_element = the element of the feed that a user
 * chose as a mapping source, $field_name = the name of the field that a user
 * chose as a mapping target, $sub_field = the name of the sub field that a user
 * chose as a mapping target.
 *
 *
 * hook_feedapi_mapper('describe') is used to generate help text on the
 * mapping form.
 *
 * Which feed elements are available for mapping is up to the parser.
 *
 * @param $op
 *   Operation to perform.
 *   Value of $op is one of 'describe', 'list' or 'map'.
 * @param $node
 *   Drupal node object.
 * @param $feed_element
 *   Parameter only present on $op = 'map'
 *   Element of the feed to map from. A simple data type (number, string) or a
 *   one dimensional array of simple types.
 * @param $field_name
 *   Parameter only present on $op = 'map'
 *   Name of the field to map to.
 * @param $sub_field
 *   Parameter only present on $op = 'map'
 *   If given, a subfield on the node to map to.
 *   This parameter will depend on if the hook implementation returns a subfield on
 *   $op = 'list'.
 *
 */
function filefield_feedapi_mapper($op, $node, $feed_element = array(), $field_name = '', $sub_field = '') {
  
  switch ($op) {
    
    case 'describe':
      
      return t('Maps a feed element image element to an cck filefield in a node');

      break;
      
    case 'list':
      
      
      
      $info = content_types($node->type);
      $fields = array();
      
      if (!empty($info['fields']) && is_array($info['fields'])) {
        
        foreach ($info['fields'] as $field_name => $field) {
          
          if (in_array($field['type'], array('filefield'))) {
            $fields[$field_name] = isset($field['widget']['label']) ? $field['widget']['label'] : $field_name;
          }
      
        }
    
      }
    
      if (!empty($fields)) {
        return $fields;
      }
    
      return FALSE;
      
      break;
      
    case 'map':

      // mapping takes place here

      $imgurl = NULL;
      
      // extract image
      if (!empty($feed_element)) {
        
        if (!is_array($feed_element) && is_string($feed_element)) {
          
          $imgurl = $feed_element;
    
        }
        else {
          
          // FIXME: these expect "exhaustive parser"
          if (!empty($feed_element['#text'])) {
            $imgurl = $feed_element['#text'];
          }
          else if (!empty($feed_element['url']['#text'])) {
            $imgurl = $feed_element['url']['#text'];
          }
          
        }
        
        if (!empty($imgurl)) {
          
          // store image in temporary location
          $image = _filefield_feedapi_mapper_save_tmp($imgurl);
          // get field info
          $field = content_fields($field_name, $node->type);
          // retrieve all validators file must go through
          $validators = array_merge(filefield_widget_upload_validators($field), imagefield_widget_upload_validators($field));
          // determine where to save image
          $files_path = filefield_widget_file_path($field);
          // save file and get imagefiled information
          $file = field_file_save_file($image, $validators, $files_path, FILE_EXISTS_REPLACE);
          // set / replace first imagefield for content type
          $node->{$field_name} = array(0 => $file);
          
        }
        
      }
      
      return $node;
      
      break;
  
  }
    
}

/**
 * save file from url into temporary location
 *
 * @param string $url
 *    url to fetch contents from
 * @param integer $replace (optional)
 *    not used for now, in theory to define whether to replace existing file or not
 * @return string
 *    path to temporary file
 */
function _filefield_feedapi_mapper_save_tmp ($url, $replace = FILE_EXISTS_REPLACE) {
  
  if ($img = file_get_contents($url)) {
    
    // FIXME: clean up temp name for real
    $filename = basename($url);
    $filepath = realpath(file_directory_temp()) . DIRECTORY_SEPARATOR . 'tmp_filefield_' . $filename;
    
    if ($filepath && file_put_contents($filepath, $img)) {
        return $filepath;
    }
  
  }
  
  return FALSE;
  
}