wikimedia/mediawiki-extensions-Wikibase

<?php

declare( strict_types = 1 );

namespace Wikibase\Repo\Diff;

use Diff\DiffOp\Diff\Diff;
use Diff\DiffOp\DiffOp;
use Diff\DiffOp\DiffOpAdd;
use Diff\DiffOp\DiffOpChange;
use Diff\DiffOp\DiffOpRemove;
use MediaWiki\Html\Html;
use UnexpectedValueException;
use Wikimedia\Diff\WordLevelDiff;

/**
 * Class for generating views of DiffOp objects.
 *
 * @license GPL-2.0-or-later
 */
class BasicDiffView implements DiffView {

    /**
     * @var string[]
     */
    private $path;

    /**
     * @var Diff
     */
    private $diff;

    /**
     * @param string[] $path
     * @param Diff $diff
     */
    public function __construct( array $path, Diff $diff ) {
        $this->path = $path;
        $this->diff = $diff;
    }

    /**
     * Builds and returns the HTML to represent the Diff.
     */
    public function getHtml(): string {
        return $this->generateOpHtml( $this->path, $this->diff );
    }

    /**
     * Does the actual work.
     *
     * @param string[] $path
     * @param DiffOp $op
     *
     * @return string
     */
    protected function generateOpHtml( array $path, DiffOp $op ) {
        if ( $op->isAtomic() ) {
            $localizedPath = $path;

            $html = $this->generateDiffHeaderHtml( implode( ' / ', $localizedPath ) );

            //TODO: no path, but localized section title

            //FIXME: complex objects as values?
            if ( $op->getType() === 'add' ) {
                /** @var DiffOpAdd $op */
                '@phan-var DiffOpAdd $op';
                $html .= $this->generateHtmlDiffTableRow(
                    null,
                    $this->getAddedLine( $op->getNewValue() )
                );
            } elseif ( $op->getType() === 'remove' ) {
                /** @var DiffOpRemove $op */
                '@phan-var DiffOpRemove $op';
                $html .= $this->generateHtmlDiffTableRow(
                    $this->getDeletedLine( $op->getOldValue() ),
                    null
                 );
            } elseif ( $op->getType() === 'change' ) {
                /** @var DiffOpChange $op */
                '@phan-var DiffOpChange $op';
                $wordLevelDiff = new WordLevelDiff(
                    [ $op->getOldValue() ],
                    [ $op->getNewValue() ]
                );
                $html .= $this->generateHtmlDiffTableRow(
                    $wordLevelDiff->orig()[0],
                    $wordLevelDiff->closing()[0]
                 );
            } else {
                throw new UnexpectedValueException( 'Invalid diffOp type' );
            }
        } else {
            $html = '';
            // @phan-suppress-next-line PhanTypeNoPropertiesForeach
            foreach ( $op as $key => $subOp ) {
                $html .= $this->generateOpHtml(
                    array_merge( $path, [ $key ] ),
                    $subOp
                );
            }
        }

        return $html;
    }

    /**
     * Generates an HTML table row for a change diffOp
     * given HTML snippets representing old and new
     * sides of the Diff
     */
    protected function generateHtmlDiffTableRow( ?string $oldHtml, ?string $newHtml ): string {
        $html = Html::openElement( 'tr' );
        if ( $oldHtml !== null ) {
            $html .= Html::rawElement( 'td', [ 'class' => 'diff-marker', 'data-marker' => '−' ] );
            $html .= Html::rawElement( 'td', [ 'class' => 'diff-deletedline' ],
                Html::rawElement( 'div', [], $oldHtml ) );
        }
        if ( $newHtml !== null ) {
            if ( $oldHtml === null ) {
                $html .= Html::element( 'td', [ 'colspan' => '2' ], "\u{00A0}" );
            }
            $html .= Html::rawElement( 'td', [ 'class' => 'diff-marker', 'data-marker' => '+' ] );
            $html .= Html::rawElement( 'td', [ 'class' => 'diff-addedline' ],
                Html::rawElement( 'div', [], $newHtml ) );
        }
        $html .= Html::closeElement( 'tr' );

        return $html;
    }

    private function getDeletedLine( string $value ): string {
        return $this->getChangedLine( 'del', $value );
    }

    private function getAddedLine( string $value ): string {
        return $this->getChangedLine( 'ins', $value );
    }

    private function getChangedLine( string $tag, string $value ): string {
        return Html::element( $tag, [ 'class' => 'diffchange diffchange-inline' ], $value );
    }

    /**
     * Generates HTML for the header of the diff operation
     */
    protected function generateDiffHeaderHtml( string $name ): string {
        $html = Html::openElement( 'tr' );
        $html .= Html::element( 'td', [ 'colspan' => '2', 'class' => 'diff-lineno' ], $name );
        // @phan-suppress-next-line PhanPluginDuplicateAdjacentStatement
        $html .= Html::element( 'td', [ 'colspan' => '2', 'class' => 'diff-lineno' ], $name );
        $html .= Html::closeElement( 'tr' );

        return $html;
    }

}