Magento 2 Integration

*/


use Unbxd\ProductFeed\Model\Indexer\Product\Full\DataSourceProviderInterface;
use Unbxd\ProductFeed\Logger\LoggerInterface;
use Magento\Framework\DB\Adapter\AdapterInterface;
use Magento\Catalog\Api\ProductRepositoryInterface;
use Magento\Review\Model\RatingFactory;
use Unbxd\ProductFeed\Helper\Data as HelperData;
use Exception;


class ProductRatingDataProvider implements DataSourceProviderInterface
{
   /**
    * Related data source code
    */
   const DATA_SOURCE_CODE = 'rating_productfeed_extension';




   const REVIEW_COUNT = "reviewCount";


   const RATING_SUM = "ratingSum";


   const FINAL_RATING = "finalRating";
  


    /**
    * @var LoggerInterface
    */
   private $logger;


    /**
    * @var HelperData
    */
   private $helperData;


   protected $productRepository;


 
   /**
    *
    *
    * @var RatingFactory
    */
   protected $ratingFactory;




   /**
    * Constructor.
    */
   public function __construct(ProductRepositoryInterface $productRepository,LoggerInterface $logger, HelperData $helperData, RatingFactory $ratingFactory) {
       $this->productRepository = $productRepository;
       $this->logger = $logger->create("feed");
       $this->helperData = $helperData;
       $this->ratingFactory = $ratingFactory;


   }


   /**
    * {@inheritdoc}
    */
   public function getDataSourceCode()
   {  
       return self::DATA_SOURCE_CODE;
   }


   /**
    * Add custom code here
    *
    * {@inheritdoc}
    */
   public function appendData($storeId, array $indexData)
   {
       /* product ID is the entity id in magento , add your custom logic for your custom attribute */
       foreach (array_keys($indexData) as $productId) {
           try {
               if ($productId != "fields"){
                   /**
                    * Replace the logic within this if condition to that of yours
                    */
                   $entitySummary = $this->ratingFactory->create()->getEntitySummary($productId);
                   if($entitySummary){
                       $data = $entitySummary->getData();
                       if($data && array_key_exists("count",$data)){
                           $reviewCount = $data["count"];
                           $indexData[$productId][self::REVIEW_COUNT] = $reviewCount;
                           $ratingSum = $data["sum"];
                           $indexData[$productId][self::RATING_SUM] = $ratingSum;
                           $ratingAvg = round($ratingSum/(20*$reviewCount));
                           $indexData[$productId][self::FINAL_RATING] = $ratingAvg;
                       }
                   }
               }
           } catch (\Exception $e) {
               $this->logger->error('Error Getting Entity Summary -'.$productId. $e->__toString());
           }
       }
       $this->addIndexedFields($indexData,self::REVIEW_COUNT);
       $this->addIndexedFields($indexData,self::RATING_SUM);
       $this->addIndexedFields($indexData,self::FINAL_RATING);


       /**
        * Replace the second argument with that of the attribute name which was included in line 75
        * addIndexedFields accepts a third optional argument which should one of the following values ('text','longText','decimal','number','link','date','bool','sku','path')
        * */
       return $indexData;
   }


   /**
    * @param $indexData
    * @return
    */
   private function addIndexedFields(array &$indexData,$attrName,$fieldType = "number")
   {
       $alreadyExistFields = array_key_exists('fields', $indexData) ? $indexData['fields'] : [];
       $indexData['fields'] = array_merge($alreadyExistFields, [$attrName => [
           'fieldName' => $attrName,
           'dataType' => $fieldType,
           'multiValued' => false, /*set it to true if the attribute will carry more than one value for the same product */
           'autoSuggest' => false
]]);
   }
}