ApiQueryRevisions.php

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<?php
class ApiQueryRevisions extends ApiQueryBase {

    private $diffto, $difftotext, $expandTemplates, $generateXML, $section,
        $token, $parseContent, $contentFormat;

    public function __construct( $query, $moduleName ) {
        parent::__construct( $query, $moduleName, 'rv' );
    }

    private $fld_ids = false, $fld_flags = false, $fld_timestamp = false, $fld_size = false, $fld_sha1 = false,
            $fld_comment = false, $fld_parsedcomment = false, $fld_user = false, $fld_userid = false,
            $fld_content = false, $fld_tags = false, $fld_contentmodel = false;

    private $tokenFunctions;

    protected function getTokenFunctions() {
        // tokenname => function
        // function prototype is func($pageid, $title, $rev)
        // should return token or false

        // Don't call the hooks twice
        if ( isset( $this->tokenFunctions ) ) {
            return $this->tokenFunctions;
        }

        // If we're in JSON callback mode, no tokens can be obtained
        if ( !is_null( $this->getMain()->getRequest()->getVal( 'callback' ) ) ) {
            return array();
        }

        $this->tokenFunctions = array(
            'rollback' => array( 'ApiQueryRevisions', 'getRollbackToken' )
        );
        wfRunHooks( 'APIQueryRevisionsTokens', array( &$this->tokenFunctions ) );
        return $this->tokenFunctions;
    }

    public static function getRollbackToken( $pageid, $title, $rev ) {
        global $wgUser;
        if ( !$wgUser->isAllowed( 'rollback' ) ) {
            return false;
        }
        return $wgUser->getEditToken(
            array( $title->getPrefixedText(), $rev->getUserText() ) );
    }

    public function execute() {
        $params = $this->extractRequestParams( false );

        // If any of those parameters are used, work in 'enumeration' mode.
        // Enum mode can only be used when exactly one page is provided.
        // Enumerating revisions on multiple pages make it extremely
        // difficult to manage continuations and require additional SQL indexes
        $enumRevMode = ( !is_null( $params['user'] ) || !is_null( $params['excludeuser'] ) ||
                !is_null( $params['limit'] ) || !is_null( $params['startid'] ) ||
                !is_null( $params['endid'] ) || $params['dir'] === 'newer' ||
                !is_null( $params['start'] ) || !is_null( $params['end'] ) );

        $pageSet = $this->getPageSet();
        $pageCount = $pageSet->getGoodTitleCount();
        $revCount = $pageSet->getRevisionCount();

        // Optimization -- nothing to do
        if ( $revCount === 0 && $pageCount === 0 ) {
            return;
        }

        if ( $revCount > 0 && $enumRevMode ) {
            $this->dieUsage( 'The revids= parameter may not be used with the list options (limit, startid, endid, dirNewer, start, end).', 'revids' );
        }

        if ( $pageCount > 1 && $enumRevMode ) {
            $this->dieUsage( 'titles, pageids or a generator was used to supply multiple pages, but the limit, startid, endid, dirNewer, user, excludeuser, start and end parameters may only be used on a single page.', 'multpages' );
        }

        if ( !is_null( $params['difftotext'] ) ) {
            $this->difftotext = $params['difftotext'];
        } elseif ( !is_null( $params['diffto'] ) ) {
            if ( $params['diffto'] == 'cur' ) {
                $params['diffto'] = 0;
            }
            if ( ( !ctype_digit( $params['diffto'] ) || $params['diffto'] < 0 )
                    && $params['diffto'] != 'prev' && $params['diffto'] != 'next' ) {
                $this->dieUsage( 'rvdiffto must be set to a non-negative number, "prev", "next" or "cur"', 'diffto' );
            }
            // Check whether the revision exists and is readable,
            // DifferenceEngine returns a rather ambiguous empty
            // string if that's not the case
            if ( $params['diffto'] != 0 ) {
                $difftoRev = Revision::newFromID( $params['diffto'] );
                if ( !$difftoRev ) {
                    $this->dieUsageMsg( array( 'nosuchrevid', $params['diffto'] ) );
                }
                if ( $difftoRev->isDeleted( Revision::DELETED_TEXT ) ) {
                    $this->setWarning( "Couldn't diff to r{$difftoRev->getID()}: content is hidden" );
                    $params['diffto'] = null;
                }
            }
            $this->diffto = $params['diffto'];
        }

