wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Repo\ChangeOp;

use InvalidArgumentException;
use ValueValidators\Result;
use Wikibase\DataModel\Entity\EntityDocument;
use Wikibase\DataModel\Entity\EntityId;
use Wikibase\DataModel\Services\Statement\GuidGenerator;
use Wikibase\DataModel\Snak\Snak;
use Wikibase\DataModel\Statement\StatementList;
use Wikibase\DataModel\Statement\StatementListProvider;
use Wikibase\Lib\Summary;
use Wikibase\Repo\Validators\SnakValidator;

/**
 * Class for mainsnak change operation
 *
 * @license GPL-2.0-or-later
 * @author Tobias Gritschacher < tobias.gritschacher@wikimedia.de >
 * @author Daniel Kinzler
 * @author Bene* < benestar.wikimedia@gmail.com >
 */
class ChangeOpMainSnak extends ChangeOpBase {

    /**
     * @var string
     */
    private $statementGuid;

    /**
     * @var Snak
     */
    private $snak;

    /**
     * @var GuidGenerator
     */
    private $guidGenerator;

    /**
     * @var SnakValidator
     */
    private $snakValidator;

    /**
     * Constructs a new mainsnak change operation
     *
     * @param string $statementGuid
     * @param Snak $snak
     * @param GuidGenerator $guidGenerator
     * @param SnakValidator $snakValidator
     *
     * @throws InvalidArgumentException
     */
    public function __construct(
        $statementGuid,
        Snak $snak,
        GuidGenerator $guidGenerator,
        SnakValidator $snakValidator
    ) {
        if ( !is_string( $statementGuid ) ) {
            throw new InvalidArgumentException( '$statementGuid needs to be a string' );
        }

        $this->statementGuid = $statementGuid;
        $this->snak = $snak;
        $this->guidGenerator = $guidGenerator;
        $this->snakValidator = $snakValidator;
    }

    /**
     * @return string
     */
    public function getStatementGuid() {
        return $this->statementGuid;
    }

    /**
     * - a new claim with $snak as mainsnak gets added when $claimGuid is empty and $snak is set
     * - the claim's mainsnak gets set to $snak when $claimGuid and $snak are set
     *
     * @inheritDoc
     */
    public function apply( EntityDocument $entity, Summary $summary = null ) {
        if ( !( $entity instanceof StatementListProvider ) ) {
            throw new InvalidArgumentException( '$entity must be a StatementListProvider' );
        }

        $statements = $entity->getStatements();

        if ( !$this->statementGuid ) {
            $this->addStatement( $statements, $entity->getId(), $summary );
        } else {
            $this->setStatement( $statements, $summary );
        }

        return new GenericChangeOpResult( $entity->getId(), true );
    }

    /**
     * @param StatementList $statements
     * @param EntityId $entityId
     * @param Summary|null $summary
     */
    private function addStatement( StatementList $statements, EntityId $entityId, Summary $summary = null ) {
        $this->statementGuid = $this->guidGenerator->newGuid( $entityId );
        $statements->addNewStatement( $this->snak, null, null, $this->statementGuid );
        $this->updateSummary( $summary, 'create', '', $this->getClaimSummaryArgs( $this->snak ) );
    }

    /**
     * @param StatementList $statements
     * @param Summary|null $summary
     *
     * @throws ChangeOpException
     */
    private function setStatement( StatementList $statements, Summary $summary = null ) {
        $statement = $statements->getFirstStatementWithGuid( $this->statementGuid );

        if ( $statement === null ) {
            throw new ChangeOpException( "Entity does not have a statement with GUID " . $this->statementGuid );
        }

        $propertyId = $statement->getPropertyId();

        if ( !$propertyId->equals( $this->snak->getPropertyId() ) ) {
            throw new ChangeOpException( "Claim with GUID "
                . $this->statementGuid . " uses property "
                . $propertyId . ", can't change to "
                . $this->snak->getPropertyId() );
        }

        $statement->setMainSnak( $this->snak );
        $this->updateSummary( $summary, null, '', $this->getClaimSummaryArgs( $this->snak ) );
    }

    /**
     * @param Snak $mainSnak
     *
     * @return array
     */
    protected function getClaimSummaryArgs( Snak $mainSnak ) {
        $propertyId = $mainSnak->getPropertyId();
        return [ [ $propertyId->getSerialization() => $mainSnak ] ];
    }

    /**
     * @see ChangeOp::validate
     *
     * @param EntityDocument $entity
     *
     * @return Result
     */
    public function validate( EntityDocument $entity ) {
        return $this->snakValidator->validate( $this->snak );
    }

}