<?php
// $Id: apachesolr_search.module,v 1.1.2.6.2.131 2009-12-27 16:47:37 pwolanin Exp $

/**
 * @file
 *   Provides a content search implementation for node content for use with the
 *   Apache Solr search application.
 */

/**
 * Implementation of hook_help().
 */
function apachesolr_search_help($section) {
  switch ($section) {
    case 'admin/settings/apachesolr/index':
      if (variable_get('apachesolr_read_only', 0)) {
        return t('Operating in read-only mode; updates are disabled.');
      }
      $remaining = 0;
      $total = 0;
      // Collect the stats
      $status = module_invoke('apachesolr_search', 'search', 'status');
      $remaining += $status['remaining'];
      $total += $status['total'];

      return t('The search index is generated by !cron. %percentage of the site content has been sent to the server. There @items left to send.', array(
        '!cron' => l(t('running cron'), 'admin/reports/status/run-cron', array('query' => array('destination' => 'admin/settings/apachesolr/index'))),
        '%percentage' => ((int)min(100, 100 * ($total - $remaining) / max(1, $total))) .'%',
        '@items' => format_plural($remaining, t('is 1 item'), t('are @count items')
      )));
  }
}

/**
 * Implementation of hook_menu().
 */
function apachesolr_search_menu() {
  $items['admin/settings/apachesolr/query-fields'] = array(
    'title'            => 'Search fields',
    'page callback'    => 'apachesolr_search_settings_page',
    'access arguments' => array('administer search'),
    'weight'           => 1,
    'type'             => MENU_LOCAL_TASK,
    'file'             => 'apachesolr_search.admin.inc',
  );
  $items['admin/settings/apachesolr/content-bias'] = array(
    'title'            => 'Content bias settings',
    'page callback'    => 'apachesolr_boost_settings_page',
    'access arguments' => array('administer search'),
    'weight'           => 1,
    'type'             => MENU_LOCAL_TASK,
    'file'             => 'apachesolr_search.admin.inc',
  );

  return $items;
}

 /**
 * Implementation of hook_menu_alter().
 */
function apachesolr_search_menu_alter(&$menu) {
  if (isset($menu['search/apachesolr_search/%menu_tail'])) {
    $menu['search']['page callback'] = 'apachesolr_search_view';
    $menu['search/apachesolr_search/%menu_tail']['page callback'] = 'apachesolr_search_view';
  }
  if (variable_get('apachesolr_search_make_default', 0)) {
    if (isset($menu['search/node/%menu_tail'])) {
      // Hide the node search tab.
      $menu['search/node/%menu_tail']['type'] = MENU_CALLBACK;
      unset($menu['search/node/%menu_tail']['title callback'], $menu['search/node/%menu_tail']['title arguments']);
      $menu['search/node/%menu_tail']['title'] = 'Search';
    }
    if (isset($menu['search/apachesolr_search/%menu_tail'])) {
      // Alter the solr search tab
      $menu['search/apachesolr_search/%menu_tail']['weight'] = -10;
      unset($menu['search/apachesolr_search/%menu_tail']['title callback'], $menu['search/apachesolr_search/%menu_tail']['title arguments']);
      $menu['search/apachesolr_search/%menu_tail']['title'] = 'Content';
    }
  }
  if (variable_get('apachesolr_search_taxonomy_links', 0)) {
    if (isset($menu['taxonomy/term/%'])) {
      $menu['taxonomy/term/%']['page callback'] = 'apachesolr_search_taxonomy_term_page';
      $menu['taxonomy/term/%']['file path'] = drupal_get_path('module', 'apachesolr_search');
      $menu['taxonomy/term/%']['file'] = 'apachesolr.taxonomy.inc';
    }
  }
}

/**
 * Implementation of hook_update_index().
 */
function apachesolr_search_update_index() {
  $cron_limit = variable_get('apachesolr_cron_limit', 50);
  $rows = apachesolr_get_nodes_to_index('apachesolr_search', $cron_limit);
  apachesolr_index_nodes($rows, 'apachesolr_search');
}

/**
 * Implementation of hook_apachesolr_types_exclude().
 */
function apachesolr_search_apachesolr_types_exclude($namespace) {
  if ($namespace == 'apachesolr_search') {
    $excluded_types = variable_get('apachesolr_search_excluded_types', array());
    return array_filter($excluded_types);
  }
}

/**
 * Implementation of hook_search().
 */
function apachesolr_search_search($op = 'search', $keys = NULL) {

  switch ($op) {
    case 'name':
      return t('Search');

    case 'reset':
      apachesolr_clear_last_index('apachesolr_search');
      return;

    case 'status':
      return apachesolr_index_status('apachesolr_search');

    case 'search':
      $filters = isset($_GET['filters']) ? $_GET['filters'] : '';
      $solrsort = isset($_GET['solrsort']) ? $_GET['solrsort'] : '';
      $page = isset($_GET['page']) ? $_GET['page'] : 0;
      try {
        $results = apachesolr_search_execute($keys, $filters, $solrsort, 'search/' . arg(1), $page);
        return $results;
      }
      catch (Exception $e) {
        watchdog('Apache Solr', nl2br(check_plain($e->getMessage())), NULL, WATCHDOG_ERROR);
        apachesolr_failure(t('Solr search'), $keys);
      }
      break;
  } // switch
}

/**
 * Re-implementation of search_view().
 */
function apachesolr_search_view($type = NULL) {
  // Search form submits with POST but redirects to GET.
  $results = '';
  if (!isset($_POST['form_id'])) {
    if (empty($type)) {
      // Note: search/X can not be a default tab because it would take on the
      // path of its parent (search). It would prevent remembering keywords when
      // switching tabs. This is why we drupal_goto to it from the parent instead.
      drupal_goto('search/apachesolr_search');
    }
    $keys = trim(search_get_keys());
    $filters = '';
    if ($type == 'apachesolr_search' && isset($_GET['filters'])) {
      $filters = trim($_GET['filters']);
    }
    // Only perform search if there is non-whitespace search term or filters:
    if ($keys || $filters) {
      // Log the search keys:
      $log = $keys;
      if ($filters) {
        $log .= 'filters='. $filters;
      }
      watchdog('search', '%keys (@type).', array('%keys' => $log, '@type' => t('Search')), WATCHDOG_NOTICE, l(t('results'), 'search/'. $type .'/'. $keys));

