/**
* Load titles that have been rated by other users which are similar to this.
*
* @param SearchObject_Solr|SearchObject_Base $db
* @param UserRating $ratedTitle
* @param integer $userId
* @param array $ratedTitles
* @param array $suggestions
* @param integer[] $notInterestedTitles
* @return int The number of suggestions for this title
*/
static function getSimilarlyRatedTitles($db, $ratedTitle, $userId, $ratedTitles, &$suggestions, $notInterestedTitles)
{
$numRecommendations = 0;
//If there is no ISBN, can we come up with an alternative algorithm?
//Possibly using common ratings with other patrons?
//Get a list of other patrons that have rated this title and that like it as much or more than the active user..
$otherRaters = new UserRating();
//Query the database to get items that other users who rated this liked.
$sqlStatement = "SELECT resourceid, record_id, " . " sum(case rating when 5 then 10 when 4 then 6 end) as rating " . " FROM `user_rating` inner join resource on resource.id = user_rating.resourceid WHERE userId in " . " (select userId from user_rating where resourceId = " . $ratedTitle->resourceid . " and rating >= 4 " . " and userid != " . $userId . ") " . " and rating >= 4 " . " and resourceId != " . $ratedTitle->resourceid . " and deleted = 0 " . " group by resourceid order by rating desc limit 10";
//Sort so the highest titles are on top and limit to 10 suggestions.
$otherRaters->query($sqlStatement);
if ($otherRaters->N > 0) {
//Other users have also rated this title.
while ($otherRaters->fetch()) {
//Process the title
disableErrorHandler();
if (!($ownedRecord = $db->getRecord($otherRaters->record_id))) {
//Old record which has been removed? Ignore for purposes of suggestions.
continue;
}
enableErrorHandler();
//get the title from the Solr Index
if (isset($ownedRecord['isbn'])) {
if (strpos($ownedRecord['isbn'][0], ' ') > 0) {
$isbnInfo = explode(' ', $ownedRecord['isbn'][0]);
$isbn = $isbnInfo[0];
} else {
$isbn = $ownedRecord['isbn'][0];
}
$isbn13 = strlen($isbn) == 13 ? $isbn : ISBNConverter::convertISBN10to13($isbn);
$isbn10 = strlen($isbn) == 10 ? $isbn : ISBNConverter::convertISBN13to10($isbn);
} else {
$isbn13 = '';
$isbn10 = '';
}
//See if we can get the series title from the record
if (isset($ownedRecord['series'])) {
$series = $ownedRecord['series'][0];
} else {
$series = '';
}
$similarTitle = array('title' => $ownedRecord['title'], 'title_short' => $ownedRecord['title_short'], 'author' => isset($ownedRecord['author']) ? $ownedRecord['author'] : '', 'publicationDate' => $ownedRecord['publishDate'], 'isbn' => $isbn13, 'isbn10' => $isbn10, 'upc' => isset($ownedRecord['upc']) ? $ownedRecord['upc'][0] : '', 'recordId' => $ownedRecord['id'], 'id' => $ownedRecord['id'], 'libraryOwned' => true, 'isCurrent' => false, 'shortId' => substr($ownedRecord['id'], 1), 'format_category' => isset($ownedRecord['format_category']) ? $ownedRecord['format_category'] : '', 'format' => $ownedRecord['format'], 'recordtype' => $ownedRecord['recordtype'], 'series' => $series, 'grouping_term' => $ownedRecord['grouping_term']);
$numRecommendations++;
Suggestions::addTitleToSuggestions($ratedTitle, $similarTitle['title'], $similarTitle['recordId'], $similarTitle, $ratedTitles, $suggestions, $notInterestedTitles);
}
}
return $numRecommendations;
}