        $db = $this->getDB();
        $this->addTables( 'page' );
        $this->addFields( Revision::selectFields() );
        $this->addWhere( 'page_id = rev_page' );

        $prop = array_flip( $params['prop'] );

        // Optional fields
        $this->fld_ids = isset( $prop['ids'] );
        // $this->addFieldsIf('rev_text_id', $this->fld_ids); // should this be exposed?
        $this->fld_flags = isset( $prop['flags'] );
        $this->fld_timestamp = isset( $prop['timestamp'] );
        $this->fld_comment = isset( $prop['comment'] );
        $this->fld_parsedcomment = isset( $prop['parsedcomment'] );
        $this->fld_size = isset( $prop['size'] );
        $this->fld_sha1 = isset( $prop['sha1'] );
        $this->fld_contentmodel = isset( $prop['contentmodel'] );
        $this->fld_userid = isset( $prop['userid'] );
        $this->fld_user = isset( $prop['user'] );
        $this->token = $params['token'];

        if ( !empty( $params['contentformat'] ) ) {
            $this->contentFormat = $params['contentformat'];
        }

        // Possible indexes used
        $index = array();

        $userMax = ( $this->fld_content ? ApiBase::LIMIT_SML1 : ApiBase::LIMIT_BIG1 );
        $botMax = ( $this->fld_content ? ApiBase::LIMIT_SML2 : ApiBase::LIMIT_BIG2 );
        $limit = $params['limit'];
        if ( $limit == 'max' ) {
            $limit = $this->getMain()->canApiHighLimits() ? $botMax : $userMax;
            $this->getResult()->setParsedLimit( $this->getModuleName(), $limit );
        }

        if ( !is_null( $this->token ) || $pageCount > 0 ) {
            $this->addFields( Revision::selectPageFields() );
        }

        if ( isset( $prop['tags'] ) ) {
            $this->fld_tags = true;
            $this->addTables( 'tag_summary' );
            $this->addJoinConds( array( 'tag_summary' => array( 'LEFT JOIN', array( 'rev_id=ts_rev_id' ) ) ) );
            $this->addFields( 'ts_tags' );
        }

        if ( !is_null( $params['tag'] ) ) {
            $this->addTables( 'change_tag' );
            $this->addJoinConds( array( 'change_tag' => array( 'INNER JOIN', array( 'rev_id=ct_rev_id' ) ) ) );
            $this->addWhereFld( 'ct_tag', $params['tag'] );
            $index['change_tag'] = 'change_tag_tag_id';
        }

        if ( isset( $prop['content'] ) || !is_null( $this->difftotext ) ) {
            // For each page we will request, the user must have read rights for that page
            $user = $this->getUser();
            foreach ( $pageSet->getGoodTitles() as $title ) {
                if ( !$title->userCan( 'read', $user ) ) {
                    $this->dieUsage(
                        'The current user is not allowed to read ' . $title->getPrefixedText(),
                        'accessdenied' );
                }
            }

            $this->addTables( 'text' );
            $this->addWhere( 'rev_text_id=old_id' );
            $this->addFields( 'old_id' );
            $this->addFields( Revision::selectTextFields() );

            $this->fld_content = isset( $prop['content'] );

            $this->expandTemplates = $params['expandtemplates'];
            $this->generateXML = $params['generatexml'];
            $this->parseContent = $params['parse'];
            if ( $this->parseContent ) {
                // Must manually initialize unset limit
                if ( is_null( $limit ) ) {
                    $limit = 1;
                }
                // We are only going to parse 1 revision per request
                $this->validateLimit( 'limit', $limit, 1, 1, 1 );
            }
            if ( isset( $params['section'] ) ) {
                $this->section = $params['section'];
            } else {
                $this->section = false;
            }
        }

