wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\DataModel\Services\Diff;

use Diff\DiffOp\AtomicDiffOp;
use Diff\DiffOp\Diff\Diff;
use Diff\DiffOp\DiffOpAdd;
use Diff\DiffOp\DiffOpChange;
use Diff\DiffOp\DiffOpRemove;
use Diff\Patcher\PatcherException;
use Wikibase\DataModel\Term\TermList;

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

    /**
     * @since 3.6
     *
     * @param TermList $terms
     * @param Diff $patch
     *
     * @throws PatcherException
     */
    public function patchTermList( TermList $terms, Diff $patch ) {
        foreach ( $patch as $lang => $diffOp ) {
            $this->patchTerm( $terms, $lang, $diffOp );
        }
    }

    /**
     * @see MapPatcher
     *
     * @param TermList $terms
     * @param string $lang
     * @param AtomicDiffOp $diffOp
     *
     * @throws PatcherException
     */
    private function patchTerm( TermList $terms, $lang, AtomicDiffOp $diffOp ) {
        $hasLang = $terms->hasTermForLanguage( $lang );

        switch ( true ) {
            case $diffOp instanceof DiffOpAdd:
                if ( !$hasLang ) {
                    $terms->setTextForLanguage( $lang, $diffOp->getNewValue() );
                }
                break;

            case $diffOp instanceof DiffOpChange:
                if ( $hasLang
                    && $terms->getByLanguage( $lang )->getText() === $diffOp->getOldValue()
                ) {
                    $terms->setTextForLanguage( $lang, $diffOp->getNewValue() );
                }
                break;

            case $diffOp instanceof DiffOpRemove:
                if ( $hasLang
                    && $terms->getByLanguage( $lang )->getText() === $diffOp->getOldValue()
                ) {
                    $terms->removeByLanguage( $lang );
                }
                break;

            default:
                throw new PatcherException( 'Invalid terms diff' );
        }
    }

}