SpecialUndelete.php

Go to the documentation of this file.

<?php
use MediaWiki\MediaWikiServices;
use MediaWiki\Revision\RevisionRecord;
use Wikimedia\Rdbms\IResultWrapper;
 
class SpecialUndelete extends SpecialPage {
    private $mAction;
    private $mTarget;
    private $mTimestamp;
    private $mRestore;
    private $mRevdel;
    private $mInvert;
    private $mFilename;
    private $mTargetTimestamp;
    private $mAllowed;
    private $mCanView;
    private $mComment;
    private $mToken;
 
    private $mTargetObj;
    private $mSearchPrefix;
 
    function __construct() {
        parent::__construct( 'Undelete', 'deletedhistory' );
    }
 
    public function doesWrites() {
        return true;
    }
 
    function loadRequest( $par ) {
        $request = $this->getRequest();
        $user = $this->getUser();
 
        $this->mAction = $request->getVal( 'action' );
        if ( $par !== null && $par !== '' ) {
            $this->mTarget = $par;
        } else {
            $this->mTarget = $request->getVal( 'target' );
        }
 
        $this->mTargetObj = null;
 
        if ( $this->mTarget !== null && $this->mTarget !== '' ) {
            $this->mTargetObj = Title::newFromText( $this->mTarget );
        }
 
        $this->mSearchPrefix = $request->getText( 'prefix' );
        $time = $request->getVal( 'timestamp' );
        $this->mTimestamp = $time ? wfTimestamp( TS_MW, $time ) : '';
        $this->mFilename = $request->getVal( 'file' );
 
        $posted = $request->wasPosted() &&
            $user->matchEditToken( $request->getVal( 'wpEditToken' ) );
        $this->mRestore = $request->getCheck( 'restore' ) && $posted;
        $this->mRevdel = $request->getCheck( 'revdel' ) && $posted;
        $this->mInvert = $request->getCheck( 'invert' ) && $posted;
        $this->mPreview = $request->getCheck( 'preview' ) && $posted;
        $this->mDiff = $request->getCheck( 'diff' );
        $this->mDiffOnly = $request->getBool( 'diffonly', $this->getUser()->getOption( 'diffonly' ) );
        $this->mComment = $request->getText( 'wpComment' );
        $this->mUnsuppress = $request->getVal( 'wpUnsuppress' ) && $user->isAllowed( 'suppressrevision' );
        $this->mToken = $request->getVal( 'token' );
 
        if ( $this->isAllowed( 'undelete' ) && !$user->isBlocked() ) {
            $this->mAllowed = true; // user can restore
            $this->mCanView = true; // user can view content
        } elseif ( $this->isAllowed( 'deletedtext' ) ) {
            $this->mAllowed = false; // user cannot restore
            $this->mCanView = true; // user can view content
            $this->mRestore = false;
        } else { // user can only view the list of revisions
            $this->mAllowed = false;
            $this->mCanView = false;
            $this->mTimestamp = '';
            $this->mRestore = false;
        }
 
        if ( $this->mRestore || $this->mInvert ) {
            $timestamps = [];
            $this->mFileVersions = [];
            foreach ( $request->getValues() as $key => $val ) {
                $matches = [];
                if ( preg_match( '/^ts(\d{14})$/', $key, $matches ) ) {
                    array_push( $timestamps, $matches[1] );
                }
 
                if ( preg_match( '/^fileid(\d+)$/', $key, $matches ) ) {
                    $this->mFileVersions[] = intval( $matches[1] );
                }
            }
            rsort( $timestamps );
            $this->mTargetTimestamp = $timestamps;
        }
    }
 
    protected function isAllowed( $permission, User $user = null ) {
        $user = $user ?: $this->getUser();
        if ( $this->mTargetObj !== null ) {
            return $this->mTargetObj->userCan( $permission, $user );
        } else {
            return $user->isAllowed( $permission );
        }
    }
 
    function userCanExecute( User $user ) {
        return $this->isAllowed( $this->mRestriction, $user );
    }
 
    function execute( $par ) {
        $this->useTransactionalTimeLimit();
 
        $user = $this->getUser();
 
        $this->setHeaders();
        $this->outputHeader();
 
        $this->loadRequest( $par );
        $this->checkPermissions(); // Needs to be after mTargetObj is set
 
        $out = $this->getOutput();
 
        if ( is_null( $this->mTargetObj ) ) {
            $out->addWikiMsg( 'undelete-header' );
 
            # Not all users can just browse every deleted page from the list
            if ( $user->isAllowed( 'browsearchive' ) ) {
                $this->showSearchForm();
            }
 
            return;
        }
 
        $this->addHelpLink( 'Help:Undelete' );
        if ( $this->mAllowed ) {
            $out->setPageTitle( $this->msg( 'undeletepage' ) );
        } else {
            $out->setPageTitle( $this->msg( 'viewdeletedpage' ) );
        }
 
