<?php
// $Id: extractor.module,v 1.8 2010/09/21 01:43:12 alexb Exp $

/**
 * @file
 * Main API functions.
 *
 * Variables:
 *
 * Name: extractor_engine
 */

/**
 * Implementation of hook_plugins().
 */
function extractor_feeds_plugins() {
  $info['ExtractorSyndicationParser'] = array(
    'name' => 'Common syndication parser with term extraction',
    'description' => 'Parse XML feeds in RSS 1, RSS 2 or Atom format, extract terms from titles and descriptions.',
    'handler' => array(
      'parent' => 'FeedsSyndicationParser',
      'class' => 'ExtractorSyndicationParser',
      'file' => 'ExtractorSyndicationParser.inc',
      'path' => drupal_get_path('module', 'extractor'),
    ),
  );
  if (feeds_library_exists('simplepie.inc', 'simplepie')) {
    $info['ExtractorSimplePieParser'] = array(
      'name' => 'SimplePie parser with term extraction',
      'description' => 'Use <a href="http://simplepie.org/">SimplePie</a> to parse XML feeds in RSS 1, RSS 2 or Atom format, extract terms from titles and descriptions.',
      'handler' => array(
        'parent' => 'FeedsSimplePieParser',
        'class' => 'ExtractorSimplePieParser',
        'file' => 'ExtractorSimplePieParser.inc',
        'path' => drupal_get_path('module', 'extractor'),
      ),
    );
  }
  $info['ExtractorTermProcessor'] = array(
    'name' => 'Extractor Term Processor',
    'description' => 'Marks every imported term for use as extraction term.',
    'handler' => array(
      'parent' => 'FeedsTermProcessor',
      'class' => 'ExtractorTermProcessor',
      'file' => 'ExtractorTermProcessor.inc',
      'path' => drupal_get_path('module', 'extractor'),
    ),
  );
  return $info;
}

/**
 * Implementation of hook_form_taxonomy_form_vocabulary_alter().
 */
function extractor_form_taxonomy_form_vocabulary_alter(&$form, &$form_state) {
  $form['extractor'] = array(
    '#type' => 'fieldset',
    '#title' => t('Term extraction'),
    '#collapsible' => TRUE,
  );
  $lookup = FALSE;
  $vocabularies = variable_get('extractor_simple_vocabularies', array());
  if ($vocabularies[$form['vid']['#value']] || $vocabularies[$form['module']['#value']]) {
    $lookup = TRUE;
  }
  $form['extractor']['extractor_lookup'] = array(
    '#type' => 'checkbox',
    '#title' => t('Use all terms of this vocabulary for extraction'),
    '#description' => t('If checked new posts containing terms of this vocabulary will be automatically tagged with them. You can alternatively pick single terms for extraction on term forms.'),
    '#default_value' => $lookup,
  );
  $form['#submit'][] = 'extractor_form_vocabulary_submit';
}

/**
 * Submit handler for extractor_form_taxonomy_form_vocabulary_alter().
 */
function extractor_form_vocabulary_submit($form, &$form_state) {
  $vocabularies = variable_get('extractor_simple_vocabularies', array());
  unset($vocabularies[$form_state['values']['module']], $vocabularies[$form_state['values']['vid']]);

  if (!empty($form_state['values']['extractor_lookup'])) {
    $id = strpos($form_state['values']['module'], 'features_') === 0 ? $form_state['values']['module'] : $form_state['values']['vid'];
    $vocabularies[$id] = TRUE;
  }
  variable_set('extractor_simple_vocabularies', $vocabularies);
}

/**
 * Implementation of specific hook_form_alter().
 */
function extractor_form_taxonomy_form_term_alter(&$form, &$form_state) {
  $form['submit']['#weight'] = isset($form['submit']['#weight']) ? $form['submit']['#weight'] + 1 : 1;
  $form['delete']['#weight'] = isset($form['delete']['#weight']) ? $form['submit']['#weight'] + 1 : 1;
  $form['extractor'] = array(
    '#type' => 'fieldset',
    '#title' => t('Term extraction'),
    '#collapsible' => TRUE,
  );

  if (extractor_use_vocabulary($form['vid']['#value'])) {
    $description = t('All terms of this vocabulary are used for term extraction. You can change this setting on the vocabulary form.');
    $default = $disabled = TRUE;
  }
  else {
    $description = t('If checked new posts containing this term will be automatically tagged with it.');
    $default = isset($form['tid']['#value']) ? extractor_use_term($form['tid']['#value']) : 0;
    $disabled = FALSE;
  }
  $form['extractor']['extractor_lookup'] = array(
    '#type' => 'checkbox',
    '#title' => t('Use for term extraction'),
    '#description' => $description,
    '#default_value' => $default,
    '#disabled' => $disabled,
  );
}

/**
 * Implementation of hook_taxonomy().
 */
function extractor_taxonomy($op = NULL, $type = NULL, $term = NULL){
  if ($type =='term' && $term) {
    switch ($op) {
      case 'delete':
        db_query("DELETE FROM {extractor_lookup} WHERE tid = %d", $term['tid']);
        break;
      case 'update':
        db_query("DELETE FROM {extractor_lookup} WHERE tid = %d", $term['tid']);
      case 'insert':
        if (!empty($term['extractor_lookup'])) {
          drupal_write_record('extractor_lookup', $term);
        }
        break;
    }
  }
}

/**
 * Implementation of hook_feeds_term_processor_targets_alter().
 */
function extractor_feeds_term_processor_targets_alter(&$targets, $vid) {
  $targets['extractor_lookup'] = array(
    'name' => t('Use for term extraction'),
    'description' => t('Boolean value determining whether a term is used for term extraction or not.'),
  );
}

/**
 * Determine whether a term should be used for term extraction or not.
 */
function extractor_use_term($tid) {
  return db_result(db_query("SELECT tid FROM {extractor_lookup} WHERE tid = %d", $tid));
}

/**
 * Determine whether a term should be used for term extraction or not.
 */
function extractor_use_vocabulary($vid) {
  $vocabulary = taxonomy_vocabulary_load($vid);
  $vocabularies = variable_get('extractor_simple_vocabularies', array());
  return (isset($vocabularies[$vocabulary->vid]) || isset($vocabularies[$vocabulary->module]));
}

/**
 * Main API function.
 *
 * @param $text
 *   The text to perform the term extraction on.
 * @param $library
 *   The extraction library to use. Possible options: 'extractor_simple' or
 *   'placemaker'.
 * @param $config
 *   An array containing a configuration for the library in use.
 *
 * @return
 *   An array of terms found in $text. They keys of the array contain the
 *   taxonomy term ids and the values the term names.
 */
function extractor_extract($text, $library = 'extractor_simple', $config = array()) {
  extractor_include($library);
  $extract = "{$library}_extract";
  return $extract($text, $config);
}

/**
 * Include from libraries.
 */
function extractor_include($name) {
  static $included;
  if (!$included[$name]) {
    include drupal_get_path('module', 'extractor') .'/libraries/'. $name .'.inc';
    $included[$name] = TRUE;
  }
}