wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Lib\Changes;

use Diff\DiffOp\Diff\Diff;
use Diff\DiffOp\DiffOpAdd;
use Diff\DiffOp\DiffOpChange;
use Diff\DiffOp\DiffOpRemove;

/**
 * @license GPL-2.0-or-later
 * @author Katie Filbert < aude.wiki@gmail.com >
 * @author Daniel Kinzler
 */
class ItemChange extends EntityChange {

    public function getSiteLinkDiff(): Diff {
        $aspects = $this->getCompactDiff();
        if ( !( $aspects instanceof EntityDiffChangedAspects ) ) {
            $this->logWarning( $aspects );
            return new Diff();
        }
        return $this->getDiffFromSiteLinkChanges( $aspects->getSiteLinkChanges() );
    }

    /**
     * @param array[] $siteLinkChanges
     * @return Diff
     */
    private function getDiffFromSiteLinkChanges( array $siteLinkChanges ): Diff {
        $siteLinkDiff = [];
        foreach ( $siteLinkChanges as $wiki => $change ) {
            if ( $change[0] === $change[1] ) {
                continue;
            }
            $siteLinkDiff[$wiki] = $this->getDiffFromSiteLinkChangesPerWiki( $change );
        }

        return new Diff( $siteLinkDiff, true );
    }

    private function getDiffFromSiteLinkChangesPerWiki( array $change ): Diff {
        if ( $change[0] === null && $change[1] !== null ) {
            return new Diff( [ 'name' => new DiffOpAdd( $change[1] ) ], true );
        } elseif ( $change[0] !== null && $change[1] === null ) {
            return new Diff( [ 'name' => new DiffOpRemove( $change[0] ) ], true );
        } else {
            return new Diff( [ 'name' => new DiffOpChange( $change[0], $change[1] ) ], true );
        }
    }

    private function logWarning( $obj ) {
        // This shouldn't happen, but we should be robust against corrupt, incomplete
        // or obsolete instances in the database, etc.
        $this->logger->warning( 'Cannot get sitelink diff from {class}. Change #{id}, type {type}', [
            'class' => $obj === null ? 'null' : get_class( $obj ),
            'id' => $this->getId(),
            'type' => $this->getType(),
        ] );
    }

}