wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Repo\Diff;

use Diff\DiffOp\Diff\Diff;
use Diff\DiffOp\DiffOpChange;

/**
 * Represents the difference between two Statement objects.
 * @fixme Contains references and rank? It's a StatementDifference!
 *
 * @license GPL-2.0-or-later
 * @author Tobias Gritschacher < tobias.gritschacher@wikimedia.de >
 * @author Thiemo Kreuz
 */
class ClaimDifference {

    /**
     * @var DiffOpChange|null
     */
    private $mainSnakChange;

    /**
     * @var Diff|null
     */
    private $qualifierChanges;

    /**
     * @var Diff|null
     */
    private $referenceChanges;

    /**
     * @var DiffOpChange|null
     */
    private $rankChange;

    /**
     * @param DiffOpChange|null $mainSnakChange
     * @param Diff|null $qualifierChanges
     * @param Diff|null $referenceChanges
     * @param DiffOpChange|null $rankChange
     */
    public function __construct(
        DiffOpChange $mainSnakChange = null,
        Diff $qualifierChanges = null,
        Diff $referenceChanges = null,
        DiffOpChange $rankChange = null
    ) {
        $this->mainSnakChange = $mainSnakChange;
        $this->qualifierChanges = $qualifierChanges;
        $this->referenceChanges = $referenceChanges;
        $this->rankChange = $rankChange;
    }

    /**
     * @return Diff
     */
    public function getReferenceChanges() {
        return $this->referenceChanges ?: new Diff( [], false );
    }

    /**
     * @return DiffOpChange|null
     */
    public function getMainSnakChange() {
        return $this->mainSnakChange;
    }

    /**
     * @return DiffOpChange|null
     */
    public function getRankChange() {
        return $this->rankChange;
    }

    /**
     * @return Diff
     */
    public function getQualifierChanges() {
        return $this->qualifierChanges ?: new Diff( [], false );
    }

    /**
     * @param mixed $target
     *
     * @return bool
     */
    public function equals( $target ) {
        if ( $target === $this ) {
            return true;
        }

        if ( !( $target instanceof self ) ) {
            return false;
        }

        return $this->mainSnakChange == $target->mainSnakChange
            && $this->getQualifierChanges()->equals( $target->getQualifierChanges() )
            && $this->getReferenceChanges()->equals( $target->getReferenceChanges() )
            && $this->rankChange == $target->rankChange;
    }

    /**
     * Checks whether the difference represented by this object is atomic, which means
     * the Statement has only changed either its main snak, qualifiers, references or rank.
     *
     * @return bool
     */
    public function isAtomic() {
        $aspects = 0;

        if ( $this->mainSnakChange !== null ) {
            $aspects++;
        }
        if ( !$this->getQualifierChanges()->isEmpty() ) {
            $aspects++;
        }
        if ( !$this->getReferenceChanges()->isEmpty() ) {
            $aspects++;
        }
        if ( $this->rankChange !== null ) {
            $aspects++;
        }

        return $aspects === 1;
    }

}