        $this->getSkin()->setRelevantTitle( $this->mTargetObj );
 
        if ( $this->mTimestamp !== '' ) {
            $this->showRevision( $this->mTimestamp );
        } elseif ( $this->mFilename !== null && $this->mTargetObj->inNamespace( NS_FILE ) ) {
            $file = new ArchivedFile( $this->mTargetObj, '', $this->mFilename );
            // Check if user is allowed to see this file
            if ( !$file->exists() ) {
                $out->addWikiMsg( 'filedelete-nofile', $this->mFilename );
            } elseif ( !$file->userCan( File::DELETED_FILE, $user ) ) {
                if ( $file->isDeleted( File::DELETED_RESTRICTED ) ) {
                    throw new PermissionsError( 'suppressrevision' );
                } else {
                    throw new PermissionsError( 'deletedtext' );
                }
            } elseif ( !$user->matchEditToken( $this->mToken, $this->mFilename ) ) {
                $this->showFileConfirmationForm( $this->mFilename );
            } else {
                $this->showFile( $this->mFilename );
            }
        } elseif ( $this->mAction === "submit" ) {
            if ( $this->mRestore ) {
                $this->undelete();
            } elseif ( $this->mRevdel ) {
                $this->redirectToRevDel();
            }
 
        } else {
            $this->showHistory();
        }
    }
 
    private function redirectToRevDel() {
        $archive = new PageArchive( $this->mTargetObj );
 
        $revisions = [];
 
        foreach ( $this->getRequest()->getValues() as $key => $val ) {
            $matches = [];
            if ( preg_match( "/^ts(\d{14})$/", $key, $matches ) ) {
                $revisions[ $archive->getRevision( $matches[1] )->getId() ] = 1;
            }
        }
        $query = [
            "type" => "revision",
            "ids" => $revisions,
            "target" => $this->mTargetObj->getPrefixedText()
        ];
        $url = SpecialPage::getTitleFor( 'Revisiondelete' )->getFullURL( $query );
        $this->getOutput()->redirect( $url );
    }
 
    function showSearchForm() {
        $out = $this->getOutput();
        $out->setPageTitle( $this->msg( 'undelete-search-title' ) );
        $fuzzySearch = $this->getRequest()->getVal( 'fuzzy', true );
 
        $out->enableOOUI();
 
        $fields[] = new OOUI\ActionFieldLayout(
            new OOUI\TextInputWidget( [
                'name' => 'prefix',
                'inputId' => 'prefix',
                'infusable' => true,
                'value' => $this->mSearchPrefix,
                'autofocus' => true,
            ] ),
            new OOUI\ButtonInputWidget( [
                'label' => $this->msg( 'undelete-search-submit' )->text(),
                'flags' => [ 'primary', 'progressive' ],
                'inputId' => 'searchUndelete',
                'type' => 'submit',
            ] ),
            [
                'label' => new OOUI\HtmlSnippet(
                    $this->msg(
                        $fuzzySearch ? 'undelete-search-full' : 'undelete-search-prefix'
                    )->parse()
                ),
                'align' => 'left',
            ]
        );
 
        $fieldset = new OOUI\FieldsetLayout( [
            'label' => $this->msg( 'undelete-search-box' )->text(),
            'items' => $fields,
        ] );
 
        $form = new OOUI\FormLayout( [
            'method' => 'get',
            'action' => wfScript(),
        ] );
 
        $form->appendContent(
            $fieldset,
            new OOUI\HtmlSnippet(
                Html::hidden( 'title', $this->getPageTitle()->getPrefixedDBkey() ) .
                Html::hidden( 'fuzzy', $fuzzySearch )
            )
        );
 
        $out->addHTML(
            new OOUI\PanelLayout( [
                'expanded' => false,
                'padded' => true,
                'framed' => true,
                'content' => $form,
            ] )
        );
 
        # List undeletable articles
        if ( $this->mSearchPrefix ) {
            // For now, we enable search engine match only when specifically asked to
            // by using fuzzy=1 parameter.
            if ( $fuzzySearch ) {
                $result = PageArchive::listPagesBySearch( $this->mSearchPrefix );
            } else {
                $result = PageArchive::listPagesByPrefix( $this->mSearchPrefix );
            }
            $this->showList( $result );
        }
    }
 
    private function showList( $result ) {
        $out = $this->getOutput();
 
        if ( $result->numRows() == 0 ) {
            $out->addWikiMsg( 'undelete-no-results' );
 
            return false;
        }
 
        $out->addWikiMsg( 'undeletepagetext', $this->getLanguage()->formatNum( $result->numRows() ) );
 