      // Collect the search results:
      $results = search_data($keys, $type);

      if ($results) {
        $results = theme('box', t('Search results'), $results);
      }
      else {
        $results = theme('box', t('Your search yielded no results'), variable_get('apachesolr_search_noresults', apachesolr_search_noresults()));
      }
    }
  }
  // Construct the search form.
  return drupal_get_form('search_form', NULL, $keys, $type) . $results;
}

function apachesolr_search_noresults() {
      return t('<ul>
<li>Check if your spelling is correct, or try removing filters.</li>
<li>Remove quotes around phrases to match each word individually: <em>"blue drop"</em> will match less than <em>blue drop</em>.</li>
<li>You can require or exclude terms using + and -: <em>big +blue drop</em> will require a match on <em>blue</em> while <em>big blue -drop</em> will exclude results that contain <em>drop</em>.</li>
</ul>');

}

/**
 * Execute a search results based on keyword, filter, and sort strings.
 *
 * @throws Exception
 */
function apachesolr_search_execute($keys, $filters, $solrsort, $base_path = '', $page = 0, $caller = 'apachesolr_search') {

  $params = array();
  // This is the object that knows about the query coming from the user.
  $query = apachesolr_drupal_query($keys, $filters, $solrsort, $base_path);
  if (empty($query)) {
    throw new Exception(t('Could not construct a Solr query in function apachesolr_search_search()'));
  }

  // This is the object that does the communication with the solr server.
  $solr = apachesolr_get_solr();
  $params += apachesolr_search_basic_params($query);
  if ($keys) {
    $params += apachesolr_search_highlighting_params($query);
    $params += apachesolr_search_spellcheck_params($query);
  }
  else {
    // No highlighting, use the teaser as a snippet.
    $params['fl'] .= ',teaser';
  }
  apachesolr_search_add_facet_params($params, $query);
  apachesolr_search_add_boost_params($params, $query, $solr);

  // Allow modules to alter the query prior to statically caching it.
  // This can e.g. be used to add available sorts.
  foreach (module_implements('apachesolr_prepare_query') as $module) {
    $function_name = $module . '_apachesolr_prepare_query';
    $function_name($query, $params, $caller);
  }

  // Cache the built query. Since all the built queries go through
  // this process, all the hook_invocations will happen later
  $current_query = apachesolr_current_query($query);

  // This hook allows modules to modify the query and params objects.
  apachesolr_modify_query($query, $params, $caller);
  $params['start'] = $page * $params['rows'];

  if (!$query) {
    return array();
  }

  if (('' == $keys) && isset($params['fq'])) {
    // Move the fq params to the q.alt for better performance.
    $params['q.alt'] = implode(' ', $params['fq']);
    unset($params['fq']);
  }

  // We must run htmlspecialchars() here since converted entities are in the index.
  // and thus bare entities &, > or < won't match.
  $response = $solr->search(htmlspecialchars($query->get_query_basic(), ENT_NOQUOTES, 'UTF-8'), $params['start'], $params['rows'], $params);
  // The response is cached so that it is accessible to the blocks and anything
  // else that needs it beyond the initial search.
  apachesolr_static_response_cache($response);
  apachesolr_has_searched(TRUE);
  // Add search terms and filters onto the breadcrumb.
  // We use $current_query to avoid exposing, for example, nodeaccess
  // filters in the breadcrumb.
  drupal_set_breadcrumb(array_merge(menu_get_active_breadcrumb(), $current_query->get_breadcrumb()));
  return apachesolr_process_response($response, $query, $params);
}

function apachesolr_search_basic_params($query) {
  $params = array(
    'fl' => 'id,nid,title,comment_count,type,created,changed,score,path,url,uid,name',
    'rows' => variable_get('apachesolr_rows', 10),
    'facet' => 'true',
    'facet.mincount' => 1,
    'facet.sort' => 'true'
  );
  return $params;
}

/**
 * Add highlighting settings to the search params.
 *
 * These settings are set in solrconfig.xml.
 * See the defaults there.
 * If you wish to override them, you can via settings.php
 */
function apachesolr_search_highlighting_params($query) {
  $params['hl'] = variable_get('apachesolr_hl_active', NULL);
  $params['hl.fragsize']= variable_get('apachesolr_hl_textsnippetlength', NULL);
  $params['hl.simple.pre'] = variable_get('apachesolr_hl_pretag', NULL);
  $params['hl.simple.post'] = variable_get('apachesolr_hl_posttag', NULL);
  $params['hl.snippets'] = variable_get('apachesolr_hl_numsnippets', NULL);
  $params['hl.fl'] = variable_get('apachesolr_hl_fieldtohightlight', NULL);
  return $params;
}

function apachesolr_search_spellcheck_params($query) {
  $params = array();
  if (variable_get('apachesolr_search_spellcheck', FALSE)) {
    //Add new parameter to the search request
    $params['spellcheck.q'] = $query->get_query_basic();
    $params['spellcheck'] = 'true';
  }
  return $params;
}

function apachesolr_search_add_facet_params(&$params, $query) {
  $facet_query_limits = variable_get('apachesolr_facet_query_limits', array());
  $facet_missing = variable_get('apachesolr_facet_missing', array());

