wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\DataModel\Services\Diff;

use Diff\Comparer\ComparableComparer;
use Diff\Differ\MapDiffer;
use Diff\DiffOp\Diff\Diff;
use UnexpectedValueException;
use Wikibase\DataModel\Statement\Statement;
use Wikibase\DataModel\Statement\StatementList;

/**
 * @since 3.6
 *
 * @license GPL-2.0-or-later
 * @author Jeroen De Dauw < jeroendedauw@gmail.com >
 */
class StatementListDiffer {

    /**
     * @since 1.0
     *
     * @param StatementList $fromStatements
     * @param StatementList $toStatements
     *
     * @return Diff
     * @throws UnexpectedValueException
     */
    public function getDiff( StatementList $fromStatements, StatementList $toStatements ) {
        return new Diff(
            $this->newDiffer()->doDiff(
                $this->toDiffArray( $fromStatements ),
                $this->toDiffArray( $toStatements )
            ),
            true
        );
    }

    private function newDiffer() {
        return new MapDiffer( false, null, new ComparableComparer() );
    }

    private function toDiffArray( StatementList $statementList ) {
        $statementArray = [];

        /**
         * @var Statement $statement
         */
        foreach ( $statementList as $statement ) {
            $statementArray[$statement->getGuid()] = $statement;
        }

        return $statementArray;
    }

}