        // add user name, if needed
        if ( $this->fld_user ) {
            $this->addTables( 'user' );
            $this->addJoinConds( array( 'user' => Revision::userJoinCond() ) );
            $this->addFields( Revision::selectUserFields() );
        }

        // Bug 24166 - API error when using rvprop=tags
        $this->addTables( 'revision' );

        if ( $enumRevMode ) {
            // This is mostly to prevent parameter errors (and optimize SQL?)
            if ( !is_null( $params['startid'] ) && !is_null( $params['start'] ) ) {
                $this->dieUsage( 'start and startid cannot be used together', 'badparams' );
            }

            if ( !is_null( $params['endid'] ) && !is_null( $params['end'] ) ) {
                $this->dieUsage( 'end and endid cannot be used together', 'badparams' );
            }

            if ( !is_null( $params['user'] ) && !is_null( $params['excludeuser'] ) ) {
                $this->dieUsage( 'user and excludeuser cannot be used together', 'badparams' );
            }

            // Continuing effectively uses startid. But we can't use rvstartid
            // directly, because there is no way to tell the client to ''not''
            // send rvstart if it sent it in the original query. So instead we
            // send the continuation startid as rvcontinue, and ignore both
            // rvstart and rvstartid when that is supplied.
            if ( !is_null( $params['continue'] ) ) {
                $params['startid'] = $params['continue'];
                $params['start'] = null;
            }

            // This code makes an assumption that sorting by rev_id and rev_timestamp produces
            // the same result. This way users may request revisions starting at a given time,
            // but to page through results use the rev_id returned after each page.
            // Switching to rev_id removes the potential problem of having more than
            // one row with the same timestamp for the same page.
            // The order needs to be the same as start parameter to avoid SQL filesort.
            if ( is_null( $params['startid'] ) && is_null( $params['endid'] ) ) {
                $this->addTimestampWhereRange( 'rev_timestamp', $params['dir'],
                    $params['start'], $params['end'] );
            } else {
                $this->addWhereRange( 'rev_id', $params['dir'],
                    $params['startid'], $params['endid'] );
                // One of start and end can be set
                // If neither is set, this does nothing
                $this->addTimestampWhereRange( 'rev_timestamp', $params['dir'],
                    $params['start'], $params['end'], false );
            }

            // must manually initialize unset limit
            if ( is_null( $limit ) ) {
                $limit = 10;
            }
            $this->validateLimit( 'limit', $limit, 1, $userMax, $botMax );

            // There is only one ID, use it
            $ids = array_keys( $pageSet->getGoodTitles() );
            $this->addWhereFld( 'rev_page', reset( $ids ) );

            if ( !is_null( $params['user'] ) ) {
                $this->addWhereFld( 'rev_user_text', $params['user'] );
            } elseif ( !is_null( $params['excludeuser'] ) ) {
                $this->addWhere( 'rev_user_text != ' .
                    $db->addQuotes( $params['excludeuser'] ) );
            }
            if ( !is_null( $params['user'] ) || !is_null( $params['excludeuser'] ) ) {
                // Paranoia: avoid brute force searches (bug 17342)
                $this->addWhere( $db->bitAnd( 'rev_deleted', Revision::DELETED_USER ) . ' = 0' );
            }
        } elseif ( $revCount > 0 ) {
            $max = $this->getMain()->canApiHighLimits() ? $botMax : $userMax;
            $revs = $pageSet->getRevisionIDs();
            if ( self::truncateArray( $revs, $max ) ) {
                $this->setWarning( "Too many values supplied for parameter 'revids': the limit is $max" );
            }

            // Get all revision IDs
            $this->addWhereFld( 'rev_id', array_keys( $revs ) );

            if ( !is_null( $params['continue'] ) ) {
                $this->addWhere( 'rev_id >= ' . intval( $params['continue'] ) );
            }
            $this->addOption( 'ORDER BY', 'rev_id' );