  foreach (apachesolr_get_enabled_facets() as $module => $module_facets) {
    if (!module_exists($module)) {
      // When modules are disabled their facet settings may remain.
      continue;
    }
    foreach($module_facets as $delta => $facet_field) {
      // TODO: generalize handling of date and range facets.
      if ($module == 'apachesolr_search' && ($facet_field == 'created' || $facet_field == 'changed')) {
        list($start, $end, $gap) = apachesolr_search_date_range($query, $facet_field);
        if ($gap) {
          $params['facet.date'][] = $facet_field;
          $params['f.'. $facet_field .'.facet.date.start'] = $start;
          $params['f.'. $facet_field .'.facet.date.end'] = $end;
          $params['f.'. $facet_field .'.facet.date.gap'] = $gap;
        }
      }
      else {
        $params['facet.field'][] = $facet_field;
        // Facet limits
        if (isset($facet_query_limits[$module][$delta])) {
          $params['f.' . $facet_field . '.facet.limit'] = $facet_query_limits[$module][$delta];
        }
        // Facet missing
        if (!empty($facet_missing[$module][$delta])) {
          $params['f.' . $facet_field . '.facet.missing'] = 'true';
        }
      }
    }
  }

  if (!empty($params['facet.field'])) {
    // Add a default limit for fields where no limit was set.
    $params['facet.limit'] = variable_get('apachesolr_facet_query_limit_default', 20);
  }
}

function apachesolr_search_add_boost_params(&$params, $query, $solr) {
  // Note - we have query fields set in solrconfig.xml, which will operate when
  // none are set.
  $qf = variable_get('apachesolr_search_query_fields', array());
  $fields = $solr->getFields();
  if ($qf && $fields) {
    foreach ($fields as $field_name => $field) {
      if (!empty($qf[$field_name])) {
        if ($field_name == 'body') {
          // Body is the only normed field.
          $qf[$field_name] *= 40.0;
        }
        $params['qf'][] = $field_name . '^'. $qf[$field_name];
      }
    }
  }

  $data = $solr->getLuke();
  if (isset($data->index->numDocs)) {
    $total = $data->index->numDocs;
  }
  else {
    $total = db_result(db_query("SELECT COUNT(nid) FROM {node}"));
  }
  // For the boost functions for the created timestamp, etc we use the
  // standard date-biasing function, as suggested (but steeper) at
  // http://wiki.apache.org/solr/DisMaxRequestHandler
  // rord() returns 1 for the newset doc, and the number in the index for
  // the oldest doc.  The function is thus: $total/(rord()*$steepness + $total).
  $date_settings = variable_get('apachesolr_search_date_boost', '4:200.0');
  list($date_steepness, $date_boost) = explode(':', $date_settings);
  if ($date_boost) {
    $params['bf'][] = "recip(rord(created),$date_steepness,$total,$total)^$date_boost";
  }
  // Boost on comment count.
  $comment_settings = variable_get('apachesolr_search_comment_boost', '0:0');
  list($comment_steepness, $comment_boost) = explode(':', $comment_settings);
  if ($comment_boost) {
    $params['bf'][] = "recip(rord(comment_count),$comment_steepness,$total,$total)^$comment_boost";
  }
  // Boost for a more recent comment or node edit.
  $changed_settings = variable_get('apachesolr_search_changed_boost', '0:0');
  list($changed_steepness, $changed_boost) = explode(':', $changed_settings);
  if ($changed_boost) {
    $params['bf'][] = "recip(rord(last_comment_or_change),$changed_steepness,$total,$total)^$changed_boost";
  }
  // Boost for nodes with sticky bit set.
  $sticky_boost = variable_get('apachesolr_search_sticky_boost', 0);
  if ($sticky_boost) {
    $params['bq'][] = "sticky:true^$sticky_boost";
  }
  // Boost for nodes with promoted bit set.
  $promote_boost = variable_get('apachesolr_search_promote_boost', 0);
  if ($promote_boost) {
    $params['bq'][] = "promote:true^$promote_boost";
  }
  // Modify the weight of results according to the node types.
  $type_boosts = variable_get('apachesolr_search_type_boosts', array());
  if (!empty($type_boosts)) {
    foreach ($type_boosts as $type => $boost) {
      // Only add a param if the boost is != 0 (i.e. > "Normal").
      if ($boost) {
        $params['bq'][] = "type:$type^$boost";
      }
    }
  }
}

function apachesolr_process_response($response, $query, $params) {
  $results = array();
  // We default to getting snippets from the body.
  $hl_fl = is_null($params['hl.fl']) ? 'body' : $params['hl.fl'];
  $total = $response->response->numFound;
  apachesolr_pager_init($total, $params['rows']);
  if ($total > 0) {
    foreach ($response->response->docs as $doc) {
      $extra = array();

      // Find the nicest available snippet.
      if (isset($response->highlighting->{$doc->id}->$hl_fl)) {
        $snippet = theme('apachesolr_search_snippets', $doc, $response->highlighting->{$doc->id}->$hl_fl);
      }
      elseif (isset($doc->teaser)) {
        $snippet = theme('apachesolr_search_snippets', $doc, array(truncate_utf8($doc->teaser, 256, TRUE)));
      }
      else {
        $snippet = '';
      }

      if (!isset($doc->body)) {
        $doc->body = $snippet;
      }
      $doc->created = strtotime($doc->created);
      $doc->changed = strtotime($doc->changed);
      // Allow modules to alter each document.
      drupal_alter('apachesolr_search_result', $doc);
      // Copy code from comment_nodeapi().
      $extra[] = format_plural($doc->comment_count, '1 comment', '@count comments');
      $results[] = array(
        'link' => url($doc->path, array('absolute' => TRUE)),
        'type' => apachesolr_search_get_type($doc->type),
        // template_preprocess_search_result() runs check_plain() on the title
        // again.  Decode to correct the display.
        'title' => htmlspecialchars_decode($doc->title, ENT_QUOTES),
        'user' => theme('username', $doc),
        'date' => $doc->created,
        'node' => $doc,
        'extra' => $extra,
        'score' => $doc->score,
        'snippet' => $snippet,
      );
    }

