wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\DataModel\Serializers;

use Serializers\DispatchableSerializer;
use Serializers\Exceptions\SerializationException;
use Serializers\Exceptions\UnsupportedObjectException;
use Serializers\Serializer;
use Wikibase\DataModel\Snak\Snak;
use Wikibase\DataModel\Snak\SnakList;
use Wikibase\DataModel\Statement\Statement;

/**
 * Package private
 *
 * @license GPL-2.0-or-later
 * @author Thomas Pellissier Tanon
 */
class StatementSerializer implements DispatchableSerializer {

    /** @var array */
    private $rankLabels = [
        Statement::RANK_DEPRECATED => 'deprecated',
        Statement::RANK_NORMAL => 'normal',
        Statement::RANK_PREFERRED => 'preferred',
    ];

    /**
     * @var Serializer
     */
    private $mainSnakSerializer;

    /**
     * @var Serializer
     */
    private $qualifierSnaksSerializer;

    /**
     * @var Serializer
     */
    private $referencesSerializer;

    public function __construct(
        Serializer $mainSnakSerializer,
        Serializer $qualifierSnaksSerializer,
        Serializer $referencesSerializer
    ) {
        $this->mainSnakSerializer = $mainSnakSerializer;
        $this->qualifierSnaksSerializer = $qualifierSnaksSerializer;
        $this->referencesSerializer = $referencesSerializer;
    }

    /**
     * @see Serializer::isSerializerFor
     *
     * @param mixed $object
     *
     * @return bool
     */
    public function isSerializerFor( $object ) {
        return $object instanceof Statement;
    }

    /**
     * @see Serializer::serialize
     *
     * @param Statement $object
     *
     * @throws SerializationException
     * @return array
     */
    public function serialize( $object ) {
        if ( !$this->isSerializerFor( $object ) ) {
            throw new UnsupportedObjectException(
                $object,
                'StatementSerializer can only serialize Statement objects'
            );
        }

        return $this->getSerialized( $object );
    }

    private function getSerialized( Statement $statement ) {
        $serialization = [
            'mainsnak' => $this->mainSnakSerializer->serialize( $statement->getMainSnak() ),
            'type' => 'statement',
        ];

        $this->addQualifiersToSerialization( $statement, $serialization );
        $this->addGuidToSerialization( $statement, $serialization );
        $this->addRankToSerialization( $statement, $serialization );
        $this->addReferencesToSerialization( $statement, $serialization );

        return $serialization;
    }

    private function addGuidToSerialization( Statement $statement, array &$serialization ) {
        $guid = $statement->getGuid();
        if ( $guid !== null ) {
            $serialization['id'] = $guid;
        }
    }

    private function addRankToSerialization( Statement $statement, array &$serialization ) {
        $serialization['rank'] = $this->rankLabels[$statement->getRank()];
    }

    private function addReferencesToSerialization( Statement $statement, array &$serialization ) {
        $references = $statement->getReferences();

        if ( $references->count() != 0 ) {
            $serialization['references'] = $this->referencesSerializer->serialize(
                $statement->getReferences()
            );
        }
    }

    private function addQualifiersToSerialization( Statement $statement, &$serialization ) {
        $qualifiers = $statement->getQualifiers();

        if ( $qualifiers->count() !== 0 ) {
            $serialization['qualifiers'] = $this->qualifierSnaksSerializer->serialize( $qualifiers );
            $serialization['qualifiers-order'] = $this->buildQualifiersOrderList( $qualifiers );
        }
    }

    private function buildQualifiersOrderList( SnakList $snaks ) {
        $list = [];

        /**
         * @var Snak $snak
         */
        foreach ( $snaks as $snak ) {
            $id = $snak->getPropertyId()->getSerialization();
            if ( !in_array( $id, $list ) ) {
                $list[] = $id;
            }
        }

        return $list;
    }

}