            // assumption testing -- we should never get more then $revCount rows.
            $limit = $revCount;
        } elseif ( $pageCount > 0 ) {
            $max = $this->getMain()->canApiHighLimits() ? $botMax : $userMax;
            $titles = $pageSet->getGoodTitles();
            if ( self::truncateArray( $titles, $max ) ) {
                $this->setWarning( "Too many values supplied for parameter 'titles': the limit is $max" );
            }

            // When working in multi-page non-enumeration mode,
            // limit to the latest revision only
            $this->addWhere( 'page_id=rev_page' );
            $this->addWhere( 'page_latest=rev_id' );

            // Get all page IDs
            $this->addWhereFld( 'page_id', array_keys( $titles ) );
            // Every time someone relies on equality propagation, god kills a kitten :)
            $this->addWhereFld( 'rev_page', array_keys( $titles ) );

            if ( !is_null( $params['continue'] ) ) {
                $cont = explode( '|', $params['continue'] );
                $this->dieContinueUsageIf( count( $cont ) != 2 );
                $pageid = intval( $cont[0] );
                $revid = intval( $cont[1] );
                $this->addWhere(
                    "rev_page > $pageid OR " .
                    "(rev_page = $pageid AND " .
                    "rev_id >= $revid)"
                );
            }
            $this->addOption( 'ORDER BY', array(
                'rev_page',
                'rev_id'
            ));

            // assumption testing -- we should never get more then $pageCount rows.
            $limit = $pageCount;
        } else {
            ApiBase::dieDebug( __METHOD__, 'param validation?' );
        }

        $this->addOption( 'LIMIT', $limit + 1 );
        $this->addOption( 'USE INDEX', $index );

        $count = 0;
        $res = $this->select( __METHOD__ );

        foreach ( $res as $row ) {
            if ( ++ $count > $limit ) {
                // We've reached the one extra which shows that there are additional pages to be had. Stop here...
                if ( !$enumRevMode ) {
                    ApiBase::dieDebug( __METHOD__, 'Got more rows then expected' ); // bug report
                }
                $this->setContinueEnumParameter( 'continue', intval( $row->rev_id ) );
                break;
            }

            $fit = $this->addPageSubItem( $row->rev_page, $this->extractRowInfo( $row ), 'rev' );
            if ( !$fit ) {
                if ( $enumRevMode ) {
                    $this->setContinueEnumParameter( 'continue', intval( $row->rev_id ) );
                } elseif ( $revCount > 0 ) {
                    $this->setContinueEnumParameter( 'continue', intval( $row->rev_id ) );
                } else {
                    $this->setContinueEnumParameter( 'continue', intval( $row->rev_page ) .
                        '|' . intval( $row->rev_id ) );
                }
                break;
            }
        }
    }

    private function extractRowInfo( $row ) {
        $revision = new Revision( $row );
        $title = $revision->getTitle();
        $vals = array();

        if ( $this->fld_ids ) {
            $vals['revid'] = intval( $revision->getId() );
            // $vals['oldid'] = intval( $row->rev_text_id ); // todo: should this be exposed?
            if ( !is_null( $revision->getParentId() ) ) {
                $vals['parentid'] = intval( $revision->getParentId() );
            }
        }

        if ( $this->fld_flags && $revision->isMinor() ) {
            $vals['minor'] = '';
        }

        if ( $this->fld_user || $this->fld_userid ) {
            if ( $revision->isDeleted( Revision::DELETED_USER ) ) {
                $vals['userhidden'] = '';
            } else {
                if ( $this->fld_user ) {
                    $vals['user'] = $revision->getUserText();
                }
                $userid = $revision->getUser();
                if ( !$userid ) {
                    $vals['anon'] = '';
                }

                if ( $this->fld_userid ) {
                    $vals['userid'] = $userid;
                }
            }
        }

        if ( $this->fld_timestamp ) {
            $vals['timestamp'] = wfTimestamp( TS_ISO_8601, $revision->getTimestamp() );
        }

        if ( $this->fld_size ) {
            if ( !is_null( $revision->getSize() ) ) {
                $vals['size'] = intval( $revision->getSize() );
            } else {
                $vals['size'] = 0;
            }
        }