    // Hook to allow modifications of the retrieved results
    foreach (module_implements('apachesolr_process_results') as $module) {
      $function = $module .'_apachesolr_process_results';
      $function($results);
    }
  }
  return $results;
}

function apachesolr_search_date_range($query, $facet_field) {
  foreach ($query->get_filters($facet_field) as $filter) {
    // If we had an ISO date library we could use ISO dates
    // directly.  Instead, we convert to Unix timestamps for comparison.
    // Only use dates if we are able to parse into timestamps.
    $start = strtotime($filter['#start']);
    $end = strtotime($filter['#end']);
    if ($start && $end && ($start < $end)) {
        $start_iso = $filter['#start'];
        $end_iso = $filter['#end'];
      // Determine the drilldown gap for this range.
      $gap = apachesolr_date_gap_drilldown(apachesolr_date_find_query_gap($start_iso, $end_iso));
    }
  }
  // If there is no $delta field in query object, get initial
  // facet.date.* params from the DB and determine the best search
  // gap to use.  This callback assumes $delta is 'changed' or 'created'.
  if (!isset($start_iso)) {
    $start_iso = apachesolr_date_iso(db_result(db_query("SELECT MIN($facet_field) FROM {node} WHERE status = 1")));
    $end_iso = apachesolr_date_iso(db_result(db_query("SELECT MAX($facet_field) FROM {node} WHERE status = 1")));
    $gap = apachesolr_date_determine_gap($start_iso, $end_iso);
  }
  // Return a query range from the beginning of a gap period to the beginning
  // of the next gap period.  We ALWAYS generate query ranges of this form
  // and the apachesolr_date_*() helper functions require it.
  return array("$start_iso/$gap", "$end_iso+1$gap/$gap", "+1$gap");
}

/**
 * Implementation of hook_apachesolr_facets().
 *
 * Returns an array keyed by block delta.
 */
function apachesolr_search_apachesolr_facets() {
  $facets = array();

  $facets['type'] = array(
    'info' => t('Apache Solr Search: Filter by content type'),
    'facet_field' => 'type',
  );
  $facets['uid'] = array(
    'info' => t('Apache Solr Search: Filter by author'),
    'facet_field' => 'uid',
  );
  $facets['language'] = array(
    'info' => t('Apache Solr Search: Filter by language'),
    'facet_field' => 'language',
  );

  $facets['changed'] = array(
    'info' => t('Apache Solr Search: Filter by updated date'),
    'facet_field' => 'changed',
  );
  $facets['created'] = array(
    'info' => t('Apache Solr Search: Filter by post date'),
    'facet_field' => 'created',
  );

  // A book module facet.
  if (module_exists('book')) {
    $facets['is_book_bid'] = array(
      'info' => t('Apache Solr Search: Filter by Book'),
      'facet_field' => 'is_book_bid',
    );
  }

  // Get taxonomy vocabulary facets.
  if (module_exists('taxonomy')) {
    $vocabs = taxonomy_get_vocabularies();
    foreach ($vocabs as $vid => $vocab) {
      // In this case the delta and facet field are the same.
      $delta = 'im_vid_' . $vid;
      $facets[$delta] = array(
        'info' => t('Apache Solr Search: Filter by taxonomy @name', array('@name' => $vocab->name)),
        'facet_field' => $delta,
      );
    }
  }

  // Get CCK field facets.
  $fields = apachesolr_cck_fields();
  if ($fields) {
    foreach ($fields as $name => $field) {
      // $delta can only be 32 chars, and the CCK field name may be this
      // long also, so we cannot add anything to it.
      $facets[$field['field_name']] = array(
        'info' => t('Apache Solr Search: Filter by @field', array('@field' => $field['label'])),
        'facet_field' => apachesolr_index_key($field),
      );
    }
  }
  return $facets;
}

/**
 * Implementation of hook_block().
 */
function apachesolr_search_block($op = 'list', $delta = 0, $edit = array()) {

  switch ($op) {
    case 'list':
      $enabled_facets = apachesolr_get_enabled_facets('apachesolr_search');
      $facets = apachesolr_search_apachesolr_facets();
      // Add the blocks
      $blocks = array();
      foreach ($enabled_facets as $delta => $facet_field) {
        if (isset($facets[$delta])) {
          $blocks[$delta] = $facets[$delta] + array('cache' => BLOCK_CACHE_PER_PAGE,);
        }
      }
      $blocks['currentsearch'] = array(
        'info' => t('Apache Solr Search: Current search'),
        'cache' => BLOCK_CACHE_PER_PAGE,
      );
      return $blocks;

    case 'view':
      if (apachesolr_has_searched()) {
        // Get the query and response. Without these no blocks make sense.
        $response = apachesolr_static_response_cache();
        if (empty($response)) {
          return;
        }
        $query = apachesolr_current_query();

        $facets = apachesolr_get_enabled_facets('apachesolr_search');
        if (empty($facets[$delta]) && ($delta != 'currentsearch')) {
          return;
        }

        // Get information needed by the taxonomy blocks about limits.
        $initial_limits = variable_get('apachesolr_facet_query_initial_limits', array());
        $limit_default = variable_get('apachesolr_facet_query_initial_limit_default', 10);

        // Handle taxonomy vocabulary facets
        if ((strpos($delta, 'im_vid_') === 0)) {
          return apachesolr_search_taxonomy_facet_block($response, $query, $delta);
        }

        switch ($delta) {
          case 'currentsearch':
            return apachesolr_search_currentsearch_block($response, $query);
          case 'is_book_bid':
            return apachesolr_facet_block($response, $query, 'apachesolr_search', $delta, $delta, t('Filter by book'), 'apachesolr_search_get_book');
          case 'language':
            return apachesolr_facet_block($response, $query, 'apachesolr_search', $delta, $delta, t('Filter by language'), 'apachesolr_search_language_name');
           case 'uid':
            return apachesolr_facet_block($response, $query, 'apachesolr_search', $delta, $delta, t('Filter by author'), 'apachesolr_search_get_username');
          case 'type':
            return apachesolr_facet_block($response, $query, 'apachesolr_search', $delta, $delta, t('Filter by type'), 'apachesolr_search_get_type');
          case 'changed':
            return apachesolr_date_facet_block($response, $query, 'apachesolr_search', $delta, $delta, t('Filter by modification date'));
          case 'created':
            return apachesolr_date_facet_block($response, $query, 'apachesolr_search', $delta, $delta, t('Filter by post date'));

          default:
           if ($fields = apachesolr_cck_fields()) {
            foreach ($fields as $name => $field) {
              if ($field['field_name'] == $delta) {
                $index_key = apachesolr_index_key($field);
                return apachesolr_facet_block($response, $query, 'apachesolr_search', $delta, $index_key, t('Filter by @field', array('@field' => $field['label'])));
              }
            }
          }
        }
        break;
      }
      break;

    case 'configure':
      if ($delta != 'currentsearch') {
        return apachesolr_facetcount_form('apachesolr_search', $delta);
      }
      break;

    case 'save':
      if ($delta != 'currentsearch') {
        apachesolr_facetcount_save($edit);
      }
      break;
  }
}