        $linkRenderer = $this->getLinkRenderer();
        $undelete = $this->getPageTitle();
        $out->addHTML( "<ul id='undeleteResultsList'>\n" );
        foreach ( $result as $row ) {
            $title = Title::makeTitleSafe( $row->ar_namespace, $row->ar_title );
            if ( $title !== null ) {
                $item = $linkRenderer->makeKnownLink(
                    $undelete,
                    $title->getPrefixedText(),
                    [],
                    [ 'target' => $title->getPrefixedText() ]
                );
            } else {
                // The title is no longer valid, show as text
                $item = Html::element(
                    'span',
                    [ 'class' => 'mw-invalidtitle' ],
                    Linker::getInvalidTitleDescription(
                        $this->getContext(),
                        $row->ar_namespace,
                        $row->ar_title
                    )
                );
            }
            $revs = $this->msg( 'undeleterevisions' )->numParams( $row->count )->parse();
            $out->addHTML( "<li class='undeleteResult'>{$item} ({$revs})</li>\n" );
        }
        $result->free();
        $out->addHTML( "</ul>\n" );
 
        return true;
    }
 
    private function showRevision( $timestamp ) {
        if ( !preg_match( '/[0-9]{14}/', $timestamp ) ) {
            return;
        }
 
        $archive = new PageArchive( $this->mTargetObj, $this->getConfig() );
        if ( !Hooks::run( 'UndeleteForm::showRevision', [ &$archive, $this->mTargetObj ] ) ) {
            return;
        }
        $rev = $archive->getRevision( $timestamp );
 
        $out = $this->getOutput();
        $user = $this->getUser();
 
        if ( !$rev ) {
            $out->addWikiMsg( 'undeleterevision-missing' );
 
            return;
        }
 
        if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
            if ( !$rev->userCan( Revision::DELETED_TEXT, $user ) ) {
                $out->wrapWikiMsg(
                    "<div class='mw-warning plainlinks'>\n$1\n</div>\n",
                $rev->isDeleted( Revision::DELETED_RESTRICTED ) ?
                    'rev-suppressed-text-permission' : 'rev-deleted-text-permission'
                );
 
                return;
            }
 
            $out->wrapWikiMsg(
                "<div class='mw-warning plainlinks'>\n$1\n</div>\n",
                $rev->isDeleted( Revision::DELETED_RESTRICTED ) ?
                    'rev-suppressed-text-view' : 'rev-deleted-text-view'
            );
            $out->addHTML( '<br />' );
            // and we are allowed to see...
        }
 
        if ( $this->mDiff ) {
            $previousRev = $archive->getPreviousRevision( $timestamp );
            if ( $previousRev ) {
                $this->showDiff( $previousRev, $rev );
                if ( $this->mDiffOnly ) {
                    return;
                }
 
                $out->addHTML( '<hr />' );
            } else {
                $out->addWikiMsg( 'undelete-nodiff' );
            }
        }
 
        $link = $this->getLinkRenderer()->makeKnownLink(
            $this->getPageTitle( $this->mTargetObj->getPrefixedDBkey() ),
            $this->mTargetObj->getPrefixedText()
        );
 
        $lang = $this->getLanguage();
 
        // date and time are separate parameters to facilitate localisation.
        // $time is kept for backward compat reasons.
        $time = $lang->userTimeAndDate( $timestamp, $user );
        $d = $lang->userDate( $timestamp, $user );
        $t = $lang->userTime( $timestamp, $user );
        $userLink = Linker::revUserTools( $rev );
 
        $content = $rev->getContent( RevisionRecord::FOR_THIS_USER, $user );
 
        // TODO: MCR: this will have to become something like $hasTextSlots and $hasNonTextSlots
        $isText = ( $content instanceof TextContent );
 
        if ( $this->mPreview || $isText ) {
            $openDiv = '<div id="mw-undelete-revision" class="mw-warning">';
        } else {
            $openDiv = '<div id="mw-undelete-revision">';
        }
        $out->addHTML( $openDiv );
 
        // Revision delete links
        if ( !$this->mDiff ) {
            $revdel = Linker::getRevDeleteLink( $user, $rev, $this->mTargetObj );
            if ( $revdel ) {
                $out->addHTML( "$revdel " );
            }
        }
 
        $out->addHTML( $this->msg( 'undelete-revision' )->rawParams( $link )->params(
            $time )->rawParams( $userLink )->params( $d, $t )->parse() . '</div>' );
 
        if ( !Hooks::run( 'UndeleteShowRevision', [ $this->mTargetObj, $rev ] ) ) {
            return;
        }
 
        if ( $this->mPreview || !$isText ) {
            // NOTE: non-text content has no source view, so always use rendered preview
 
            $popts = $out->parserOptions();
            $renderer = MediaWikiServices::getInstance()->getRevisionRenderer();
 
            $rendered = $renderer->getRenderedRevision(
                $rev->getRevisionRecord(),
                $popts,
                $user,
                [ 'audience' => RevisionRecord::FOR_THIS_USER ]
            );
 
            // Fail hard if the audience check fails, since we already checked
            // at the beginning of this method.
            $pout = $rendered->getRevisionParserOutput();
 
            $out->addParserOutput( $pout, [
                'enableSectionEditLinks' => false,
            ] );
        }
 