        if ( $this->fld_sha1 && !$revision->isDeleted( Revision::DELETED_TEXT ) ) {
            if ( $revision->getSha1() != '' ) {
                $vals['sha1'] = wfBaseConvert( $revision->getSha1(), 36, 16, 40 );
            } else {
                $vals['sha1'] = '';
            }
        } elseif ( $this->fld_sha1 ) {
            $vals['sha1hidden'] = '';
        }

        if ( $this->fld_contentmodel ) {
            $vals['contentmodel'] = $revision->getContentModel();
        }

        if ( $this->fld_comment || $this->fld_parsedcomment ) {
            if ( $revision->isDeleted( Revision::DELETED_COMMENT ) ) {
                $vals['commenthidden'] = '';
            } else {
                $comment = $revision->getComment();

                if ( $this->fld_comment ) {
                    $vals['comment'] = $comment;
                }

                if ( $this->fld_parsedcomment ) {
                    $vals['parsedcomment'] = Linker::formatComment( $comment, $title );
                }
            }
        }

        if ( $this->fld_tags ) {
            if ( $row->ts_tags ) {
                $tags = explode( ',', $row->ts_tags );
                $this->getResult()->setIndexedTagName( $tags, 'tag' );
                $vals['tags'] = $tags;
            } else {
                $vals['tags'] = array();
            }
        }

        if ( !is_null( $this->token ) ) {
            $tokenFunctions = $this->getTokenFunctions();
            foreach ( $this->token as $t ) {
                $val = call_user_func( $tokenFunctions[$t], $title->getArticleID(), $title, $revision );
                if ( $val === false ) {
                    $this->setWarning( "Action '$t' is not allowed for the current user" );
                } else {
                    $vals[$t . 'token'] = $val;
                }
            }
        }

        $content = null;
        global $wgParser;
        if ( $this->fld_content || !is_null( $this->diffto ) || !is_null( $this->difftotext ) ) {
            $content = $revision->getContent();
            // Expand templates after getting section content because
            // template-added sections don't count and Parser::preprocess()
            // will have less input
            if ( $content && $this->section !== false ) {
                $content = $content->getSection( $this->section, false );
                if ( !$content ) {
                    $this->dieUsage( "There is no section {$this->section} in r" . $revision->getId(), 'nosuchsection' );
                }
            }
        }
        if ( $this->fld_content && $content && !$revision->isDeleted( Revision::DELETED_TEXT ) ) {
            $text = null;

            if ( $this->generateXML ) {
                if ( $content->getModel() === CONTENT_MODEL_WIKITEXT ) {
                    $t = $content->getNativeData(); # note: don't set $text

                    $wgParser->startExternalParse( $title, ParserOptions::newFromContext( $this->getContext() ), OT_PREPROCESS );
                    $dom = $wgParser->preprocessToDom( $t );
                    if ( is_callable( array( $dom, 'saveXML' ) ) ) {
                        $xml = $dom->saveXML();
                    } else {
                        $xml = $dom->__toString();
                    }
                    $vals['parsetree'] = $xml;
                } else {
                    $this->setWarning( "Conversion to XML is supported for wikitext only, " .
                                        $title->getPrefixedDBkey() .
                                        " uses content model " . $content->getModel() );
                }
            }

            if ( $this->expandTemplates && !$this->parseContent ) {
                #XXX: implement template expansion for all content types in ContentHandler?
                if ( $content->getModel() === CONTENT_MODEL_WIKITEXT ) {
                    $text = $content->getNativeData();

                    $text = $wgParser->preprocess( $text, $title, ParserOptions::newFromContext( $this->getContext() ) );
                } else {
                    $this->setWarning( "Template expansion is supported for wikitext only, " .
                        $title->getPrefixedDBkey() .
                        " uses content model " . $content->getModel() );