/**
 * Generate a list including the field and all its children.
 */
function apachesolr_search_collect_children($field) {
  $remove[] = $field;
  if (!empty($field['#children'])) {
    foreach ($field['#children'] as $child_field) {
      $remove = array_merge($remove, apachesolr_search_collect_children($child_field));
    }
  }
  return $remove;
}

/**
 * Generate the facet block for a taxonomy vid delta.
 */
function apachesolr_search_taxonomy_facet_block($response, $query, $delta) {
  $vid = substr($delta, 7);
  if (!module_exists('taxonomy') || !is_numeric($vid)) {
    return;
  }

  // Check that we have a response and a valid vid.
  if (is_object($response->facet_counts->facet_fields->$delta) && ($vocab = taxonomy_vocabulary_load($vid))) {
    $reflect_hierarchy = apachesolr_search_get_hierarchical_vocabularies();
    $contains_active = FALSE;
    $facets = array();

    foreach ($response->facet_counts->facet_fields->$delta as $tid => $count) {
       // TODO - for now we don't handle facet missing.
      if ($tid != '_empty_') {
        $active = $query->has_filter('tid', $tid);
        if ($active) {
          $contains_active = TRUE;
        }
        $facets[$tid] = array(
          '#name' => 'tid',
          '#value' => $tid,
          '#exclude' => FALSE,
          '#count' => $count,
          '#parent' => 0,
          '#children' => array(),
          '#has_children' => FALSE,
          '#active' => $active,
        );
      }
    }

    if ($facets && $reflect_hierarchy[$vocab->vid]) {
      $placeholders = db_placeholders($facets);
      $tids = array_keys($facets);
      // @todo: faster as 2x separate queries?
      $result = db_query("SELECT tid, parent FROM {term_hierarchy} WHERE parent > 0 AND (tid IN ($placeholders) OR parent IN ($placeholders))", array_merge($tids, $tids));
      while ($term = db_fetch_object($result)) {
        // Mark all terms that are parents for later CSS class.
        // We assume data in the Solr index is complete - potential for some
        // breakage here.
        if (isset($facets[$term->parent])) {
          $facets[$term->parent]['#has_children'] = TRUE;
          if (isset($facets[$term->tid])) {
            $facets[$term->tid]['#parent'] = $term->parent;
            // Use a reference so we see the updated data.
            $facets[$term->parent]['#children'][] = &$facets[$term->tid];
          }
        }
      }
      // Check for the case like starting on a taxonomy/term/$tid page
      // where parents are not marked as active.
      // @todo: can we make this more efficient?
      do {
        $added_active = FALSE;
        foreach ($facets as $tid => $field) {
          if ($field['#active'] && $field['#parent'] && !$facets[$field['#parent']]['#active']) {
            // This parent has an active child.
            $added_active = TRUE;
            $query->add_filter('tid', $field['#parent']);
            $facets[$field['#parent']]['#active'] = TRUE;
          }
        }
      } while ($added_active);
      foreach ($facets as $tid => $field) {
        if (!empty($field['#parent'])) {
          // We will render it via its parent.
          unset($facets[$tid]);
        }
      }
    }

    $items = apachesolr_search_nested_facet_items($query, $facets, $response->response->numFound);
    // Process all terms into an item list
    if ($items && ($response->response->numFound > 1 || $contains_active)) {
      $limit = isset($initial_limits['apachesolr_search'][$delta]) ? $initial_limits['apachesolr_search'][$delta] : $limit_default;
      return array(
        'subject' => t('Filter by @name', array('@name' => $vocab->name)),
        'content' => theme('apachesolr_facet_list', $items, $limit),
      );
    }
  }
}

/**
 * Callback function for the 'Filter by book' facet block.
 */
function apachesolr_search_get_book($facet, &$options) {
  if (is_numeric($facet)) {
    return db_result(db_query('SELECT title FROM {node} WHERE nid = %d', $facet));
  }
  else {
    $options['html'] = TRUE;
    return theme('placeholder', t('Not in any book'));
  }
}

function apachesolr_search_language_name($lang) {
  static $list = NULL;

  if (!isset($list)) {
    if (function_exists('locale_language_list')) {
      $list = locale_language_list();
    }
    $list['und'] = t('Language neutral');
    // TODO - remove this line - only present for rc4 update.
    $list['zxx'] = $list['und'];
  }
  return ($lang && isset($list[$lang])) ? $list[$lang] : $lang;
}


/**
 * Recursive function that returns a nested array of facet values for use with
 * theme_item_list().
 *
 * @param $query
 *   The current Solr query.
 * @param $facets
 *   Array of facet items to prepare for rendering, possibly as nested lists.
 * @param $num_found
 *   The number of documents in the current response.
 * @param $sort
 *   If true, the returned list will be sorted based on the count of each
 *   facets, it's text representation and wither it's active.  If false,
 *   the facets will be returned in the order they were received.
 */
function apachesolr_search_nested_facet_items($query, $facets, $num_found, $sort = TRUE) {