        $out->enableOOUI();
        $buttonFields = [];
 
        if ( $isText ) {
            // TODO: MCR: make this work for multiple slots
            // source view for textual content
            $sourceView = Xml::element( 'textarea', [
                'readonly' => 'readonly',
                'cols' => 80,
                'rows' => 25
            ], $content->getNativeData() . "\n" );
 
            $buttonFields[] = new OOUI\ButtonInputWidget( [
                'type' => 'submit',
                'name' => 'preview',
                'label' => $this->msg( 'showpreview' )->text()
            ] );
        } else {
            $sourceView = '';
            $previewButton = '';
        }
 
        $buttonFields[] = new OOUI\ButtonInputWidget( [
            'name' => 'diff',
            'type' => 'submit',
            'label' => $this->msg( 'showdiff' )->text()
        ] );
 
        $out->addHTML(
            $sourceView .
                Xml::openElement( 'div', [
                    'style' => 'clear: both' ] ) .
                Xml::openElement( 'form', [
                    'method' => 'post',
                    'action' => $this->getPageTitle()->getLocalURL( [ 'action' => 'submit' ] ) ] ) .
                Xml::element( 'input', [
                    'type' => 'hidden',
                    'name' => 'target',
                    'value' => $this->mTargetObj->getPrefixedDBkey() ] ) .
                Xml::element( 'input', [
                    'type' => 'hidden',
                    'name' => 'timestamp',
                    'value' => $timestamp ] ) .
                Xml::element( 'input', [
                    'type' => 'hidden',
                    'name' => 'wpEditToken',
                    'value' => $user->getEditToken() ] ) .
                new OOUI\FieldLayout(
                    new OOUI\Widget( [
                        'content' => new OOUI\HorizontalLayout( [
                            'items' => $buttonFields
                        ] )
                    ] )
                ) .
                Xml::closeElement( 'form' ) .
                Xml::closeElement( 'div' )
        );
    }
 
    function showDiff( $previousRev, $currentRev ) {
        $diffContext = clone $this->getContext();
        $diffContext->setTitle( $currentRev->getTitle() );
        $diffContext->setWikiPage( WikiPage::factory( $currentRev->getTitle() ) );
 
        $diffEngine = $currentRev->getContentHandler()->createDifferenceEngine( $diffContext );
        $diffEngine->showDiffStyle();
 
        $formattedDiff = $diffEngine->generateContentDiffBody(
            $previousRev->getContent( Revision::FOR_THIS_USER, $this->getUser() ),
            $currentRev->getContent( Revision::FOR_THIS_USER, $this->getUser() )
        );
 
        $formattedDiff = $diffEngine->addHeader(
            $formattedDiff,
            $this->diffHeader( $previousRev, 'o' ),
            $this->diffHeader( $currentRev, 'n' )
        );
 
        $this->getOutput()->addHTML( "<div>$formattedDiff</div>\n" );
    }
 
    private function diffHeader( $rev, $prefix ) {
        $isDeleted = !( $rev->getId() && $rev->getTitle() );
        if ( $isDeleted ) {
            $targetPage = $this->getPageTitle();
            $targetQuery = [
                'target' => $this->mTargetObj->getPrefixedText(),
                'timestamp' => wfTimestamp( TS_MW, $rev->getTimestamp() )
            ];
        } else {
            $targetPage = $rev->getTitle();
            $targetQuery = [ 'oldid' => $rev->getId() ];
        }
 
        // Add show/hide deletion links if available
        $user = $this->getUser();
        $lang = $this->getLanguage();
        $rdel = Linker::getRevDeleteLink( $user, $rev, $this->mTargetObj );
 
        if ( $rdel ) {
            $rdel = " $rdel";
        }
 
        $minor = $rev->isMinor() ? ChangesList::flag( 'minor' ) : '';
 
        $tags = wfGetDB( DB_REPLICA )->selectField(
            'tag_summary',
            'ts_tags',
            [ 'ts_rev_id' => $rev->getId() ],
            __METHOD__
        );
        $tagSummary = ChangeTags::formatSummaryRow( $tags, 'deleteddiff', $this->getContext() );
 
        // FIXME This is reimplementing DifferenceEngine#getRevisionHeader
        // and partially #showDiffPage, but worse
        return '<div id="mw-diff-' . $prefix . 'title1"><strong>' .
            $this->getLinkRenderer()->makeLink(
                $targetPage,
                $this->msg(
                    'revisionasof',
                    $lang->userTimeAndDate( $rev->getTimestamp(), $user ),
                    $lang->userDate( $rev->getTimestamp(), $user ),
                    $lang->userTime( $rev->getTimestamp(), $user )
                )->text(),
                [],
                $targetQuery
            ) .
            '</strong></div>' .
            '<div id="mw-diff-' . $prefix . 'title2">' .
            Linker::revUserTools( $rev ) . '<br />' .
            '</div>' .
            '<div id="mw-diff-' . $prefix . 'title3">' .
            $minor . Linker::revComment( $rev ) . $rdel . '<br />' .
            '</div>' .
            '<div id="mw-diff-' . $prefix . 'title5">' .
            $tagSummary[0] . '<br />' .
            '</div>';
    }
 