                    $text = false;
                }
            }
            if ( $this->parseContent ) {
                $po = $content->getParserOutput( $title, $revision->getId(), ParserOptions::newFromContext( $this->getContext() ) );
                $text = $po->getText();
            }

            if ( $text === null ) {
                $format = $this->contentFormat ? $this->contentFormat : $content->getDefaultFormat();
                $model = $content->getModel();

                if ( !$content->isSupportedFormat( $format ) ) {
                    $name = $title->getPrefixedDBkey();

                    $this->dieUsage( "The requested format {$this->contentFormat} is not supported " .
                                    "for content model $model used by $name", 'badformat' );
                }

                $text = $content->serialize( $format );

                // always include format and model.
                // Format is needed to deserialize, model is needed to interpret.
                $vals['contentformat'] = $format;
                $vals['contentmodel'] = $model;
            }

            if ( $text !== false ) {
                ApiResult::setContent( $vals, $text );
            }
        } elseif ( $this->fld_content ) {
            if ( $revision->isDeleted( Revision::DELETED_TEXT ) ) {
                $vals['texthidden'] = '';
            } else {
                $vals['textmissing'] = '';
            }
        }

        if ( !is_null( $this->diffto ) || !is_null( $this->difftotext ) ) {
            global $wgAPIMaxUncachedDiffs;
            static $n = 0; // Number of uncached diffs we've had

            if ( is_null( $content ) ) {
                $vals['textmissing'] = '';
            } elseif ( $n < $wgAPIMaxUncachedDiffs ) {
                $vals['diff'] = array();
                $context = new DerivativeContext( $this->getContext() );
                $context->setTitle( $title );
                $handler = $revision->getContentHandler();

                if ( !is_null( $this->difftotext ) ) {
                    $model = $title->getContentModel();

                    if ( $this->contentFormat
                        && !ContentHandler::getForModelID( $model )->isSupportedFormat( $this->contentFormat ) ) {

                        $name = $title->getPrefixedDBkey();

                        $this->dieUsage( "The requested format {$this->contentFormat} is not supported for " .
                                            "content model $model used by $name", 'badformat' );
                    }

                    $difftocontent = ContentHandler::makeContent( $this->difftotext, $title, $model, $this->contentFormat );

                    $engine = $handler->createDifferenceEngine( $context );
                    $engine->setContent( $content, $difftocontent );
                } else {
                    $engine = $handler->createDifferenceEngine( $context, $revision->getID(), $this->diffto );
                    $vals['diff']['from'] = $engine->getOldid();
                    $vals['diff']['to'] = $engine->getNewid();
                }
                $difftext = $engine->getDiffBody();
                ApiResult::setContent( $vals['diff'], $difftext );
                if ( !$engine->wasCacheHit() ) {
                    $n++;
                }
            } else {
                $vals['diff']['notcached'] = '';
            }
        }
        return $vals;
    }

    public function getCacheMode( $params ) {
        if ( isset( $params['token'] ) ) {
            return 'private';
        }
        if ( !is_null( $params['prop'] ) && in_array( 'parsedcomment', $params['prop'] ) ) {
            // formatComment() calls wfMessage() among other things
            return 'anon-public-user-private';
        }
        return 'public';
    }

