wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\DataModel\Services\Diff;

use InvalidArgumentException;
use RuntimeException;
use Wikibase\DataModel\Entity\EntityDocument;

/**
 * @since 1.0
 *
 * @license GPL-2.0-or-later
 * @author Jeroen De Dauw < jeroendedauw@gmail.com >
 */
class EntityDiffer {

    /**
     * @var EntityDifferStrategy[]
     */
    private $differStrategies;

    public function __construct() {
        $this->registerEntityDifferStrategy( new ItemDiffer() );
        $this->registerEntityDifferStrategy( new PropertyDiffer() );
    }

    public function registerEntityDifferStrategy( EntityDifferStrategy $differStrategy ) {
        $this->differStrategies[] = $differStrategy;
    }

    /**
     * @param EntityDocument $from
     * @param EntityDocument $to
     *
     * @return EntityDiff
     * @throws InvalidArgumentException
     * @throws RuntimeException
     */
    public function diffEntities( EntityDocument $from, EntityDocument $to ) {
        $this->assertTypesMatch( $from, $to );

        return $this->getDiffStrategy( $from->getType() )->diffEntities( $from, $to );
    }

    private function assertTypesMatch( EntityDocument $from, EntityDocument $to ) {
        if ( $from->getType() !== $to->getType() ) {
            throw new InvalidArgumentException( 'Can only diff two entities of the same type' );
        }
    }

    /**
     * @param string $entityType
     *
     * @throws RuntimeException
     * @return EntityDifferStrategy
     */
    private function getDiffStrategy( $entityType ) {
        foreach ( $this->differStrategies as $diffStrategy ) {
            if ( $diffStrategy->canDiffEntityType( $entityType ) ) {
                return $diffStrategy;
            }
        }

        throw new RuntimeException( 'Diffing the provided types of entities is not supported' );
    }

    /**
     * @param EntityDocument $entity
     *
     * @return EntityDiff
     * @throws InvalidArgumentException
     */
    public function getConstructionDiff( EntityDocument $entity ) {
        return $this->getDiffStrategy( $entity->getType() )->getConstructionDiff( $entity );
    }

    /**
     * @param EntityDocument $entity
     *
     * @return EntityDiff
     * @throws InvalidArgumentException
     */
    public function getDestructionDiff( EntityDocument $entity ) {
        return $this->getDiffStrategy( $entity->getType() )->getDestructionDiff( $entity );
    }

}