    private function showFileConfirmationForm( $key ) {
        $out = $this->getOutput();
        $lang = $this->getLanguage();
        $user = $this->getUser();
        $file = new ArchivedFile( $this->mTargetObj, '', $this->mFilename );
        $out->addWikiMsg( 'undelete-show-file-confirm',
            $this->mTargetObj->getText(),
            $lang->userDate( $file->getTimestamp(), $user ),
            $lang->userTime( $file->getTimestamp(), $user ) );
        $out->addHTML(
            Xml::openElement( 'form', [
                    'method' => 'POST',
                    'action' => $this->getPageTitle()->getLocalURL( [
                        'target' => $this->mTarget,
                        'file' => $key,
                        'token' => $user->getEditToken( $key ),
                    ] ),
                ]
            ) .
                Xml::submitButton( $this->msg( 'undelete-show-file-submit' )->text() ) .
                '</form>'
        );
    }
 
    private function showFile( $key ) {
        $this->getOutput()->disable();
 
        # We mustn't allow the output to be CDN cached, otherwise
        # if an admin previews a deleted image, and it's cached, then
        # a user without appropriate permissions can toddle off and
        # nab the image, and CDN will serve it
        $response = $this->getRequest()->response();
        $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
        $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
        $response->header( 'Pragma: no-cache' );
 
        $repo = RepoGroup::singleton()->getLocalRepo();
        $path = $repo->getZonePath( 'deleted' ) . '/' . $repo->getDeletedHashPath( $key ) . $key;
        $repo->streamFile( $path );
    }
 
    protected function showHistory() {
        $this->checkReadOnly();
 
        $out = $this->getOutput();
        if ( $this->mAllowed ) {
            $out->addModules( 'mediawiki.special.undelete' );
        }
        $out->wrapWikiMsg(
            "<div class='mw-undelete-pagetitle'>\n$1\n</div>\n",
            [ 'undeletepagetitle', wfEscapeWikiText( $this->mTargetObj->getPrefixedText() ) ]
        );
 
        $archive = new PageArchive( $this->mTargetObj, $this->getConfig() );
        Hooks::run( 'UndeleteForm::showHistory', [ &$archive, $this->mTargetObj ] );
 
        $out->addHTML( '<div class="mw-undelete-history">' );
        if ( $this->mAllowed ) {
            $out->addWikiMsg( 'undeletehistory' );
            $out->addWikiMsg( 'undeleterevdel' );
        } else {
            $out->addWikiMsg( 'undeletehistorynoadmin' );
        }
        $out->addHTML( '</div>' );
 
        # List all stored revisions
        $revisions = $archive->listRevisions();
        $files = $archive->listFiles();
 
        $haveRevisions = $revisions && $revisions->numRows() > 0;
        $haveFiles = $files && $files->numRows() > 0;
 
        # Batch existence check on user and talk pages
        if ( $haveRevisions ) {
            $batch = new LinkBatch();
            foreach ( $revisions as $row ) {
                $batch->addObj( Title::makeTitleSafe( NS_USER, $row->ar_user_text ) );
                $batch->addObj( Title::makeTitleSafe( NS_USER_TALK, $row->ar_user_text ) );
            }
            $batch->execute();
            $revisions->seek( 0 );
        }
        if ( $haveFiles ) {
            $batch = new LinkBatch();
            foreach ( $files as $row ) {
                $batch->addObj( Title::makeTitleSafe( NS_USER, $row->fa_user_text ) );
                $batch->addObj( Title::makeTitleSafe( NS_USER_TALK, $row->fa_user_text ) );
            }
            $batch->execute();
            $files->seek( 0 );
        }
 
        if ( $this->mAllowed ) {
            $out->enableOOUI();
 
            $action = $this->getPageTitle()->getLocalURL( [ 'action' => 'submit' ] );
            # Start the form here
            $form = new OOUI\FormLayout( [
                'method' => 'post',
                'action' => $action,
                'id' => 'undelete',
            ] );
        }
 
        # Show relevant lines from the deletion log:
        $deleteLogPage = new LogPage( 'delete' );
        $out->addHTML( Xml::element( 'h2', null, $deleteLogPage->getName()->text() ) . "\n" );
        LogEventsList::showLogExtract( $out, 'delete', $this->mTargetObj );
        # Show relevant lines from the suppression log:
        $suppressLogPage = new LogPage( 'suppress' );
        if ( $this->getUser()->isAllowed( 'suppressionlog' ) ) {
            $out->addHTML( Xml::element( 'h2', null, $suppressLogPage->getName()->text() ) . "\n" );
            LogEventsList::showLogExtract( $out, 'suppress', $this->mTargetObj );
        }
 
        if ( $this->mAllowed && ( $haveRevisions || $haveFiles ) ) {
            $fields[] = new OOUI\Layout( [
                'content' => new OOUI\HtmlSnippet( $this->msg( 'undeleteextrahelp' )->parseAsBlock() )
            ] );
 