    public function getAllowedParams() {
        return array(
            'prop' => array(
                ApiBase::PARAM_ISMULTI => true,
                ApiBase::PARAM_DFLT => 'ids|timestamp|flags|comment|user',
                ApiBase::PARAM_TYPE => array(
                    'ids',
                    'flags',
                    'timestamp',
                    'user',
                    'userid',
                    'size',
                    'sha1',
                    'contentmodel',
                    'comment',
                    'parsedcomment',
                    'content',
                    'tags'
                )
            ),
            'limit' => array(
                ApiBase::PARAM_TYPE => 'limit',
                ApiBase::PARAM_MIN => 1,
                ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
                ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
            ),
            'startid' => array(
                ApiBase::PARAM_TYPE => 'integer'
            ),
            'endid' => array(
                ApiBase::PARAM_TYPE => 'integer'
            ),
            'start' => array(
                ApiBase::PARAM_TYPE => 'timestamp'
            ),
            'end' => array(
                ApiBase::PARAM_TYPE => 'timestamp'
            ),
            'dir' => array(
                ApiBase::PARAM_DFLT => 'older',
                ApiBase::PARAM_TYPE => array(
                    'newer',
                    'older'
                )
            ),
            'user' => array(
                ApiBase::PARAM_TYPE => 'user'
            ),
            'excludeuser' => array(
                ApiBase::PARAM_TYPE => 'user'
            ),
            'tag' => null,
            'expandtemplates' => false,
            'generatexml' => false,
            'parse' => false,
            'section' => null,
            'token' => array(
                ApiBase::PARAM_TYPE => array_keys( $this->getTokenFunctions() ),
                ApiBase::PARAM_ISMULTI => true
            ),
            'continue' => null,
            'diffto' => null,
            'difftotext' => null,
            'contentformat' => array(
                ApiBase::PARAM_TYPE => ContentHandler::getAllContentFormats(),
                ApiBase::PARAM_DFLT => null
            ),
        );
    }

    public function getParamDescription() {
        $p = $this->getModulePrefix();
        return array(
            'prop' => array(
                'Which properties to get for each revision:',
                ' ids            - The ID of the revision',
                ' flags          - Revision flags (minor)',
                ' timestamp      - The timestamp of the revision',
                ' user           - User that made the revision',
                ' userid         - User id of revision creator',
                ' size           - Length (bytes) of the revision',
                ' sha1           - SHA-1 (base 16) of the revision',
                ' contentmodel   - Content model id',
                ' comment        - Comment by the user for revision',
                ' parsedcomment  - Parsed comment by the user for the revision',
                ' content        - Text of the revision',
                ' tags           - Tags for the revision',
            ),
            'limit' => 'Limit how many revisions will be returned (enum)',
            'startid' => 'From which revision id to start enumeration (enum)',
            'endid' => 'Stop revision enumeration on this revid (enum)',
            'start' => 'From which revision timestamp to start enumeration (enum)',
            'end' => 'Enumerate up to this timestamp (enum)',
            'dir' => $this->getDirectionDescription( $p, ' (enum)' ),
            'user' => 'Only include revisions made by user (enum)',
            'excludeuser' => 'Exclude revisions made by user (enum)',
            'expandtemplates' => "Expand templates in revision content (requires {$p}prop=content)",
            'generatexml' => "Generate XML parse tree for revision content (requires {$p}prop=content)",
            'parse' => array( "Parse revision content (requires {$p}prop=content).",
                'For performance reasons if this option is used, rvlimit is enforced to 1.' ),
            'section' => 'Only retrieve the content of this section number',
            'token' => 'Which tokens to obtain for each revision',
            'continue' => 'When more results are available, use this to continue',
            'diffto' => array( 'Revision ID to diff each revision to.',
                'Use "prev", "next" and "cur" for the previous, next and current revision respectively' ),
            'difftotext' => array( 'Text to diff each revision to. Only diffs a limited number of revisions.',
                "Overrides {$p}diffto. If {$p}section is set, only that section will be diffed against this text" ),
            'tag' => 'Only list revisions tagged with this tag',
            'contentformat' => 'Serialization format used for difftotext and expected for output of content',
        );
    }

    public function getResultProperties() {
        $props = array(
            '' => array(),
            'ids' => array(
                'revid' => 'integer',
                'parentid' => array(
                    ApiBase::PROP_TYPE => 'integer',
                    ApiBase::PROP_NULLABLE => true
                )
            ),
            'flags' => array(
                'minor' => 'boolean'
            ),
            'user' => array(
                'userhidden' => 'boolean',
                'user' => 'string',
                'anon' => 'boolean'
            ),
            'userid' => array(
                'userhidden' => 'boolean',
                'userid' => 'integer',
                'anon' => 'boolean'
            ),
            'timestamp' => array(
                'timestamp' => 'timestamp'
            ),
            'size' => array(
                'size' => 'integer'
            ),
            'sha1' => array(
                'sha1' => 'string'
            ),
            'comment' => array(
                'commenthidden' => 'boolean',
                'comment' => array(
                    ApiBase::PROP_TYPE => 'string',
                    ApiBase::PROP_NULLABLE => true
                )
            ),
            'parsedcomment' => array(
                'commenthidden' => 'boolean',
                'parsedcomment' => array(
                    ApiBase::PROP_TYPE => 'string',
                    ApiBase::PROP_NULLABLE => true
                )
            ),
            'content' => array(
                '*' => array(
                    ApiBase::PROP_TYPE => 'string',
                    ApiBase::PROP_NULLABLE => true
                ),
                'texthidden' => 'boolean',
                'textmissing' => 'boolean',
            ),
            'contentmodel' => array(
                'contentmodel' => 'string'
            ),
        );

