/**
* @param string $modelId Id of model
* @param integer $targetId Current value of primary key
*/
public static function updateRating($modelId, $targetId)
{
$likes = static::find()->where(['model_id' => $modelId, 'target_id' => $targetId, 'value' => self::VOTE_LIKE])->count();
$dislikes = static::find()->where(['model_id' => $modelId, 'target_id' => $targetId, 'value' => self::VOTE_DISLIKE])->count();
if ($likes + $dislikes !== 0) {
// Рейтинг = Нижняя граница доверительного интервала Вильсона (Wilson) для параметра Бернулли
// http://habrahabr.ru/company/darudar/blog/143188/
$rating = (($likes + 1.9208) / ($likes + $dislikes) - 1.96 * SQRT($likes * $dislikes / ($likes + $dislikes) + 0.9604) / ($likes + $dislikes)) / (1 + 3.8416 / ($likes + $dislikes));
} else {
$rating = 0;
}
$rating = round($rating * 10, 2);
$aggregateModel = AggregateRating::findOne(['model_id' => $modelId, 'target_id' => $targetId]);
if (null === $aggregateModel) {
$aggregateModel = new AggregateRating();
$aggregateModel->model_id = $modelId;
$aggregateModel->target_id = $targetId;
}
$aggregateModel->likes = $likes;
$aggregateModel->dislikes = $dislikes;
$aggregateModel->rating = $rating;
$aggregateModel->save();
}