            $conf = $this->getConfig();
            $oldCommentSchema = $conf->get( 'CommentTableSchemaMigrationStage' ) === MIGRATION_OLD;
 
            $fields[] = new OOUI\FieldLayout(
                new OOUI\TextInputWidget( [
                    'name' => 'wpComment',
                    'inputId' => 'wpComment',
                    'infusable' => true,
                    'value' => $this->mComment,
                    'autofocus' => true,
                    // HTML maxlength uses "UTF-16 code units", which means that characters outside BMP
                    // (e.g. emojis) count for two each. This limit is overridden in JS to instead count
                    // Unicode codepoints (or 255 UTF-8 bytes for old schema).
                    'maxLength' => $oldCommentSchema ? 255 : CommentStore::COMMENT_CHARACTER_LIMIT,
                ] ),
                [
                    'label' => $this->msg( 'undeletecomment' )->text(),
                    'align' => 'top',
                ]
            );
 
            $fields[] = new OOUI\FieldLayout(
                new OOUI\Widget( [
                    'content' => new OOUI\HorizontalLayout( [
                        'items' => [
                            new OOUI\ButtonInputWidget( [
                                'name' => 'restore',
                                'inputId' => 'mw-undelete-submit',
                                'value' => '1',
                                'label' => $this->msg( 'undeletebtn' )->text(),
                                'flags' => [ 'primary', 'progressive' ],
                                'type' => 'submit',
                            ] ),
                            new OOUI\ButtonInputWidget( [
                                'name' => 'invert',
                                'inputId' => 'mw-undelete-invert',
                                'value' => '1',
                                'label' => $this->msg( 'undeleteinvert' )->text()
                            ] ),
                        ]
                    ] )
                ] )
            );
 
            if ( $this->getUser()->isAllowed( 'suppressrevision' ) ) {
                $fields[] = new OOUI\FieldLayout(
                    new OOUI\CheckboxInputWidget( [
                        'name' => 'wpUnsuppress',
                        'inputId' => 'mw-undelete-unsuppress',
                        'value' => '1',
                    ] ),
                    [
                        'label' => $this->msg( 'revdelete-unsuppress' )->text(),
                        'align' => 'inline',
                    ]
                );
            }
 
            $fieldset = new OOUI\FieldsetLayout( [
                'label' => $this->msg( 'undelete-fieldset-title' )->text(),
                'id' => 'mw-undelete-table',
                'items' => $fields,
            ] );
 
            $form->appendContent(
                new OOUI\PanelLayout( [
                    'expanded' => false,
                    'padded' => true,
                    'framed' => true,
                    'content' => $fieldset,
                ] ),
                new OOUI\HtmlSnippet(
                    Html::hidden( 'target', $this->mTarget ) .
                    Html::hidden( 'wpEditToken', $this->getUser()->getEditToken() )
                )
            );
        }
 
        $history = '';
        $history .= Xml::element( 'h2', null, $this->msg( 'history' )->text() ) . "\n";
 
        if ( $haveRevisions ) {
            # Show the page's stored (deleted) history
 
            if ( $this->getUser()->isAllowed( 'deleterevision' ) ) {
                $history .= Html::element(
                    'button',
                    [
                        'name' => 'revdel',
                        'type' => 'submit',
                        'class' => 'deleterevision-log-submit mw-log-deleterevision-button'
                    ],
                    $this->msg( 'showhideselectedversions' )->text()
                ) . "\n";
            }
 
            $history .= '<ul class="mw-undelete-revlist">';
            $remaining = $revisions->numRows();
            $earliestLiveTime = $this->mTargetObj->getEarliestRevTime();
 
            foreach ( $revisions as $row ) {
                $remaining--;
                $history .= $this->formatRevisionRow( $row, $earliestLiveTime, $remaining );
            }
            $revisions->free();
            $history .= '</ul>';
        } else {
            $out->addWikiMsg( 'nohistory' );
        }
 
        if ( $haveFiles ) {
            $history .= Xml::element( 'h2', null, $this->msg( 'filehist' )->text() ) . "\n";
            $history .= '<ul class="mw-undelete-revlist">';
            foreach ( $files as $row ) {
                $history .= $this->formatFileRow( $row );
            }
            $files->free();
            $history .= '</ul>';
        }
 
        if ( $this->mAllowed ) {
            # Slip in the hidden controls here
            $misc = Html::hidden( 'target', $this->mTarget );
            $misc .= Html::hidden( 'wpEditToken', $this->getUser()->getEditToken() );
            $history .= $misc;
 
            $form->appendContent( new OOUI\HtmlSnippet( $history ) );
            $out->addHTML( $form );
        } else {
            $out->addHTML( $history );
        }
 
        return true;
    }
 
    protected function formatRevisionRow( $row, $earliestLiveTime, $remaining ) {
        $rev = Revision::newFromArchiveRow( $row,
            [
                'title' => $this->mTargetObj
            ] );
 
