<?php


namespace App\Elasticsearch\DataProvider;


use ApiPlatform\Core\Bridge\Elasticsearch\DataProvider\Extension\RequestBodySearchCollectionExtensionInterface;
use ApiPlatform\Core\Bridge\Elasticsearch\Metadata\Document\Factory\DocumentMetadataFactoryInterface;
use ApiPlatform\Core\DataProvider\ContextAwareCollectionDataProviderInterface;
use ApiPlatform\Core\DataProvider\Pagination;
use ApiPlatform\Core\DataProvider\RestrictedDataProviderInterface;
use Doctrine\ORM\EntityManagerInterface;
use Elasticsearch\Client;

/**
 * Class ElasticsearchCollectionDataProvider
 * @package App\Elasticsearch\DataProvider
 */
class ElasticsearchCollectionDataProvider implements ContextAwareCollectionDataProviderInterface, RestrictedDataProviderInterface
{
    public const CONTEXT_ENTITY_CLASS = 'entity_class';
    public const CONTEXT_ELASTICSEARCH_CLASS = 'elasticsearch_class';

    /** @var EntityManagerInterface */
    private $entityManager;

    /** @var Client */
    private $client;

    /** @var DocumentMetadataFactoryInterface */
    private $documentMetadataFactory;

    /** @var Pagination */
    private $pagination;

    /** @var iterable|RequestBodySearchCollectionExtensionInterface[] */
    private $collectionExtensions;

    public function __construct(
        EntityManagerInterface $entityManager,
        Client $client,
        DocumentMetadataFactoryInterface $documentMetadataFactory,
        Pagination $pagination,
        iterable $collectionExtensions = []
    )
    {
        $this->entityManager = $entityManager;
        $this->client = $client;
        $this->documentMetadataFactory = $documentMetadataFactory;
        $this->pagination = $pagination;
        $this->collectionExtensions = $collectionExtensions;
    }

    /**
     * {@inheritDoc}
     * @throws \ApiPlatform\Core\Bridge\Elasticsearch\Exception\IndexNotFoundException
     */
    public function getCollection(string $resourceClass, string $operationName = null, array $context = [])
    {
        $entityClassName = $context[self::CONTEXT_ENTITY_CLASS];
        $searchClassName = $context[self::CONTEXT_ELASTICSEARCH_CLASS];

        $documentMetadata = $this->documentMetadataFactory->create($searchClassName);
        $body = [];

        foreach ($this->collectionExtensions as $collectionExtension) {
            $body = $collectionExtension->applyToCollection($body, $searchClassName, $operationName, $context);
        }

        if (!isset($body['query']) && !isset($body['aggs'])) {
            $body['query'] = ['match_all' => new \stdClass()];
        }

        $body['_source'] = ['id'];

        $limit = $body['size'] = $body['size'] ?? $this->pagination->getLimit($entityClassName, $operationName, $context);
        $offset = $body['from'] = $body['from'] ?? $this->pagination->getOffset($entityClassName, $operationName, $context);

        $documents = $this->client->search([
            'index' => $documentMetadata->getIndex(),
            'type' => $documentMetadata->getType(),
            'body' => $body,
        ]);

        $ids = [];

        foreach ($documents['hits']['hits'] as $document) {
            $ids[] = $document['_source']['id'];
        }

        $queryBuilder = null;

        if (count($ids) > 0) {
            $idsList = implode("', '", $ids);
            $idsList = "'{$idsList}'";

            $queryBuilder = $this->entityManager->createQueryBuilder();

            $queryBuilder
                ->from($entityClassName, 't')
                ->select('t')
                ->where($queryBuilder->expr()->in('t.id', $ids))
                ->orderBy("FIELD(t.id, {$idsList})");
        }

        return new Paginator($queryBuilder, $documents, $limit, $offset);
    }

    /** @inheritDoc */
    public function supports(string $resourceClass, string $operationName = null, array $context = []): bool
    {
        return $operationName === 'search'; //isset($context[self::CONTEXT_ELASTICSEARCH_CLASS]);
    }
}