  $items = array();
  foreach($facets as $field) {
    $facet_text = theme('apachesolr_breadcrumb_' . $field['#name'], $field['#value'], $field['#exclude']);
    if (!$facet_text) {
      $facet_text = $field['#value'];
    }
    $link = array();
    $new_query = clone $query;
    if (!empty($field['#active'])) {
      // '*' sorts before all numbers.
      $sortpre = '*';
      foreach (apachesolr_search_collect_children($field) as $child) {
        $new_query->remove_filter($child['#name'], $child['#value']);
      }
      $options['query'] = $new_query->get_url_queryvalues();
      $link['data'] = theme('apachesolr_unclick_link', $facet_text, $new_query->get_path(), $options);
    }
    else {
      $sortpre = 1000000 - $field['#count'];
      $new_query->add_filter($field['#name'], $field['#value']);
      $options = array('query' => $new_query->get_url_queryvalues());
      $link['data'] = theme('apachesolr_facet_link', $facet_text, $new_query->get_path(), $options, $field['#count'], FALSE, $num_found);
    }
    // We don't display children unless the parent is clicked.
    if (!empty($field['#children']) && $field['#active'] == TRUE) {
      $link['children'] = apachesolr_search_nested_facet_items($query, $field['#children'], $num_found, $sort);
      $link['class'] = "expanded-facet";
    }
    elseif (!empty($field['#has_children'])) {
      $link['class'] = "collapsed";
    }
    $items[$sortpre . '*' . $facet_text . $field['#name'] . $field['#value']] = $link;
  }

  if ($sort) {
    ksort($items);
  }
  return array_values($items);
}

/**
 * Callback function for the 'Filter by name' facet block.
 */
function apachesolr_search_get_username($facet) {
  if (is_numeric($facet)) {
    return theme('apachesolr_breadcrumb_uid', $facet);
  }
  return '';
}

/**
 * Callback function for the 'Filter by type' facet block.
 */
function apachesolr_search_get_type($facet) {
  $type = node_get_types('name', $facet);
  // A disabled or missing node type returns FALSE.
  return ($type === FALSE) ? $facet : $type;
}

/**
 * Implementation of hook_form_[form_id]_alter().
 *
 * This adds the 0 option to the search admin form.
 */
function apachesolr_search_form_search_admin_settings_alter(&$form, $form_state) {
  $form['indexing_throttle']['search_cron_limit']['#options']['0'] = '0';
  ksort($form['indexing_throttle']['search_cron_limit']['#options']);
}

/**
 * Implementation of hook_form_[form_id]_alter().
 */
function apachesolr_search_form_search_theme_form_alter(&$form, $form_state) {
  apachesolr_search_form_search_block_form_alter($form, $form_state);
}

/**
 * Implementation of hook_form_[form_id]_alter().
 */
function apachesolr_search_form_search_block_form_alter(&$form, $form_state) {
  if (variable_get('apachesolr_search_make_default', 0)) {
    if (!isset($form['#submit'])) {
      $form['#submit'] = array('apachesolr_search_search_box_form_submit');
    }
    else {
      $key = array_search('search_box_form_submit', $form['#submit']);
      if ($key !== FALSE) {
        // Replace the search module's function.
        $form['#submit'][$key] = 'apachesolr_search_search_box_form_submit';
      }
    }
  }
}

/**
 * Process a block search form submission.
 */
function apachesolr_search_search_box_form_submit($form, &$form_state) {
  $form_id = $form['form_id']['#value'];
  $keys = $form_state['values'][$form_id];
  // Handle Apache webserver clean URL quirks.
  if (variable_get('clean_url', '0')) {
    $keys = str_replace('+', '%2B', $keys);
  }
  $form_state['redirect'] = 'search/apachesolr_search/'. trim($keys);
}

/**
 * Implementation of hook_form_[form_id]_alter().
 *
 * This adds spelling suggestions, retain filters to the search form.
 */
function apachesolr_search_form_search_form_alter(&$form, $form_state) {
  if ($form['module']['#value'] == 'apachesolr_search') {
    $form['#submit'] = array('apachesolr_search_form_search_submit');
    // No other modification make sense unless a query is active.
    // Note - this means that the query must always be run before
    // calling drupal_get_form('search_form').
    $apachesolr_has_searched = apachesolr_has_searched();

    $queryvalues = array();
    if ($apachesolr_has_searched) {
      $query = apachesolr_current_query();
      $queryvalues = $query->get_url_queryvalues();
    }

    $form['basic']['apachesolr_search']['#tree'] = TRUE;
    $form['basic']['apachesolr_search']['queryvalues'] = array(
      '#type' => 'hidden',
      '#default_value' => serialize($queryvalues),
    );
    $form['basic']['apachesolr_search']['get'] = array(
      '#type' => 'hidden',
      '#default_value' => serialize(array_diff_key($_GET, array('q' => 1, 'page' => 1, 'filters' => 1, 'solrsort' => 1, 'retain-filters' => 1))),
    );
    if ($queryvalues || isset($form_state['post']['apachesolr_search']['retain-filters'])) {
      $form['basic']['apachesolr_search']['retain-filters'] = array(
        '#type' => 'checkbox',
        '#title' => t('Retain current filters'),
        '#default_value' => (int) isset($_GET['retain-filters']),
      );
    }

    if (variable_get('apachesolr_search_spellcheck', FALSE) && $apachesolr_has_searched && ($response = apachesolr_static_response_cache())) {
      //Get spellchecker suggestions into an array.
      $suggestions = get_object_vars($response->spellcheck->suggestions);

      if ($suggestions) {
        //Get the original query and replace words.
        $query = apachesolr_current_query();

        foreach($suggestions as $word => $value) {
          $replacements[$word] = $value->suggestion[0];
        }
        $new_keywords = strtr($query->get_query_basic(), $replacements);

        // Show only if suggestion is different than current query.
        if ($query->get_query_basic() != $new_keywords) {
          $form['basic']['suggestion'] = array(
            '#prefix' => '<div class="spelling-suggestions">',
            '#suffix' => '</div>',
            '#type' => 'item',
            '#title' => t('Did you mean'),
            '#value' => l($new_keywords, $query->get_path($new_keywords)),
          );
        }
      }
    }
  }
}