        $revTextSize = '';
        $ts = wfTimestamp( TS_MW, $row->ar_timestamp );
        // Build checkboxen...
        if ( $this->mAllowed ) {
            if ( $this->mInvert ) {
                if ( in_array( $ts, $this->mTargetTimestamp ) ) {
                    $checkBox = Xml::check( "ts$ts" );
                } else {
                    $checkBox = Xml::check( "ts$ts", true );
                }
            } else {
                $checkBox = Xml::check( "ts$ts" );
            }
        } else {
            $checkBox = '';
        }
 
        // Build page & diff links...
        $user = $this->getUser();
        if ( $this->mCanView ) {
            $titleObj = $this->getPageTitle();
            # Last link
            if ( !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
                $pageLink = htmlspecialchars( $this->getLanguage()->userTimeAndDate( $ts, $user ) );
                $last = $this->msg( 'diff' )->escaped();
            } elseif ( $remaining > 0 || ( $earliestLiveTime && $ts > $earliestLiveTime ) ) {
                $pageLink = $this->getPageLink( $rev, $titleObj, $ts );
                $last = $this->getLinkRenderer()->makeKnownLink(
                    $titleObj,
                    $this->msg( 'diff' )->text(),
                    [],
                    [
                        'target' => $this->mTargetObj->getPrefixedText(),
                        'timestamp' => $ts,
                        'diff' => 'prev'
                    ]
                );
            } else {
                $pageLink = $this->getPageLink( $rev, $titleObj, $ts );
                $last = $this->msg( 'diff' )->escaped();
            }
        } else {
            $pageLink = htmlspecialchars( $this->getLanguage()->userTimeAndDate( $ts, $user ) );
            $last = $this->msg( 'diff' )->escaped();
        }
 
        // User links
        $userLink = Linker::revUserTools( $rev );
 
        // Minor edit
        $minor = $rev->isMinor() ? ChangesList::flag( 'minor' ) : '';
 
        // Revision text size
        $size = $row->ar_len;
        if ( !is_null( $size ) ) {
            $revTextSize = Linker::formatRevisionSize( $size );
        }
 
        // Edit summary
        $comment = Linker::revComment( $rev );
 
        // Tags
        $attribs = [];
        list( $tagSummary, $classes ) = ChangeTags::formatSummaryRow(
            $row->ts_tags,
            'deletedhistory',
            $this->getContext()
        );
        if ( $classes ) {
            $attribs['class'] = implode( ' ', $classes );
        }
 
        $revisionRow = $this->msg( 'undelete-revision-row2' )
            ->rawParams(
                $checkBox,
                $last,
                $pageLink,
                $userLink,
                $minor,
                $revTextSize,
                $comment,
                $tagSummary
            )
            ->escaped();
 
        return Xml::tags( 'li', $attribs, $revisionRow ) . "\n";
    }
 
    private function formatFileRow( $row ) {
        $file = ArchivedFile::newFromRow( $row );
        $ts = wfTimestamp( TS_MW, $row->fa_timestamp );
        $user = $this->getUser();
 
        $checkBox = '';
        if ( $this->mCanView && $row->fa_storage_key ) {
            if ( $this->mAllowed ) {
                $checkBox = Xml::check( 'fileid' . $row->fa_id );
            }
            $key = urlencode( $row->fa_storage_key );
            $pageLink = $this->getFileLink( $file, $this->getPageTitle(), $ts, $key );
        } else {
            $pageLink = htmlspecialchars( $this->getLanguage()->userTimeAndDate( $ts, $user ) );
        }
        $userLink = $this->getFileUser( $file );
        $data = $this->msg( 'widthheight' )->numParams( $row->fa_width, $row->fa_height )->text();
        $bytes = $this->msg( 'parentheses' )
            ->plaintextParams( $this->msg( 'nbytes' )->numParams( $row->fa_size )->text() )
            ->plain();
        $data = htmlspecialchars( $data . ' ' . $bytes );
        $comment = $this->getFileComment( $file );
 
        // Add show/hide deletion links if available
        $canHide = $this->isAllowed( 'deleterevision' );
        if ( $canHide || ( $file->getVisibility() && $this->isAllowed( 'deletedhistory' ) ) ) {
            if ( !$file->userCan( File::DELETED_RESTRICTED, $user ) ) {
                // Revision was hidden from sysops
                $revdlink = Linker::revDeleteLinkDisabled( $canHide );
            } else {
                $query = [
                    'type' => 'filearchive',
                    'target' => $this->mTargetObj->getPrefixedDBkey(),
                    'ids' => $row->fa_id
                ];
                $revdlink = Linker::revDeleteLink( $query,
                    $file->isDeleted( File::DELETED_RESTRICTED ), $canHide );
            }
        } else {
            $revdlink = '';
        }
 
        return "<li>$checkBox $revdlink $pageLink . . $userLink $data $comment</li>\n";
    }
 
    function getPageLink( $rev, $titleObj, $ts ) {
        $user = $this->getUser();
        $time = $this->getLanguage()->userTimeAndDate( $ts, $user );
 
        if ( !$rev->userCan( Revision::DELETED_TEXT, $user ) ) {
            return '<span class="history-deleted">' . $time . '</span>';
        }
 