        self::addTokenProperties( $props, $this->getTokenFunctions() );

        return $props;
    }

    public function getDescription() {
        return array(
            'Get revision information',
            'May be used in several ways:',
            ' 1) Get data about a set of pages (last revision), by setting titles or pageids parameter',
            ' 2) Get revisions for one given page, by using titles/pageids with start/end/limit params',
            ' 3) Get data about a set of revisions by setting their IDs with revids parameter',
            'All parameters marked as (enum) may only be used with a single page (#2)'
        );
    }

    public function getPossibleErrors() {
        return array_merge( parent::getPossibleErrors(), array(
            array( 'nosuchrevid', 'diffto' ),
            array( 'code' => 'revids', 'info' => 'The revids= parameter may not be used with the list options '
                    . '(limit, startid, endid, dirNewer, start, end).' ),
            array( 'code' => 'multpages', 'info' => 'titles, pageids or a generator was used to supply multiple pages, '
                    . ' but the limit, startid, endid, dirNewer, user, excludeuser, '
                    . 'start and end parameters may only be used on a single page.' ),
            array( 'code' => 'diffto', 'info' => 'rvdiffto must be set to a non-negative number, "prev", "next" or "cur"' ),
            array( 'code' => 'badparams', 'info' => 'start and startid cannot be used together' ),
            array( 'code' => 'badparams', 'info' => 'end and endid cannot be used together' ),
            array( 'code' => 'badparams', 'info' => 'user and excludeuser cannot be used together' ),
            array( 'code' => 'nosuchsection', 'info' => 'There is no section section in rID' ),
            array( 'code' => 'badformat', 'info' => 'The requested serialization format can not be applied '
                                                    . ' to the page\'s content model' ),
        ) );
    }

    public function getExamples() {
        return array(
            'Get data with content for the last revision of titles "API" and "Main Page"',
            '  api.php?action=query&prop=revisions&titles=API|Main%20Page&rvprop=timestamp|user|comment|content',
            'Get last 5 revisions of the "Main Page"',
            '  api.php?action=query&prop=revisions&titles=Main%20Page&rvlimit=5&rvprop=timestamp|user|comment',
            'Get first 5 revisions of the "Main Page"',
            '  api.php?action=query&prop=revisions&titles=Main%20Page&rvlimit=5&rvprop=timestamp|user|comment&rvdir=newer',
            'Get first 5 revisions of the "Main Page" made after 2006-05-01',
            '  api.php?action=query&prop=revisions&titles=Main%20Page&rvlimit=5&rvprop=timestamp|user|comment&rvdir=newer&rvstart=20060501000000',
            'Get first 5 revisions of the "Main Page" that were not made made by anonymous user "127.0.0.1"',
            '  api.php?action=query&prop=revisions&titles=Main%20Page&rvlimit=5&rvprop=timestamp|user|comment&rvexcludeuser=127.0.0.1',
            'Get first 5 revisions of the "Main Page" that were made by the user "MediaWiki default"',
            '  api.php?action=query&prop=revisions&titles=Main%20Page&rvlimit=5&rvprop=timestamp|user|comment&rvuser=MediaWiki%20default',
        );
    }

    public function getHelpUrls() {
        return 'https://www.mediawiki.org/wiki/API:Properties#revisions_.2F_rv';
    }
}