/**
 * Added form submit function to account for Apache mode_rewrite quirks.
 *
 * @see apachesolr_search_form_search_form_alter()
 */
function apachesolr_search_form_search_submit($form, &$form_state) {
  $fv = $form_state['values'];
  $keys = $fv['processed_keys'];
  $base = 'search/'. $fv['module'] . '/';
  if (variable_get('clean_url', '0')) {
    $keys = str_replace('+', '%2B', $keys);
  }
  $get = unserialize($fv['apachesolr_search']['get']);
  $queryvalues = unserialize($fv['apachesolr_search']['queryvalues']);
  if (!empty($fv['apachesolr_search']['retain-filters']) && $queryvalues) {
    $get = $queryvalues + $get;
    $get['retain-filters'] = '1';
  }
  $form_state['redirect'] = array($base . $keys, $get);
  if ($keys == '' && !$queryvalues) {
    form_set_error('keys', t('Please enter some keywords.'));
  }
}

/**
 * Implementation of hook_form_[form_id]_alter().
 *
 * This adds options to the apachesolr admin form.
 */
function apachesolr_search_form_apachesolr_settings_alter(&$form, $form_state) {
  $form['advanced']['apachesolr_search_make_default'] = array(
    '#type' => 'radios',
    '#title' => t('Make Apache Solr Search the default'),
    '#default_value' => variable_get('apachesolr_search_make_default', 0),
    '#options' => array(0 => t('Disabled'), 1 => t('Enabled')),
    '#description' => t('Hides core node search, and makes the search block submit to Apache Solr Search'),
  );
  $form['advanced']['apachesolr_search_default_previous'] = array(
    '#type' => 'value',
    '#value' => variable_get('apachesolr_search_make_default', 0),
  );
  $form['advanced']['apachesolr_search_taxonomy_links'] = array(
    '#type' => 'radios',
    '#title' => t('Use Apache Solr for taxonomy links'),
    '#default_value' => variable_get('apachesolr_search_taxonomy_links', 0),
    '#description' => t('Note: Vocabularies that need this behavior need to be checked off on the <a href="@enabled_filters_url">enabled filters</a> settings page', array('@enabled_filters_url' => url('admin/settings/apachesolr/enabled-filters'))),
    '#options' => array(0 => t('Disabled'), 1 => t('Enabled')),
  );
  $form['advanced']['apachesolr_search_taxonomy_previous'] = array(
    '#type' => 'value',
    '#value' => variable_get('apachesolr_search_taxonomy_links', 0),
  );

  $form['apachesolr_search_spellcheck'] = array(
    '#type' => 'checkbox',
    '#title' => t('Enable spellchecker and suggestions'),
    '#default_value' => variable_get('apachesolr_search_spellcheck', FALSE),
    '#description' => t('Enable spellchecker and get word suggestions. Also known as the "Did you mean ... ?" feature.'),
  );

  $form['#submit'][] = 'apachesolr_search_build_spellcheck';
  $form['#submit'][] = 'apachesolr_search_make_default_submit';
  // Move buttons to the bottom.
  $buttons = $form['buttons'];
  unset($form['buttons']);
  $form['buttons'] = $buttons;
}

/**
 * Form submit funtion - do a menu rebuild if needed.
 *
 * @see apachesolr_search_form_apachesolr_settings_alter()
 */
function apachesolr_search_make_default_submit($form, &$form_state) {
  // We use variable_get() instead of the form values so as to also handle reset to defaults.
  if ($form_state['values']['apachesolr_search_default_previous'] != variable_get('apachesolr_search_make_default', 0) ||
      $form_state['values']['apachesolr_search_taxonomy_previous'] != variable_get('apachesolr_search_taxonomy_links', 0)) {
    // Take account of path changes
    menu_rebuild();
  }
}

/**
 * Implementation of hook_form_[form_id]_alter().
 *
 * Rebuild (empty) the spellcheck dictionary when the index is deleted..
 */
function apachesolr_search_form_apachesolr_delete_index_form_alter(&$form, $form_state) {
  $form['submit']['#submit'][] = 'apachesolr_search_build_spellcheck';
}

function apachesolr_search_build_spellcheck() {
  try {
    $solr = apachesolr_get_solr();
    $params['spellcheck'] = 'true';
    $params['spellcheck.build'] = 'true';
    $response = $solr->search('solr', 0, 0, $params);
  }
  catch (Exception $e) {
    watchdog('Apache Solr', nl2br(check_plain($e->getMessage())), NULL, WATCHDOG_ERROR);
  }
}

/**
 * Implementation of hook_theme().
 */
function apachesolr_search_theme() {
  return array(
    'apachesolr_breadcrumb_is_book_bid' => array(
      'arguments' => array('bid' => NULL, 'exclude' => FALSE),
    ),
    'apachesolr_breadcrumb_uid' => array(
      'arguments' => array('uid' => NULL, 'exclude' => FALSE),
    ),
    'apachesolr_breadcrumb_tid' => array(
      'arguments' => array('tid' => NULL, 'exclude' => FALSE),
    ),
    'apachesolr_breadcrumb_type' => array(
      'arguments' => array('type' => NULL, 'exclude' => FALSE),
    ),
    'apachesolr_breadcrumb_language' => array(
      'arguments' => array('lang' => NULL, 'exclude' => FALSE),
    ),
    'apachesolr_breadcrumb_changed' => array(
      'arguments' => array('type' => NULL),
    ),
    'apachesolr_breadcrumb_created' => array(
      'arguments' => array('type' => NULL),
    ),
    'apachesolr_currentsearch' => array(
      'arguments' => array('total_found' => NULL, 'links' => NULL),
    ),
    'apachesolr_search_snippets' => array(
      'arguments' => array('doc' => NULL, 'snippets' => NULL),
    ),
  );
}

function theme_apachesolr_breadcrumb_language($lang, $exclude = FALSE) {
  return apachesolr_search_language_name($lang);
}

function theme_apachesolr_breadcrumb_date_range($range) {
  if (preg_match('@[\[\{](\S+) TO (\S+)[\]\}]@', $range, $match)) {
    return apachesolr_date_format_range($match[1], $match[2]);
  }
  return $range;
}

function theme_apachesolr_breadcrumb_changed($range) {
  return theme_apachesolr_breadcrumb_date_range($range);
}

function theme_apachesolr_breadcrumb_created($range) {
  return theme_apachesolr_breadcrumb_date_range($range);
}