        $link = $this->getLinkRenderer()->makeKnownLink(
            $titleObj,
            $time,
            [],
            [
                'target' => $this->mTargetObj->getPrefixedText(),
                'timestamp' => $ts
            ]
        );
 
        if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
            $link = '<span class="history-deleted">' . $link . '</span>';
        }
 
        return $link;
    }
 
    function getFileLink( $file, $titleObj, $ts, $key ) {
        $user = $this->getUser();
        $time = $this->getLanguage()->userTimeAndDate( $ts, $user );
 
        if ( !$file->userCan( File::DELETED_FILE, $user ) ) {
            return '<span class="history-deleted">' . htmlspecialchars( $time ) . '</span>';
        }
 
        $link = $this->getLinkRenderer()->makeKnownLink(
            $titleObj,
            $time,
            [],
            [
                'target' => $this->mTargetObj->getPrefixedText(),
                'file' => $key,
                'token' => $user->getEditToken( $key )
            ]
        );
 
        if ( $file->isDeleted( File::DELETED_FILE ) ) {
            $link = '<span class="history-deleted">' . $link . '</span>';
        }
 
        return $link;
    }
 
    function getFileUser( $file ) {
        if ( !$file->userCan( File::DELETED_USER, $this->getUser() ) ) {
            return '<span class="history-deleted">' .
                $this->msg( 'rev-deleted-user' )->escaped() .
                '</span>';
        }
 
        $link = Linker::userLink( $file->getRawUser(), $file->getRawUserText() ) .
            Linker::userToolLinks( $file->getRawUser(), $file->getRawUserText() );
 
        if ( $file->isDeleted( File::DELETED_USER ) ) {
            $link = '<span class="history-deleted">' . $link . '</span>';
        }
 
        return $link;
    }
 
    function getFileComment( $file ) {
        if ( !$file->userCan( File::DELETED_COMMENT, $this->getUser() ) ) {
            return '<span class="history-deleted"><span class="comment">' .
                $this->msg( 'rev-deleted-comment' )->escaped() . '</span></span>';
        }
 
        $link = Linker::commentBlock( $file->getRawDescription() );
 
        if ( $file->isDeleted( File::DELETED_COMMENT ) ) {
            $link = '<span class="history-deleted">' . $link . '</span>';
        }
 
        return $link;
    }
 
    function undelete() {
        if ( $this->getConfig()->get( 'UploadMaintenance' )
            && $this->mTargetObj->getNamespace() == NS_FILE
        ) {
            throw new ErrorPageError( 'undelete-error', 'filedelete-maintenance' );
        }
 
        $this->checkReadOnly();
 
        $out = $this->getOutput();
        $archive = new PageArchive( $this->mTargetObj, $this->getConfig() );
        Hooks::run( 'UndeleteForm::undelete', [ &$archive, $this->mTargetObj ] );
        $ok = $archive->undelete(
            $this->mTargetTimestamp,
            $this->mComment,
            $this->mFileVersions,
            $this->mUnsuppress,
            $this->getUser()
        );
 
        if ( is_array( $ok ) ) {
            if ( $ok[1] ) { // Undeleted file count
                Hooks::run( 'FileUndeleteComplete', [
                    $this->mTargetObj, $this->mFileVersions,
                    $this->getUser(), $this->mComment ] );
            }
 
            $link = $this->getLinkRenderer()->makeKnownLink( $this->mTargetObj );
            $out->addHTML( $this->msg( 'undeletedpage' )->rawParams( $link )->parse() );
        } else {
            $out->setPageTitle( $this->msg( 'undelete-error' ) );
        }
 
        // Show revision undeletion warnings and errors
        $status = $archive->getRevisionStatus();
        if ( $status && !$status->isGood() ) {
            $out->addWikiText( '<div class="error" id="mw-error-cannotundelete">' .
                $status->getWikiText(
                    'cannotundelete',
                    'cannotundelete'
                ) . '</div>'
            );
        }
 
        // Show file undeletion warnings and errors
        $status = $archive->getFileStatus();
        if ( $status && !$status->isGood() ) {
            $out->addWikiText( '<div class="error">' .
                $status->getWikiText(
                    'undelete-error-short',
                    'undelete-error-long'
                ) . '</div>'
            );
        }
    }
 
    public function prefixSearchSubpages( $search, $limit, $offset ) {
        return $this->prefixSearchString( $search, $limit, $offset );
    }
 
    protected function getGroupName() {
        return 'pagetools';
    }
}