/**
 * Return the username from $uid
 */
function theme_apachesolr_breadcrumb_uid($uid) {
  if ($uid == 0) {
    return variable_get('anonymous', t('Anonymous'));
  }
  else {
    return db_result(db_query("SELECT name FROM {users} WHERE uid = %d", $uid));
  }
}

/**
 * Return the term name from $tid, or $tid as a fallback.
 */
function theme_apachesolr_breadcrumb_tid($tid) {
  if (function_exists('taxonomy_get_term')) {
    if ($term = taxonomy_get_term($tid)) {
      return $term->name;
    }
  }
  return $tid;
}

/**
 * Return the human readable text for a content type.
 */
function theme_apachesolr_breadcrumb_type($type) {
  return node_get_types('name', $type);
}

/**
 * Return the title of a book.
 */
function theme_apachesolr_breadcrumb_is_book_bid($bid) {
  if (is_numeric($bid)) {
    return db_result(db_query('SELECT title FROM {node} WHERE nid = %d', $bid));
  }
  else {
    return t('Not in any book');
  }
}

/**
 * Return current search block contents
 */
function theme_apachesolr_currentsearch($total_found, $links) {
  return theme_item_list($links, format_plural($total_found, 'Search found 1 item', 'Search found @count items'));
}

/**
 * Theme the highlighted snippet text for a search entry.
 *
 * @param object $doc
 * @param array $snippets
 *
 */
function theme_apachesolr_search_snippets($doc, $snippets) {
  return implode(' ... ', $snippets) .' ...';
}


function apacehsolr_get_parent_terms($tids) {
  // Find the starting tid terms and then all their parents.
  $parent_terms = array();
  $new_tids = $tids;
  do {
    $result = db_query(db_rewrite_sql("SELECT t.tid, t.parent FROM {term_hierarchy} t WHERE t.tid IN (". db_placeholders($new_tids) .")",'t', 'tid'), $new_tids);
    $new_tids = array();
    while ($term = db_fetch_object($result)) {
      $parent_terms[$term->tid] = $term;
      if ($term->parent > 0) {
        $new_tids[] = $term->parent;
      }
    }
  } while ($new_tids);
  return $parent_terms;
}

/**
 * Return the contents of the "Current search" block.
 *
 * @param $response
 *   The Solr response object.
 * @param $query
 *   The Solr query object.
 */
function apachesolr_search_currentsearch_block($response, $query) {
  $fields = $query->get_filters();
  $links = array();

  // If current search has keys, offer current search without them
  if ($keys = $query->get_query_basic()) {
    $links[] = theme('apachesolr_unclick_link', $keys, $query->get_path(''), array('query' => $query->get_url_queryvalues()));
  }
  // Find all taxonomy terms to be treated in a hierarchy.
  if (module_exists('taxonomy')) {
    $reflect_hierarchy = apachesolr_search_get_hierarchical_vocabularies();
    foreach($fields as $index => $field) {
      if ($field['#name'] && 'tid' == $field['#name']) {
        $term = taxonomy_get_term($field['#value']);
        if ($reflect_hierarchy[$term->vid]) {
          $fields[$index] += array('#parent' => 0, '#children' => array());
          // Just save the index for later lookup.
          $facets[$term->tid] = $index;
        }
      }
    }
    if ($facets) {
      // Get all term hierarchy information.
      $all_terms = apacehsolr_get_parent_terms(array_keys($facets));
      foreach ($all_terms as $tid => $term) {
        if (!isset($facets[$tid])) {
          // This is a parent that is missing from the query.  E.g. we started
          // on a taxonomy/term/$tid page.
          $query->add_filter('tid', $tid);
          // Ordering is wonky, but oh well...
          $fields[] = array('#name' => 'tid', '#value' => $tid, '#exclude' => FALSE, '#parent' => 0, '#children' => array());
          // Get the index of the newly added facet.
          end($fields);
          $facets[$tid] = key($fields);
        }
      }
      foreach ($all_terms as $tid => $term) {
        $index = $facets[$term->tid];
        if (isset($facets[$term->parent])) {
          // Use a reference so we see the updated data.
          $fields[$facets[$term->parent]]['#children'][] = &$fields[$index];
          $fields[$index]['#parent'] = $term->parent;
        }
      }
    }
  }

  // We don't directly render any items with a parent.
  foreach($fields as $index => $field) {
    $fields[$index]['#active'] = TRUE;
    if (!empty($fields[$index]['#parent']) || !$field['#name']) {
      // We will render it via its parent.
      unset($fields[$index]);
    }
  }

  $links = array_merge($links, apachesolr_search_nested_facet_items($query, $fields, $response->response->numFound, FALSE));
  if ($links) {
    $content = theme('apachesolr_currentsearch', $response->response->numFound, $links);
    return array('subject' => t('Current search'), 'content' => $content);
  }
}

/**
 * Return an array of taxonomy facets that should be displayed hierarchically.
 */
function apachesolr_search_get_hierarchical_vocabularies() {
  static $result;

  if (!isset($result)) {
    $result = array();
    if (function_exists('taxonomy_get_vocabularies')) {
      $vocabularies = taxonomy_get_vocabularies();
      $force_flat = variable_get('apachesolr_search_force_flat_vocabularies', array());
      foreach ($vocabularies as $voc) {
        // If the vocabulary is not multiple-parent hierarchical and not
        // freetagging and not designated to be forced to display flat.
        if ($voc->hierarchy != 2 && $voc->tags != 1 && empty($force_flat[$voc->vid])) {
          $result[$voc->vid] = 1;
        }
      }
    }
  }

  return $result;
}